compositor-drm: Add hardware accelerated capture of screen using libva

Graphics / Wayland / Weston - Ander Conselvan de Oliveira [intel.com] - 30 August 2013 15:44 UTC

This patch adds a feature to the DRM backend that uses libva for encoding the screen contents in H.264. Screen recording can be activated by pressing mod-shift-space q. A file named capture.h264 will be created in the current directory, which can be muxed into an MP4 file with gstreamer using

gst-launch filesrc location=capture.h264 ! h264parse ! mp4mux ! \ filesink location=file.mp4

This is limitted to the DRM compositor in order to avoid a copy when submitting the front buffer to libva. The code in vaapi-recorder.c takes a dma_buf fd referencing it, does a colorspace conversion using the video post processing pipeline and then uses that as input to the encoder.

I'm sending this now so I get comments, but this is not ready for prime time yet. I have a somewhat consistent GPU hang when using i915 with SandyBridge. Sometimes a page flip never completes. If you want to try this anyway and your system get stuck, you might need to run the following:

# echo 1 > /sys/kernel/debug/dri/0/i915_wedged

After that, alt-sysrq [rv] should work.

Once that's fixed it would also be good to make the parameters used by the encoder more flexible. For now the QP parameter is hardcoded to 0 and we have only I and P frames (no B frames), which causes the resulting files to be very large.

6aae4d3 compositor-drm: Add hardware accelerated capture of screen using libva
configure.ac | 6 +
src/Makefile.am | 6 +
src/compositor-drm.c | 109 ++++++
src/vaapi-recorder.c | 1062 ++++++++++++++++++++++++++++++++++++++++++++++++++
src/vaapi-recorder.h | 35 ++
5 files changed, 1218 insertions(+)

Upstream: cgit.freedesktop.org

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