WebGL fallback

[ssleptsov]

Hi,
Is this correct that webGL need here only to convert YUV image to rgb, right?
So is it possible to convert it to rgb without webGL, by this it will be possible to draw image in 2D canvas, right?

Thanks.

    this.webGLCanvas.YTexture.fill(buffer.subarray(0, lumaSize));
    this.webGLCanvas.UTexture.fill(buffer.subarray(lumaSize, lumaSize + chromaSize));
    this.webGLCanvas.VTexture.fill(buffer.subarray(lumaSize + chromaSize, lumaSize + 2 * chromaSize));
    this.webGLCanvas.drawScene();

[mbebenita]

Yeah, WebGL is not needed. You can do the conversion in Canvas2D and use putImageData()

[ssleptsov]

Any suggestion why I fail with conversion YUV(i420) to rgb and draw? I all the time get white canvas. Here is my post in stackoverflow http://stackoverflow.com/questions/21264648/javascript-convert-yuv-to-rgb
Thanks.

[mbebenita]

Here is some code that performs the conversion:

https://github.com/mbebenita/Broadway/blob/master/Decoder/paint_2.js

[ssleptsov]

Thanks, last question is how to get Luma,cb,cr arrays from one array? any examples, can't find here?

[mbebenita]

Well in the code above, the luma, cb, cr arrays are allocated somewhere on the emscripten heap, and passed in as pointer arguments.

[ssleptsov]

Hm..but how $cb and $cr can be arrays if then they have
u = HEAPU8[$cr++];
v = HEAPU8[$cb++];
or I miss something?

[mbebenita]

There's really only one large array, HEAPU8 that represents the entire emscripten heap. $cr and cb are integer offsets into that array that point to logical arrays (allocated by the C code using malloc).

[soliton4]

@ssleptsov
@mbebenita
#44

[soliton4]

webgl auto detection and fallback solution works:
http://mbebenita.github.io/Broadway/storyDemo.html

@ssleptsov

[soliton4]

@ssleptsov hasnt been active for month