AudioReader: fix description of the src audio frame desc

Clement Champetier · Clement Champetier · commit 61c4d8082f1a · 2017-01-31T12:29:20.000+01:00
If the user asks to decode only one channel in the audio stream, the src
frame should have the corresponding description (if not, the transform
that follow won't be the one expected).
diff --git a/src/AvTranscoder/reader/AudioReader.cpp b/src/AvTranscoder/reader/AudioReader.cpp
@@ -45,12 +45,14 @@ void AudioReader::init()
     _currentDecoder = _decoder;
 
     // create src frame
-    const AudioFrameDesc srcFrameDesc = _inputFile->getStream(_streamIndex).getAudioCodec().getAudioFrameDesc();
+    AudioFrameDesc srcFrameDesc = _inputFile->getStream(_streamIndex).getAudioCodec().getAudioFrameDesc();
+    if(_channelIndex != -1)
+        srcFrameDesc._nbChannels = 1;
     _srcFrame = new AudioFrame(srcFrameDesc, false);
     AudioFrame* srcFrame = static_cast<AudioFrame*>(_srcFrame);
     // create dst frame
     _outputSampleRate = srcFrame->getSampleRate();
-    _outputNbChannels = (_channelIndex == -1) ? srcFrame->getNbChannels() : 1;
+    _outputNbChannels = srcFrame->getNbChannels();
     _dstFrame = new AudioFrame(AudioFrameDesc(_outputSampleRate, _outputNbChannels, getSampleFormatName(_outputSampleFormat)));
 
     // generator
