Ticket #1008 (closed defect: invalid)
Can't generate video with undefined aspect
|Reported by:||hadmut||Owned by:|
|Blocking:||Reproduced by developer:||no|
|Analyzed by developer:||no|
I'm currently converting several videos (most from mpeg2 or mpeg4 with wrong aspect ratio) for efficient storing, watching with a streamer (such as WD TV Live) and iPad2. Usually using x264/aac as codecs, converting to ?x720, depending on the required ratio (in most cases 1280x720).
The problem: iPad2's computation power seems to be limited. While it can properly display most videos of my collection (especially with lower resolutions), it has trouble, hangs or even stops playing 1280x720 videos generated with ffmpeg. Lower resolutions solve the problem, but obviously reduce quality.
But then, I have other videos downloaded from the Web (or youtube) which as well are 1280x720, H264, AAC, and they are displayed correctly on the iPad.
The only difference I have figured out so far is that in those videos iPad can play without problems the Video Aspect (as reported by mplayer) is undefined. I guess that this might cause the iPad to rescale images and waste computation time.
The problem with ffmpeg: I can't remove the aspect ratio. If I omit the -aspect parameter, ffmpeg copies the (wrong) aspect ratio from the MPEG2 (=1.333). If I use the -aspect parameter, ffmpeg rejects giving 0 as a parameter.
So I don't see any way to create a video with ffmpeg where the aspect is not set (i.e. just use the width/height).
(ffmpeg version is 0.7.3 as of ubuntu latest, but this ticket system does not offer this version for selection)