Mailinglist Archive: radeonhd (427 mails)

[Rafał Miłecki <zajec5@xxxxxxxxx>]

2009/5/12 Anders Eriksson <aeriksson@xxxxxxxxxxx>:
> > With normal, standard analog jack out you will transfer sound in quite poor
> > quality.
>
> Sure. But still, it's on par with what people are use to from the pre-digital
> era, and non-stuttering, and non-skuppy and all that. It "just works".

Yeah, that whole digital era makes me crazy for many years already ;)
People buy great, expensive audio devices... and use poor analog
connections to them (from DVD / TV / computer / whatever). Next ppl
spend even more money for fantastic 48 or even 52 inches TVs... and
(yes, you guess right) connect DVDs or terrestrial television
receivers to them, not even considering Blu-Ray players or notebooks
with (at least) 720p :)

I consider myself far from being audiophile, but there IS difference
between analog single-jack signal and digital signal with nice audio
receiver.

That's definitely crazy: connection of digital era with "it just works" :)


> > Solution for better quality is digital output: S/PDIF in form of RCA/jack
> > (coaxial) or optical (Toslink)... or HDMI of course. With S/PDIF and RCA/jack
> > problem is that it's usually not available in most notebooks and not awlays
> > available in motherboards with integrated audio cards. So having ATI card in
> > notebooks I can play digital sound to /some/ device.
>
> <snip: pros for digital suff which I agree with>
>
> If I have to _choose_ between high-end audio with broken video, or traditional
> audio and _working_ video playback, I sure know where my vote is.

I don't think using audio in HDMI actually affects video playback.
Didn't notice that ever.


> But of course, if I can have it all, so much the better! How far off is HD
> video playback on the RS690, anyway?

You can split whole video playback into two / three main parts:
1) Decoding video from some file format (ex. h264)
2) Converting colors
3) Scaling video (for example you have video 1200x720 but you want to
play it fullscreen on 1920x1080)

2 and 3 are done in GPU thanks to Xv - that works since "always" on
RS690 and since months on R6xx-R7xx (DRM needed for that will hit
2.6.30). So here you shouldn't experience problems.

More problematic may be decoding. That can be in 4 ways:
1) Software (CPU) decoding
2) Software (CPU) multi-thread decoding
3) Hardware (GPU) decoding with special hardware engine (vendor specified)
4) Hardware (GPU) decoding with shaders (universal)

1) On modern CPUs you can succesfully decode most 720p movies.

2) Problem comes with 1080p, when one core (for example on my Intel
C2D P8400) is often not enought. Then you have to use more cores but
standard ffmpeg (used by MPlayer) can't do that. It's implemented in
experimental ffmpeg-mt but it is not stable yet (and won't be soon).

3) Both AMD and NVidia has special hardware blocks to decode video
(RS690 doesn't AFAIR). Unfortunately that won't become available in
open source driver due to some legal issues. NVidia offers it in it's
closed driver (VDPAU), AMD doesn't even in fglrx.

4) Nothing special available for now, read http://bitblitter.blogspot.com/

So it's really hard to play full HD material on ATI :( What's worse I
don't see any solution coming soon. Personally I use ffmpeg-mt for
playing 1080p materials. It sometimes crashes but it mostly happens on
starting, stoping and seeking video. Almost never after you already
started playback.

If I missed something I would love to hear other solutions.

-- 
Rafał Miłecki
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