PCM -> AAC (Encoder) -> PCM(Decoder) in real-time with correct optimization

Question

I\'m trying to implement

AudioRecord (MIC) ->

PCM -> AAC Encoder
AAC -> PCM Decode

-> AudioTrack??  (SPEAKER)

with Me

Answer 1

I have tried the above code and it didn't work properly.I was getting lot of silence injected to the decoded output. Issue was not setting proper "csd" value to the decoder.

So if you see "silence" in log or Decoder throwing error make sure you have added the following to your media decoder format

int profile = 2;  //AAC LC
int freqIdx = 11;  //8KHz
int chanCfg = 1;  //Mono

ByteBuffer csd = ByteBuffer.allocate(2);
csd.put(0, (byte) (profile << 3 | freqIdx >> 1));
csd.put(1, (byte)((freqIdx & 0x01) << 7 | chanCfg << 3));
mediaFormat.setByteBuffer("csd-0", csd);