1185356 - Wrong colors at start while playing YouTube mp4 videos in 480p

Status: RESOLVED INCOMPLETE

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

Description

[mozbugrep]

User Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:39.0) Gecko/20100101 Firefox/39.0
Build ID: 20150630154324

Steps to reproduce:

Environment:
- Windows 7 64bit
- nVidia 9300 GE
- Firefox 39

1. Open any YouTube video. Most of them will work.
2. Before the first seconds load, switch video quality to 480p
2.1 An easy way to do this is setting up Theatre Mode and refreshing. Most times it will automatically switch the video to 480p on start.
3. After the first 5 seconds or so play, go back to 0:00 and notice the difference. Bug seems to be solved for this video after this, unless you pause the video for a while and switch tabs or refresh the page, in which case it will be back.
Note: pausing and playing the video or jumping to any other point will cause the anomalies to disappear instantly.

You can use https://www.youtube.com/watch?v=143k1fqPukk, which shows the bug might be some sort of XOR filter from the first frame over the following frames (white on black text appears completely black and later "burns in" in black when the beige tower shows), or https://www.youtube.com/watch?v=CM5zVqhj8Do for a static image being used in a video (completely black for the first seconds), or https://www.youtube.com/watch?v=FGpa11KRh9I for a video where the "fog effect" square shows completely black but the text and the white squares that appear later do.

In addition, I want to point out that this bug doesn't seem to affect Chrome on latest Android and Firefox 30 on Arch, according to other users. Furthermore, there is a certain mp4 video where this bug is very outstanding (artifacts are shown very clearly and it lasts for more than the first 5 seconds, unlike YouTube videos), but it is very NSFW so I am not sure if I should post it here.


Actual results:

Video colors were distorted for the first seconds of playback, usually to a darker shade. Some videos also show ugly artifacts, like they were extremely compressed, in addition to looking much darker than usual.


Expected results:

Video should play with normal colors from start to end.

Comment 1

[Chris Peterson [:cpeterson]]

hi mozbugrep, thanks for reporting this problem!

Video color problems suggest this is a problem with Firefox and the GPU. Can you please test whether you can reproduce the problem after flipping the about:config pref "media.hardware-video-decoding.enabled" to false (and restarting Firefox)?

Can you please post your about:support information (using "Copy text to clipboard" button)? That will give us more details about your GPU type and driver version.

Comment 2

[Ryan VanderMeulen [:RyanVM]]

The videos from comment 0 that are still available all play without any visual oddities AFAICT on a current nightly build on Windows 10 x64. Reporter, are you still seeing issues on your end? If so, as Chris mentioned in comment 1, more information about your system setup would be helpful for possibly diagnosing the problem.

Thanks!