Video, colour format

[runningbug]

Hi,

I am trying to get video playback working in DirectX9 using the libtheoraplayer.

The video is playing fine (performance is fantastic), except the colours are all wrong!

I am loading the video clip with the theora output mode set to TH_XRGB. I therefore create a texture to paste this data to in DirectX with the flag D3DFMT_X8R8G8B8 specified.

So I am assuming that TheoraPLayback lib will provide me with data: 4 bytes per pixel, the first byte we don't care about, then then Red, then the Green then the Blue.

However, when I playback I get a weird colour effect, as though the pixel values I have been returned are wrong:

http://www.dropbox.com/s/4m754e8124luswz/libtheoraplayer.jpg

Here is the code I am using to draw to the texture's surface: (texture of the format D3DFMT_X8R8G8B8)

WritePixelData(unsigned char pixelData, int dataWidth, int dataHeight)
{
D3DLOCKED_RECT lockedRect;
IDirect3DSurface9 surface;
_texture->GetSurfaceLevel(0, &surface);

surface->LockRect(&lockedRect, 0, D3DLOCK_DISCARD);

unsigned char *dst = (unsigned char*)lockedRect.pBits;

for (int y = 0; y < dataHeight; y++)
{
    memcpy(dst, pixelData, dataWidth * 4);

    dst += lockedRect.Pitch;
    pixelData += (dataWidth*4);
}

surface->UnlockRect();
surface->Release();

}

I have obviously got the widths/strides etc correct as the video fills the texture exactly, but it seems the pixel colour information is wrong?

Can anybody see if I am doing it wrong, or confirm that they have got video working with the same theora output mode and DirectX texture format I am trying to use?

Thanks for any help!

[Krešimir Špes]

Hi,

just try using TH_XBGR, that's what I use in my projects on dx9. dx9 has some weird texture byte ordering...

[runningbug]

Hi kspes,

Thanks for the quick reply!

I have tried to use TH_XBGR... my gfx card does not support D3DFMT_X8B8G8R8, only D3DFMT_A8R8G8B8 and D3DFMT_X8R8G8B8. So as a test I manually twizzled the colour values given from frame->getBuffer() like this just to see if that gave me the correctly coloured image:

for (int y = 0; y < dataHeight; y++)
{
unsigned char* toTwizzle = pixelData;

    for (int i = 0; i < dataWidth; i++)
    {
        unsigned char temp = toTwizzle[1];
        toTwizzle[1] = toTwizzle[3];
        toTwizzle[3] = temp;

        toTwizzle += 4;
    }

    memcpy(dst, pixelData, dataWidth * 4);

    dst += pitchInBytes;
    pixelData += (dataWidth*4);
}

But the colours are still wrong...

The performance of the playback is fantastic, (hardly dents my FPS counter at all!). So I would really like to get it going... do you have any other ideas?

Cheers for any help!

[runningbug]

Hi,

I have sorted this. It was a problem my end... I was using TH_XRGB when I meant to use TH_BGRX!

Thanks for your help.

[Krešimir Špes]

oh yeah, that one :) that's why I made all those supported formats :)

And yeah, part of why this library is so useful is because the video decoding is done in separate threads thus not incurring a noticeable penalty on your main thread's FPS. you will notice a speed decrease if you use a lot of videos (or large videos) or are on a single core CPU.