gstreamer/subprojects/gst-plugins-good/ext/jpeg
Marek Vasut 4ee4a9bff9 jpegdec: Factor out gst_jpeg_turbo_parse_ext_fmt_convert()
Pull out peer caps checking code into gst_jpeg_turbo_parse_ext_fmt_convert().
This code is used by libjpeg-turbo extras to determine whether peer is capable
of handling buffers into which libjpeg-turbo can directly decode data. This
kind of check must be performed before jpeg_start_decompress() is called in
gst_jpeg_dec_prepare_decode() as well as in gst_jpeg_dec_negotiate(), hence
the common code.

This commit does modify the code a little to make it easier to call from both
call sites without much duplication, hence the extra `if (*clrspc)` test.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1687>
2022-02-13 14:46:31 +01:00
..
gstjpeg.c Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstjpeg.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstjpegdec.c jpegdec: Factor out gst_jpeg_turbo_parse_ext_fmt_convert() 2022-02-13 14:46:31 +01:00
gstjpegdec.h jpegdec: Support libjpeg-turbo colorspace conversion 2021-10-07 12:40:29 +00:00
gstjpegelements.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstjpegenc.c Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstjpegenc.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstjpegplugin.c Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstsmokedec.c Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstsmokedec.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstsmokeenc.c Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
gstsmokeenc.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
meson.build Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
README Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
smokecodec.c Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
smokecodec.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00
smokeformat.h Move files from gst-plugins-good into the "subprojects/gst-plugins-good/" subdir 2021-09-24 16:13:50 -03:00

The Smoke Codec
---------------

This is a very simple compression algorithm I was toying with when doing a
Java based player. Decoding a JPEG in Java has acceptable speed so this codec
tries to exploit that feature. The algorithm first compares the last and the 
new image and finds all 16x16 blocks that have a squared difference bigger than
a configurable threshold. Then all these blocks are compressed into an NxM JPEG.
The quality of the JPEG is inversely proportional to the number of blocks, this
way, the picture quality degrades with heavy motion scenes but the bitrate stays
more or less constant.
Decoding decompresses the JPEG and then updates the old picture with the new
blocks.


TODO:
----
- make format extensible
- motion vectors
- do some real bitrate control