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Mosu · 5th April 2018, 07:40

The storage format for AV1-in-Matroska is the same as the one for AV1-in-WebM, it's even the same for AV1-in-IVF. No CodecPrivate, each Block starts with a TD OBU and contains all following OBUs up to but excluding the following TD OBU. Dead simple.

And yes, they're still changing the bitstream. Just yesterday an additional bit ("still_picture") was added to the sequence header OBU, and five days ago the profile indicator was changed from two to three bits. Luckily reading AV1 from IVF or WebM doesn't require parsing the sequence header OBU (and therefore mkvmerge already supports those two source containers for AV1), but it is required for reading raw OBU streams. I do have the code for that already, but I won't include it as long as the bitstream is in that much flux.

5th April 2018, 07:40	#592 \| Link
Mosu MKVToolNix author Join Date: Sep 2002 Location: Braunschweig, Germany Posts: 4,281	The storage format for AV1-in-Matroska is the same as the one for AV1-in-WebM, it's even the same for AV1-in-IVF. No CodecPrivate, each Block starts with a TD OBU and contains all following OBUs up to but excluding the following TD OBU. Dead simple. And yes, they're still changing the bitstream. Just yesterday an additional bit ("still_picture") was added to the sequence header OBU, and five days ago the profile indicator was changed from two to three bits. Luckily reading AV1 from IVF or WebM doesn't require parsing the sequence header OBU (and therefore mkvmerge already supports those two source containers for AV1), but it is required for reading raw OBU streams. I do have the code for that already, but I won't include it as long as the bitstream is in that much flux. __________________ Latest MKVToolNix is v83.0 If I ever ask you to upload something, please use my file server. Last edited by Mosu; 5th April 2018 at 07:42.