Black isn't always just memset(ptr, 0, size). Limited YUV in particular
requires relatively non-obvious values, and filling a frame with
repeating 0 bytes is disallowed in some contexts. With component sizes
larger than 8 or packed YUV, this can become relatively complicated. So
having a generic function for this seems helpful.
In order to handle the complex cases in a generic way without destroying
performance, this code attempts to compute a black pixel, and then uses
that value to clear the image data quickly by using a function like
memset.
Common cases like yuv410p10 or rgba can't be handled with a simple
memset, so there is some code to fill memory with 2/4/8 byte patterns.
For the remaining cases, a generic slow fallback is used.
Signed-off-by: Anton Khirnov <anton@khirnov.net>
Move the lavc/imgconvert functions and rename them as follows:
avpicture_get_size -> av_image_get_buffer_size()
avpicture_fill -> av_image_fill_arrays()
avpicture_layout -> av_image_copy_to_buffer()
The new functions have an align parameter, which allows to define the
linesize alignment assumed in the buffer (which is set or read).
The names of the functions are consistent with the lavu/samples API
(av_samples_get_buffer_size(), av_samples_fill_arrays()).
A redundant check has been dropped from av_image_fill_arrays().
Signed-off-by: Vittorio Giovara <vittorio.giovara@gmail.com>
It is pretty hopeless that other considerable projects will adopt
libavutil alone in other projects. Projects that need small footprint
are better off with more specialized libraries such as gnulib or rather
just copy the necessary parts that they need. With this in mind, nobody
is helped by having libavutil and libavcore split. In order to ease
maintenance inside and around FFmpeg and to reduce confusion where to
put common code, avcore's functionality is merged (back) to avutil.
Signed-off-by: Reinhard Tartler <siretart@tauware.de>
