avfilter: add QSV variants of the stack filters

Include hstack_qsv, vstack_qsv and xstack_qsv. They may accept input
streams with different sizes.

Examples:
$ ffmpeg -hwaccel qsv -hwaccel_output_format qsv -i input.mp4 \
-filter_complex "[0:v][0:v]hstack_qsv" -f null -

$ ffmpeg \
-hwaccel qsv -hwaccel_output_format qsv -i input.mp4 \
-hwaccel qsv -hwaccel_output_format qsv -i input.mp4 \
-hwaccel qsv -hwaccel_output_format qsv -i input.mp4 \
-hwaccel qsv -hwaccel_output_format qsv -i input.mp4 \
-filter_complex "[0:v][1:v][2:v][3:v]xstack_qsv=inputs=4:fill=0x000000:layout=0_0_1920x1080|w0_0_1920x1080|0_h0_1920x1080|w0_h0_1920x1080" \
-f null -

Signed-off-by: Haihao Xiang <haihao.xiang@intel.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/Changelog b/Changelog
index d15acbe678..0644f39d59 100644
--- a/Changelog
+++ b/Changelog
@@ -44,6 +44,7 @@ version <next>:
 - RKA decoder and demuxer
 - filtergraph syntax in ffmpeg CLI now supports passing file contents
   as option values, by prefixing option name with '/'
+- hstack_qsv, vstack_qsv and xstack_qsv filters
 
 
 version 5.1: