ojph_expand .ppm file output not quite right as per ffmpeg about openjph HOT 5 CLOSED

Thank you for reporting this.

I am not familiar with ffprobe.

What commandline was used to generate test.j2c? and if possible, can I have access to test.j2c?

from openjph.

ffprobe is an ffmpeg app that gathers information from multimedia streams and prints it in human- and machine-readable fashion. https://ffmpeg.org/ffprobe.html

I made an artificial test image "bars.ppm", with HTJ2K encode file "bars.j2c", and decoded file "bars_out.ppm". ffprobe still says bars_out.ppm: Invalid data found when processing input

The files are in this repository: https://github.com/NEOAdvancedTechnology/htj2k_test_files

from openjph.

Thank you for the files. I had a look.

Next is a speculation.

I think this might be a bug in ffprobe.
I can open both bars.ppm and bars_out.ppm with IrfanView64 without any issues.

I think the difference that is causing the issue is related to how white spaces are interpreted.

bars.ppm:
ASCII code: 50 36 0a 31 32 38 30 20 37 32 30 0a 32 35 35 0a
ASCII char: P6.1280 720.255.

bars_out.ppm:
ASCII code: 50 36 20 31 32 38 30 20 37 32 30 20 32 35 35 0a
ASCII char: P6 1280 720 255.

Note the whitespace between P6 and 1280, and then again between 720 and 255. bars_out.ppm is using a space (0x20) while bars.ppm is using \newline (0x0a).

According to this document:
http://netpbm.sourceforge.net/doc/ppm.html
Any white space should be alright.

It is very easy to modify from my side, but ffprobe should have better support for the ppm format.

from openjph.

Indeed, I converted bars_out.ppm using ImageMagick to another ppm file, and it also has the 0x0a "." after the P6, which ffprobe/ffmpeg seems too be happier with.

from openjph.

I forgot to send this.

The version I have of ffprobe does not have this issue.

ffprobe version 4.1 Copyright (c) 2007-2018 the FFmpeg developers
  built with Apple LLVM version 10.0.0 (clang-1000.11.45.5)
  configuration: --prefix=/usr/local/Cellar/ffmpeg/4.1_1 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-ffplay --enable-gpl --enable-libmp3lame --enable-libopus --enable-libsnappy --enable-libtheora --enable-libvorbis --enable-libvpx --enable-libx264 --enable-libx265 --enable-libxvid --enable-lzma --enable-opencl --enable-videotoolbox
  libavutil      56. 22.100 / 56. 22.100
  libavcodec     58. 35.100 / 58. 35.100
  libavformat    58. 20.100 / 58. 20.100
  libavdevice    58.  5.100 / 58.  5.100
  libavfilter     7. 40.101 /  7. 40.101
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  3.100 /  5.  3.100
  libswresample   3.  3.100 /  3.  3.100
  libpostproc    55.  3.100 / 55.  3.100
Input #0, image2, from 'bars_out.ppm':
  Duration: 00:00:00.04, start: 0.000000, bitrate: 552963 kb/s
    Stream #0:0: Video: ppm, rgb24, 1280x720, 25 tbr, 25 tbn, 25 tbc

In any case, I am modifying the code to generate a header acceptable to the older version of ffprobe you are using. I think this is better.

from openjph.