387 lines
84 KiB
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387 lines
84 KiB
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<!--Weave of 'Sound Durations' generated by Inweb-->
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<ul class="crumbs"><li><a href="../index.html">Home</a></li><li><a href="index.html">foundation</a></li><li><a href="index.html#6">Chapter 6: Media</a></li><li><b>Sound Durations</b></li></ul></div>
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<p class="purpose">These utility routines look at the headers of AIFF, OGG Vorbis or MIDI files to find the durations, and verify that they are what they purport to be.</p>
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<ul class="toc"><li><a href="6-sd.html#SP1">§1. AIFF files</a></li><li><a href="6-sd.html#SP2">§2. OGG Vorbis files</a></li><li><a href="6-sd.html#SP3">§3. MIDI files</a></li></ul><hr class="tocbar">
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<p class="commentary firstcommentary"><a id="SP1" class="paragraph-anchor"></a><b>§1. AIFF files. </b>The code in this section was once again originated by Toby Nelson. To
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explicate the following, see the specifications for AIFF and OGG headers.
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Durations are measured in centiseconds.
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</p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">SoundFiles::get_AIFF_duration</span><span class="plain-syntax">(</span><span class="reserved-syntax">FILE</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pDuration</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pBitsPerSecond</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pChannels</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">sig</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">chunkID</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">chunkLength</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">numSampleFrames</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">sampleSize</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x464F524D</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"FORM"</span></span><span class="comment-syntax"> indicating an IFF file</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x41494646</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"AIFF"</span></span><span class="comment-syntax"> indicating an AIFF file</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Read chunks, skipping over those we are not interested in</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> (</span><span class="constant-syntax">TRUE</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">chunkID</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">chunkLength</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">chunkID</span><span class="plain-syntax"> == </span><span class="constant-syntax">0x434F4D4D</span><span class="plain-syntax">) { </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"COMM"</span></span><span class="comment-syntax"> indicates common AIFF data</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">chunkLength</span><span class="plain-syntax"> < </span><span class="constant-syntax">18</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> Check we have enough data to read</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int16</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pChannels</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">numSampleFrames</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int16</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sampleSize</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP5" class="function-link"><span class="function-syntax">BinaryFiles::read_float80</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (*</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> Sanity check to avoid a divide by zero</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Result is in centiseconds</span>
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<span class="plain-syntax"> *</span><span class="identifier-syntax">pDuration</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax">) (((</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">long</span><span class="plain-syntax"> </span><span class="reserved-syntax">long</span><span class="plain-syntax">) </span><span class="identifier-syntax">numSampleFrames</span><span class="plain-syntax"> * </span><span class="constant-syntax">100</span><span class="plain-syntax">) / *</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> *</span><span class="identifier-syntax">pBitsPerSecond</span><span class="plain-syntax"> = *</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax"> * *</span><span class="identifier-syntax">pChannels</span><span class="plain-syntax"> * </span><span class="identifier-syntax">sampleSize</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Skip unwanted chunk</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) </span><span class="identifier-syntax">chunkLength</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax">}</span>
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</pre>
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<p class="commentary firstcommentary"><a id="SP2" class="paragraph-anchor"></a><b>§2. OGG Vorbis files. </b></p>
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<pre class="displayed-code all-displayed-code code-font">
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<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">SoundFiles::get_OggVorbis_duration</span><span class="plain-syntax">(</span><span class="reserved-syntax">FILE</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pDuration</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pBitsPerSecond</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pChannels</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">sig</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">version</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">numSegments</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">packetType</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">vorbisSig1</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">vorbisSig2</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">fileLength</span><span class="plain-syntax">, </span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax">, </span><span class="identifier-syntax">lastSig</span><span class="plain-syntax">, </span><span class="identifier-syntax">index</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">long</span><span class="plain-syntax"> </span><span class="reserved-syntax">long</span><span class="plain-syntax"> </span><span class="identifier-syntax">granulePosition</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> </span><span class="identifier-syntax">buffer</span><span class="plain-syntax">[256];</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x4F676753</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"OggS"</span></span><span class="comment-syntax"> indicating an OGG file</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Check OGG version is zero</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">version</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">version</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Skip header type, granule position, serial number, page sequence and CRC</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="constant-syntax">21</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Read number of page segments</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">numSegments</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Skip segment table</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) </span><span class="identifier-syntax">numSegments</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Vorbis Identification header</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">packetType</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">packetType</span><span class="plain-syntax"> != </span><span class="constant-syntax">1</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">vorbisSig1</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">vorbisSig1</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x766F7262</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"VORB"</span></span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int16</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">vorbisSig2</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">vorbisSig2</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x6973</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"IS"</span></span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Check Vorbis version is zero</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">version</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">version</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read number of channels</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pChannels</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read sample rate</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><a href="6-bf.html#SP3" class="function-link"><span class="function-syntax">BinaryFiles::swap_bytes32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">); </span><span class="comment-syntax"> Ogg Vorbis uses LSB first</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Skip bitrate maximum</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="constant-syntax">4</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read Nominal Bitrate</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pBitsPerSecond</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><a href="6-bf.html#SP3" class="function-link"><span class="function-syntax">BinaryFiles::swap_bytes32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pBitsPerSecond</span><span class="plain-syntax">); </span><span class="comment-syntax"> Ogg Vorbis uses LSB first</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Encoders can be unhelpful and give no bitrate in the header</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pBitsPerSecond</span><span class="plain-syntax"> == </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Search for the final Ogg page (near the end of the file) to read duration,</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> i.e., read the last 4K of the file and look for the final </span><span class="extract"><span class="extract-syntax">"OggS"</span></span><span class="comment-syntax"> sig</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="constant-syntax">0</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_END</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">fileLength</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax">) </span><span class="identifier-syntax">ftell</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fileLength</span><span class="plain-syntax"> < </span><span class="constant-syntax">4096</span><span class="plain-syntax">) </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax"> = </span><span class="identifier-syntax">fileLength</span><span class="plain-syntax"> - </span><span class="constant-syntax">4096</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">lastSig</span><span class="plain-syntax"> = </span><span class="constant-syntax">0xFFFFFFFF</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> (</span><span class="identifier-syntax">seekPos</span><span class="plain-syntax"> < </span><span class="identifier-syntax">fileLength</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_SET</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax"> = </span><span class="identifier-syntax">fileLength</span><span class="plain-syntax"> - </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax"> > </span><span class="constant-syntax">256</span><span class="plain-syntax">) </span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax"> = </span><span class="constant-syntax">256</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fread</span><span class="plain-syntax">(</span><span class="identifier-syntax">buffer</span><span class="plain-syntax">, </span><span class="constant-syntax">1</span><span class="plain-syntax">, </span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax">, </span><span class="identifier-syntax">pFile</span><span class="plain-syntax">) != </span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">for</span><span class="plain-syntax">(</span><span class="identifier-syntax">index</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">; </span><span class="identifier-syntax">index</span><span class="plain-syntax"> < </span><span class="identifier-syntax">bytesToRead</span><span class="plain-syntax">; </span><span class="identifier-syntax">index</span><span class="plain-syntax">++) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">buffer</span><span class="plain-syntax">[</span><span class="identifier-syntax">index</span><span class="plain-syntax">] == </span><span class="constant-syntax">0x4F</span><span class="plain-syntax">) &&</span>
|
|
<span class="plain-syntax"> (</span><span class="identifier-syntax">buffer</span><span class="plain-syntax">[</span><span class="identifier-syntax">index</span><span class="plain-syntax"> + </span><span class="constant-syntax">1</span><span class="plain-syntax">] == </span><span class="constant-syntax">0x67</span><span class="plain-syntax">) &&</span>
|
|
<span class="plain-syntax"> (</span><span class="identifier-syntax">buffer</span><span class="plain-syntax">[</span><span class="identifier-syntax">index</span><span class="plain-syntax"> + </span><span class="constant-syntax">2</span><span class="plain-syntax">] == </span><span class="constant-syntax">0x67</span><span class="plain-syntax">) &&</span>
|
|
<span class="plain-syntax"> (</span><span class="identifier-syntax">buffer</span><span class="plain-syntax">[</span><span class="identifier-syntax">index</span><span class="plain-syntax"> + </span><span class="constant-syntax">3</span><span class="plain-syntax">] == </span><span class="constant-syntax">0x53</span><span class="plain-syntax">)) {</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">lastSig</span><span class="plain-syntax"> = </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax"> + </span><span class="identifier-syntax">index</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> }</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Next place to read from is 256 bytes further on, but to catch</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> sigs that span between these blocks, read the last four bytes again</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">seekPos</span><span class="plain-syntax"> += </span><span class="constant-syntax">256</span><span class="plain-syntax"> - </span><span class="constant-syntax">4</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">lastSig</span><span class="plain-syntax"> == </span><span class="constant-syntax">0xFFFFFFFF</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) </span><span class="identifier-syntax">lastSig</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_SET</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x4F676753</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">; </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"OggS"</span></span><span class="comment-syntax"> indicating an OGG file</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Check OGG version is zero</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">version</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">version</span><span class="plain-syntax"> != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Skip header Type</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="constant-syntax">1</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int64</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">granulePosition</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><a href="6-bf.html#SP3" class="function-link"><span class="function-syntax">BinaryFiles::swap_bytes64</span></a><span class="plain-syntax">(&</span><span class="identifier-syntax">granulePosition</span><span class="plain-syntax">);</span>
|
|
|
|
<span class="plain-syntax"> *</span><span class="identifier-syntax">pDuration</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax">) ((</span><span class="identifier-syntax">granulePosition</span><span class="plain-syntax"> * </span><span class="constant-syntax">100</span><span class="plain-syntax">) /</span>
|
|
<span class="plain-syntax"> (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">long</span><span class="plain-syntax"> </span><span class="reserved-syntax">long</span><span class="plain-syntax">) *</span><span class="identifier-syntax">pSampleRate</span><span class="plain-syntax">);</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax">}</span>
|
|
</pre>
|
|
<p class="commentary firstcommentary"><a id="SP3" class="paragraph-anchor"></a><b>§3. MIDI files. </b>At one time it was proposed that Inform 7 should allow a third sound file
|
|
format: MIDI. This provoked considerable debate in July 2007 and enough
|
|
doubts were raised that the implementation below was never in fact
|
|
officially used. It is preserved here in case we ever revive the issue.
|
|
</p>
|
|
|
|
<p class="commentary">Inform is not really able to decide this for itself, in any case, since
|
|
it can only usefully provide sound files which the virtual machines it
|
|
compiles for will allow. At present, the Glulx virtual machine does not
|
|
officially support MIDI, which makes the question moot.
|
|
</p>
|
|
|
|
<pre class="displayed-code all-displayed-code code-font">
|
|
<span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="function-syntax">SoundFiles::get_MIDI_information</span><span class="plain-syntax">(</span><span class="reserved-syntax">FILE</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pType</span><span class="plain-syntax">,</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> *</span><span class="identifier-syntax">pNumTracks</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">sig</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">length</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">pulses</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">frames_per_second</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">subframes_per_frame</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">clocks_per_second</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">start_of_chunk_data</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">status</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">clocks</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">sysex_length</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">non_midi_event_length</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">start_of_non_midi_data</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">non_midi_event</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"RIFF"</span></span><span class="comment-syntax"> indicating a RIFF file</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> == </span><span class="constant-syntax">0x52494646</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Skip the filesize and typeID</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="constant-syntax">8</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> now read the real MIDI sig</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"MThd"</span></span><span class="comment-syntax"> indicating a MIDI file</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> != </span><span class="constant-syntax">0x4D546864</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read length of chunk</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">length</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Make sure we have enough data to read</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">length</span><span class="plain-syntax"> < </span><span class="constant-syntax">6</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read the MIDI type: 0,1 or 2</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> 0 means one track containing up to 16 channels to make a single tune</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> 1 means one or more tracks, commonly each with a single channel, making up a single tune</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> 2 means one or more tracks, where each is a separate tune in it's own right</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int16</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pType</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read the number of tracks</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int16</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">pNumTracks</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read "Pulses Per Quarter Note" (PPQN)</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int16</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">pulses</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
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|
<span class="plain-syntax"> </span><span class="comment-syntax"> if top bit set, then number of subframes per second can be deduced</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">pulses</span><span class="plain-syntax"> >= </span><span class="constant-syntax">0x8000</span><span class="plain-syntax">) {</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> First byte is a negative number for the frames per second</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Second byte is the number of subframes in each frame</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">frames_per_second</span><span class="plain-syntax"> = (256 - (</span><span class="identifier-syntax">pulses</span><span class="plain-syntax"> & </span><span class="constant-syntax">0xff</span><span class="plain-syntax">));</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">subframes_per_frame</span><span class="plain-syntax"> = (</span><span class="identifier-syntax">pulses</span><span class="plain-syntax"> >> </span><span class="constant-syntax">8</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">clocks_per_second</span><span class="plain-syntax"> = </span><span class="identifier-syntax">frames_per_second</span><span class="plain-syntax"> * </span><span class="identifier-syntax">subframes_per_frame</span><span class="plain-syntax">;</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"frames_per_second = %d\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">frames_per_second</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"subframes_per_frame = %d\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">subframes_per_frame</span><span class="plain-syntax">);</span>
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|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"clocks_per_second = %d\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">clocks_per_second</span><span class="plain-syntax">);</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Number of pulses per quarter note unknown</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">pulses</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> unknown values</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">frames_per_second</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">subframes_per_frame</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">clocks_per_second</span><span class="plain-syntax"> = </span><span class="constant-syntax">0</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"pulses per quarter note = %d\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">pulses</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> }</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Skip any remaining bytes in the MThd chunk</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) (</span><span class="identifier-syntax">length</span><span class="plain-syntax"> - </span><span class="constant-syntax">6</span><span class="plain-syntax">), </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Keep reading chunks, looking for </span><span class="extract"><span class="extract-syntax">"MTrk"</span></span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">do</span><span class="plain-syntax"> {</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read chunk signature and length</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sig</span><span class="plain-syntax">)) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">feof</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int32</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">length</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">start_of_chunk_data</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax">) </span><span class="identifier-syntax">ftell</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">);</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">sig</span><span class="plain-syntax"> == </span><span class="constant-syntax">0x4D54726B</span><span class="plain-syntax">) { </span><span class="comment-syntax"> </span><span class="extract"><span class="extract-syntax">"MTrk"</span></span>
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"track starts\n"</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read each event, looking for information before the real tune starts, e.g., tempo</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">do</span><span class="plain-syntax"> {</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read the number of clocks since the previous event</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP4" class="function-link"><span class="function-syntax">BinaryFiles::read_variable_length_integer</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">clocks</span><span class="plain-syntax">))</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> We bail out when the track starts</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">clocks</span><span class="plain-syntax"> > </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read the MIDI Status byte</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">status</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Start or continuation of system exclusive data</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> ((</span><span class="identifier-syntax">status</span><span class="plain-syntax"> == </span><span class="constant-syntax">0xF0</span><span class="plain-syntax">) || (</span><span class="identifier-syntax">status</span><span class="plain-syntax"> == </span><span class="constant-syntax">0xF7</span><span class="plain-syntax">)) {</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read length of system exclusive event data</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP4" class="function-link"><span class="function-syntax">BinaryFiles::read_variable_length_integer</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">sysex_length</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Skip sysex event</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) </span><span class="identifier-syntax">sysex_length</span><span class="plain-syntax">, </span><span class="identifier-syntax">SEEK_CUR</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">status</span><span class="plain-syntax"> == </span><span class="constant-syntax">0xFF</span><span class="plain-syntax">) { </span><span class="comment-syntax"> Non-MIDI event</span>
|
|
<span class="plain-syntax"> </span><span class="comment-syntax"> Read the Non-MIDI event type and length</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP1" class="function-link"><span class="function-syntax">BinaryFiles::read_int8</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">non_midi_event</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP4" class="function-link"><span class="function-syntax">BinaryFiles::read_variable_length_integer</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, &</span><span class="identifier-syntax">non_midi_event_length</span><span class="plain-syntax">))</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="identifier-syntax">start_of_non_midi_data</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax">) </span><span class="identifier-syntax">ftell</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">);</span>
|
|
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">switch</span><span class="plain-syntax">(</span><span class="identifier-syntax">non_midi_event</span><span class="plain-syntax">) {</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x01</span><span class="identifier-syntax">:</span><span class="plain-syntax"> </span><span class="comment-syntax"> Comment text</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x02</span><span class="identifier-syntax">:</span><span class="plain-syntax"> </span><span class="comment-syntax"> Copyright text</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x03</span><span class="identifier-syntax">:</span><span class="plain-syntax"> </span><span class="comment-syntax"> Track name</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x04</span><span class="identifier-syntax">:</span><span class="plain-syntax"> { </span><span class="comment-syntax"> Instrument name</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">char</span><span class="plain-syntax"> </span><span class="identifier-syntax">text</span><span class="plain-syntax">[257];</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (!</span><a href="6-bf.html#SP6" class="function-link"><span class="function-syntax">BinaryFiles::read_string</span></a><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, </span><span class="identifier-syntax">text</span><span class="plain-syntax">, </span><span class="identifier-syntax">non_midi_event_length</span><span class="plain-syntax">))</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> </span><span class="identifier-syntax">LOG</span><span class="plain-syntax">(</span><span class="string-syntax">"%d: %s\n"</span><span class="plain-syntax">, </span><span class="identifier-syntax">non_midi_event</span><span class="plain-syntax">, </span><span class="identifier-syntax">text</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x51</span><span class="identifier-syntax">:</span><span class="plain-syntax"> </span><span class="comment-syntax"> Tempo change</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x58</span><span class="identifier-syntax">:</span><span class="plain-syntax"> </span><span class="comment-syntax"> Time signature</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">case</span><span class="plain-syntax"> </span><span class="constant-syntax">0x59</span><span class="identifier-syntax">:</span><span class="plain-syntax"> </span><span class="comment-syntax"> Key signature</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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|
<span class="plain-syntax"> }</span>
|
|
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<span class="plain-syntax"> </span><span class="comment-syntax"> Skip non-midi event</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">,</span>
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<span class="plain-syntax"> (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) (</span><span class="identifier-syntax">start_of_non_midi_data</span><span class="plain-syntax"> + </span><span class="identifier-syntax">non_midi_event_length</span><span class="plain-syntax">), </span><span class="identifier-syntax">SEEK_SET</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">)</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> } </span><span class="reserved-syntax">else</span><span class="plain-syntax"> {</span>
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<span class="plain-syntax"> </span><span class="comment-syntax"> Real MIDI data found: we've read all we can so bail out at this point</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">break</span><span class="plain-syntax">;</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> }</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> (</span><span class="constant-syntax">TRUE</span><span class="plain-syntax">);</span>
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<span class="plain-syntax"> }</span>
|
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<span class="plain-syntax"> </span><span class="comment-syntax"> Seek to start of next chunk</span>
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">fseek</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">, (</span><span class="reserved-syntax">long</span><span class="plain-syntax">) (</span><span class="identifier-syntax">start_of_chunk_data</span><span class="plain-syntax"> + </span><span class="identifier-syntax">length</span><span class="plain-syntax">), </span><span class="identifier-syntax">SEEK_SET</span><span class="plain-syntax">) != </span><span class="constant-syntax">0</span><span class="plain-syntax">) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">FALSE</span><span class="plain-syntax">;</span>
|
|
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|
<span class="plain-syntax"> </span><span class="comment-syntax"> Reached end of file</span>
|
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<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">feof</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
|
|
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|
<span class="plain-syntax"> </span><span class="comment-syntax"> Did we try to seek beyond the end of the file?</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax"> </span><span class="identifier-syntax">position_in_file</span><span class="plain-syntax"> = (</span><span class="reserved-syntax">unsigned</span><span class="plain-syntax"> </span><span class="reserved-syntax">int</span><span class="plain-syntax">) </span><span class="identifier-syntax">ftell</span><span class="plain-syntax">(</span><span class="identifier-syntax">pFile</span><span class="plain-syntax">);</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">if</span><span class="plain-syntax"> (</span><span class="identifier-syntax">position_in_file</span><span class="plain-syntax"> < (</span><span class="identifier-syntax">start_of_chunk_data</span><span class="plain-syntax"> + </span><span class="identifier-syntax">length</span><span class="plain-syntax">)) </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
|
|
<span class="plain-syntax"> }</span>
|
|
<span class="plain-syntax"> </span><span class="reserved-syntax">while</span><span class="plain-syntax"> (</span><span class="constant-syntax">TRUE</span><span class="plain-syntax">);</span>
|
|
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|
<span class="plain-syntax"> </span><span class="reserved-syntax">return</span><span class="plain-syntax"> </span><span class="constant-syntax">TRUE</span><span class="plain-syntax">;</span>
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|
<span class="plain-syntax">}</span>
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</pre>
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