lossless YV12 codecs (was: YV12 FAQ)

[ariga]

I am looking for a lossless YV12 codec to save the output of avisynth. Seems like vble and loco can do it. But neither can handle interlaced video, is that correct ? Are there any new codecs now ?

[Boulder]

Originally Posted by ariga

I am looking for a lossless YV12 codec to save the output of avisynth. Seems like vble and loco can do it. But neither can handle interlaced video, is that correct ? Are there any new codecs now ?

ffdshow has a YV12-capable HuffYUV codec. You need to install the vfw support for it to be available I think.

[ariga]

That's nice. But ffdshow looks like one of the all-in-one codec packs. Will it interfere with my existing codec setup ? Is it possible to limit it to just the yv12 encoding/decoding ?
Also, how can I determine which codec is being used by avisynth (or other app) at any time ?

[Wilbert]

Look in the documentation of AviSource and the fourCC option.

I splitted the thread from the sticky if you don't mind.

That's nice. But ffdshow looks like one of the all-in-one codec packs. Will it interfere with my existing codec setup ?

No, you can select which decoders in ffdshow should be used for decoding some format.

Is it possible to limit it to just the yv12 encoding/decoding ?

Yes, that's also possible.

[Poutnik]

Originally Posted by ariga

I am looking for a lossless YV12 codec to save the output of avisynth. Seems like vble and loco can do it. But neither can handle interlaced video, is that correct ? Are there any new codecs now ?

You can try Lagarith lossless codec, supporting RGBs, YUY2 and YV12

Edit: Not sure about interlacing....

http://lags.leetcode.net/codec.html

Originally Posted by ariga

That's nice. But ffdshow looks like one of the all-in-one codec packs. Will it interfere with my existing codec setup ? Is it possible to limit it to just the yv12 encoding/decoding ?

It's not a codec pack. And yes you can limit it to only encode/decode whatever you want. If you don't want it decoding something you just disable that feature.

[Hellworm]

In ffdshow you can also try FFV1, pretty good compression, slow, can handle yv12, afaik.
Don' t know about interlaced.

[IanB]

Think about it guys. A YV12 frame does not know it is interlaced it just has 3 planes of data a Y plane and 2 of 0.25 sized U and V planes. A lossless codec will just store the plane data and return it unchanged.

As for being able to tell the codec the plane data is interlaced there may be a slight improvement in correlation within a single field that might allow a slightly better compression but it is probably not worth the hassle with intermediate workfiles. If your are really worried about it do a SeparateFields() at the end of the script and an AssumeFieldBased().Weave() when you re-import the data.

[Wilbert]

Think about it guys. A YV12 frame does not know it is interlaced it just has 3 planes of data a Y plane and 2 of 0.25 sized U and V planes. A lossless codec will just store the plane data and return it unchanged.

As for being able to tell the codec the plane data is interlaced (...)

I guess it only matters when you feed or request RGB from the codec.

[IanB]

Originally Posted by Wilbert

I guess it only matters when you feed or request RGB from the codec.

Which you probably should not do, else why bother with the lossless "YV12" codec. Letting arbitary unknown code do your colour space translations is fraught.

[GrofLuigi]

I have used Loco codec few times to store interlaced YV12 with no visible problems, although in the readme it says "interlaced support is todo".

GL

[ariga]

The author of Lagarith claims the codec is fast and compresses better than other codecs. (FFV1 only slightly better but slower). Tried it, works well, supports interlacing (but then IanB pointed out, it's irrelevant if there's no colorspace conversion)

Is this a good way to determine if the codec is lossless ?
orig=AviSource("orig_pal_dv.avi") # 50 frames, 7041 KB
lags=AviSource("lags_pal.avi") # 50 frames, 10900 KB
Subtract(orig, lags).Histogram("levels")

BTW, uncompressed YV12 was 30385 KB.

EDIT: Interlacing support not available !! Mail from author...

On Tue, 29 Nov 2005 Ben Greenwood(RIT Student) wrote :
Adding support for interlaced video is on my 'to-do' list for Lagarith, athough I have no idea when it will be implemented. The reason it is not in there yet is that interlaced YV12 is kinda messy to deal with during colorspace conversions. As the posts say, you should be fine as long as you do not do any colorspace conversions within Lagarith when working with interlaced video.

[foxyshadis]

An easier method is a PSNR (or any other metric) comparison. In fact, MSU has a tool for this.

Which brings me around to my suggestion, the MSU Lossless codec is basically the most efficient lossless available, more so than lag or loco, and still reasonably fast (it's around half the speed of huffyuv on mine, I think, but I use the fastest mode). And it does support interlaced YV12, fwiw.

[ariga]

With uncompressed YV12 (480 frames of 720x576 @ 25fps) 292 MB

Codec  Duration   Size       Settings
MSUD    1:58      137 MB !! Lossless; Mode=Maximise speed; Enable delta frames
MSUD    0:59      121 MB    Lossless; Mode=Maximise speed
MSUD    0:59      121 MB    Lossless; Mode=Max compression,slow decomp
LAGS    0:22      130 MB    Default settings

Lagarith decompression took the same time. Excellent for intermediate files.
MSU decompression was similarly slow. I'd say good for archiving only.

[gamr]

am i still the only 1 using vble? can post it on a site if anyone wants it (last i knew it was hard to find)

[ariga]

Links vble and loco are available via the YV12 FAQ, particularly in this thread

But it would help if comparison/stats were posted here along with the time. Mostly the comparison is only w.r.t size and not time.

[Alain2]

What about Helix codec 1.2 ? Don't know if it handles interlaced video though

[foxyshadis]

Guess I was wrong. I'll give lagarith a try then.

[Poutnik]

Originally Posted by Alain2

What about Helix codec 1.2 ? Don't know if it handles interlaced video though

I am afraid this codec support YV12 in non uncompressed way,
or I recall badly....

[Leak]

Originally Posted by Poutnik

I am afraid this codec support YV12 in non uncompressed way,
or I recall badly....

Yep. The Helix codec takes uncompressed YV12 or I420 and converts it to YUY2 or RGB - so it's more of a colorspace converter than a "real" codec.