496714 - Firefox ignores display aspect ratio specified in video headers

Status: RESOLVED DUPLICATE of bug 480058

(Core :: Audio/Video, defect)

Description

[Denver Gingerich]

User-Agent:       Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b4pre) Gecko/20090401 Ubuntu/9.04 (jaunty) Shiretoko/3.5b4pre
Build Identifier: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.9.1b4pre) Gecko/20090401 Ubuntu/9.04 (jaunty) Shiretoko/3.5b4pre

Firefox seems to assume that the pixel aspect ratio is always 1:1, ie. that the pixel width by height is equal to the display aspect ratio, even when the video header specifies otherwise by defining a different display aspect ratio.  The example video contains 720x540 pixels but specifies its aspect ratio is 16:9 in the header.  This should cause Firefox to scale the video to 960x540 but instead Firefox displays it at 720x540.

Reproducible: Always

Steps to Reproduce:
1. Load the example video (http://ossguy.com/sc09/ossguy-sc09-720x540.ogv) in Firefox 3.5
Actual Results:  
The video is skewed (displayed at 720x540).

Expected Results:  
The video is scaled to 16:9 (960x540) as specified in the video's header.

VLC, mplayer, and Totem all correctly scale the video to 16:9.  You can verify this by downloading the example video and opening it in these players.

This problem is also present in the following video, a larger version of the example:
http://ossguy.com/sc09/ossguy-sc09-1440x1080.ogv

For more information about this video, see http://ossguy.com/?p=365 .  Note that the JVC video camera which recorded the video uses a 4:3 pixel aspect ratio (ie. it uses 1440x1080 pixels to store 1080p video at a 16:9 display aspect ratio), which is why the resulting Theora files have that property.  Since many HD video cameras use 1440x1080 for 16:9 1080p video, fixing this should be a priority.

For more on pixel aspect ratios, see http://en.wikipedia.org/wiki/Pixel_aspect_ratio .

Comment 1

[Jo Hermans]

bug 480058 ? That's already fixed in the latest Firefox3.5

Mozilla/5.0 (Windows; U; Windows NT 5.1; en-US; rv:1.9.1pre) Gecko/20090606 Shiretoko/3.5pre

Comment 2

[Denver Gingerich]

Yes, you're right.  I've confirmed that it's fixed in a 20090612 daily build for Ubuntu 9.04.