embed media player into c# interface play webm file

[heinekenball wade]

hello,

I'm trying to embed a media player which could play .webm file. in c#
interface.

c# allow embed windows media player but it couldn't play .webm files,

but windows media player 12 could play .webm file when i click
the .webm file.

have any way to play webm file in c# interface?

thanks,

[heinekenball wade]

After decoded .webm to .yuv file, i could display frames in picturebox
now.
but i have a new problem, how could i display color correctly while
convert YUV(i420)to RGB.
below, is my example, frame size is 352*288, i got gray color frames
after the code...
have someone could give me advise?
//Y
int Y = MyStreamData[y * 352 + x];
//U
int V = MyStreamData[352*288 + (y * 352 + x)/4];
//V
int U = MyStreamData[352 * 288*5/4 + (y * 352 + x)/4];
//R
int R = (int)(Y + ( 1.4075 * (V - 128)));
//G
int G = (int)(Y - (0.3455 * (U - 128) - (0.7169 * (V - 128))));
//B
int B = (int)(Y + (1.7790 * (U - 128)));

[Matthew Heaney]

There are both DirectShow components to play WebM files, and Media
Foundation components. WMP12 can play back WebM files if either is
installed on the system.

What version of windows are you using?

What components do you have installed?

What C# interface are you using?

Are you embedding WMP in a web page? Can you send us the HTML?

If your C# interface is simply for embedding WMP, then I think it
should work. But we need more to have more specifics about your C#
code, the HTML, your operating system, and the configuration of your
machine.

-Matt

[Mike Melanson]

> After decoded .webm to .yuv file, i could display frames in picturebox
> now.
> but i have a new problem, how could i display color correctly while
> convert YUV(i420)to RGB.
> below, is my example, frame size is 352*288, i got gray color frames
> after the code...
> have someone could give me advise?

So the frames look correct, except that they're gray scale? Or are they
solid gray? If they're gray scale, that sounds like the U and V planes
were not decoded correctly. Print out the first few U & V values to
verify.

--
-Mike Melanson

[heinekenball wade]

Thanks for reply,

> What version of windows are you using?

Windows 7

> What components do you have installed?

my windows media player could play webm files out of my interface, but
if WMP embedded into interface it couldn't play webm.

> What C# interface are you using?

windows form application program.

> Are you embedding WMP in a web page?  Can you send us the HTML?

No.

> If your C# interface is simply for embedding WMP, then I think it
> should work.  But we need more to have more specifics about your C#
> code,

the standard video WMP could play, but webm couldn't.

thanks again.
ball,

[heinekenball wade]

> So the frames look correct, except that they're gray scale? Or are they
> solid gray? If they're gray scale, that sounds like the U and V planes
> were not decoded correctly. Print out the first few U & V values to
> verify.

i thought problem is i misunderstood the i420 format how the Y U V
stored.
no matter how i change U V, the color always wrong.
the same .yuv file could play correctly by vidview.exe

//U
int V = MyStreamData[352*288 + (y * 352 + x)/4];
//V
int U = MyStreamData[352 * 288*5/4 + (y * 352 + x)/4];

thanks and regards,
ball.

[heinekenball wade]

Excuse me,
if i want to transform YUV 4:2:0 to RGB
i need to transform YUV 4:2:0 to YUV 4:4:4 first,
and then transform to RGB.
or
YUV 4:2:0 could transfomr to RGB directly?

thanks,
ball.

[Attila Nagy]

you can transform directly, just have to remember that chroma is subsampled on both vertical and horizontal.

for every 2x2 Y samples you get 1 U and 1 V sample.

http://www.fourcc.org/yuv.php#IYUV

http://en.wikipedia.org/wiki/YUV#BT.709_and_BT.601

remember also that I420 is top-down scanned while display expects bottom-up.

-Atti

ball.

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