ffmpeg/libavdevice
Andriy Gelman 8e0a4d2d4d avdevice/xcbgrab: don't assume xserver endianness
xserver defines the endianness of the grabbed images. Use this information
to set the correct pixel format.

This also fixes format selection in configuration depth=32/bpp=32 with
xserver on a little endian machine. Before the patch, the big endian
layout 0RGB was always selected which is incorrect because BGR0 should
be used. RGB24 was also incorrectly assumed (but this format was removed
in xserver 1.20).

The big-endian settings can be tested using docker+qemu from a little-endian
machine:

$ docker run --rm --privileged multiarch/qemu-user-static --reset -p yes
$ docker run --rm -it -v /tmp:/tmp powerpc64/debian /bin/bash

In docker container
$ apt-get update
$ apt-get install xvfb
$ apt-get install x11-apps

To test AV_PIX_FMT_0RGB32
$ Xvfb :2 -screen 0 720x480x24 &
$ export DISPLAY=:2
$ xclock -geometry 720x480 -bg green #test different colors

On your host machine grab the frames using the following
command. View output to check that colors are rendered correctly
$ ./ffmpeg -y -f x11grab -i :2.0 -codec:v mpeg2video out.mp4

Other pixel formats can be tested by modifying how Xvfb is started in the docker
container:

AV_PIX_FMT_RGB565
$ Xvfb :2 -screen 0 720x480x16

AV_PIX_FMT_RGB555
$ Xvfb :2 -screen 0 720x480x15

AV_PIX_FMT_BGR24 / AV_PIX_FMT_RGB24
This is difficult to test because bpp=24 support was removed in xserver 1.20
https://lists.x.org/archives/xorg-devel/2018-February/056175.html?hmsr=joyk.com&utm_source=joyk.com&utm_medium=referral
However, I was able to run previous version of Xvfb (with some
modifications to force 24bpp) to check that images are rendered correctly.

Reviewed-by: Carl Eugen Hoyos <ceffmpeg@gmail.com>
Signed-off-by: Andriy Gelman <andriy.gelman@gmail.com>
2021-02-06 11:42:12 -05:00
..
tests
.gitignore
Makefile
alldevices.c avdevice/alldevices: stop using deprecated linked list API 2020-10-19 11:54:45 -03:00
alsa.c
alsa.h
alsa_dec.c
alsa_enc.c
android_camera.c
audiotoolbox.m
avdevice.c avdevice/alldevices: stop using deprecated linked list API 2020-10-19 11:54:45 -03:00
avdevice.h
avdeviceres.rc
avfoundation.m
bktr.c
caca.c lavd/caca: do not access deprecated codec context 2020-12-10 09:45:19 +01:00
decklink_common.cpp avdevice/decklink: warn about too old decklink API version 2020-12-03 18:32:57 +01:00
decklink_common.h avdevice/decklink_enc: simplify usage of buffercount type 2020-12-03 18:32:57 +01:00
decklink_common_c.h avdevice/decklink_dec: add support for querying RP188 High Frame Rate timecode 2020-09-13 18:06:54 +02:00
decklink_dec.cpp avdevice/decklink_dec: mark get_frame_timecode and get_bmd_timecode static 2021-01-09 17:37:02 +01:00
decklink_dec.h
decklink_dec_c.c avdevice/decklink: remove the duplicated warning message 2020-12-05 09:00:53 +08:00
decklink_enc.cpp avdevice/decklink: remove the duplicated warning message 2020-12-05 09:00:53 +08:00
decklink_enc.h
decklink_enc_c.c avdevice/decklink: remove the duplicated warning message 2020-12-05 09:00:53 +08:00
dshow.c avdevice/dshow: Add namespace prefix to the remaining global symbols 2021-01-25 19:31:11 -03:00
dshow_capture.h avdevice/dshow: Add namespace prefix to the remaining global symbols 2021-01-25 19:31:11 -03:00
dshow_common.c
dshow_crossbar.c lavd/dshow: Add namespace prefix to global functions 2021-01-21 20:02:23 -03:00
dshow_enummediatypes.c avdevice/dshow: Add namespace prefix to the remaining global symbols 2021-01-25 19:31:11 -03:00
dshow_enumpins.c avdevice/dshow: Add namespace prefix to the remaining global symbols 2021-01-25 19:31:11 -03:00
dshow_filter.c avdevice/dshow: Add namespace prefix to the remaining global symbols 2021-01-25 19:31:11 -03:00
dshow_pin.c avdevice/dshow: Add namespace prefix to the remaining global symbols 2021-01-25 19:31:11 -03:00
fbdev_common.c
fbdev_common.h
fbdev_dec.c
fbdev_enc.c
file_open.c
gdigrab.c
iec61883.c
internal.h
jack.c
kmsgrab.c kmsgrab: Do not require the modifier to stay constant. 2021-01-13 23:08:02 +00:00
lavfi.c avdevice/lavfi: av_malloc -> av_malloc_array 2020-09-21 09:30:55 +08:00
libavdevice.v
libcdio.c
libdc1394.c
openal-dec.c
opengl_enc.c
opengl_enc_shaders.h
oss.c
oss.h
oss_dec.c
oss_enc.c
pulse_audio_common.c
pulse_audio_common.h
pulse_audio_dec.c
pulse_audio_enc.c
reverse.c
sdl2.c
sndio.c
sndio.h
sndio_dec.c
sndio_enc.c
timefilter.c
timefilter.h
utils.c
v4l2-common.c
v4l2-common.h
v4l2.c
v4l2enc.c
version.h avdevice/decklink_dec: map the raw_format instead of hardcode 2020-11-21 09:14:52 +08:00
vfwcap.c
xcbgrab.c avdevice/xcbgrab: don't assume xserver endianness 2021-02-06 11:42:12 -05:00
xv.c