Quicktime 7 / Perian encoded video won't open outside of QT7

[Busty]

I have a h.264 video which I created in Quicktime Player 7. QT7 seems to have used the perian codec plugin while creating the video.

Only Quicktime Player 7 is capable of playing that video, and that only as long as perian is installed. I tried VLC, VideoSpec and ffmpeg and they all failed. ffmpeg and VLC fail to play it saying "unknown decoder 'CAVC'."

As Quicktime Player 7 is unsupported starting Catalina, I'd like to losslessly convert that video into a new file. The info panel in QuickTime describes the codec as H.264 (Perian) and ac3 (Perian). Unfortunately, passthrough is greyed out when exporting as mp4.

So, is there a way to play that file, apart from Quicktime Player 7
or
is there a way to losslessly convert the video?

Thanks for any insight

[october262]

I have a h.264 video which I created in Quicktime Player 7. QT7 seems to have used the perian codec plugin while creating the video.

Only Quicktime Player 7 is capable of playing that video, and that only as long as perian is installed. I tried VLC, VideoSpec and ffmpeg and they all failed. ffmpeg and VLC fail to play it saying "unknown decoder 'CAVC'."

As Quicktime Player 7 is unsupported starting Catalina, I'd like to losslessly convert that video into a new file. The info panel in QuickTime describes the codec as H.264 (Perian) and ac3 (Perian). Unfortunately, passthrough is greyed out when exporting as mp4.

So, is there a way to play that file, apart from Quicktime Player 7
or
is there a way to losslessly convert the video?

Thanks for any insight

try ffmpeg -i input.mov -pix_fmt yuv420p output.mov

[Cornucopia]

assuming its profile & level is standard (e.g. main@main, high@4.1, etc), h264 is h264. so unless it is non-standard (10bit+, lossless intraframe, mvc, alpha channel), h264-encoded media should be playable by ANY h264 decoder.
Is it non-standard? check with MediaInfo.

Assuming it isn't non-standard, my educated guess is that it is using a non-standard fourcc (CAVC??). The most common standard fourcc for h264 is "h264" (also "v264", "x264", "avc1", "jvt3").
Since this is just an assignment of decoder based on signature, just change the fourcc! I would use a hex editor.

BTW, QT7 (on Windows & Mac) is SO deprecated, I strongly don't recommend its use except as an intermediary when converting old assets to modern codecs (so they don't become technological orphans). If this experience here was an example of that, I would also say the implementation of h264 present in QT is NOT optimal, so I would have gone a different way (ProRes, uncompressed - converting later to final format using better methods).


Scott

[Busty]

thanks for your answers, october262 and Cornucopia, much appreciated.

@ october262: As ffmpeg cannot open the file (Could not find codec parameters for stream 0 (Video: none (CAVC / 0x43564143), none(bt709), 1920x1080, 26181 kb/s): unknown codec), it also fails in reencoding it.

@ Cornucopia: Media info doesn't say something about the video being standard or non-standard, However it gives some info under general:
Video Stream AVC, writing library Apple QuickTime 7.6.6, com.apple.quicktime.software: mkvmerge v5.9.0

and some under video:
AVC (High@L4.2) (CABAC / 2 Ref Frames) (1 conformance errors)

Does this give some hints about how to open it? Is there a hex editor you could recommend for editing the fourcc of the video?

[Cyrax9]

Busty, do you still have access to a system with Perian and QT7 installed? If so what I would do is use an app like MPEGStreamclip (which I believe hooked into the Perian library as well,) and basically export the file to uncompressed/raw video, then reencode into a modern codec. (My recommendation would be to use ProRes_Videotoolbox from FFMPEG if you have a Mac that supports it as that's the official Apple implementation of the codec. You'll have a huge file, but it'll be future–proof for archival purposes. FFV1 is another good archival option, and you can always create a standard AVC/H264 MP4 for playback as well.)

I'm wondering if the CAVC came from mkvmerge as I've never run into it using Perian before. I'm not sure if this would work, but you could try to change the fourcc per Cornucopia's instructions, or via MP4Box. If you use MP4Box be sure to duplicate the file before you mess with it though. By default MP4Box overwrites the source file and it's very easy to forget to add "-out" to the end of your command if you're not careful/inexperienced with MP4Box. It might be a little easier than a hex editor though if you're not familiar with them. The fact that FFMPEG doesn't recognize it is somewhat troubling though; usually it picks up on obscure and esoteric formats and fourCCs.