[FFmpeg-user] convert mkv to mp4

[Moritz Barsnick]

On Thu, Jan 30, 2025 at 14:53:57 +0100, KoSza wrote:
> Hello,
>
> Maybe the answer was not delivered.
> Regarding to subtitles the suggestion was right and worked, to convert is
> to mov_text is worked

For some reason, ffmpeg is skipping the audio tracks:

Stream mapping:
  Stream #0:0 -> #0:0 (copy)
  Stream #0:3 -> #0:1 (subrip (srt) -> mov_text (native))
  Stream #0:4 -> #0:2 (subrip (srt) -> mov_text (native))
  Stream #0:5 -> #0:3 (subrip (srt) -> mov_text (native))
  Stream #0:6 -> #0:4 (subrip (srt) -> mov_text (native))

I cannot exactly see why, as they are detected as EAC3 audio (edited
for brevity):
Input #0, matroska,webm, from 'Dune.Prophecy.S01E02.2160p.MAX.WEB-DL.DDP5.1.Atmos.DV.HDR.H.265.HUN.ENG-PTHD.mkv':
  Duration: 01:02:44.45, start: 0.000000, bitrate: 20570 kb/s
    Stream #0:0: Video: hevc, none, 3840x1920, SAR 1:1 DAR 2:1, 23.98 fps, 23.98 tbr, 1k tbn, 1k tbc (default)
    Stream #0:1(hun): Audio: eac3, 48000 Hz, 5.1 (default)
    Stream #0:2(eng): Audio: eac3, 48000 Hz, 5.1
    Stream #0:3(hun): Subtitle: subrip (default) (forced)
    Stream #0:4(hun): Subtitle: subrip
    Stream #0:5(eng): Subtitle: subrip
    Stream #0:6(eng): Subtitle: subrip
Output #0, mp4, to 'Dune.Prophecy.S01E02.2160p.MAX.WEB-DL.DDP5.1.Atmos.DV.HDR.H.265.HUN.ENG-PTHD22.mp4':
    Stream #0:0: Video: hevc (hev1 / 0x31766568), none, 3840x1920 [SAR 1:1 DAR 2:1], q=2-31, 23.98 fps, 23.98 tbr, 16k tbn, 1k tbc (default)
    Stream #0:1(hun): Subtitle: mov_text (tx3g / 0x67337874) (default) (forced)
    Stream #0:2(hun): Subtitle: mov_text (tx3g / 0x67337874)
    Stream #0:3(eng): Subtitle: mov_text (tx3g / 0x67337874)
    Stream #0:4(eng): Subtitle: mov_text (tx3g / 0x67337874)

I am wondering whether it's due to some feature missing - I do see a
lot of disabled stuff in your ffmpeg build:
    --disable-protocols --disable-protocol=rtp --enable-protocol=file
    --enable-protocol=pipe --disable-muxer=image2
    --disable-muxer=image2pipe --disable-swscale-alpha --disable-ffplay
    --disable-ffprobe --disable-doc --disable-devices --disable-bzlib
    --disable-altivec --enable-libopencore-amrnb --enable-libopencore-amrwb
    --enable-libmp3lame --disable-v4l2-m2m --disable-vaapi --disable-cuvid
    --disable-nvenc --disable-decoder=aac --disable-decoder=aac_fixed
    --disable-encoder=aac --disable-decoder=amrnb --disable-decoder=ac3
    --disable-decoder=ac3_fixed --disable-encoder=zmbv
    --disable-encoder=dca --disable-decoder=dca --disable-encoder=ac3
    --disable-encoder=ac3_fixed --disable-encoder=eac3
    --disable-decoder=eac3 --disable-encoder=truehd
    --disable-decoder=truehd --disable-encoder=hevc_vaapi
    --disable-decoder=hevc --disable-muxer=hevc --disable-demuxer=hevc
    --disable-parser=hevc --disable-bsf=hevc_metadata
    --disable-bsf=hevc_mp4toannexb --disable-encoder=h264_v4l2m2m
    --disable-decoder=h264 --disable-decoder=h264_v4l2m2m
    --disable-muxer=h264 --disable-demuxer=h264 --disable-parser=h264
    --disable-bsf=h264_metadata --disable-bsf=h264_mp4toannexb
    --disable-bsf=h264_redundant_pps --disable-decoder=vc1
    --disable-decoder=vc1_v4l2m2m --disable-muxer=vc1 --disable-demuxer=vc1
    --disable-parser=vc1

Why would you disable the hevc parser if you intend on feeding it files
with hevc? Not sure it matters, it justs seems overly sparse to me.

Moritz