private long getLong(MediaFormat mediaFormat, string key)
{
if (mediaFormat.ContainsKey(key))
{
return mediaFormat.GetLong(key);
}
return -1;
}
public static Result DecodeAudio(FileDescriptor descriptor, long offset, long length)
{
using (var extractor = new MediaExtractor())
{
extractor.SetDataSource(descriptor, offset, length);
MediaFormat format = null;
string mime = null;
for (int i = 0; i < extractor.TrackCount; i++)
{
format = extractor.GetTrackFormat(i);
mime = format.GetString(MediaFormat.KeyMime);
if (!mime.StartsWith("audio/"))
{
continue;
}
extractor.SelectTrack(i);
}
if (format == null || !mime.StartsWith("audio/"))
{
throw new ContentLoadException("Could not find any audio track.");
}
int sampleRate = format.GetInteger(MediaFormat.KeySampleRate);
long duration = format.GetLong(MediaFormat.KeyDuration);
int channels = format.GetInteger(MediaFormat.KeyChannelCount);
int samples = (int)(sampleRate * duration / 1000000d);
var output = new byte[samples * 2];
int timeoutsLeft = 1000;
var decoder = MediaCodecPool.RentDecoder(mime);
try
{
decoder.Configure(format, null, null, MediaCodecConfigFlags.None);
decoder.Start();
ByteBuffer[] inputBuffers = decoder.GetInputBuffers();
ByteBuffer[] outputBuffers = decoder.GetOutputBuffers();
var bufferInfo = new MediaCodec.BufferInfo();
int totalOffset = 0;
bool endOfStream = false;
while (true)
{
// we dont need to have a endOfStream local,
// but it saves us a few calls to the decoder
if (!endOfStream)
{
int inputBufIndex = decoder.DequeueInputBuffer(5000);
if (inputBufIndex >= 0)
{
int size = extractor.ReadSampleData(inputBuffers[inputBufIndex], 0);
if (size > 0)
{
decoder.QueueInputBuffer(
inputBufIndex, 0, size, extractor.SampleTime, MediaCodecBufferFlags.None);
}
if (!extractor.Advance())
{
endOfStream = true;
decoder.QueueInputBuffer(
inputBufIndex, 0, 0, 0, MediaCodecBufferFlags.EndOfStream);
}
}
}
int decoderStatus = decoder.DequeueOutputBuffer(bufferInfo, 5000);
if (decoderStatus >= 0)
{
IntPtr bufferPtr = outputBuffers[decoderStatus].GetDirectBufferAddress();
IntPtr offsetPtr = bufferPtr + bufferInfo.Offset;
int size = bufferInfo.Size;
Marshal.Copy(offsetPtr, output, totalOffset, size);
decoder.ReleaseOutputBuffer(decoderStatus, render: false);
totalOffset += size;
if (bufferInfo.Flags == MediaCodecBufferFlags.EndOfStream)
{
if (totalOffset != output.Length)
{
throw new ContentLoadException(
"Reached end of stream before reading expected amount of samples.");
}
break;
}
}
else if (decoderStatus == (int)MediaCodecInfoState.OutputBuffersChanged)
{
outputBuffers = decoder.GetOutputBuffers();
}
else if (decoderStatus == (int)MediaCodecInfoState.TryAgainLater)
{
if (timeoutsLeft-- <= 0)
{
break;
}
}
}
}
finally
{
decoder.Stop();
MediaCodecPool.ReturnDecoder(mime, decoder);
}
if (timeoutsLeft <= 0)
{
throw new ContentLoadException("Could not load sound effect in designated time frame.");
}
return(new Result(output, sampleRate, channels, mime));
}
}
private static String printVideoMetadata(Context context, MediaFormat mediaFormat)
{
if (mediaFormat == null)
{
return("\n");
}
StringBuilder stringBuilder = new StringBuilder();
if (mediaFormat.ContainsKey(MediaFormat.KeyMime))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_mime_type, mediaFormat.GetString(MediaFormat.KeyMime)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyWidth))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_width, mediaFormat.GetInteger(MediaFormat.KeyWidth)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyHeight))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_height, mediaFormat.GetInteger(MediaFormat.KeyHeight)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyBitRate))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_bitrate, mediaFormat.GetInteger(MediaFormat.KeyBitRate)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyDuration))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_duration, mediaFormat.GetLong(MediaFormat.KeyDuration)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyFrameRate))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_frame_rate, MediaFormatUtils.GetFrameRate(mediaFormat, new Java.Lang.Integer(0)).IntValue()));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyIFrameInterval))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_key_frame_interval, MediaFormatUtils.GetIFrameInterval(mediaFormat, new Java.Lang.Integer(0)).IntValue()));
}
if (mediaFormat.ContainsKey(KEY_ROTATION))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_rotation, mediaFormat.GetInteger(KEY_ROTATION)));
}
return(stringBuilder.ToString());
}
private static String printAudioMetadata(Context context, MediaFormat mediaFormat)
{
if (mediaFormat == null)
{
return("\n");
}
StringBuilder stringBuilder = new StringBuilder();
if (mediaFormat.ContainsKey(MediaFormat.KeyMime))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_mime_type, mediaFormat.GetString(MediaFormat.KeyMime)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyChannelCount))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_channel_count, mediaFormat.GetInteger(MediaFormat.KeyChannelCount)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyBitRate))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_bitrate, mediaFormat.GetInteger(MediaFormat.KeyBitRate)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeyDuration))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_duration, mediaFormat.GetLong(MediaFormat.KeyDuration)));
}
if (mediaFormat.ContainsKey(MediaFormat.KeySampleRate))
{
stringBuilder.AppendLine(context.GetString(Resource.String.stats_sampling_rate, mediaFormat.GetInteger(MediaFormat.KeySampleRate)));
}
return(stringBuilder.ToString());
}