Error when create AAC encoder with MediaCodec
The question is simple, But I have no any clue to solve it:
I write a single line code to create an AAC encoder on my Nexus 4 (Android 4.4.2)
MediaCodec codec = MediaCodec.createEncoderByType("audio/mp4a-latm");
The return value saved in "codec" is not null, but I get a red error message in Logcat:
03-20 15:25:08.985: E/OMXMaster(24517): A component of name 'OMX.qcom.audio.decoder.aac' already exists, ignoring this one.
I have also tried another line:
MediaCodec codec = MediaCodec.createByCodecName("OMX.google.aac.encoder");
And get the same error result.
Did I miss any initialization steps before using MediaCodec? I did not find any information about this in the official document.
Did anyone run into this problem?
Actually I am trying to encode PCM to AAC file. And I have read this post @hubeir. It seems that he has made it work. I did the same thing:(1)setup the mediacodec and feed in PCM data to get encoded frame. To do that, I read the code from cts . Every encoded frame length is about 371-379. (2)Add adts header to the frame, then save to file. I have checked the head bit by bit, it is correct. But the file is still not playable. So I think maybe the error log is the problem.
The following is my whole code, for reference:
MediaCodec codec = MediaCodec.createByCodecName("OMX.google.aac.encoder");
MediaFormat format = new MediaFormat();
format.setString(MediaFormat.KEY_MIME, "audio/mp4a-latm");
format.setInteger(MediaFormat.KEY_AAC_PROFILE,
MediaCodecInfo.CodecProfileLevel.AACObjectELD);
format.setInteger(MediaFormat.KEY_SAMPLE_RATE, nSamplerate);
format.setInteger(MediaFormat.KEY_BIT_RATE, 128000);
format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, nChannels);
codec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
codec.start();
ByteBuffer[] inputBuffers = codec.getInputBuffers();
ByteBuffer[] outputBuffers = codec.getOutputBuffers();
boolean bEndInput = false;
boolean bEndOutput = false;
while(true)
{
if (!bEndInput)
{
int inputBufferIndex = codec.dequeueInputBuffer(0);
if (inputBufferIndex >= 0)
{
int nLen = app.readPCM(nHandle,inputBuffers[inputBufferIndex]);//This line read PCM, return 0 if end of data.
int nBufLen = inputBuffers[inputBufferIndex].capacity();
if (nLen == nBufLen)
codec.queueInputBuffer(inputBufferIndex, 0, nLen, 0, MediaCodec.BUFFER_FLAG_SYNC_FRAME);
else if (nLen < nBufLen)
{
codec.queueInputBuffer(inputBufferIndex, 0, nLen, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
bEndInput = true;
break;
}
}
}
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
if (!bEndOutput)
{
int outputBufferIndex = codec.dequeueOutputBuffer(info, 0);
if (outputBufferIndex >= 0)
{
int outBitsSize = info.size;
Log.d("test", "Offset:"+info.offset);
Log.d("test", "Size:"+info.size);
Log.d("test", "Time:"+info.presentationTimeUs);
Log.d("test", "Flags:"+info.flags);
if (outBitsSize <= 10)
{
codec.releaseOutputBuffer(outputBufferIndex, false /* render */);
continue;
}
int outPacketSize = outBitsSize + 7; // 7 is ADTS size
ByteBuffer outBuf = outputBuffers[outputBufferIndex];
outBuf.position(info.offset);
outBuf.limit(info.offset + outBitsSize);
try {
byte[] data = new byte[outPacketSize]; //space for ADTS header included
addADTStoPacket(data, outPacketSize);
outBuf.get(data, 7, outBitsSize);
outBuf.position(info.offset);
outputStream.write(data, 0, outPacketSize); //open FileOutputStream beforehand
} catch (IOException e) {
Log.e("test", "failed writing bitstream data to file");
e.printStackTrace();
}
outBuf.clear();
codec.releaseOutputBuffer(outputBufferIndex, false /* render */);
Log.d("test", " dequeued " + outBitsSize + " bytes of output data.");
Log.d("test", " wrote " + outPacketSize + " bytes into output file.");
if (info.flags == MediaCodec.BUFFER_FLAG_END_OF_STREAM)
{
bEndOutput = true;
//break;
}
}
else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
{
outputBuffers = codec.getOutputBuffers();
}
else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
{
}
}
if (bEndInput && bEndOutput)
break;
}
Answer
I figured out it.
(1) The error setting in the media format:
format.setInteger(MediaFormat.KEY_AAC_PROFILE,
MediaCodecInfo.CodecProfileLevel.AACObjectELD);
should be
format.setInteger(MediaFormat.KEY_AAC_PROFILE,
MediaCodecInfo.CodecProfileLevel.AACObjectLC);
(2) The encoded frame could be written to file with adts file only when (info.flags == 0)
(3) And the output file name suffix should be "aac". "mp4" or "m4a" may not work for some application.
MediaCodec codec = MediaCodec.createByCodecName("OMX.google.aac.encoder");
MediaFormat format = new MediaFormat();
format.setString(MediaFormat.KEY_MIME, "audio/mp4a-latm");
format.setInteger(MediaFormat.KEY_AAC_PROFILE,
MediaCodecInfo.CodecProfileLevel.AACObjectLC); //fixed version
format.setInteger(MediaFormat.KEY_SAMPLE_RATE, nSamplerate);
format.setInteger(MediaFormat.KEY_BIT_RATE, 128000);
format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, nChannels);
codec.configure(format, null, null, MediaCodec.CONFIGURE_FLAG_ENCODE);
codec.start();
ByteBuffer[] inputBuffers = codec.getInputBuffers();
ByteBuffer[] outputBuffers = codec.getOutputBuffers();
boolean bEndInput = false;
boolean bEndOutput = false;
while(true)
{
if (!bEndInput)
{
int inputBufferIndex = codec.dequeueInputBuffer(0);
if (inputBufferIndex >= 0)
{
int nLen = app.readPCM(nHandle,inputBuffers[inputBufferIndex]);//This line read PCM, return 0 if end of data.
int nBufLen = inputBuffers[inputBufferIndex].capacity();
if (nLen == nBufLen)
codec.queueInputBuffer(inputBufferIndex, 0, nLen, 0, MediaCodec.BUFFER_FLAG_SYNC_FRAME);
else if (nLen < nBufLen)
{
codec.queueInputBuffer(inputBufferIndex, 0, nLen, 0, MediaCodec.BUFFER_FLAG_END_OF_STREAM);
bEndInput = true;
break;
}
}
}
MediaCodec.BufferInfo info = new MediaCodec.BufferInfo();
if (!bEndOutput)
{
int outputBufferIndex = codec.dequeueOutputBuffer(info, 0);
if (outputBufferIndex >= 0)
{
int outBitsSize = info.size;
Log.d("test", "Offset:"+info.offset);
Log.d("test", "Size:"+info.size);
Log.d("test", "Time:"+info.presentationTimeUs);
Log.d("test", "Flags:"+info.flags);
if (info.flags != 0) //fixed version
{
codec.releaseOutputBuffer(outputBufferIndex, false /* render */);
continue;
}
int outPacketSize = outBitsSize + 7; // 7 is ADTS size
ByteBuffer outBuf = outputBuffers[outputBufferIndex];
outBuf.position(info.offset);
outBuf.limit(info.offset + outBitsSize);
try {
byte[] data = new byte[outPacketSize]; //space for ADTS header included
addADTStoPacket(data, outPacketSize);
outBuf.get(data, 7, outBitsSize);
outBuf.position(info.offset);
outputStream.write(data, 0, outPacketSize); //open FileOutputStream beforehand
} catch (IOException e) {
Log.e("test", "failed writing bitstream data to file");
e.printStackTrace();
}
outBuf.clear();
codec.releaseOutputBuffer(outputBufferIndex, false /* render */);
Log.d("test", " dequeued " + outBitsSize + " bytes of output data.");
Log.d("test", " wrote " + outPacketSize + " bytes into output file.");
if (info.flags == MediaCodec.BUFFER_FLAG_END_OF_STREAM)
{
bEndOutput = true;
//break;
}
}
else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_BUFFERS_CHANGED)
{
outputBuffers = codec.getOutputBuffers();
}
else if (outputBufferIndex == MediaCodec.INFO_OUTPUT_FORMAT_CHANGED)
{
}
}
if (bEndInput && bEndOutput)
break;
}