Closed Bug 1347538 Opened 4 years ago Closed 4 years ago
Seeking in Web
M video causes corruption message
I have a problem with Firefox Nightly 55. It doesn't happen in Firefox Beta 53. When I was watching my discarded video of Bug 1344339, the video occasionally showed message "file is corrupt". So far I only saw it in one video. One specific scenario when it happens 1. Open attached video 2. Click on the center of timeline Result: Playback stops. Video shows error message "Video can’t be played because the file is corrupt." Expected: Video shouldn't stop, because the file is not corrupt. (* not corrupt enough for Beta 53 to be unable to play it)
I looked into this, just for fun. This looks like a regression from https://hg.mozilla.org/mozilla-central/rev/13ce99c3c8af.
The WebM file at issue here says it has two tracks (video, audio) but it contains only video data. So during WebMTrackDemuxer::Seek() for the audio track, after seeking, WebMDemuxer::NextPacket gets called to find the next audio packet, but it doesn't find one before the end-of-stream, so it bails out with a seek error which eventually gets treated as a corrupt file. Before 13ce99c3c8af, WebMTrackDemuxer::Seek would basically ignore failure of GetNextPacket. This WebM file may or may not be valid, but Chrome can play and seek in it without error.
The behaviour of the WebMDemuxer + MediaFormatReader appears correct to me, the seek promise is rejected with END_OF_STREAM. The MDSM however doesn't handle this case and cause the media element to enter in error mode. Not sure on the best approach here: Work around the issue in WebMDemuxer, have the seek completes but in a dummy fashion, the next GetSample will return EOS. Or fix the MDSM so that it correctly handles EOS during seeking. JW, what do you think? Jean-Yves
Assignee: nobody → jyavenard
Flags: needinfo?(jyavenard) → needinfo?(jwwang)
It will be easier and quicker to always let seek be resolved.
Given that seeking in this file works in Chrome and used to work in Firefox, seems to me that it should keep working.
Comment on attachment 8851049 [details] Bug 1347538: Don't reject seeks with EOS. https://reviewboard.mozilla.org/r/123496/#review126510
Attachment #8851049 - Flags: review?(kinetik) → review+
Pushed by firstname.lastname@example.org: https://hg.mozilla.org/integration/autoland/rev/e86850951152 Don't reject seeks with EOS. r=kinetik
Comment on attachment 8851049 [details] Bug 1347538: Don't reject seeks with EOS. Approval Request Comment [Feature/Bug causing the regression]: 1334508 [User impact if declined]: Some videos no longer play [Is this code covered by automated tests?]: yes [Has the fix been verified in Nightly?]: by myself [Needs manual test from QE? If yes, steps to reproduce]: Yes, instructions provided in first description [List of other uplifts needed for the feature/fix]: none [Is the change risky?]: no [Why is the change risky/not risky?]: we handle an error later in the timeline [String changes made/needed]: none
Attachment #8851049 - Flags: approval-mozilla-aurora?
Hi Brindusa, could you help find someone to verify if this issue was fixed as expected on a latest Nightly build? Thanks!
Verified fixed using the latest Nightly 55.0a1 (2017-03-29) on Ubuntu 16.04, Mac OS X 10.10 and Windows 10 x64.
Comment on attachment 8851049 [details] Bug 1347538: Don't reject seeks with EOS. fix webm regression in aurora54
Attachment #8851049 - Flags: approval-mozilla-aurora? → approval-mozilla-aurora+
I’ve reproduced the issue described in comment 0 using Firefox 55.0a1 (Build Id:20170314110401) and verified that the issue is not reproducible anymore using Firefox 54.0b1 (Build Id:20170420081804) on Ubuntu 16.04 64bit,
It seems that I forgot to mention that this issue was also verified on Windows 10 64bit and macOS 10.11.6. (Sorry for the mistake).
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