AMD's UVD2-based XvBA Finally Does Something On Linux

[Kano]

Basically the app could force vsync on too. Don't know why this is not done.

[xzero2]

vsync issue

Go into the control panel (amdcccle) opengl/3d options and make sure you have "sync to vblank" enabled.

When I enable "Wait for vertical refresh" in amdcccle, I get very jerky playback of some h.264 files. These same files play well using XvBA, with little tearing, without this setting. I don't have a "sync to vblank" option in my amdcccle.

Could the frame rate be a problem? A seperate 1080p 24fps plays fine.

File info:
[CODEmediainfo hannity.ts
General
ID : 0
Complete name : hannity.ts
Format : MPEG-TS
File size : 318 MiB
Duration : 7mn 8s
Overall bit rate : 6 223 Kbps
Maximum Overall bit rate : 18.0 Mbps

Video
ID : 4113 (0x1011)
Menu ID : 1 (0x1)
Format : AVC
Format/Info : Advanced Video Codec
Format profile : [email protected]
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Duration : 7mn 8s
Bit rate : 5 407 Kbps
Width : 1 280 pixels
Height : 720 pixels
Display aspect ratio : 16:9
Frame rate : 59.940 fps
Resolution : 24 bits
Colorimetry : 4:2:0
Scan type : Progressive
Bits/(Pixel*Frame) : 0.098
Stream size : 276 MiB (87%)
colour_primaries : BT.709-5, BT.1361, IEC 61966-2-4, SMPTE RP177
transfer_characteristics : BT.709-5, BT.1361
matrix_coefficients : BT.709-5, BT.1361, IEC 61966-2-4 709, SMPTE RP177

Audio
ID : 4352 (0x1100)
Menu ID : 1 (0x1)
Format : AC-3
Format/Info : Audio Coding 3
Duration : 7mn 8s
Bit rate mode : Constant
Bit rate : 384 Kbps
Channel(s) : 6 channels
Channel positions : Front: L C R, Surround: L R, LFE
Sampling rate : 48.0 KHz
Video delay : -50ms
Stream size : 19.6 MiB (6%)
[/CODE]

[bridgman]

Yeah, "sync to vblank" and "wait for vertical refresh" are the same.

What is your display refresh rate set to ? Maybe it's just a bit slower than the video frame rate - that might result in jerky playback.

[xzero2]

Yeah, "sync to vblank" and "wait for vertical refresh" are the same.

What is your display refresh rate set to ? Maybe it's just a bit slower than the video frame rate - that might result in jerky playback.

While the video is playing, according to the monitor it is 60Hz. If I can change it (I don't know if the monitor can go much higher), I will try again and report the results.

[bridgman]

I'm just guessing based on your comment that some 720p 60Hz were jerky with sync-to-vblank enabled while 24Hz videos were not. If tweaking the refresh rate doesn't help (I'm thinking your display might be at 59 rather than 60 Hz) think about things like memory shortages, swapping etc...

[xzero2]

I'm just guessing based on your comment that some 720p 60Hz were jerky with sync-to-vblank enabled while 24Hz videos were not. If tweaking the refresh rate doesn't help (I'm thinking your display might be at 59 rather than 60 Hz) think about things like memory shortages, swapping etc...

Sorry if I was not clear, but you are correct. I have tested at 1280x1024 @75 and the effect is still there but much less pronounced. Looking at a news crawl it is almost like a vibration. Without vsync the crawl is very smooth with only occasional tearing.

[bridgman]

I don't remember if fglrx has an option for triple-buffering but if you see something like that give it a try.

[Kano]

Wouldn't it be reasonable to release the xvba sdk as mentioned in

http://www.splitted-desktop.com/~gbeauchesne/hwdecode-demos/

And opensource the xvba-video wrapper? Then the pcom output should work for everybody too and gl output would not be needed.

[bridgman]

No. That SDK was not designed for public release.

[Kano]

That's the wrong decision, vdpau should show clearly how to define new standards.