Overlay: what's it about, and why doesn't it work sometimes?
 

Hi,

Can anybody explain what the "overlay" feature does, and what is the difference between mode 1 and 2?

Also, I noticed that sometimes BsPlayer "fails to create overlay", yet other times it works fine (i use v0.86 build 493). In case it has to do with hardware: I have a GeForce4 Ti4200 128Mb using NVidia's Detonator 30.82 driver (and shitloads of free ram).

I even noticed that some movies won't play if I disable this Overlay, or only play in mode 1 or 2. Why is that? Does overlay have anything to do with decoding a movie??

Overlay is a nifty solution to provide quick picture composition on screen, without raising CPU load much. The GPU on your graphic board does most of the work.
Overlay can be created in different formats, i.e. color space formats.
If you're eager to learn more on that have a look here:
http://www.fourcc.org/.
Most important for quick overlay drawing are YUY2, YV12 and UYVY.
These color space formats differ from RGB (RedGreenBlue) color information storage in that way that they only distinguish between a luminance (brightness) and chrominance value.
They are generally speaken faster.
YV12 is the fastest AFAIK, but causes some trouble with cards which however don't properly support this format, thus image quality is decreased. For instance Matrox cards as well as NVIDIA are said to have bad driver architecture, bad overlay support. But, I own one myself (TNT2) and never had difficulties.
YV12 is usefull on slow machines for MPEG4 decoding (DivX and XVid) is heavy work for CPU, so every off-load is "good".
You can try to switch it on in bsplayer trough overlay mode 1, though curiously you will get YUY2 anyway when your XVid/DivX resides in an OGM container (instead AVI). Cannot explain.
If you switch to bsplayer overlay mode 2, you'll get YUY2 output which is default and preferred overlay output from most players and DirectShowFilters (ffdshow !).
On modern graphic cards there ought to be no visibile difference.
Changing between those two modes is only advised if your card does not support one mode. Also it's better to not manipulate this during playback, some systems don't tolerate this and bsplayer crashes. After mode switch close player and re-open to make it store overlay initialisation info in registry.
To find out which color overlays your graphic system supports try to use Sisoft Sandra 2003 to find out: http://www.sisoftware.co.uk/?dir=&lo...ate&a=&lang=en

Unfortunately, I feel helpless myself with bsplayer sometimes being unable to create overlay surface.
If there's a second application running using overlay, ok, but sometimes it just fails right after start-up. :shock:
Maybe BST can explain some day...

Hope this explained a bit!!

Bluedan, where do you look in Sandra for best video overlay?

click DirectX module. Scroll down to bottom.

I've noticed that is seems to happen when you have "preview" enabled in your windows explorer. It usually works when you disable that, don't know why the preview would need to use overlay but it seems like it does.

Netmeeting issue
 

If you have Netmeeting or similar software running on your computer, Direct Draw surface cannot be created, and overlay doesn't work, so BSA player (or any other player) switches to RGB mode, and picture is bad and slow... You have to turn off Netmeeting, and then it works perfectly!

hey, stuck to that problem over and over again.
why is bsplayer unable to steal focus on that surface creation if it rivals with other apps with that?
when opening wmp instead there isn't such problem.
with zoomplayer neither!

WMP and zoomplayer, and koalafilmplayer and divxplayer and so on, don't use overlay. They use media player window .Bsplayer uses it's own window renderer. It does not use windows media player window. Uninstall WMP and all other players will fail to play. Bsplayer no. Probably when it reaches release 1.0 this problem will be solved.

any possibility to enable "overlay mixer" in bsplayer?
overlay mode 1/2 doesnt use it in the graph....

To enable overlay...

First, click start -> Run -> "dxdiag", Click "Display" tab
Make sure directdraw acceleration is enabled.

Then, make sure you have no other players running, close all preview windows, all other programs and excess windows and leave only BSplayer running. Then...

Lower your resolution first to 800*600 then to 640*480
Lower your desktop colors count to 16bit depth, if it doesn't work then to 256 colors
Lower your display refresh frequency to 60hz.

You may not only have a slow PC, you may also have a graphics card with 8mb or less. After doing one or all three above BSplay should work in overlay. And if you have only 4mb graphics card or less, well, it was time to upgrade anyway :-)

If you use 256 colors and want to use subtitles, make sure you set in BSplayer preferences to display subtitles in overlay. Otherwise you may get crashes with subtitles.

Katharsis

800x600x16bit per pixel makes 4,8 MB. An older card with 4 MB can display a movie a little smaler than that in resolution.

thanks, but i asked about the directshow filter "overlay mixer" :)

Sorry Mr Bond.
I was answering another post made by Katharsis.
About overlay mixer. I think this question can be answered only by BST itself. But, as overlay mixer is the older filter for directshow and VMR9 is the newest, and is implemented allready, don't know if this will go back.

just asked for overlay mixer, because the realvideo/audio decoder only works with overlay mixer without choppy playback...

Have you tried it, dude? I was btw not referring to the movie resolution which of course affects possibility to display it in overlay.

It's obviously not just about resolution, refresh rate counts too. And I suspect desktop resolution has something to do in BSplayer only at 16bpp color depth. Why? BSplayer makes some wonderful tricks when it comes to 256 color desktop, as desktop stays in 256 colors (8bpp -- thus reducing card memory load) and BSplayer seems to play the movie in unbelievable 32bpp depth. I have never seen anything parallel to that nor I can explain sufficiently how it is done. BST rocks. I just hope this feature makes it to 1.0.

Overlay failed / Diamond fire gl1
 

Hi, everytime I start movie in BSP overlay failed message appears. I have Dell Precision Pentium III/450 256MB RAM with Diamond Fire gl1/32MB card.I have downloaded DirectX 9,card driver for win xp but it did not solve the problem.When i start DXdiag and try to test direct3d and directx there are some errors,because graphic card support only true color,not lower.When dxdiag tryes to test direct3d 9,it fails with not enough video memory message.I thing problem may be in fact that my card does not support directx very good. It was deweloped for NT OpenGl apps. Open gl apps and games (Quake2 (800*600/true color)) are running perfectly.Playing video in window is smooth,but when i try to resize it then picture is broken and parts of it appears out of bsp window.Please help :o)

how to know which type of overlay is better?

Try. It also depends on your graphics card. (See e.g. the second post in this thread by bluedan).
:wink:

To enable overlay...

First, click start -> Run -> "dxdiag", Click "Display" tab
Make sure directdraw acceleration is enabled.

Then, make sure you have no other players running, close all preview windows, all other programs and excess windows and leave only BSplayer running. Then...

Lower your resolution first to 800*600 then to 640*480
Lower your desktop colors count to 16bit depth, if it doesn't work then to 256 colors
Lower your display refresh frequency to 60hz.

You may not only have a slow PC, you may also have a graphics card with 8mb or less. After doing one or all three above BSplay should work in overlay. And if you have only 4mb graphics card or less, well, it was time to upgrade anyway

If you use 256 colors and want to use subtitles, make sure you set in BSplayer preferences to display subtitles in overlay. Otherwise you may get crashes with subtitles.

help l tried to use overlay in 256 color, but the bs player say my graphics hardware is not capable of something and l need to update its driver. sorry but how do l check my notebook's graphics card and how do l update its driver? how to lower the display refresh frequency and disable both active desktop and overlay mode in winsdows ME?