Concat Impossible to open file

[Alkl]

Summary of the bug:

OS: Win 10 Pro x64 1909

How to reproduce:

% ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mkv

Latest working version: ffmpeg-20200504-5767a2e-win64-static (build from zeranoe)
Defective Builds: ffmpeg-20200510-fc99a24-win64-static and newer

Additional information:
When doing concat on windows ffmpeg will take the "m" of mylist.txt and add it to the path of the referenced files in that text file.

In that picture example it cant find: "cout0.mkv-av1.ivf" because the "c" is from the chunks.txt

That issue is also being experienced by multiple users on multiple compiles. Linux users might also have a problem. Not 100% confirmed yet.

[Carl Eugen Hoyos]

Please understand that screenshots are not appreciated here, instead post the command line you tested together with the complete, uncut console output to make this a valid ticket.

[Alkl]

ffmpeg started on 2020-05-15 at 10:47:39
Report written to "ffmpeg-20200515-104739.log"
Log level: 48
Command line:
ffmpeg -f concat -safe 0 -i mylist.txt -c copy output.mkv -report
ffmpeg version git-2020-05-10-fc99a24 Copyright (c) 2000-2020 the FFmpeg developers
  built with gcc 9.3.1 (GCC) 20200328
  configuration: --enable-gpl --enable-version3 --enable-sdl2 --enable-fontconfig --enable-gnutls --enable-iconv --enable-libass --enable-libdav1d --enable-libbluray --enable-libfreetype --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libsrt --enable-libtheora --enable-libtwolame --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libzimg --enable-lzma --enable-zlib --enable-gmp --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvo-amrwbenc --enable-libmysofa --enable-libspeex --enable-libxvid --enable-libaom --disable-w32threads --enable-libmfx --enable-ffnvcodec --enable-cuda-llvm --enable-cuvid --enable-d3d11va --enable-nvenc --enable-nvdec --enable-dxva2 --enable-avisynth --enable-libopenmpt --enable-amf
  libavutil      56. 44.100 / 56. 44.100
  libavcodec     58. 83.100 / 58. 83.100
  libavformat    58. 43.100 / 58. 43.100
  libavdevice    58.  9.103 / 58.  9.103
  libavfilter     7. 80.100 /  7. 80.100
  libswscale      5.  6.101 /  5.  6.101
  libswresample   3.  6.100 /  3.  6.100
  libpostproc    55.  6.100 / 55.  6.100
Splitting the commandline.
Reading option '-f' ... matched as option 'f' (force format) with argument 'concat'.
Reading option '-safe' ... matched as AVOption 'safe' with argument '0'.
Reading option '-i' ... matched as input url with argument 'mylist.txt'.
Reading option '-c' ... matched as option 'c' (codec name) with argument 'copy'.
Reading option 'output.mkv' ... matched as output url.
Reading option '-report' ... matched as option 'report' (generate a report) with argument '1'.
Finished splitting the commandline.
Parsing a group of options: global .
Applying option report (generate a report) with argument 1.
Successfully parsed a group of options.
Parsing a group of options: input url mylist.txt.
Applying option f (force format) with argument concat.
Successfully parsed a group of options.
Opening an input file: mylist.txt.
[concat @ 000001c2b79ccb80] Opening 'mylist.txt' for reading
[file @ 000001c2b79cdc00] Setting default whitelist 'file,crypto,data'
[NULL @ 000001c2b79d6840] Opening 'mout00.mkv-av1.ivf' for reading
[concat @ 000001c2b79ccb80] Impossible to open 'mout00.mkv-av1.ivf'
[AVIOContext @ 000001c2b79d5e00] Statistics: 130 bytes read, 0 seeks
mylist.txt: No such file or directory

mylist.txt:

file 'out00.mkv-av1.ivf'
file 'out01.mkv-av1.ivf'
file 'out02.mkv-av1.ivf'
file 'out03.mkv-av1.ivf'
file 'out04.mkv-av1.ivf'

[Andriy Gelman]

The regression happened in commit 648051f07cffd0d91c89dc6706e3d0d6a286de43

You can still get concat to work if you use an absolute path for each file in mylist.txt

[Steven Liu]

try this patch please.
​https://patchwork.ffmpeg.org/project/ffmpeg/patch/20200515100146.12548-1-lq@chinaffmpeg.org/

[Alkl]

Patch confirmed working under Windows and Linux from multiple persons :)

[Steven Liu]

fixed by commit : b707abf0911b1cb997bf8b1912c970e1e15996cf