AVI to MP4 aspect ratio problems

[lostatredrock]

I have a library of movies encoded as AVIs ffmpeg MPEG4 and AC3 audio. This library worked fine when all I was using was XBMC, but now that I have started playing with the AppleTV, having my files in an MP4 container rather than AVI as MP4 is supported natively by iTunes and even in the add-on apps it is much more responsive.

So I have been trying to use ffmpegX to do this conversion keeping my video exactly the same and then re-encoding the audio to AAC instead of AC3 which MP4 does not support. The conversion goes through and I get a resulting video file which plays fine in iTunes and on the AppleTV but has a distorted aspect ratio in MPlayer, QuickTime and on XBMC (which used mplayer I believe). Opening up in QuickTime and examining the file properties I see that the file format lists the size as 704 X 304 but the listed normal size if 405 X 304.


I have auto-size (which I kind of assumed controlled this) set to 2.35:1
The info on the encode is:

FFmpeg version CVS, Copyright (c) 2000-2004 Fabrice Bellard
Sat Jan 19 16:40:05 EST 2008
Mac OSX universal build for ffmpegX
  libavutil version: 49.0.0
  libavcodec version: 51.9.0
  libavformat version: 50.4.0
Seems that stream 0 comes from film source: 24000.00 (24000/1) -> 23.98 (24000/1001)
Input #0, avi, from '/Users/annagel/Movies/ANIMATRIX.avi':
  Duration: 00:28:17.9, start: 0.000000, bitrate: 1758 kb/s
  Stream #0.0, 23.98 fps(r): Video: mpeg4, yuv420p, 704x304
  Stream #0.1: Audio: ac3, 48000 Hz, 5:1, 448 kb/s
Output #0, mp4, to '/Users/annagel/Movies/ANIMATRIX.avi.ff.mp4':
  Stream #0.0, 23.98 fps(c): Video: mpeg4, yuv420p, 704x304, q=2-9, 1516 kb/s
  Stream #0.1: Audio: aac, 48000 Hz, stereo, 160 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
  Stream #0.1 -> #0.1
video:313819kB audio:33158kB global headers:0kB muxing overhead 0.275414%
bench: utime=312.507s
Encoding completed on Sat Jan 19 16:44:35 EST 2008

Any ideas on either how to make ffmpegX set the correct display ratio or how to alter the ratio after ffmpegX finishes?

Thanks,
Andrew

[simonhead666]

Did you end up finding the fix to this...I had the same problem
only when I imported to Itunes, The aspect ratio looked fine...only when I was using airtunes was it showing 4:3

help!!

[rumplestiltskin]

I never use the "auto-size" function; rather, I set it manually in ffmpegX. Never have a problem.

[simonhead666]

Oh Ok
Show choose 'unconstrained' in the drop down menu?
The strange thing is that the aspect ratio is fine once it's imported into itunes yet in the info window in the itunes folder, the aspect ratio reads 405x304..

I'll try your advice
thanks

[simonhead666]

It seems that the aspect ratio is fine when I use Airtunes between my macbook pro and PPC Dual processor at work...but the issue remains between my slower 667mhz laptop and 833mhz desktop @ home

Would it be a processor saver issue and nothing else? meaning...go buy faster computers?