Lossless video codecs

[Max of S2D]

I use a codec bundled with Windows, Intel IYUV (the 4:2:0 variant). It divides the size of the original AVIs per two, so it doesn't compress really efficiently, but it still does a job good enough for me, as it does not hammer my CPU during the decoding.

[LoRd_MuldeR]

I use a codec bundled with Windows, Intel IYUV (the 4:2:0 variant).

Are you sure that one actually compresses the data? Or is it just smaller, because the RGB32 data is subsampled to YV12?

[qyot27]

HuffYUV, despite the name, supports RGB.
The original HuffYUV, which apparently is used in ffdshow's VFW interface, didn't. I think only FF HuffYUV does...
Regular old HuffYUV supports RGB (at least, 2.1.1 does (http://neuron2.net/www.math.berkeley.edu/benrg/huffyuv.html)). It was YV12 and adaptive huffman tables that ffvhuff added. But yeah, the HuffYUV coder in ffdshow's VFW interface doesn't have RGB offered. It can decode RGB-mode HuffYUV just fine, though.

[hoboX10]

Hmm so does is there any lossless codec that supports multi-core processors, with hyper-threading? Basically that works great with the intel core i7's?

My friend told me Lagarith only supports 2 threads.

[nm]

Ut and AMV are also multithreaded. But would the lossless codec really be such a bottleneck that it needs to be multithreaded, in your case? Usually rendering or re-encoding with a lossy codec will take a lot more time, and during editing playback only needs to be real-time.

[LoRd_MuldeR]

Hmm so does is there any lossless codec that supports multi-core processors, with hyper-threading? Basically that works great with the intel core i7's?

I don't think there is any Codec (or any software in general) that "supports" Hyperthreading. And there also should be no need for Hyperthreading-support on the software level!

Hyperthreading will "simulate" two logical CPU cores for each physical CPU core. This is done by running two threads on each physical CPU core.

To the Operating System (and to all software running on it) those logical cores will appear just like "normal" CPU cores.

So from the application's point of view, there is no difference between a Quadcore CPU with HT (4 physical cores, 8 logical cores) and a "real" Octocore without HT (8 physical cores).

Consequently any software that is properly multi-threaded will fully utilize a Hyperthreading CPU, as long as it creates enough threads to keep all (logical) core busy.

However a Hyperthreaded CPU with n cores wont achieve the same performance as a Non-Hyperthreaded CPU with 2*n cores (at the same clock speed).

[hoboX10]

I don't think there is any Codec (or any software in general) that "supports" Hyperthreading. And there also should be no need for Hyperthreading-support on the software level!

Hyperthreading will "simulate" two logical CPU cores for each physical CPU core. This is done by running two threads on each physical CPU core.

To the Operating System (and to all software running on it) those logical cores will appear just like "normal" CPU cores.

So from the application's point of view, there is no difference between a Quadcore CPU with HT (4 physical cores, 8 logical cores) and a "real" Octocore without HT (8 physical cores).

Consequently any software that is properly multi-threaded will fully utilize a Hyperthreading CPU, as long as it creates enough threads to keep all (logical) core busy.

However a Hyperthreaded CPU with n cores wont achieve the same performance as a Non-Hyperthreaded CPU with 2*n cores (at the same clock speed).

Well is there any ones that support multi-cores?

[LoRd_MuldeR]

Well, did you read nm's post? He names at least two lossless Codecs that are multi-threaded.

Also x264 certainly will scale up to eight cores and there definitely are H.264 decoders that are multi-threaded (ffmpeg-MT, CoreAVC, DivX H.264 Decoder).

[Leeloo Minaï]

This test does not reflect real usage at all.
Lagarith codec is known to have data corruption problems and YULS has a resolution limitation to 1024x768.

Take some time to try other codecs and forge your own opinion : if we are several users to recommend UT or FFV1 codec, there is a good reason, but not because we have read an 2-year old theorical test...

[(*|*)]

what lossless codec do you recommend for capturing/editing?

[nm]

Ut Video Codec Suite is a good choice for capturing and editing If your toolchain supports VFW. Ut is optimized for speed on modern multi-core CPUs and it's also open-source (GPLed).

See:
http://forum.doom9.org/showthread.php?t=143624
http://umezawa.dyndns.info/wordpress/