Re: Gray scale video output from theora

thanks very much for your help

So I already tried to remove the U & V components from the stream..

But unfortunately I was unable to do it successfully

*what I did is.......*

Changed some code segments in theora_encode_YUVin() which is in
theencoder_toplevel.c


  for ( i = 0; i < yuv->uv_height; i++ ){
    memcpy( LocalDataPtr, InputDataPtr, yuv->uv_width );
    LocalDataPtr -= yuv->uv_width;
    InputDataPtr += yuv->uv_stride;
  }


the above code segment is use to copy the U data into the LocalDataPtr

So i just avoid this input U component (copy the value zero into the
LocalDataPtr
) as follow

int temp = 0;
  for ( i = 0; i < yuv->uv_height; i++ ){
    memset( LocalDataPtr, &temp, yuv->uv_width );
    LocalDataPtr -= yuv->uv_width;
    InputDataPtr += yuv->uv_stride;
  }

The same thing was done for the V component also

But the result was differ from my expectations and at the same time the
result was differ from each other when I get encoded the same stream at
different time.

These videos looks like it is lay over a colored mist on top of the video.

I have attached two snapshots of the resulted video and the original video.


*Please can I know that *

what I have done is correct or not...?

if this way is not the correct way, please help me to do this...



On Feb 17, 2008 12:32 AM, Ralph Giles <[email protected]> wrote:

> On 16-Feb-08, at 5:33 AM, janaka priyadarshana wrote:
>
> *If the above is true.....(*theora use YUV color space*)*
>
>
> Yes, Theora always encodes video in a YUV colour space.
>
> it is possible that get a gray scale video output by just considering only
> the Y component of the video (ignore the U and V components)
>
>
> Using just the Y plane is a reasonable way to convert a YUV image to a
> monochrome one.
>
>  -r
>
>


-- 
-----------
Regards,
Janaka Priyadarshana

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