www.bilibili.com - Video doesn't play

[webcompat-bot]

URL: https://www.bilibili.com/video/BV184411x7F9?p=1

Browser / Version: Firefox 76.0b5
Operating System: Windows 10
Tested Another Browser: Yes Edge

Problem type: Video or audio doesn't play
Description: Media controls are broken or missing
Steps to Reproduce:
no

View the screenshot

Browser Configuration

• None

From webcompat.com with ❤️

[cipriansv]

@softvision-oana-arbuzov, could you please test this on your Windows machine and see if the issue is reproducible?

[softvision-oana-arbuzov]

Thanks for the report, I was able to reproduce the issue. The audio works but the video is not displayed.

Note:

1. The issue is not reproducible on Chrome.
2. The issue is reproducible on Firefox Nightly regardless if ETP is enabled or not.

Tested with:
Browser / Version: Firefox Nightly 86.0a1 (2020-12-29)
Operating System: Windows 10 Pro

Moving to Needsdiagnosis for further investigation.

[karlcow]

window.player.getMediaInfo() returns

​
audioChannelCount: 0
​
audioCodec: "mp4a.40.2"
​
audioCodecID: 0
​
audioDataRate: 132484
​
audioSampleRate: 0
​
fps: "15.152"
​
height: 480
​
mimeType: "video/mp4;codecs=\"avc1.64001F\", audio/mp4;codecs=\"mp4a.40.2\""
​
sar: "1:1"
​
videoCodec: "avc1.64001F"
​
videoCodecID: 7
​
videoDataRate: 155373
​
width: 850

per https://bugzilla.mozilla.org/show_bug.cgi?id=806139 this should be ok for the videoCodec.
@SingingTree Do you know if there is an issue with the mimetype or codec?

[SingingTree]

I've debugged this and suspect the site is not creating a video source buffer (though why it's not doing so is unclear to me).

Running Firefox with MOZ_LOG=sync,timestamp,MediaSource:5 I get the following in my logs:

2021-01-13 18:21:21.366000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4; codecs="avc1.42E01E,mp4a.40.2") OK
2021-01-13 18:21:21.378000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4; codecs="hev1.1.6.L120.90") [not supported]
2021-01-13 18:21:21.378000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4; codecs="hev1.1.6.L120.90") [not supported]
2021-01-13 18:21:21.379000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4; codecs="hev1.1.6.L120.90") [not supported]
2021-01-13 18:21:21.379000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4; codecs="hev1.1.6.L120.90") [not supported]
2021-01-13 18:21:21.426000 UTC - [Child 26432: Main Thread]: D/MediaSource dom::MediaSource[0000012870704700] ::MediaSource: MediaSource(aWindow=1286d34e820) mSourceBuffers=1286d878b00 mActiveSourceBuffers=1286d878ba0
2021-01-13 18:21:21.428000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4;codecs="avc1.640028";width="1274";height="720") OK
2021-01-13 18:21:21.429000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4;codecs="avc1.64001F";width="850";height="480") OK
2021-01-13 18:21:21.430000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4;codecs="avc1.640028";width="1360";height="768") OK
2021-01-13 18:21:21.430000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=audio/mp4;codecs="mp4a.40.2") OK
2021-01-13 18:21:21.431000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=audio/mp4;codecs="mp4a.40.2") OK
2021-01-13 18:21:21.432000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=video/mp4;codecs="avc1.F40016") [not supported]
2021-01-13 18:21:21.434000 UTC - [Child 26432: Main Thread]: D/MediaSource MediaSource::IsTypeSupported: IsTypeSupported(aType=audio/mp4;codecs="mp4a.40.2") OK

i.e. the site is checking various types, some we support some we don't.

In the same logs I see

2021-01-13 18:21:21.650000 UTC - [Child 26432: Main Thread]: D/MediaSource dom::MediaSource[0000012870704700] ::AddSourceBuffer: AddSourceBuffer(aType=audio/mp4;codecs="mp4a.40.2")

i.e. a source buffer is being added to handle just audio. I don't see a log where a source buffer is added for video.

Checking the network tabs in Fx and Chrome, I wasn't able to find the video file in Fx, but could in Chrome. This suggests the video is not being downloaded in Fx (the site isn't initiating it). Interestingly, if I copy the URL for the video from Chrome into Firefox it plays fine (I'm not sure if the URLs expire but here is the one I got).

So the problem is likely not with our decode, but somewhere earlier. It may be a bug in the site that it's failing to serve video.

[karlcow]

Thanks a lot. I'll try to dig a bit more and then let's contact them.

[softvision-oana-arbuzov]

The issue has been fixed. The video is displayed now and plays.

Tested with:
Browser / Version: Firefox Nightly 107.0a1 (2022-10-11)
Operating System: Windows 10 Pro

[inv_41/2022]