x262 Development Thread

[Reel.Deel]

Can someone please build the latest x262 (https://github.com/kierank/x262/commits/master)? zerowalkers' link (http://forum.doom9.org/showthread.php?t=157675&page=7#post1688501) is dead and ifb's binaries (http://forum.doom9.org/showthread.php?t=157675&page=7#post1623674) are from 2013 :(.

[Sparktank]

Can someone please build the latest x262 (https://github.com/kierank/x262/commits/master)? zerowalkers' link (http://forum.doom9.org/showthread.php?t=157675&page=7#post1688501) is dead and ifb's binaries (http://forum.doom9.org/showthread.php?t=157675&page=7#post1623674) are from 2013 :(.

I would love to second this.

Would love to do some comparisons with recent builds of everything, especially since my downscaling has changed over the years.

[Boulder]

Can you try this one : https://drive.google.com/file/d/0BzeF_1syecQwQ0NyelFTSm92WTA/view?usp=sharing (Avisynth or raw input only)? I just did a quick compile to see how it goes.

[Reel.Deel]

Can you try this one : https://drive.google.com/file/d/0BzeF_1syecQwQ0NyelFTSm92WTA/view?usp=sharing (Avisynth or raw input only)? I just did a quick compile to see how it goes.

Thanks Boulder :). If it's not too much trouble can you also provide a 64-bit binary?

[Emulgator]

Many thanks, Boulder and kierank for r2633 !
CPU: i7-4960X, Win7U64
Avisource failed as expected (source was DV-AVI), fallback to ffmpegsource2 worked.

Residual block artifacts 1 frame after cuts to black still there.

[lithoc]

Just read about pied piper , https://github.com/danielrh/losslessh264

It would be fantastic if someone can port these to MPEG-2

[Boulder]

Thanks Boulder :). If it's not too much trouble can you also provide a 64-bit binary?Strange - the forum didn't send me an email until now.

I can make a 64-bit build probably on Sunday when I get back home.

[rwill]

Just read about pied piper , https://github.com/danielrh/losslessh264

It would be fantastic if someone can port these to MPEG-2

lithoc,

it appears pied piper applies to the recompression layer placed on top of the h.264 encoder in question. Given that this h.264 encoder is only supporting constrained baseline profile ( CAVLC ) a recompression layer with well designed context models will give at least 10% ( I am speculating here ) compression gain. This compression gain is also in the range someone would get when switching from CAVLC to CABAC ( I am not speculating here ) as the entropy coder.

A lossless recompression layer for older standards will almost always produce compression gain simply from implementing context models and arithmetic coding. For example there are lossless compression methods for JPEGs that are able to store a JPEG at a significantly reduced size. If this interests you reading up on the "PAQ" compressor or Context Mixing ( CM ) compressors in general is a good start.

Sadly the resulting files are not backwards compatible - so for example a DVD player will not know what to do with a recompressed MPEG-2 stream. So unless you control the whole ecosystem of generation, distribution and playback device such a thing cannot be just ported to MPEG-2.

And using an encoder of a more recent standard will most likely produce higher compression gain than switching out the entropy coder of some old standard.

[Boulder]

Here's an x64 build: https://drive.google.com/file/d/0BzeF_1syecQwSDZxZ25PQ3YtbEk/view?usp=sharing

I was unable to fprofile it, the binary kept on crashing at one profiling step (there were also some warnings shown during configure), lossless if I'm not mistaken. Hopefully the x262 portion works fine for you.

[Blue_MiSfit]

Mine (https://code.google.com/p/y262/) is not ready either... I think mpeg2 is dead.

MPEG-2 is FAR from dead :)

The vast majority of linear TV is originated from MPEG-2 masters - quite commonly XDCAM HD422 which is Long GOP 4:2:2 MPEG-2 at 50 Mbps.

The HD-SDI output from a playout chain is most commonly encoded and uplinked on satellite using H.264, but not always. There are lots of MPEG-2 channels still. More importantly, cable distribution still uses a ton of MPEG-2, even for VOD. At work we encode MANY 15 Mbps CableLabs MPEG-2 streams every month!

I think we'll be living with MPEG-2 for at least another 5-10 years!