The existing code attempts to clear the frame by painting in OVER
mode with transparent black - which is a no-op. As a result if you
have many input frames (e.g. you're using a sequence of svg files),
you'll start to see new frames drawn over old frames as memory gets
re-used.
Switch the code to paint using the CLEAR compositing operator,
which fills every channel with 0 values (setting a source colour
is not required).
Explicitly identify decoder/encoder wrappers with a common name. This
saves API users from guessing by the name suffix. For example, they
don't have to guess that "h264_qsv" is the h264 QSV implementation, and
instead they can just check the AVCodec .codec and .wrapper_name fields.
Explicitly mark AVCodec entries that are hardware decoders or most
likely hardware decoders with new AV_CODEC_CAPs. The purpose is allowing
API users listing hardware decoders in a more generic way. The proposed
AVCodecHWConfig does not provide this information fully, because it's
concerned with decoder configuration, not information about the fact
whether the hardware is used or not.
AV_CODEC_CAP_HYBRID exists specifically for QSV, which can have software
implementations in case the hardware is not capable.
Based on a patch by Philip Langdale <philipl@overt.org>.
Merges Libav commit 47687a2f8a.
Enables rendering of SVG images. This is possible since SVG images
still contain and specify the dimensions in pixels to which they've
been drawn to and thus enable browsers to display them without any
external data. Users can still override and generate images with
arbitrary resolutions.
Signed-off-by: Rostislav Pehlivanov <atomnuker@gmail.com>
