partial void InitializeImpl()
{
using (var inputFile = new Java.IO.File(mediaDataUrl))
{
if (!inputFile.CanRead())
{
throw new Exception(string.Format("Unable to read: {0} ", inputFile.AbsolutePath));
}
using (var inputFileStream = new Java.IO.FileInputStream(inputFile.AbsolutePath))
{
var audioMediaExtractor = new MediaExtractor();
audioMediaExtractor.SetDataSource(inputFileStream.FD, startPosition, length);
var trackIndexAudio = StreamedBufferSoundSource.FindAudioTrack(audioMediaExtractor);
if (trackIndexAudio < 0)
{
return;
}
audioMediaExtractor.SelectTrack(trackIndexAudio);
var audioFormat = audioMediaExtractor.GetTrackFormat(trackIndexAudio);
//Get the audio settings
//should we override the settings (channels, sampleRate, ...) from DynamicSoundSource?
Channels = audioFormat.GetInteger(MediaFormat.KeyChannelCount);
SampleRate = audioFormat.GetInteger(MediaFormat.KeySampleRate);
MediaDuration = TimeSpanExtensions.FromMicroSeconds(audioFormat.GetLong(MediaFormat.KeyDuration));
}
}
}
partial void InitializeMediaExtractor(string mediaDataUrl, long startPosition, long length)
{
if (mediaDataUrl == null)
{
throw new ArgumentNullException(nameof(mediaDataUrl));
}
ReleaseMediaInternal();
InputFile = new Java.IO.File(mediaDataUrl);
if (!InputFile.CanRead())
{
throw new Exception(string.Format("Unable to read: {0} ", InputFile.AbsolutePath));
}
InputFileStream = new Java.IO.FileInputStream(InputFile.AbsolutePath);
audioMediaExtractor = new MediaExtractor();
audioMediaExtractor.SetDataSource(InputFileStream.FD, startPosition, length);
trackIndexAudio = FindAudioTrack(audioMediaExtractor);
if (trackIndexAudio < 0)
{
ReleaseMediaInternal();
Logger.Error($"The input file '{mediaDataUrl}' does not contain any audio track.");
return;
}
audioMediaExtractor.SelectTrack(trackIndexAudio);
var audioFormat = audioMediaExtractor.GetTrackFormat(trackIndexAudio);
var mime = audioFormat.GetString(MediaFormat.KeyMime);
audioMediaDecoder = MediaCodec.CreateDecoderByType(mime);
audioMediaDecoder.Configure(audioFormat, null, null, 0);
//Get the audio settings
//should we override the settings (channels, sampleRate, ...) from DynamicSoundSource?
Channels = audioFormat.GetInteger(MediaFormat.KeyChannelCount);
SampleRate = audioFormat.GetInteger(MediaFormat.KeySampleRate);
MediaDuration = TimeSpanExtensions.FromMicroSeconds(audioFormat.GetLong(MediaFormat.KeyDuration));
audioMediaDecoder.Start();
extractionOutputDone = false;
extractionInputDone = false;
}
private bool ExtractSomeAudioData(out bool endOfFile)
{
endOfFile = extractionOutputDone;
if (endOfFile)
{
return(false);
}
var hasExtractedData = false;
int TimeoutUs = 20000;
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
if (!extractionInputDone)
{
int inputBufIndex = audioMediaDecoder.DequeueInputBuffer(TimeoutUs);
if (inputBufIndex >= 0)
{
Java.Nio.ByteBuffer inputBuffer = audioMediaDecoder.GetInputBuffer(inputBufIndex);
//Read the sample data into the ByteBuffer. This neither respects nor updates inputBuf's position, limit, etc.
int chunkSize = audioMediaExtractor.ReadSampleData(inputBuffer, 0);
if (chunkSize < 0)
{
//End of stream: send empty frame with EOS flag set
audioMediaDecoder.QueueInputBuffer(inputBufIndex, 0, 0, 0L, MediaCodecBufferFlags.EndOfStream);
extractionInputDone = true;
//Logger.Verbose("sent input EOS");
}
else
{
if (audioMediaExtractor.SampleTrackIndex != trackIndexAudio)
{
Logger.Warning(string.Format("got audio sample from track {0}, expected {1}", audioMediaExtractor.SampleTrackIndex, trackIndexAudio));
}
var presentationTimeMicroSeconds = audioMediaExtractor.SampleTime;
audioMediaDecoder.QueueInputBuffer(inputBufIndex, 0, chunkSize, presentationTimeMicroSeconds, 0);
audioMediaExtractor.Advance();
}
}
else
{
//do nothing: the input buffer queue is full (we need to output them first)
//continue;
}
}
int decoderStatus = audioMediaDecoder.DequeueOutputBuffer(info, TimeoutUs);
switch (decoderStatus)
{
case (int)MediaCodecInfoState.TryAgainLater:
{
Logger.Verbose("no output from decoder available");
break;
}
case (int)MediaCodecInfoState.OutputFormatChanged:
{
MediaFormat newFormat = audioMediaDecoder.OutputFormat;
string newFormatStr = newFormat.ToString();
Logger.Verbose("audio decoder output format changed: " + newFormatStr);
break;
}
case (int)MediaCodecInfoState.OutputBuffersChanged:
{
//deprecated: we just ignore it
break;
}
default:
{
if (decoderStatus < 0)
{
throw new InvalidOperationException(string.Format("unexpected result from audio decoder.DequeueOutputBuffer: {0}", decoderStatus));
}
if ((info.Flags & MediaCodecBufferFlags.EndOfStream) != 0)
{
Logger.Verbose("audio: output EOS");
extractionOutputDone = true;
}
if (info.Size > 0)
{
hasExtractedData = true;
var buffer = audioMediaDecoder.GetOutputBuffer(decoderStatus);
var presentationTime = TimeSpanExtensions.FromMicroSeconds(info.PresentationTimeUs);
if (StorageBuffer.CountDataBytes + info.Size <= StorageBuffer.Data.Length)
{
buffer.Get(StorageBuffer.Data, StorageBuffer.CountDataBytes, info.Size); // Read the buffer all at once
buffer.Clear(); // MUST DO!!! OTHERWISE THE NEXT TIME YOU GET THIS SAME BUFFER BAD THINGS WILL HAPPEN
buffer.Position(0);
if (StorageBuffer.CountDataBytes == 0)
{
StorageBuffer.PresentationTime = presentationTime;
}
StorageBuffer.CountDataBytes += info.Size;
}
else
{
Logger.Error("The storage buffer has reached full capacity. Current data will be dropped");
}
}
audioMediaDecoder.ReleaseOutputBuffer(decoderStatus, false);
break;
}
}
endOfFile = extractionOutputDone;
return(hasExtractedData);
}