[FFmpeg-user] convert mkv to mp4

[Ferdi Scholten]

On 31-01-2025 12:11, KoSza wrote:
> Hello,
>
> Thank you for your help.
>
> I did not disabled anything, only istalled the package to my Synology nas
> and tried to convert. You can undestand if I am searching for an out-of
> -the-box solution I did not start to cut the boxes to pieces :)
> So the solution may could be to find out how to enable features and try
> again?
>
> Thank you,
> kosza
>
> Moritz Barsnick via ffmpeg-user<ffmpeg-user at ffmpeg.org> ezt írta (időpont:
> 2025. jan. 31., P, 11:58):
>
>> 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
>>

--disable-encoder=eac3 --disable-decoder=eac3
This is why the audio is not copied. This FFmpeg package from synology is severely crippled. Probably has to do with licensing i guess.