[FFmpeg-devel] [PATCH] lavfi: add xbr filter

Clément Bœsch u at pkh.me
Sun Oct 26 20:10:35 CET 2014

On Mon, Oct 27, 2014 at 12:28:35AM +0530, arwa arif wrote:
> 1. I think I understood what is giving you segmentation fault. The mask
> that I am creating is going out of bounds for the boundary pixels. I will
> try to fix it. But, I am curious why is it working on my laptop?

> 2. Thank you Clement for the mode part. It made the code look smaller.
> Also, I chose numbers instead of alphabets because I was initially
> accessing the required values by considering the numbers as indices of  a
> matrix. If you want, I  can convert it to alphabets instead.

It might be easier for maintaining and understanding the code since that's
the convention of the specifications

> 3. I think 4x can be done fast enough, but 3x will take time.

Yeah, likely like hqx, right.

> 4. I tried reading the hqx code, I am not very sure with what they have
> done in init part. It will be grateful if you can maybe explain the
> algorithm or maybe provide me with a link which explicitly explains it.

In the init() callback the rgb2yuv map (which you can find in the local
context) is initialized. Then you have the function rgb2yuv() to do the
convert, which takes in argument that map and the rgb24 color to lookup


Clément B.
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