AAC/AC3/EAC3 5.1 tracks at 44.1 kHz played as stereo through mpv on Android:
ao_audiotrack sized its buffer as 75 ms aligned to the sample size, which at
44.1 kHz is not a whole number of 6-channel frames, so AudioTrack refused it
("Invalid audio buffer size") and mpv fell back to the stereo-only OpenSL ES
output. 48 kHz sources (DTS, or audio-samplerate=48000) happened to align.
Pin mpv-build 1779135, which frame-aligns the audiotrack PCM buffer
(edde746/mpv-build@d89cfbb). Only the Android libmpv key moves.
close #1445