h.264 as an editing codec? just to get this out of the way

Minion · Post by **Minion** » Mon Jan 22, 2007 8:23 am

if this has been covered already, i must have missed it.
h.264 seems to be taking over the scene for final encodes.

it has a lossless mode, and i'm told makes files smaller than lagarith.

it's listed on amv wiki as one of the codecs not to edit with in the "edting with divx" article, but i'm curious if anything changes when you use lossless mode.

in the project i'm working on right now, i've been exporting my clips from after effects as h.264 in .mov containers, and dropping them into premiere.
thus far, there hasn't been any problems.
but anything that can go wrong, eventually will, so i wanna know if i should stop now, or if i'm "safe" to export my compositions as h.264

Keeper of Hellfire · Post by **Keeper of Hellfire** » Mon Jan 22, 2007 9:52 am

If a codec is good for editing has (nearly) nothing to do with if is lossless or lossy. It has to do with interframe compression vs. intraframe compression. And even in the so called lossless mode h.264 uses interframe compression, which is bad for editing.

Minion · Post by **Minion** » Mon Jan 22, 2007 9:54 am

thats what i was wondering - if lossless mode still uses i-frames

Keeper of Hellfire · Post by **Keeper of Hellfire** » Mon Jan 22, 2007 10:07 am

It aren't the I-frames that are problematic, it are the P- and B-Frames and the distance between the I-frames. If it'd use I-frames only it'd be ok, because that are the intraframe compressed frames.

Minion · Post by **Minion** » Mon Jan 22, 2007 10:11 am

i see
well, damnit

DJ_Izumi · Post by **DJ_Izumi** » Mon Jan 22, 2007 11:38 am

AFAIK, lossless h.264 is not very fast. AS in it will take a lot of power to encode and decode. The advantages of HufYUV and Lagarith are not only that they are lossless, but that they are lossless and FAST.

Lossless h.264 would probably only be useful if you are making a lossless master of a final project. For editing, it's most likely far to CPU demanding to be useful, even if it is lossless.

Purge · Post by **Purge** » Tue Jan 23, 2007 3:40 am

just do it minion - try something new - you can replace em with huffys if it stuffs and just save your work evry few minutes

DJ_Izumi · Post by **DJ_Izumi** » Tue Jan 23, 2007 8:44 am

Not to mention all the decoders capable of decoding h.264 Lossless are DirectShow based, and DS just has no love for Premiere.

DJ_Izumi · Post by **DJ_Izumi** » Thu Jan 25, 2007 11:44 am

I... Think we may have been wrong here. While traditionally we say 'I frames only for editing', I actually put this to the test and have had supirising results.

I was initially just testing Lagarith agianst H.264 Lossless for compression for the purpose of storing masters. Not for editing.

For those interested, the souces was 60 seconds from the 5cm Per Second 720p trailer (I did this all at 720)

The Lagarith YV12 is 376mb (For 60 seconds of video)
The h.264 Lossless YV12 is 212mb. (Same segment of video)

Impressive savings, no? I noticed that the Lagarith used twice as much CPU speed as the h.264 Lossless for playback in Core Media Player. (Using CoreAVC)

So out of curiosity, I wanted to see how fast this h.264 seeks. I have 3 copies of VirtualDub open. One has the Lagarith opened directly. One has the h.264 Lossless loaded using DirectShowSource in an AVS script. The other has the original h.264 lossy encode of the trailer using the same AVS script.

Impressively, the Lagarith and the h.264 Lossless seem to seek equally as fast, infact very easily, and I sort of feel the h.264 may be seeking a bit FASTER and smoother than the Lagarith. I can drag the slider around and get my requested frames as I want them quickly and easily, and only with an Athlon 3200+ XP. The h.264 Lossy on the other hand, is slow as snot.

I think there may be actual merit in using h.264 Lossless as an editing codec, except for the problem of having to use AVISynth to get it into Premiere or something. At the least, I think this might be worth looking into.

For the sake of argument, our guides to tell people to use MPEG-2 streams via an AVISynth script to get them into Premiere, and MPEG-2 streams from DVDs arn'tt all I frames, are they?

I think I'm going to re-download Premiere (Recently reinstalled windows) and see what my results are.

Zarxrax · Post by **Zarxrax** » Thu Jan 25, 2007 1:18 pm

DJ_Izumi wrote:For the sake of argument, our guides to tell people to use MPEG-2 streams via an AVISynth script to get them into Premiere, and MPEG-2 streams from DVDs arn'tt all I frames, are they?

That's why you have to index it with DGindex first. This is what allows you frame accuracy. You could load the mpeg-2 straight through DirectShowSource too, if you wanted. However, DirectShowSource is not frame-accurate, which is why it can't be used for editing.