concat protocol with data format does not work at all

[superbonaci]

Summary of the bug: do cat with ffmpeg without any remuxing at all. Should work with any file type.

How to reproduce:

% ffmpeg -f concat -safe 0 -i "concat:tsfiles/index-0000000000.ts|tsfiles/index-0000000001.ts|tsfiles/index-0000000002.ts|tsfiles/index-0000000003.ts|tsfiles/index-0000000004.ts" -f data -c copy data.ts
ffmpeg version 7.0.1 Copyright (c) 2000-2024 the FFmpeg developers
  built with Apple clang version 15.0.0 (clang-1500.3.9.4)
  configuration: --prefix=/opt/homebrew/Cellar/ffmpeg/7.0.1 --enable-shared --enable-pthreads --enable-version3 --cc=clang --host-cflags= --host-ldflags='-Wl,-ld_classic' --enable-ffplay --enable-gnutls --enable-gpl --enable-libaom --enable-libaribb24 --enable-libbluray --enable-libdav1d --enable-libharfbuzz --enable-libjxl --enable-libmp3lame --enable-libopus --enable-librav1e --enable-librist --enable-librubberband --enable-libsnappy --enable-libsrt --enable-libssh --enable-libsvtav1 --enable-libtesseract --enable-libtheora --enable-libvidstab --enable-libvmaf --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxml2 --enable-libxvid --enable-lzma --enable-libfontconfig --enable-libfreetype --enable-frei0r --enable-libass --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libspeex --enable-libsoxr --enable-libzmq --enable-libzimg --disable-libjack --disable-indev=jack --enable-videotoolbox --enable-audiotoolbox --enable-neon
  libavutil      59.  8.100 / 59.  8.100
  libavcodec     61.  3.100 / 61.  3.100
  libavformat    61.  1.100 / 61.  1.100
  libavdevice    61.  1.100 / 61.  1.100
  libavfilter    10.  1.100 / 10.  1.100
  libswscale      8.  1.100 /  8.  1.100
  libswresample   5.  1.100 /  5.  1.100
  libpostproc    58.  1.100 / 58.  1.100
[concat @ 0x123e05940] Line 1: unknown keyword 'G@'
[in#0 @ 0x600003790100] Error opening input: Invalid data found when processing input
Error opening input file concat:tsfiles/index-0000000000.ts|tsfiles/index-0000000001.ts|tsfiles/index-0000000002.ts|tsfiles/index-0000000003.ts|tsfiles/index-0000000004.ts.
Error opening input files: Invalid data found when processing input

All attachments are in ​https://trac.ffmpeg.org/ticket/10629

[Marton Balint]

You are mixing concat demuxer and concat protocol. You don't need the -f concat if you want to concat the files. Or you must use a valid ffconcat file if you want to use a concat demuxer.