ffdshow tryouts project: Discussion & Development

[HeadlessCow]

For both of my test samples (see previous posts), overlay and blend worked perfectly with the beta2 build.

CPU usage on the 720p video was 1% with post-processing disabled, 4% with overlay, 6% with blend and 12.5% (1 fully loaded core) with full-postprocessing.

For the 720p sample, full post-processing caused color corruption and the FPS dropped down to 18fps. After a few seconds, visual corruption also occurred (image turned blocky and the blocks kinda randomly moved around). For the other sample, full post-processing took 8% of the CPU and ran at full framerate, but still had the same green lines as before.

For a 1080p sample, I resized the source of the smaller vid and encoded it to a resolution of 1920x1080 with similar settings as the 720p vid. Playback used 2% CPU. Enabling overlay or blend increased that to 8%.

Also of note, the ATI 4670 cannot handle 5 ref frames in DXVA mode with 1080p video.

[tal.aloni]

Originally Posted by mark0077

I suspect 3205 or 3206 work by tal_aloni on deinterlacing related files will be the cause of the bug.

Thanks for letting me know,
Edit:
I'll fix that today.

Tal

[HeadlessCow]

When the MPC DXVA filter detects subtitles (or the presence of DirectVobSub, I dunno how it really works) it doesn't load, allowing the subs to be handled by DirectVobSub. I think that the ffdshow DXVA filter should do the same thing if internal subtitle handling is turned off. As it is, there is just a NullTextRenderer inserted into the graph and the subtitles go nowhere :'(

Actually, I can't get ffdshow (direct or not) to load my subtitles embedded in an mkv file, so maybe I'm just doing something wrong here :-D

[CiNcH]

Does anybody know where one can quickly get a MKV sample with H.264 4.1 video and subtitles in a format that ffdshow can read (so no PGS please)?

[tal.aloni]

HeadlessCow,
I've been meaning to fix that in future betas:
currently, the DXVA decoder does not have input pin for subtitles.
also, when DXVA is loaded, DirectVobSub cannot operate. (it cannot post-process DXVA, only internal ffdshow filters can)

also, thanks for the cpu utilization tests.

p.s.
I'm debating whether to fix those full-post-processing bugs (the colorspace issue is one of them),
or just remove this mode.
as albain noted, our performance tests shows that we're only achieving 2% of the theoretical bandwidth,
but I can't figure out anything wrong we're doing.

[HeadlessCow]

Yeah, I know you can't have DXVA and DirectVobSub, but the way I've been running is to have the MPC-HC DXVA filter set up to use DXVA with fallback to ffmpeg. When a file has no subtitles, it'll decode using DXVA, when there are subs present it uses the ffmpeg decoder and DirectVobSub is able to do its job. It'd be nice if the ffdshow DXVA decoder did the same thing.

[rsd78]

Originally Posted by tal.aloni

HeadlessCow,
I've been meaning to fix that in future betas:
currently, the DXVA decoder does not have input pin for subtitles.
also, when DXVA is loaded, DirectVobSub cannot operate. (it cannot post-process DXVA, only internal ffdshow filters can)

also, thanks for the cpu utilization tests.

p.s.
I'm debating whether to fix those full-post-processing bugs (the colorspace issue is one of them),
or just remove this mode.
as albain noted, our performance tests shows that we're only achieving 2% of the theoretical bandwidth,
but I can't figure out anything wrong we're doing.

Any chance you guys could contact the author of the intel article? They list the name but not an email. Just a guess but maybe he is a fellow enthusiast as he references mpc-hc in it .

[STaRGaZeR]

Originally Posted by rsd78

Any chance you guys could contact the author of the intel article? They list the name but not an email. Just a guess but maybe he is a fellow enthusiast as he references mpc-hc in it .

I'd do that. DXVA + full postprocessing is worth the effort IMO.

[MatMaul]

@albain :
http://git.ffmpeg.org/?p=ffmpeg;a=co...0fb77ad73c8e79

[dann23]

I have a problem with some movies when using dxva.some of them are not working with matroska splitter from mpchc website. the movie seems to play but the image is black. Should I post a sample?
And two suggestion.
1. please add support for MPEG2 in dxva.
2. this one is more complicated. don't know if it's possible. What I like about DXVA is that a cheap graphic card can decode the movie without much trouble. For me it;s about power consumption and silence. My card is a radeon 3850 with passive cooling and a 125w athlon x2 proccesor. You realize that using the CPU to watch movies is very loud. Not to mentions that the cpu is most of the time at 100% but the vga card is at 4-6% doing the same thing. So my suggestions is if it is possbile to make subtitles go directly to dxva render (not using overlay). Using no post processing takes 6-10% from cpu, but when using overlay it goes to 30-40%. Hope it is possible and somebody is willing to implement this for people like me.
And thank you for your hard work.

[Nyquist]

Originally Posted by tal.aloni

Beta 2 improves overlay mode visibility, and also adds Blend mode,
I'm not really sure if blend mode is very useful, because those read operations are very resource-hungry.
[full-processing-mode seems less and less practical, it's not fully implemented in this beta (and the previous one)]

While in Beta 1 the subs were working, in Beta 2 they don't.

On a Q9300 I get about 20% CPU load with Overlay, 22% with Blend and only about 10% using ffmpeg-mt.

[tal.aloni]

mark0077,
the doubling frames bug is fixed with rev. 3211,
I updated 4 filters: DGBob, KernelBob, Yadif, Framerate Doubler.
if there are any other filters that adds frames, let me know.

dann23,
are you referring to my beta2?
please clarify what exactly are you saying / asking.

regarding overlay / blend mode in beta 2:
I have to confess that there is some room for optimizations:

1. osd / subtitles are rendered 3 times for each frames instead of 1,
this is necessary to create opacity map without modifying or rewriting the osd / subtitles filter.

2. Right now the CPU is likely caching all overlay / blend reads and writes, this can be optimized more easily, but I don't have the time right now.

keep in mind that those optimizations are not very significant for a modern CPU (1-2%).

much more important IMO is to enable the text input pin for the DXVA decoder.

Tal

[noee]

if there are any other filters that adds frames, let me know.

I use avisynth to double framerate with the following script:

setmtmode(2)
Last=ffdshow_source()
setmemorymax(550)
setmtmode(2)
SeeSaw(sstr=1.45)
super = MSuper(pel=2,hpad=4,vpad=4)
backward_vec = MAnalyse(super,chroma=false, blksize=16, isb = true, search=5, searchparam=1)
forward_vec = MAnalyse(super, chroma=false, blksize=16)
MBlockFps(super, backward_vec, forward_vec, num=FramerateNumerator(last)*2, den=FramerateDenominator(last)*1, mode=1)
distributor()

This was broken after 3204 like the others. Might be worth a look too?

[therealjoeblow]

Originally Posted by HeadlessCow

Also of note, the ATI 4670 cannot handle 5 ref frames in DXVA mode with 1080p video.

That's correct, ATI strictly enforces the H.264 profile/level High@L4.1 for HD content as developed/approved by the associations responsible for the HD DVD and BluRay Disc standards. Nvidia doesn't so they can generally decode L5.1@1080p video with DXVA.

If you are interested in all of the compliant combinations of resolution, ref. frames, b frames and b-pyramids, you can look at this page on AVS Forum:

http://www.avsforum.com/avs-vb/showthread.php?t=972503

Cheers,
The REAL Joe

[albain]

Originally Posted by MatMaul

@albain :
http://git.ffmpeg.org/?p=ffmpeg;a=co...0fb77ad73c8e79

Great, we will make the merge once we will have a stable version

[tal.aloni]

Originally Posted by Nyquist

While in Beta 1 the subs were working, in Beta 2 they don't.

I've PMed Nyquist, the issue is solved.

[Mr VacBob]

I've changed the delay reporting API in ffmpeg-mt. Instead of the delay being has_b_frames + thread_count - 1, it's just has_b_frames now, matching mainline ffmpeg. I don't know if overestimated delay will cause a problem for you or not anyway.

[tal.aloni]

regarding VC-1 DXVA:

Originally Posted by tal.aloni

the "bug" is related to B frame ordering (bReorderBFrame variable),
MPC-HC filter behaves differently for each splitter,

we have started to imitate this behavior with rev. 3212
I would still like to implement a better solution, but it would require modifying some of the splitters involved.

[CiNcH]

Even though nobody here wants to communicate with me I want to point you to where Casimir once implemented Access Unit parsing for H.264 and VC-1 but did not release it, see MPCVideoDecFilter.cpp >= line 1524.

[cca]

@tal.aloni

rev 3205 broke DVD menu highlighting, latest rev. is still broken in that regard.