XAVC-I ( mxf ) support?

Hi all,

I just noticed that hitfilm express won't open my mxf / XAVC-I files, but has no issues with XAVC-S.

So far no big deal as I'm recording stuff on an A7S in XAVC-S and on an Atomos flame in DNxHD simultaneously, and my main editor Vegas pro 15 takes both, but with Sony FS7 files, it'll be more problematic. Are there any plans to support mxf in the future?



Edit:sorry just realized it's the wrong forum. I'll post in express.



  • edited June 2018

    erm...anyone from Hitfilm care to comment?

  • It would be nice to know if it's an intentional thing or should I be troubleshooting. 
    Is .MXF not compatible? 

  • Triem23Triem23 Moderator

    Hitfilm is "MXF compatible," but you both misunderstand what that means. 

    Here's the short metaphor. Effectively you've asked something like "Do you want pizza?" without discussing the toppings. Pepperoni? For me, yes, please, but the vegetarian isn't going to want that. Mushroom and olive? That's vile, but maybe the vegetarian would like that. The point is, there's a lot of variation in the word, "pizza."

    MXF, MOV, AVI, etc are "CONTAINERS." This means the file specification determines how many audio/video streams exist, whether audio/video streams are muxed or separate, what metadata can be held, among other things. However, the CONTAINER has nothing to do with how the video and audio are encoded. 

    Encoding is handled by a CODEC (COmpressor/DEComoressor). A container might be able to hold video or audio in several codecs.

    To move away from MXF for a second, an "MP4" container usually holds h.264 (mp4) video, which Hitfilm supports (mostly, but I'll come back to this in a minute). An "MP4" file might use h.265 as its codec - and Hitfilm can't read h.265. So, while Hitfilm can read "MP4" files, if the MP4 file holds h.265 video, it won't read. 

    So, that's what's going on with the MXF file. Hitfilm is perfectly happy with the MXF container, but might not be happy with the codec. My Canon XF 305 creates MXF files in an MPEG-2 codec. Hitfilm has no issues with this container/codec combination.

    @mindmatter/@patchrik here's where we come back to Hitfilm being "mostly" h.264 compatible. H.264 comes in many flavors and versions. Depending on the exact settings/profile/level, etc h.264 can be 8-bit to 14-bit/channel. You have a range of pixel dimensions from SD to 8k. There are even different ways of packing color data from 4:2:0, and 4:2:2 to 4:4:4. H.264 can also support different frame rates (again, depending on Profile and Level), as well as Inter or Intra frame recording, not to mention different bitrates. H.264 supports varied audio codecs, like uncompressed LPCM or mp3. Technically h.264 only holds one audio track and all those screen recorders that record multiple audio tracks are creating "illegal" files.

    Some of these variations Hitfilm probably can't handle.

    Mindmatter, you're discussing two types of Sony XAVC. Guess what? XAVC is several Sony-tweaked versions of h.264 video with LPCM audio. XAVC-S you already know works in Hitfilm. XAVC-I might not. (XAVC-I is actually a codec known to be problematic in other software as well). In fact, even saying "XAVC-I" isn't enough, since XAVC-I HD is a Level 4, 4:2:2, up to 12-bit, 720p or 1080p codec that supports frame rates up to 180fps at bitrates up to 440mbps. XAVC-I 4K is a Level 4.2, 4:2:0, 10-bit, 2k or 4k codec that supports frame rates up to 60p at up to 960mbps.

    In other words, despite the similarity of names (XAVC-S, XAVC-I), and both being in an MXF container, the video files are radically different.

    Patchrik you haven't provided any information about the types of files you may be trying to load.

    So, here's the actual final point. Hitfilm IS MXF compatible... What's the codec? That might be an issue. Hitfilm might not read the MXF files a particular camera creates. 

    This video discusses containers, codecs, why some codecs are better for editing, how to use the free program MEDIAINFO to check your files, and several methods to convert/transcode your footage into another format. 

    Cuz if Hitfilm doesn't read your flavor of MXF, transcode is your only option (other than changing camera, I guess).


    Disclaimer: mods aren't FXHOME STAFF we're user volunteers. So questions directed at me like "will codec XYC work" I'd answer with "I don't know. Did you load it?" 

  • "H.264 supports varied audio codecs, like uncompressed LPCM or mp3. "

    Video codecs have no concept of audio. I think you maybe meant to say MP4 instead of H.264.

    "Technically h.264 only holds one audio track and all those screen recorders that record multiple audio tracks are creating "illegal" files."

    Disagree WRT the use of the term illegal. Again, I think you probably meant to say MP4 and not H.264 here.

    "XAVC is several Sony-tweaked versions of h.264 video with LPCM audio."

    XAVC is not a tweaked version of the AVC/H.264 codec. It is the same codec. AVC is AVC. The XAVC spec just lists allowed technical parameters of an AVC encode.

    "In fact, even saying "XAVC-I" isn't enough"

    Hell yes it is enough. That is the whole point of having a spec like XAVC-I. It lists the allowed technical specifics within the broad AVC spec. If one claims compatibility then you must meet at least those specs at minimum.


    One thing we can say about the Hitfilm software AVC decoder. It is limited to 8-bit 4:2:0. I don't know if Hitfilm tries to support any AVC flavor in the MXF container. Even simple 8-bit 4:2:0 AVC. The only spec/use I've heard of that puts AVC into MXF containers is XAVC, and that is typically 4:2:2.

  • Triem23Triem23 Moderator

    @NormanPCN only point I re-rebut. "In fact, even saying 'XAVC-I' isn't enough." I'm being a lil pedantic, but since the HD and 4k don't overlap at all, they are two codecs. One should specify. Otherwise, as always, thanks for the corrections. 👍 In a discussion of codec/container one shouldn't muddy the argument with imprecise language. 

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