A2DP stream stops sending data after 15 minutes 51 seconds

[ftab]

Try modifying the sbc read function in run_a2dp_source.py like so:

            async def read(byte_count):
                return sbc_file.read(byte_count)

->

            async def read(byte_count):
                data = sbc_file.read(byte_count)
                if len(data) < byte_count:
                    sbc_file.seek(0)
                    data += sbc_file.read(byte_count-len(data))
                return data

This gives a very rudimentary neverending loop. I've found that it quits sending data after 15 minutes 51 seconds (without a stream "suspend") and stopping the stream and starting again does not work:

On attempting to stop:

Traceback (most recent call last):
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/qasync/__init__.py", line 780, in _error_handler
    task.result()
  File "/home/pi/MrData/py/BtTools.py", line 412, in stopTestAudio
    await self.audio_stream.stop()
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/bumble/avdtp.py", line 1849, in stop
    await self.local_endpoint.stop()
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/bumble/avdtp.py", line 2197, in stop
    return await self.packet_pump.stop()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/bumble/avdtp.py", line 411, in stop
    await self.pump_task
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/bumble/avdtp.py", line 397, in pump_packets
    rtp_channel.send_pdu(bytes(packet))
                         ^^^^^^^^^^^^^
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/bumble/avdtp.py", line 344, in __bytes__
    ) + struct.pack('>HII', self.sequence_number, self.timestamp, self.ssrc)
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
struct.error: 'H' format requires 0 <= number <= 65535

On attempting to start again:

Traceback (most recent call last):
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/qasync/__init__.py", line 780, in _error_handler
    task.result()
  File "/home/pi/MrData/py/BtTools.py", line 406, in playTestAudio
    await self.audio_stream.start()
  File "/home/pi/MrData/mrdata/lib/python3.11/site-packages/bumble/avdtp.py", line 1834, in start
    raise InvalidStateError('current state is not OPEN')
bumble.core.InvalidStateError: current state is not OPEN

It seems to not currently be possible to stream long-term without tearing down the stream and reconnecting after 15 minutes and 51 seconds.