Uncompressed Audio in MP4 Container not possible?

1. offizieller Beitrag

    The Voukoder plugin I use in Resolve does not allow LPCM audio (i.e., uncompressed) in MP4 containers. When I select “Uncompressed PCM” in the audio menu, only .mkv, .avi, and .mov are offered as containers, not .mp4. Why is that? Would this work with the Voukoder Pro version?

  • Vouk 16. September 2025 um 12:03

    Hat das Thema freigeschaltet.
    • Offizieller Beitrag

    Some formats / muxers support not all codecs. In Voukoder this is hardcoded. Voukoder Pro let's FFmpeg the decision what codec can be used for which muxer. Give it a try with a free trial license.

    LPCM is generally not allowed in MP4, in MP4 only lossy codecs are allowed.
    Since this is a technical limitation by container, Voukoder can not break that limitation.
    You have to select a lossy audio codec to use within MP4, or use some other container like mkv or mov, avi.

    Zitat von mbc

    LPCM is generally not allowed in MP4, in MP4 only lossy codecs are allowed.
    Since this is a technical limitation by container, Voukoder can not break that limitation.
    You have to select a lossy audio codec to use within MP4, or use some other container like mkv or mov, avi.

    Contrary to popular belief, PCM is allowed in a MP4 container but nobody knows about it so it never gets implemented.
    That is because MP4 is a variation MOV which allows for PCM. According to Wikipedia, it could also accept FLAC and ALAC which was added to the format in 2018. The latter was given this as the source: https://web.archive.org/web/2019010620…in_isobmff.html

    However, if you really need PCM, you'd much rather go for the MOV container because players can expect the file to have PCM while the MP4 can have PCM, they might get tripped up by a very, very rare format combination.