[FFmpeg-devel] [RFC] What should pixdesc.h:write_line() do with PAL formats?

[Stefano Sabatini]

Hi,

read_line() currently reads from the image the components
corresponding to c and puts them in dst:

(index, c) -> comp(index, c)

The inverse operations cannot be done, so maybe write_line() should
simply take in input a list of indexes and write them down to the
destination image, but this will not be simmetric with read_line().

To remove the asymmetry we could treat PAL formats like non-PAL ones,
so having read_line() read the indexes and writing them to dst, while
write_line() would write the indexes back to the image. 

Then we could define a new function:
read_line_pal(const uint16_t *src, uint8_t *data[4], const int linesize[4],
              const AVPixFmtDescriptor *desc, int x, int y, int c, int w);

with the current behavior as read_line().

Would this fit well?

Regards.
-- 
FFmpeg = Fierce Fast Mournful Prodigious Eretic Goblin