Large opus files fail to play or cause UI lag

[yump]

I don't know enough about Android to say much for sure, but I think this is an "ANR".

I've noticed some slowness with longer (3+ hours) files before, but it's so severe on Ian Cutress' 9:30 Hot Chips livestream that playback dies after a few seconds. Youtube-hosted files aren't exactly stable, but this ffmpeg command generates a file that exhibits the problem:

ffmpeg \
    -f lavfi -i anoisesrc=r=48000:a=0.5:c=pink \
    -t 10:00:00 \
    -c:a libopus \
    -b:a 64k \
    -ac 2 \
    10_hours_noise.opus

Attempting to play that results in a failure after 5-ish seconds. Replace libopus with libmp3lame, and .opus with .mp3, and it plays just fine. Attached is a logcat dump started just before pressing play, and ^C'd just after playback stopped. The interesting part begins at timestamp 08-24 21:23:12.424. AudioAnchor is uid=10249, pid=32752.

attempt_to_play_opus_everything.log

It seems like there's maybe some computation/memory cost that scales with file size or length. top shows 70-ish % CPU usage from mediaserver and media.extractor aextractor, but their RSS is < 15 MiB. I see no spike in memory or CPU footprint from AudioAnchor itself.

(Although the baseline of ~16% CPU just paused on the playback screen with any file is somewhat concerning. surfaceflinger is ~20%. Is it redrawing continuously?)