vo_opengl: add direct rendering support

Can be enabled via --vd-lavc-dr=yes. See manpage additions for what it
does.

This reminds of the MPlayer -dr flag, but the implementation is
completely different. It's the same basic concept: letting the decoder
render into a GPU buffer to avoid a copy. Unlike MPlayer, this doesn't
try to go through filters (libavfilter doesn't support this anyway).
Unless a filter can work in-place, DR will be silently disabled. MPlayer
had very complex semantics about buffer types and management (which
apparently nobody ever understood) and weird restrictions that mostly
limited it to mpeg2 style codecs. The mpv code does not do any of this,
and just lets the decoder allocate an arbitrary number of untyped
images. (No MPlayer code was used.)

Parts of the code based on work by atomnuker (starting point for the
generic code) and haasn (some GL definitions, some basic PBO code, and
correct fencing).

1 files changed, 1 insertions, 0 deletions

diff --git a/video/decode/dec_video.h b/video/decode/dec_video.h
index 261f47fca8..73570f8ed5 100644
--- a/video/decode/dec_video.h
+++ b/video/decode/dec_video.h
@@ -37,6 +37,7 @@ struct dec_video {
     struct mp_hwdec_devices *hwdec_devs; // video output hwdec handles
     struct sh_stream *header;
     struct mp_codec_params *codec;
+    struct vo *vo; // required for direct rendering into video memory
 
     char *decoder_desc;