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Comment by latexr

7 months ago

I always thought the name AV1 was partly a play on/homage to AVI (Audio Video Interlace), but AV2 breaks that. Even if it’s meant to be embedded into other container formats such as MP4, there are files with the .av1 extension and there is a video/AV1 MIME type (and possibly a UTI?). Does this mean we now need to duplicate all that to .av2 and video/AV2? What about the AVIF file format?

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latexr

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uyzstvqs  7 months ago

Files with the .av1 extension are for raw AV1 data. For AV2 this should become .av2, yes. That's by design, as they're two different incompatible formats. Typically you use a container like Matroska (.mkv, video/x-matroska), WebM or MP4 which contains your video stream with a type code specifying the codec (av01, av02).

AVIF is also a container format, and I believe should be adaptable to AV2, even if the name stands for "AV1 image format". It could simply just be renamed to AOMedia Video Image Format for correctness.

ttoinou  7 months ago

Do you mean the file extension should only reflect the file format and not the codecs it has inside ?

Maybe that’s what we did in the past and it was a bad idea. It’d be useful to know if you can read the file by looking only at its extension

  • amiga386  7 months ago

    File extension shouldn't matter at all, because data should have associated metadata (e.g. HTTP content-type, CSS image-set, HTML <video><source type=""/></video>)

    > It’d be useful to know if you can read the file by looking only at its extension

    That would be madness, and there's already a workaround - the filename itself.

    For most people, all that matters is an MKV file is a video file, and your configured player for this format is VLC. Only in a small number of cases does it matter about an "inner" format, or choice of parameter - e.g. for videos, what video codec or audio codec is in use, what the bitrate is, what the frame dimensions are.

    For where it _matters_, people write "inner" file formats in the filename, e.g. "Gone With The Wind (1939) 1080p BluRay x265 HEVC FLAC GOONiES.mkv", to let prospective downloaders choose what to download from many competing encodings of exactly the same media, on websites where a filename is the _only_ place to write that metadata (if it were a website not standardised around making files available and searching only by filenames, it could just write it in the link description and filename wouldn't matter at all)

    Most people don't care, for example, that their Word document is A4 landscape, so much that they need to know _in the filename_.

  • lxgr  7 months ago

    > Do you mean the file extension should only reflect the file format and not the codecs it has inside ?

    That's pretty much always been the case. File extensions are just not expressive enough to capture all the nuances of audio and video codecs. MIME types are a bit better.

    Audio is a bit of an exception with the popularity of MP3 (which is both a codec and a relatively minimal container format for it).