1077519 - H264 MP4 playback, dropped frames

Status: RESOLVED INACTIVE

(Core :: Audio/Video: Playback, defect)

Description

[Maarten]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:32.0) Gecko/20100101 Firefox/32.0
Build ID: 20140923175406

Steps to reproduce:

1. Open a new FF tab with URL https://dl.dropboxusercontent.com/u/6679751/fragment2.mp4
2. Look at the video playback


Actual results:

The video is encoded at 24 FPS, while the playback in FF is visibly dropping frames. If you compare the video playback with VLC, the difference is quite obvious. I never noticed this before with other MP4 files. 

I don't have the encoding settings right now, but could probably retrieve them if required.

Other browsers: Chrome stalls if you play the MP4 file (in CPU decode mode) after ~0.5 seconds. (So, even worse)


Expected results:

Video plays for ~10 seconds at 24 fps.

Comment 1

[Loic]

Attachment: fragment2.mp4

Comment 2

[Jet Villegas (inactive)]

I posted a test case for this bug here:
http://media.junglecode.net/test/1077519/test.html

The video file was encoded at exactly 60FPS. Each frame of the video contains either a cyan or a magenta square. If we render at 60Hz, you shouldn't see either color and a smooth gray square should animate on the screen. Flashes of cyan or magenta indicate pauses or dropped frames. Can we use this to profile our video and graphics pipeline?

Comment 3

[Michael Bebenita [:mbx]]

The cyan / magenta trick is described here: http://www.vsynctester.com/

Comment 4

[bull500]

Attachment: drop720p.png

I came across this dropped frame problem while playing a 720p video on Firefox 42.0a1 (2015-07-11) on Linux Fedora 22
Total dropped frames - 887/14263
Video - https://www.youtube.com/watch?v=PLLQK9la6Go 

The frames constantly kept dropping when it was waiting/trying to play new buffered content.
Everything except webM enabled on youtube.com/html5
Attached screenshot for more info.

Comment 5

[bull500]

Another video where i noticed considerable frame-drops 329/3006

This had a special video quality - 360p60
Video link - https://www.youtube.com/watch?v=a5ARUj9q_ME

Comment 6

[Jean-Yves Avenard [:jya]]

This isn't an MSE issue ; this is graphics

Comment 7

[Anthony Jones (:ajones, :kentuckyfriedtakahe, :k17e)]

Should be fixed with https://hg.mozilla.org/integration/mozilla-inbound/rev/ebf348f1e465

Comment 8

[Nils Ohlmeier [:drno]]

Mass closing because of inactivity.
Please feel free to re-open if still relevant.