Marek Vasut
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e6d83d8f96
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jpegdec: Support libjpeg-turbo colorspace conversion
The libjpeg-turbo has a built-in support for performing colorspace
conversion. The performance of this conversion is much better than
doing the same separately using videoconvert. Implement support for
this conversion to RGBx/xRGB/BGRx/xBGR formats. Other formats can
be easily added later.
- The decoding of various pixel formats can be tested and compared to
non-libjpeg-turbo decoding as follows:
for gfmt in {RGB,BGR}{,x} x{RGB,BGR} ; do
echo "$gfmt"
gst-launch-1.0 -q \
videotestsrc pattern=colors ! \
video/x-raw,format=${gfmt} ! \
fakesink dump=true | \
head -n 200 | tail -n 1
gst-launch-1.0 -q --gst-plugin-path=build/ext/jpeg/ \
videotestsrc pattern=colors ! \
video/x-raw,format=${gfmt} ! \
jpegenc ! \
jpegdec ! \
video/x-raw,format=${gfmt} ! \
fakesink dump=true | \
head -n 200 | tail -n 1
done
Result looks as follows, i.e. comparable:
RGB
00000c70 (0x7f7736fbdd10): 05 33 19 05 33 26 05 33 33 05 33 40 05 33 4c 05 .3..3&.33.3@.3L.
00000c70 (0x7f389e8f7d10): 05 32 17 04 32 22 04 32 31 04 32 3e 04 32 4a 04 .2..2".21.2>.2J.
RGBx
00000c70 (0x7f79efd0ad10): cc 07 22 ff d9 07 22 ff e6 07 22 ff f3 07 22 ff .."..."..."...".
00000c70 (0x7fb6989f3d10): cd 06 22 00 d9 06 22 00 e6 06 22 00 f4 06 22 00 .."..."..."...".
BGR
00000c70 (0x7fa0a6c42d10): 05 0c 33 05 19 33 05 26 33 05 33 33 05 40 33 05 ..3..3.&3.33.@3.
00000c70 (0x7fc74165fd10): 05 08 32 04 17 32 04 22 32 04 31 32 04 3e 32 04 ..2..2."2.12.>2.
BGRx
00000c70 (0x7fbf399f1d10): 22 07 cc ff 22 07 d9 ff 22 07 e6 ff 22 07 f3 ff "..."..."..."...
00000c70 (0x7f50e3d1cd10): 22 06 cd 00 22 06 d9 00 22 06 e6 00 22 06 f4 00 "..."..."..."...
xRGB
00000c70 (0x7f0b950a2d10): ff cc 07 22 ff d9 07 22 ff e6 07 22 ff f3 07 22 ..."..."..."..."
00000c70 (0x7f4416b8dd10): 00 cd 06 22 00 d9 06 22 00 e6 06 22 00 f4 06 22 ..."..."..."..."
xBGR
00000c70 (0x7f237d74dd10): ff 22 07 cc ff 22 07 d9 ff 22 07 e6 ff 22 07 f3 ."..."..."..."..
00000c70 (0x7f095547dd10): 00 22 06 cd 00 22 06 d9 00 22 06 e6 00 22 06 f4 ."..."..."..."..
^^ ^^ ^^ ^^
Notice how the alpha channel is set to arbitrary value in case of the
libjpeg-turbo decoding into RGBx/BGRx/xRGB/xBGR pixel formats. This is
documented in libjpeg-turbo README.md as follows:
"
When using the RGBX, BGRX, XBGR, and XRGB colorspaces during decompression, the
X byte is undefined, and in order to ensure the best performance, libjpeg-turbo
can set that byte to whatever value it wishes.
"
- The interlaced num_fields=2 mjpeg stream can be generated and
tested as follows (this does require mjpegtools):
$ gst-launch-1.0 videotestsrc num-buffers=10 ! jpegenc ! multifilesink location=in%04d.jpg
$ jpeg2yuv -f 25 -I t -L 0 -j in%04d.jpg | yuv2lav -f avi -o result.avi
...
$ gst-launch-1.0 --gst-plugin-path=build/ext/jpeg/ filesrc location=result.avi ! \
avidemux ! jpegdec ! video/x-raw,format=RGBx ! videoconvert ! autovideosink
Signed-off-by: Marek Vasut <marex@denx.de>
Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1091>
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2021-10-07 12:40:29 +00:00 |
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