Yining,

Matt just rolled ffmpeg (which Chrome uses for demuxing and decoding). (Rolled means he updated the ffmpeg library to its latest version in the Chromium repository).

Here's what Matt says about it:

"""
tl;dr: Yes - the roll, since it includes about 8 months of upstream changes, is quite extensive. Current Canary vs Current Dev contains the roll delta. The roll, plus some follow-up work listed below, landed in range 433075-433433 in trunk.

Details:
The roll landed last Thursday in trunk. Friday night, the branch announcement made it clear that it missed this M56 cut @r433059 by < 20 commits. I've requested it be merged back to M56, and that request is pending manual review by the TPMs currently.

Apart from possible performance changes (improvements/regressions), feature changes of which I'm aware are:

- FLAC demux+decode support on all Chrom* brandings (not just ChromeOS)

- Opus audio decode capability as a shim to our third_party/libopus (Note, the roll disabled this new ability temporarily until Dale's https://codereview.chromium.org/2435603009/ landed over the weekend), rather than our custom OpusAudioDecoder.

- Anything related to cropped post-decode video; e.g. anything where ffmpeg previously emitted a coded width/height different than the actual decoded width/height: we no longer have access to the coded width/height during ffmpeg demux; actual decode though should not regress, since actual decode by ffmpeg still observes internally available coded size info, and decoders other than ffmpeg must be able to similarly function correctly. TBH, the latter is where I'm less familiar, and regardless I recall sandersd@ mentioning our pipeline (even before the roll) didn't handle all cropping cases correctly.
"""

Would you to able to write additional test cases to cover these changes and also consider what existing test cases could also be affected? Matt is a good contact to help with questions.

We should also look for regressions in AVA in power, freezing, smoothness, etc.

Please let me know if you can cover this work.