[FFmpeg-user] ffmpeg with x264 codec - Aspect ratio doesn't follow input

Richard F lists at keynet-technology.com
Sat May 28 10:11:28 CEST 2016

To answer myself and for the benefit of others...

After a fair bit of testing it seems that the very recent H264 builds
(x264 and libx264) do incorporate auto-switching aspect ratio, and some,
not all current players support it, older ones don't.

In my testing Kodi on the Raspberry Pi has a problem seeing the aspect
changes (hardware acceleration issue).
Current versions of ffplay and VLC player are OK, but current Mplayer
still has some problems after aspect switching (plays video at wrong speed).

I have been stuck on VLC player 2.08 as I have an application that
requires window sizing using --width= and --height= which hasn't worked
for several versions (for me, and others: old bug
https://trac.videolan.org/vlc/ticket/9931).  2.08 doesn't auto switch.

Hope that helps someone.

On 25/05/2016 15:17, Richard F wrote:
> OK, so this comes up every so often - I found similar refs on list archives
> A useful keyword seems to be WSS "wide screen switching" from the old
> analogue days
> https://en.wikipedia.org/wiki/Widescreen_signaling
> http://ffmpeg-users.933282.n4.nabble.com/Aspect-ratio-td3255527.html
> http://ffmpeg-users.933282.n4.nabble.com/template/NamlServlet.jtp?macro=search_page&node=933282&query=wss
> https://www.mail-archive.com/search?l=ffmpeg-issues@lscube.org&q=subject:%22%5C%5Bissue2255%5C%5D+ffmpeg+h264+wss%22&o=newest&f=1
> I'm surprised it's not in the tree - it's an obvious requirement
> (and ffmpeg's native MP4 encoder does it out of the box...)
> I'd like to make a feature request - it seems a lot of the work is
> already done - how to do?
> Thanks

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