AudioGenerator: fixed assign of audio buffer of silence

Clement Champetier · Clement Champetier · commit e886c8a34721 · 2016-04-01T10:59:57.000+02:00
* This was an old bug, which occured if we try to generate silence,
after transcoding a real audio stream with a last packet very small.
* Add pyTest to check this execution.
* It could be much beffer to reallocate the given frame of the
generator, and put in it more samples of silence.
diff --git a/src/AvTranscoder/decoder/AudioGenerator.cpp b/src/AvTranscoder/decoder/AudioGenerator.cpp
@@ -54,9 +54,12 @@ bool AudioGenerator::decodeNextFrame(Frame& frameBuffer)
             msg << "sample format = " << getSampleFormatName(_silent->getSampleFormat()) << std::endl;
             msg << "number of samples per channel = " << _silent->getNbSamplesPerChannel() << std::endl;
             LOG_INFO(msg.str())
+
+            // Set the number of samples of silence to the number of samples of the given frame
+            // (which was allocated to expect this number of samples).
+            _silent->setNbSamplesPerChannel(frameBuffer.getAVFrame().nb_samples);
         }
         LOG_DEBUG("Copy data of the silence when decode next frame")
-        frameBuffer.getAVFrame().nb_samples = _silent->getAVFrame().nb_samples;
         frameBuffer.copyData(*_silent);
     }
     // Take audio frame from _inputFrame
diff --git a/test/pyTest/testTranscoderTranscodeAudioWave.py b/test/pyTest/testTranscoderTranscodeAudioWave.py
@@ -43,6 +43,7 @@ def testTranscodeWave24b48k5_1():
     assert_equals( 48000, dst_audioStream.getSampleRate() )
     assert_equals( 6, dst_audioStream.getNbChannels() )
 
+
 def testTranscodeWave24b48kstereo():
     """
     Transcode one audio stream (profile wave24b48kstereo).
@@ -76,6 +77,7 @@ def testTranscodeWave24b48kstereo():
     assert_equals( 48000, dst_audioStream.getSampleRate() )
     assert_equals( 2, dst_audioStream.getNbChannels() )
 
+
 def testTranscodeWave24b48kmono():
     """
     Transcode one audio stream (profile wave24b48kmono).
@@ -109,6 +111,7 @@ def testTranscodeWave24b48kmono():
     assert_equals( 48000, dst_audioStream.getSampleRate() )
     assert_equals( 1, dst_audioStream.getNbChannels() )
 
+
 def testTranscodeWave16b48kmono():
     """
     Transcode one audio stream (profile wave16b48kmono).
@@ -141,3 +144,40 @@ def testTranscodeWave16b48kmono():
     assert_equals( "signed 16 bits", dst_audioStream.getSampleFormatLongName() )
     assert_equals( 48000, dst_audioStream.getSampleRate() )
     assert_equals( 1, dst_audioStream.getNbChannels() )
+
+
+def testTranscodeWave16b48kmonoWithSilence():
+    """
+    Transcode one audio stream (profile wave16b48kmono).
+    Complete with silence.
+    """
+    inputFileName = os.environ['AVTRANSCODER_TEST_AUDIO_WAVE_FILE']
+    outputFileName = "testTranscodeWave16b48kmonoWithSilence.wav"
+    outputDuration = 50
+
+    ouputFile = av.OutputFile( outputFileName )
+    transcoder = av.Transcoder( ouputFile )
+    transcoder.setProcessMethod( av.eProcessMethodBasedOnDuration, 0, outputDuration )
+
+    inputFile = av.InputFile( inputFileName )
+    src_audioStream = inputFile.getProperties().getAudioProperties()[0]
+    audioStreamIndex = src_audioStream.getStreamIndex()
+    transcoder.add( inputFileName, audioStreamIndex, "wave16b48kmono" )
+
+    progress = av.ConsoleProgress()
+    processStat = transcoder.process( progress )
+
+    # check process stat returned
+    audioStat = processStat.getAudioStat(0)
+    assert_almost_equals( audioStat.getDuration(), outputDuration, delta=0.01 )
+
+    # get dst file of transcode
+    dst_inputFile = av.InputFile( outputFileName )
+    dst_properties = dst_inputFile.getProperties()
+    dst_audioStream = dst_properties.getAudioProperties()[0]
+
+    assert_equals( "pcm_s16le", dst_audioStream.getCodecName() )
+    assert_equals( "s16", dst_audioStream.getSampleFormatName() )
+    assert_equals( "signed 16 bits", dst_audioStream.getSampleFormatLongName() )
+    assert_equals( 48000, dst_audioStream.getSampleRate() )
+    assert_equals( 1, dst_audioStream.getNbChannels() )

Original file line number	Diff line number	Diff line change
`@@ -54,9 +54,12 @@ bool AudioGenerator::decodeNextFrame(Frame& frameBuffer)`
`54`	`54`	`msg << "sample format = " << getSampleFormatName(_silent->getSampleFormat()) << std::endl;`
`55`	`55`	`msg << "number of samples per channel = " << _silent->getNbSamplesPerChannel() << std::endl;`
`56`	`56`	`LOG_INFO(msg.str())`
	`57`	`+`
	`58`	`+ // Set the number of samples of silence to the number of samples of the given frame`
	`59`	`+ // (which was allocated to expect this number of samples).`
	`60`	`+ _silent->setNbSamplesPerChannel(frameBuffer.getAVFrame().nb_samples);`
`57`	`61`	`}`
`58`	`62`	`LOG_DEBUG("Copy data of the silence when decode next frame")`
`59`		`- frameBuffer.getAVFrame().nb_samples = _silent->getAVFrame().nb_samples;`
`60`	`63`	`frameBuffer.copyData(*_silent);`
`61`	`64`	`}`
`62`	`65`	`// Take audio frame from _inputFrame`