AVC-Intra codec

[Peter Corbett]

My experience producing a drama with XDCAM HD showed me that not unlike HDV, on static images the quality is quite excellent, but as soon as software slomo, filters and grading is applied in post the whole stack of cards start to come down. The much-touted overcranked slo-mo also looked soft and smeary compared with Varicam sourced slomos.

Long-GOP maybe works for shooting but as soon as you start posting, it just doesn’t do it for me. I notice that Sony really plugs what shooters say about XDCAM HD, but where are the testimonials from the editors and compositors.

It’s my whole discomfort with Sony’s long-GOP approach to 24P/25P Progressive. How can they say it’s “true progressive” if each frame is made up of 15 sub-frames?

Peter Corbett
Powerhouse Productions
Australia
http://www.php.com.au

[Lars Wikstrom]

that is interesting. I always wondered how it would hold up in editing. But it sounds like the AVC is an ‘intra codec’ not GOP. I was not aware that you could break down the H.264 into an intra codec since it’s real power seems to come from GOP.

-Lars

[Barry Green]

[doka15] “But it sounds like the AVC is an ‘intra codec’ not GOP”

There are two new formats coming. AVC-Intra is intra-frame only and is going to be an optional codec card for Panasonic’s 2/3″ professional P2 lineup. It is frame-discrete, no GOP, and based on AVC/H.264, at 50 megabits or 100 megabits. At 50 megabits they say it’s equivalent to 100-megabit DVCPRO-HD; at 100 megabits and 10-bit they claim it’s comparable to HD-D5.

AVC-HD is a low-bitrate long-GOP version, the replacement for HDV. It’s made by both Panasonic and Sony, at up to 24 megabits per second, recorded tapelessly to SD memory cards, hard disks, or mini-DVD discs. Like HDV it’s a 4:2:0 8-bit long-GOP codec, but it’s over twice as efficient (8 megabits of AVC-HD delivers picture quality comparable to 25 megabits of HDV), it has much better audio (up to 7.1 channels of uncompressed PCM or 5.1 channels of AC-3), it is cross-compatible between manufacturers (imagine that!), it supports full-raster 1920×1080 recording, and it has native support for 1080/24p and 720/24p right from the beginning. As a format it should prove to be notably superior to HDV, but there are no “worthy” camera heads available yet, only little consumer palmcorders. Hopefully in 2007 we’ll see some appropriate professional camera heads using the new format.

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[Lars Wikstrom]

That was interesting to know those facts.

Thanks,

-Lars