Codecs

[James Linder]

 If I play an mp4, generated another way, in a browser (I’ve tried firefox, chrome and mac’s safari they all play:

[mov,mp4,m4a,3gp,3g2,mj2 @ 0x17adb80] st: 0 edit list: 2 Missing key frame while searching for timestamp: -1
[mov,mp4,m4a,3gp,3g2,mj2 @ 0x17adb80] st: 0 edit list 2 Cannot find an index entry before timestamp: -1.
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'Channel1.27Jan2021.124703.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 1
    compatible_brands: isommp42
  Duration: 00:00:33.07, start: 0.000000, bitrate: 1233 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuvj420p(pc), 1920x1080 [SAR 1:1 DAR 16:9], 1039 kb/s, 31.17 fps, 60 tbr, 90k tbn, 119.88 tbc (default)
    Metadata:
      handler_name    : Video
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
    Metadata:
 
ffprobe version v31.0-85-gd3088629de Copyright (c) 2007-2019 the FFmpeg developers
  built with gcc 7 (SUSE Linux)

If I try an mp4 from gstreamer

Input #0, mpegts, from 'pict.mp4':
  Duration: 00:01:25.99, start: 3600.000000, bitrate: 10404 kb/s
    Stream #0:0[0x41]: Video: h264 (High) (HDMV / 0x564D4448), yuv420p(tv, progressive), 1920x1080 [SAR 1:1 DAR 16:9], 30 fps, 30 tbr, 90k tbn, 60 tbc
    Stream #0:1[0x42](en): Audio: aac (LC), 16000 Hz, stereo, fltp, 122 kb/s

and all the browsers choke.
VLC and mplayer play without complaint.

Please can someone explain

(gstreamer and plugins are from packman, that may affect results)
James