Serato Video General Discussion

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 Serato Video General Discussion
B-Frame support
Talk about Serato Video and Video-SL.

B-Frame support

VJ Justin Allen 11:35 AM - 11 June, 2009
Has anyone had any issues with enabling B-Frames when playing back H.264 files in Serato? This would fall under support for the Extended Profile* area of the H.264 Profile spec.

This might just be a tech support question here.

Thanks!


Note:There are 4 separate profile areas in the H.264 spec, Baseline, Extended, Main and High.
nik39 11:24 PM - 11 June, 2009
ORLY.

No problems with B-frames.
VJ Justin Allen 11:50 PM - 11 June, 2009
Thanks Nik...but what is orly mean? :)

Also, how are you using the B-frames, on auto, 2-5 or higher than that?
nik39 11:56 PM - 11 June, 2009
What is "auto"?

You should not overdo the b-frames. It has various negative side effects (esp. during encoding).
VJ Justin Allen 12:03 AM - 12 June, 2009
Some higher-end encoders have automatic settings. As to over-doing the B-frames, there are some side effects but the ones I would be concerned about is not during the encoding process but during the playback process. There is a tendency to get stuttering with excessing B-frames, just didn't know how Serato treated them.
nik39 12:11 AM - 12 June, 2009
Works fine for me.
VJ Justin Allen 12:13 AM - 12 June, 2009
And how many B-frames are you using?
nik39 12:15 AM - 12 June, 2009
IIRC it was two.
VJ Justin Allen 12:17 AM - 12 June, 2009
Cool, thanks. I'll play with that.
a-swift 9:59 PM - 12 June, 2009
has anyone tried h.264 with all i frames yet?
VJ Justin Allen 10:02 PM - 12 June, 2009
Not yet but it's on my list. I'm playing with AVC profiles and CABAC coding now.
nik39 8:28 AM - 13 June, 2009
Quote:
has anyone tried h.264 with all i frames yet?

Keyframes=1? Why would you do that?
nik39 8:28 AM - 13 June, 2009
(keyframedistance that is)
a-swift 5:37 PM - 13 June, 2009
AVC-Intra doesn't use temporal compression. Less CPU power since there are not GOP groups. Every frame is encoded by itself like a regular codec, not like an MPEG codec that uses GOP.

I'm curious if keyframes = 1 would work with VSL and use less CPU.
VJ Justin Allen 5:52 PM - 13 June, 2009
Actually wouldn't keyframes=1 be the same as keyframes=0
nik39 8:30 PM - 13 June, 2009
Quote:
AVC-Intra doesn't use temporal compression.

What#s that?

Quote:
Less CPU power since there are not GOP groups. Every frame is encoded by itself like a regular codec, not like an MPEG codec that uses GOP.

Just guessing here - but I always thought uncompressed (in terms of only keyframes - no interframe dependencies) would add additional stress on all i/o components and would slow down the whole process.
a-swift 1:44 AM - 14 June, 2009
that's backwards nik. each frame encoded by itself with no dependence on other frames uses LESS CPU power.

temporal means time. the frame's encoding is spread out over many frames. that's all it means.
nik39 2:11 AM - 14 June, 2009
i/o components... I am focussing on i/o components. USB/IDE whatever. You are not reading 3mbit/s, you are reading a lot more.
nik39 2:11 AM - 14 June, 2009
Oh, and USB is also taxing the CPU. I am not sure, but I guess there is no DMA for USB.
a-swift 3:28 AM - 14 June, 2009
yes you are correct, disk i/o is slower with larger files but CPU is my bottleneck, not IO. I'm not even taxing the I/O channel a bit.
Serato
Nathan H 10:49 PM - 14 June, 2009
Quote:
Not yet but it's on my list. I'm playing with AVC profiles and CABAC coding now.
Please don't use CABAC. It looks good on paper but the 3-4% quality increase is matched by a 10-15% CPU load increase. Is it really worth it? ;-)

Quote:
yes you are correct, disk i/o is slower with larger files but CPU is my bottleneck, not IO. I'm not even taxing the I/O channel a bit.
I think this is what most people will be experiencing. What would be a more interesting question is H.264 with all I frames vs. MJPEG-B or something like that.
VJ Justin Allen 11:03 PM - 14 June, 2009
Thanks Nathan on the CABAC feedback. I guess I was looking at it for snow leopard when the graphics card handles all of that. But it does seem that the quality increase doesn't justify it at all.

Do you have any thoughts on using the High AVC profile?
Serato
Nathan H 12:14 AM - 15 June, 2009
I haven't really played much with the different profiles I'm afraid. Just the underlying 'how to make them not compressed' stuff. If you can get it to work and it doesn't kill your CPU then that is good :-)
VJ Justin Allen 12:51 AM - 15 June, 2009
Thanks Nathan. I'll keep everyone updated and maybe even pass a file around so others can check it.
D-Twizzle 4:47 PM - 16 June, 2009
B-Frames and CABAC have been working fine for many people. SV uses it as well and they have hundreds if not thousands of people using their videos now.
Millz 5:30 PM - 16 June, 2009
thousands +
Rebelguy 5:52 PM - 16 June, 2009
Quote:
thousands +


Gazillions plus infinity.
Millz 5:57 PM - 16 June, 2009
hehe