CODEWITHSUNDEEP
androidaacandroid-mediacodec
Marianna D
Marianna D

Reputation: 51

Using MediaCodec to decode raw AAC audio data works on Android 4.4 but not 4.3

I have successfully implemented encoding/decoding raw AAC-LC using MediaCodec. I'm using the same technique described here to encode the data. However, I store the raw AAC data (without headers) and then attach headers on the fly as I pass the data through a MediaCodec decoder. This all works absolutely perfectly on the Nexus 4 and Nexus 5 both running Android 4.4. However, on the Galaxy Nexus (running Android 4.3) I get:

W/SoftAAC2(1234): AAC decoder returned error 16388, substituting silence

Error 16388 means a decode frame error.

I've tried with and without an initial MediaCodec.BUFFER_FLAG_CODEC_CONFIG but that doesn't make a difference.

Here is the simplest case (using config packet) to reproduce the error:

MediaFormat format = new MediaFormat();
format.setInteger(MediaFormat.KEY_SAMPLE_RATE, 44100);
format.setInteger(MediaFormat.KEY_CHANNEL_COUNT, 1);
format.setString(MediaFormat.KEY_MIME, "audio/mp4a-latm");
format.setInteger(MediaFormat.KEY_AAC_PROFILE, MediaCodecInfo.CodecProfileLevel.AACObjectLC);
format.setInteger(MediaFormat.KEY_IS_ADTS, 1); 

byte[] bytes = new byte[]{(byte) 0x11, (byte)0x90};
ByteBuffer bb = ByteBuffer.wrap(bytes);
format.setByteBuffer("csd-0", bb);

MediaCodec codec = MediaCodec.createDecoderByType("audio/mp4a-latm");
codec.configure(format, null /* surface */, null /* crypto */, 0 /* flags */);
codec.start();
ByteBuffer[] codecInputBuffers = codec.getInputBuffers();

int inputBufIndex = codec.dequeueInputBuffer(TIMEOUT_US);
if (inputBufIndex >= 0) {
    ByteBuffer dstBuf = codecInputBuffers[inputBufIndex];
    byte[] data = {-1, -7, 80, 0, 1, 63, -4, 18, 8}; // values taken from SO answer linked above (chanCfg = 1, packetLen = 9)
    dstBuf.clear();
    dstBuf.put(data);
    codec.queueInputBuffer(inputBufIndex, 0, data.length, 0, MediaCodec.BUFFER_FLAG_CODEC_CONFIG);
}

Obviously there is a lot more to the code than this, but this includes all the executed code up to the point of the error message.

Upvotes: 1

Views: 3145

Answers (1)

Marianna D
Marianna D

Reputation: 51

The solution is to not include the ADTS headers. Both 4.3 and 4.4 support packets without ADTS headers.

Upvotes: 3

Related Questions