gistfile1.txt

roroco@roroco ~/Dropbox/rbs/ro_cmds_global $ avconv -i ~/Downloads/test.mp4 -metadata my_key=prpr -c copy output.mp4 -y
avconv version 11.3-6:11.3-1~trusty, Copyright (c) 2000-2014 the Libav developers
  built on Apr 13 2015 22:25:55 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/roroco/Downloads/test.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41isomavc1
    creation_time   : 2016-08-18 21:19:35
  Duration: 00:00:16.08, start: 0.000000, bitrate: 396 kb/s
    Stream #0.0(und): Video: h264 (Main), yuv420p, 640x360 [PAR 1:1 DAR 16:9], 274 kb/s, 25 fps, 25 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2016-08-18 21:19:35
      encoder         : AVC Coding
    Stream #0.1(und): Audio: aac, 48000 Hz, stereo, fltp, 117 kb/s (default)
    Metadata:
      creation_time   : 2016-08-18 21:19:35
Output #0, mp4, to 'output.mp4':
  Metadata:
    major_brand     : mp42
    minor_version   : 0
    compatible_brands: mp42mp41isomavc1
    creation_time   : 2016-08-18 21:19:35
    my_key          : prpr
    encoder         : Lavf56.1.0
    Stream #0.0(und): Video: libx264, yuv420p, 640x360 [PAR 1:1 DAR 16:9], q=2-31, 274 kb/s, 25 tbn, 25 tbc (default)
    Metadata:
      creation_time   : 2016-08-18 21:19:35
      encoder         : AVC Coding
    Stream #0.1(und): Audio: aac, 48000 Hz, stereo, 117 kb/s (default)
    Metadata:
      creation_time   : 2016-08-18 21:19:35
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:1 -> #0:1 (copy)
Press ctrl-c to stop encoding
frame=  401 fps=  0 q=-1.0 Lsize=     782kB time=15.92 bitrate= 402.4kbits/s    
video:538kB audio:231kB other streams:0kB global headers:0kB muxing overhead: 1.665395%
roroco@roroco ~/Dropbox/rbs/ro_cmds_global $ avprobe -show_format -of json output.mp4 
avprobe version 11.3-6:11.3-1~trusty, Copyright (c) 2007-2014 the Libav developers
  built on Apr 13 2015 22:25:55 with gcc 4.8 (Ubuntu 4.8.2-19ubuntu1)
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'output.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    creation_time   : 2016-08-18 21:19:35
    encoder         : Lavf56.1.0
  Duration: 00:00:16.08, start: 0.000000, bitrate: 398 kb/s
    Stream #0.0(und): Video: h264 (Main), yuv420p, 640x360 [PAR 1:1 DAR 16:9], 274 kb/s, 25 fps, 25 tbn, 50 tbc (default)
    Metadata:
      creation_time   : 2016-08-18 21:19:35
    Stream #0.1(und): Audio: aac, 48000 Hz, stereo, fltp, 117 kb/s (default)
    Metadata:
      creation_time   : 2016-08-18 21:19:35
{  "format" : {
    "filename" : "output.mp4",
    "nb_streams" : 2,
    "format_name" : "mov,mp4,m4a,3gp,3g2,mj2",
    "format_long_name" : "QuickTime / MOV",
    "start_time" : "0.000000",
    "duration" : "16.085333",
    "size" : "800799.000000",
    "bit_rate" : "398275.000000",
    "tags" : {
      "major_brand" : "isom",
      "minor_version" : "512",
      "compatible_brands" : "isomiso2avc1mp41",
      "creation_time" : "2016-08-18 21:19:35",
      "encoder" : "Lavf56.1.0"
    }
  }}