Dumping streams with -f data is broken

[Carl Eugen Hoyos]

Dumping streams with -f data is broken since 6f69f7a8

$ ffmpeg -f data -i fate-suite/svq3/Vertical400kbit.sorenson3.mov -f data -codec copy -map 0 out
ffmpeg version N-82415-g0674d19 Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 4.7 (SUSE Linux)
  configuration: --enable-gpl
  libavutil      55. 40.100 / 55. 40.100
  libavcodec     57. 66.103 / 57. 66.103
  libavformat    57. 57.100 / 57. 57.100
  libavdevice    57.  2.100 / 57.  2.100
  libavfilter     6. 67.100 /  6. 67.100
  libswscale      4.  3.101 /  4.  3.101
  libswresample   2.  4.100 /  2.  4.100
  libpostproc    54.  2.100 / 54.  2.100
Input #0, data, from 'fate-suite/svq3/Vertical400kbit.sorenson3.mov':
  Duration: N/A, start: 0.000000, bitrate: N/A
    Stream #0:0: Data: none
Output #0, data, to 'out':
  Metadata:
    encoder         : Lavf57.57.100
    Stream #0:0: Data: none
Stream mapping:
  Stream #0:0 -> #0:0 (copy)
Press [q] to stop, [?] for help
size=       0kB time=00:00:00.00 bitrate=N/A speed=   0x
video:0kB audio:0kB subtitle:0kB other streams:0kB global headers:0kB muxing overhead: unknown
Output file is empty, nothing was encoded (check -ss / -t / -frames parameters if used)

[Elon Musk]

Can not reproduce with exact command.

[Carl Eugen Hoyos]

Fixed by Baptiste in dc58e33dd35e1a216cdc1a629d1ea8ee4429fbbb