Recommended intermediate HD codec

[Sagittaire]

No problem except complex decoding-more complex than all intermediate codecs for the price of smaller size. These days storage is cheap, so I prefer easier decoding.

AVC-I 100 is CAVLC by Panasonic standard, but it's not really transparent at 100Mbit (you need something like 150Mbit).


Andrew

100 Mbits is not enough ... ?

It's certainely not transparent with loop in particular condition because lossy will be always lossy. Anyway I doubt seriousely that you can see compression artefact at this quality. I doubt seriousely that you can say "this is original and this is lossy compression". 100 Mbps for AVC at 100 Mbps is by far enough for original master ... simply because production will be more destructive and by far ...

[kolak]

Try it:)

AVC-I is great in many areas TVs, news, documentary, etc), but not for feature movies, grading or as BD master.

I don't have to doubt- I've tried it.

Intermediate codec should be as good as HDCAM-SR- that's the whole idea of it. AVC-I at 100mbit is not as good, by quite a lot.


Andrew

[poisondeathray]

kolak is correct; Panasonic's AVC-I 100 isn't good enough for mastering or high end acquisition. It probably needs 150-200Mb/s.

People who use cameras with AVC-I for TV shows (e.g. HPX3700), use external recorder because AVCI-100 isn't good enough

You can see artifacts and detail loss with naked eye (unzoomed) compared to simultaneous uncompressed recording, or even compared to ProResHQ

[kolak]

Yes- about 1.3-1.5x less bitrate than other intermediate codecs, but 100Mbit is not enough.
In the same time decoding is more complicated and these days (with cheap storage) it's not worth it.

Andrew

[poisondeathray]

Like you said, it's fine for some purposes, but not ok for others... But it's not even in the category of "visually lossless"

There have been rumors of an "AVC-Ultra" by Panasonic , a 200Mbps 4:2:2 10-bit variant, but it never got released .

[kolak]

All of the intermediate codecs are good and have about the same efficiency- ProRes, DNxHD, Cineform and Canopus HQX- all great and very fast, but HQX in Edius is unbeatable:)


Andrew

[henryho_hk]

but HQX in Edius is unbeatable:)

Any subjective measurement?

[kolak]

Any subjective measurement?

In what terms? Speed is unmatched by any other NLE+their native codec. AVID+DNxHD is a joke in comparison :)
Quality- at highest setting it's almost lossless. You need to zoom 5x to see single pixel changes. PSNR 55dB+.

It's like other intermediate codecs, but more scalable and performance is amazing. You can do 4K color grading in RT on modern machine.

UtVideo is also very fast (and lossless), but 8bit only.


Andrew

[mp3dom]

kolak, since HQX is a 10bit codec, do you know if the conversion to 8bit (for final encoding for example) is forced to be done inside Edius or is there a way to convert it to 8bit outsite the NLE? With proper codec installed I think VDub or AviSynth see it as a 8bit codec (truncating the 2 bits) or am I wrong?

[kolak]

Yes- no access to 10bit in HQX outside Edius at this point. It has been passed to GV and they confirmed it. It may change soon. HQX decoder (outside Edius) has no higher than 8bit output pin for now.


Andrew

[kolak]

Here is some white paper:

http://www.grassvalley.com/docs/WhitePapers/professional/GV-4097M_HQX_Whitepaper.pdf

It looks "real"- no cheating- some text is marketing crap, but graphs seams to be fine.
Advantage of HQX is that you have huge range of quality- from 25:1 to nearly lossless. Other codecs are more strict, but efficiency is basically the same.


Andrew