Other Parts Discussed in Thread: CC2564
We are able to establish the connection and send music. But the music comes in pieces. As per our observation we think there are not enough SBC frames being received by our A2DP sink. Below are the calculations we have done to come to this conclusion. Please see if we are missing on something.
- Music Stream: 16bit stereo @ 44.1kHz (1.4112Mbps)
- Our DMA which is dumping data on I2S is working at this speed - we have verified that by different ways
- We are receiving SBC frames - each frame being of 119bytes which gets decoded to 128 stereo 16bit samples
- So 1 SBC packet we receive gives 4096bits of audio data. To play at the above quality we would need 1.4112Mb/4096b = 344.53 SBC frames / s
- This number seems to match with the SBC specs - the SBC decoder reports 44.1kHz, Joint Stereo, Bitpool: 53, Frame length: 119, Resulting bit rate: 328kbps (328kb/(119*8) = 344.53)
- However when we counted / timed the SBC frames being received when playing music from a mobile we receive around 90 frames / s only. And more interestingly if we see the packet number inside these frames they are consecutive so nothing seems to be getting dropped.
- The same music obviously plays on a bluetooth speaker.
- But because of this when we play it, it plays broken sound in our hardware.
- Just to verify we did the same experiment on the CC2564 eval kit - and there also we receive around that many frames only.
So it seems we are obviously missing on something - but don't know what - can you please help us here ?
