This patch enables paletteuse to identify the transparency in incoming
video and tag transparent pixels on outgoing video with the correct
index from the palette.
This requires tracking the transparency index in the palette,
establishing an alpha threshold below which a pixel is considered
transparent and above which the pixel is considered opaque, and
additional changes to track the alpha value throughout the conversion
process.
This change is a partial fix for https://trac.ffmpeg.org/ticket/4443
However, animated GIFs are still output incorrectly due to a bug
in gif optimization which does not correctly handle transparency.
Signed-off-by: Clément Bœsch <u@pkh.me>
AVFilterLink.frame_count is supposed to count the number of frames
that were passed on the link, but with min_samples, that number is
not always the same for the source and destination filters.
With the addition of a FIFO on the link, the difference will become
more significant.
Split the variable in two: frame_count_in counts the number of
frames that entered the link, frame_count_out counts the number
of frames that were sent to the destination filter.
Fixes crash due to unprocessed input being passed through
This fixes the last segfault caused by mixing 3.0 and 3.1 libs and
applications
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
Many of the functions from avfilter/formats can return errors, usually AVERROR(ENOMEM).
This propagates the return values.
All of these were found by using av_warn_unused_result, demonstrating its utility.
Tested with FATE. I am least sure of the changes to avfilter/filtergraph,
since I don't know what/how reduce_format is intended to behave and how it should
react to errors.
Fixes: CID 1325680, 1325679, 1325678.
Reviewed-by: Michael Niedermayer <michael@niedermayer.cc>
Previous version Reviewed-by: Nicolas George <george@nsup.org>
Previous version Reviewed-by: Clément Bœsch <u@pkh.me>
Signed-off-by: Ganesh Ajjanagadde <gajjanagadde@gmail.com>
