Playing an empty AudioFrame never returns

[microbit-carlos]

This in the REPL never returns until Ctrl+C is sent:

>>> audio.play(audio.AudioFrame())

But as soon as something else larger is played (like Sound.HAPPY) it does work until the next power cycle.

Might be related to increasing AUDIO_OUTPUT_BUFFER_SIZE to 64, as audio.play(audio.AudioTrack(bytearray(63))) doesn't return either, but audio.play(audio.AudioTrack(bytearray(64))) does.

[dpgeorge]

I can reproduce the problem. It looks like a CODAL issue and related to the recently fixed #182 which used uBit.audio.isPlaying() to check if audio is playing or not.

It seems that upon startup, CODAL reports that audio is playing:

int main() {
    uBit.init();
    uBit.audio.isPlaying(); // returns true!
    return 0;
}

I can work around this, but it should probably be fixed in CODAL.

[dpgeorge]

It seems that upon startup, CODAL reports that audio is playing

And this is reflected in MicroPython by doing audio.is_playing() after a reset, it returns True.

[dpgeorge]

On the audio-recording branch, I have fixed the issue with short audio not returning, by fixing a related issue where the last part of audio may not have been sent out the pipeline if it was shorter than 64 bytes.

But, the issue with audio.is_playing() returning True after a reset still remains.