BC127 / Melody 7.2 / Major bugs when operating as 44100Hz source

(Originally posted this in the parent forum by mistake - reposting here, with the addition of some comparative results obtained using firmware 6.1.5)

I’ve configured the BC127 to act as a 44100Hz A2DP source, and have run into a number of issues:

  1. Despite setting AUDIO_DIGITAL=0 44100 128 100310 OFF, the link opened to the headset is always reported (in response to ‘status’) as 48000Hz (using each of the SBC, APTX and APTX_LL codecs). Suggesting the BC127 is resampling the audio rather than transmitting a 44100Hz stream? We have previously been using 5.6rc3, which successfully opens a 44100Hz link (or at least reports that it does).
  2. When I change the volume using a discrete level command, the audio jumps in pitch and starts glitching – this happens regularly, but not always, using ‘volume 10 f’ (or whatever level), but not when using the relative ‘volume 10 <up/down>’. It sounds like the volume command somehow causes the resampling stage to be bypassed and the 44100 data stream is just getting used as a 48000hz data stream with gaps.
  3. (This one probably isn’t specific to the 44100 Hz mode). When I issue ‘music 10 play’ immediately/soon after opening the link (i.e. receiving the A2DP, AVRCP and ROLE_OK notifications), I get an ‘AVRCP_PLAY 11’ notification, but no ‘A2DP_STREAM_START 10’, and the stream isn’t opened. Issuing ‘music 10 play’ again doesn’t open the stream, but ‘music 10 stop’ followed by ‘music 10 play’ does.

Are these known issues? Any plans to release updated firmware soon?

I’ve since repeated the same tests with 6.1.5 and don’t see item 2. above occurring, although the stream status (item 1) still reports the link sample rate as 48000. Is the status output incorrect, or does this indicate that the BC127 is resampling?

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