Some Scanity 10-bit monochrome DPX are rejected

[Jérôme Martinez]

The DPX related code has a check which does not compute correctly the minimum file size in case of (out ouf specs) Scanity 10-bit monochrome DPX.

./ffmpeg -i y10bit_scanity_realsize_zeroed.dpx a%06d.png
ffmpeg version N-110014-ga6e9d01f88 Copyright (c) 2000-2023 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.4.0-1ubuntu1~20.04.1)
  configuration:
  libavutil      58.  3.100 / 58.  3.100
  libavcodec     60.  6.101 / 60.  6.101
  libavformat    60.  4.100 / 60.  4.100
  libavdevice    60.  2.100 / 60.  2.100
  libavfilter     9.  4.100 /  9.  4.100
  libswscale      7.  2.100 /  7.  2.100
  libswresample   4. 11.100 /  4. 11.100
[dpx @ 0x7fffce94ce80] Cannot map DPX color specification 1 to colorspace.
[dpx @ 0x7fffce94ce80] Overread buffer. Invalid header?
[dpx_pipe @ 0x7fffce94b5c0] Could not find codec parameters for stream 0 (Video: dpx, none, 2150x1820 [SAR 1:1 DAR 215:182]): unspecified pixel format
Consider increasing the value for the 'analyzeduration' (0) and 'probesize' (5000000) options
Input #0, dpx_pipe, from 'y10bit_scanity_realsize_zeroed.dpx':
  Duration: N/A, bitrate: N/A
  Stream #0:0: Video: dpx, none, 2150x1820 [SAR 1:1 DAR 215:182], 25 fps, 25 tbr, 25 tbn
Stream mapping:
  Stream #0:0 -> #0:0 (dpx (native) -> png (native))
Press [q] to stop, [?] for help
[dpx @ 0x7fffce952500] Cannot map DPX color specification 1 to colorspace.
[dpx @ 0x7fffce952500] Overread buffer. Invalid header?
Error while decoding stream #0:0: Invalid data found when processing input
Cannot determine format of input stream 0:0 after EOF
Error marking filters as finished
Conversion failed!

ls -l y10bit_scanity_realsize_zeroed.dpx
-rwxrwxrwx 1 jerome jerome 5283840 Mar 14 10:58 y10bit_scanity_realsize_zeroed.dpx

zeroed file attached (the file size is the one from the hardware, not modified).

[Jérôme Martinez]

Analysis of the issue and patch are available at https://ffmpeg.org/pipermail/ffmpeg-devel/2023-March/307418.html

[Marton Balint]

Fixed in 05e34523bc5db91618c0f1e9c8923eaf3ed1e74d.