[FFmpeg-devel] [WIP][RFC][PATCH] avfilter: add zscale filter

[Derek Buitenhuis]

On 9/21/2015 8:22 PM, Paul B Mahol wrote:
> Signed-off-by: Paul B Mahol <onemda at gmail.com>
> ---
>  configure                |   4 +
>  libavfilter/Makefile     |   1 +
>  libavfilter/allfilters.c |   1 +
>  libavfilter/vf_zscale.c  | 546 +++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 552 insertions(+)
>  create mode 100644 libavfilter/vf_zscale.c

Author of zimg took a look at the patch on IRC, so I am forwarding
his comments here:

[20:31] < wm4> http://ffmpeg.org/pipermail/ffmpeg-devel/2015-September/179287.html
[20:32] < zimg_author> this is going to break when I rename zimg3.h to zimg.h
[20:32] < zimg_author> and possibly remove the 2 prefixes from the functions

[... snip ...]

[20:34] < zimg_author> also, if convert_trc and convert_primaries convert two different unknown formats to ZIMG_XXX_UNSPECIFIED
[20:34] < zimg_author> the wrong thing will happen (should cause an exception, but will result in a bad conversion)
[20:35] < zimg_author> or actually, he traps the matrix to MATRIX_UNSPECIFIED when it's YUV
[20:35] < zimg_author> how could this ever work?
[20:36] < zimg_author> also, of course the performance is terrible if you call graph_build on every frame
[20:36] < zimg_author> (creating a resizer takes like 3-4 resize frames)
[20:36] < wm4> you should tell him that

Comments are his, not mine; I am merely forwarding them.

- Derek