WMP does not accept sample aspect ratio close to 1 but != 1 in mov

[mfz]

Summary of the bug:
I have a screen recorded video with frame rate 15, video codec H.264 (MP4) and AAC as audio. The target via FFmpeg should contain frame rate 25, height of 720 pixel and the codecs without change.

After encoding, the file is playable in VLC player, Chrome browser (HTML5 video tag) and Firefox. In Windows Media player I just get the audio played (no video to see) and in Internet Explorer 11, I get an error ("Unknown source.")

How to reproduce:

% ffmpeg -i input_file.mp4 -vf "scale='(trunc((out_h*a)/2)*2):(min(720, in_h))'" output_file.mp4
VERSION: N-63439-g96470ca
N-63439-g96470ca

Strange is: If I encode the video with a height of 718 or 722 (or any other height I tried), the video is playable anywhere - without problems.

Test video file for input (short, length of 1 second):
​http://www.datafilehost.com/d/1ca920ac

[mfz]

Report output for test case

[Carl Eugen Hoyos]

The issue can be reproduced with the following command line:

$ ffmpeg -f lavfi -i testsrc=s=1280x832 -pix_fmt yuv420p -t 10 -vcodec h264 -vf scale=1106x720 out.mp4

Work-around is to specify -vf setsar=1

Since so many players have no problem with the sample aspect ratio: Did you report the problem to Micrososft?

[mfz]

I could successfully use your specified workaround to get it working. Thanks a lot!

I have not yet reported the issue to Microsoft but will do exactly that in a minute.

[Carl Eugen Hoyos]

Seems to be a regression since 4557d7d0 related to ticket #570.

[Carl Eugen Hoyos]

I attached three addtional samples to make an analysis slightly simpler (and to show that the issue is not the different video and container sample aspect ratio):
Only equal1.mp4 can be played with WMP, both different.mp4 and equal2.mp4 fail.

The issue is not just a DAR overflow, I created a file with the following properties that plays fine:

Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1280x962 [SAR 1309:1307 DAR 837760:628667], 123 kb/s, SAR 7200:7189 DAR 833978:625829, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)

[Carl Eugen Hoyos]

$ ffmpeg -i equal1.mp4 -i equal2.mp4 -i different.mp4
ffmpeg version N-63441-g99d742a Copyright (c) 2000-2014 the FFmpeg developers
  built on May 26 2014 16:51:14 with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl --enable-libx264
  libavutil      52. 86.100 / 52. 86.100
  libavcodec     55. 65.100 / 55. 65.100
  libavformat    55. 41.100 / 55. 41.100
  libavdevice    55. 13.101 / 55. 13.101
  libavfilter     4.  5.100 /  4.  5.100
  libswscale      2.  6.100 /  2.  6.100
  libswresample   0. 19.100 /  0. 19.100
  libpostproc    52.  3.100 / 52.  3.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'equal1.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.41.100
  Duration: 00:00:10.00, start: 0.000000, bitrate: 98 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1106x720 [SAR 7200:7189 DAR 20:13], 94 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
Input #1, mov,mp4,m4a,3gp,3g2,mj2, from 'equal2.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.41.100
  Duration: 00:00:10.00, start: 0.000000, bitrate: 98 kb/s
    Stream #1:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1106x720 [SAR 1309:1307 DAR 723877:470520], 94 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
Input #2, mov,mp4,m4a,3gp,3g2,mj2, from 'different.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf55.41.100
  Duration: 00:00:10.00, start: 0.000000, bitrate: 98 kb/s
    Stream #2:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1106x720 [SAR 1309:1307 DAR 723877:470520], 94 kb/s, SAR 7200:7189 DAR 20:13, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler
At least one output file must be specified