GPU transcoding

[jofarmer]

Hi. I know that badaboom is not yet there and CUDA-only. On the other hand the sheer numbers of stream processors of ATI's Radeon HD4670 and 4850 made me order two today (at that price, who can resist?) - and then cancel the order.

Why?

The Radeon HD 48xx series promises "Accelerated Video Transcoding", the 46xx does not.

And the AVIVO video transcoding app from ATI is Radeon X1xxx-only.

I wanted to use those two 4670 in crossfire mode to do all that transcoding to h264 that I was too lazy to do old-school, since even though I have a Q6600 transcoding in good quality takes time. Plenty of it.

So could please someone enlighten me on what ATI means when they post "Accelerated Video Transcoding (AVT)"-capabilities of their newer cards - just that someday in the future someone may or may not have written an app that uses the ATI Video transcoding API?

I did google and search the forum, but found no answer.

[Hellworm]

Originally Posted by jofarmer

I wanted to use those two 4670 in crossfire mode to do all that transcoding to h264 that I was too lazy to do old-school, since even though I have a Q6600 transcoding in good quality takes time. Plenty of it.

But you know that the quality of hardware transcoding is not yet nowhere near to x264, even with x264 at highest speed?
So transcoding in good quality will take months or years .

[ajp_anton]

GPU transcoding is always fast but horrible quality.
x264 running on a fast CPU (Q6600) gives you the option to be either as fast (or faster) with same low quality as GPU, or slower but better quality.

[jofarmer]

Yeah. Back when I had a powerbook I had a Turbo.264 - quality WAS noticably worse than using x.264 or even quicktime h.264.

But I found some answers by now: seems like nothing is there yet and PowerDirector should have that functionality... anytime soon now.

http://forums.anandtech.com/messagev...readid=2208040

http://forums.amd.com/game/messagevi...threadid=97340

http://forums.techpowerup.com/showthread.php?p=855745

sorry for starting this thread with a question that was answered elsewhere, but maybe this is interesting news to some after all.

Cheers!

[jofarmer]

Originally Posted by ajp_anton

GPU transcoding is always fast but horrible quality.
x264 running on a fast CPU (Q6600) gives you the option to be either as fast (or faster) with same low quality as GPU, or slower but better quality.

Now imagine trying to run x.264 with maxed quality settings trying to downsize a Bluray to a DVD9. If done properly (8-11MBps x264 can look good, even at 1080p) the loss of quality is neglectible, but it takes ages.

If only handbrake would extend its support to HD formats...

[Atak_Snajpera]

If only handbrake would extend its support to HD formats...

In meantime you can always use RipBot264...

[Ranguvar]

RipBot264, MeGUI, StaxRip, AutoMKV, and AviDemux are all excellent GUIs. I much prefer them over HandBrake, which is quite limited, especially since it can't even do AviSynth, can only convert from DVDs, and can't use new/custom mencoder/x264 versions.

[refulgentis]

Originally Posted by Ranguvar

RipBot264, MeGUI, StaxRip, AutoMKV, and AviDemux are all excellent GUIs. I much prefer them over HandBrake, which is quite limited, especially since it can't even do AviSynth, can only convert from DVDs, and can't use new/custom mencoder/x264 versions.

If you use the current SVN, the second two can be done. The second is already implemented, and the 3rd is trivial. I haven't programmed regularly since I was 13 and I can amend the build system to include whatever patch I need for x264 easily.

[Ranguvar]

Trivial to some, sure, but not many of those that are using HandBrake in the first place. Come to think of it, even using SVN is beyond the comfort zone of some users.

[LoRd_MuldeR]

Originally Posted by jofarmer

And the AVIVO video transcoding app from ATI is Radeon X1xxx-only.

From all that I know AVIVO is a pure CPU encoder. It requires a recent ATI Radeon card to run, but it doesn't actually use the GPU yet...

[jofarmer]

Originally Posted by Atak_Snajpera

In meantime you can always use RipBot264...

This is indeed a very good app and does exactly what I was hoping to do. Since my normal routine would be to decode the BD to yuv and then let x264 work its magic, your app saved me a LOT of disk space. And the quality I got was very good, I am very satisfied - so thank you, for coding it, and for telling me about it; I am very new to using Windows as a platform, its OS X and Ubuntu for me. But new technology always takes time to come to these platforms, so...

But my initial interest in GPU transcoding remains: creating a BD9 took around 6 hours with my Q6600 (and it kept muxing for two till I aborted, but sound was fine).

[refulgentis]

Originally Posted by jofarmer

This is indeed a very good app and does exactly what I was hoping to do. Since my normal routine would be to decode the BD to yuv and then let x264 work its magic, your app saved me a LOT of disk space. And the quality I got was very good, I am very satisfied - so thank you, for coding it, and for telling me about it; I am very new to using Windows as a platform, its OS X and Ubuntu for me. But new technology always takes time to come to these platforms, so...

But my initial interest in GPU transcoding remains: creating a BD9 took around 6 hours with my Q6600 (and it kept muxing for two till I aborted, but sound was fine).

You're lucky to have it be that short, whenever I start transcoding a 1080p movie, I just assume my computer is gone for a day. :/

[Sagekilla]

When I start transcoding a 1080p movie, I usually come back after 3 1/2 days.. Muxing only takes 5 mins though.

[Blue_MiSfit]

Yeah - when I do a BluRay rip I typically use CRF mode, and little to no AviSynth filtering (fft3dgpu to clean chroma if its noisy).

I start an encode when I go to bed, and it's always done by the time I get home from work the next day (18 hours later +/-).

If I could get the same quality in hardware at faster speeds, I would love to do so, but I can't

Core i7 will help things!

~MiSfit

[mikeytown2]

Review of GPU Encoders
http://www.maximumpc.com/article/fea...really_upon_us

via slashdot
http://hardware.slashdot.org/article.../09/12/0156222

[Comatose]

The review is from a few days ago, but they're using a version of x264 from February...
What an unfair comparison. Man, when a site like that does an encoder review, they should pay somebody from here to do it...

[jofarmer]

Whew, what I expected. Good thing I went with my Q6600, then ;-)
But still I have high hopes in the ATI 4xxx series GPU with 320 to 800 stream processors. I know, not directly comparable to nVidia's number of stream processors, bus as soon as both (so far only ATI) support OpenCL, things will start to get really sweet...

[BlackSharkfr]

Originally Posted by jofarmer

Whew, what I expected. Good thing I went with my Q6600, then ;-)
But still I have high hopes in the ATI 4xxx series GPU with 320 to 800 stream processors. I know, not directly comparable to nVidia's number of stream processors, bus as soon as both (so far only ATI) support OpenCL, things will start to get really sweet...

And by the time they actually do support it, and then that a good high profile H264 encoder uses them, there will be the 6xxx or 7xxx series.

Never buy hardware for future potential features or you'll always be disappointed.

[jofarmer]

Originally Posted by BlackSharkfr

Never buy hardware for future potential features or you'll always be disappointed.

Agreed.