Chrome Version: 71.*
OS: Android

We currently didn't copy the side data from AVPacket extracted by ffmpeg. However, for vp8/vp9 videos, it may contain alpha plane, which is contained in the side data currently.

http://wiki.webmproject.org/alpha-channel

If we use the first key frame as thumbnail, this might not be an issue. But if we want to seek to a particular timestamp, decoding will fail on VPX_CODEC_UNSUP_BITSTREAM, probably because of the side data.