[FFmpeg-devel] [PATCH] Try to make new VDPAU usable by adding context to callback.

[Reimar Döffinger]

Using VDPAU correctly means checking for preemption
and possibly regenerating the context all the time.
With the current API there is no context or other
user-defined pointer and thus this in not possible
unless using some hack like global variables.
This introduces a new decode function that gets
both the AVCodecContext and AVFrame in addition,
in both the user can store additional opaque data.
Unfortunately the HWAccel API has no way of providing
API/ABI compatibility, so a currently disallowed
state (render pointer being NULL) is used to extend it.
An alloc function is added as well to ease future extensions.

Signed-off-by: Reimar Döffinger <Reimar.Doeffinger at gmx.de>
---
 libavcodec/vdpau.c      | 14 +++++++++++++-
 libavcodec/vdpau.h      | 12 ++++++++++++
 libavcodec/vdpau_h264.c |  7 ++++++-
 3 files changed, 31 insertions(+), 2 deletions(-)

diff --git a/libavcodec/vdpau.c b/libavcodec/vdpau.c
index cf564a5..27cc3a3 100644
--- a/libavcodec/vdpau.c
+++ b/libavcodec/vdpau.c
@@ -38,6 +38,13 @@
  * @{
  */
 
+AVVDPAUContext *av_alloc_vdpau_hwaccel(void)
+{
+    return av_mallocz(sizeof(AVVDPAUContext));
+}
+
+MAKE_ACCESSORS(AVVDPAUContext, vdpau_hwaccel, AVVDPAU_Render2, render2)
+
 int ff_vdpau_common_start_frame(Picture *pic,
                                 av_unused const uint8_t *buffer,
                                 av_unused uint32_t size)
@@ -55,19 +62,24 @@ int ff_vdpau_common_start_frame(Picture *pic,
     CONFIG_VC1_VDPAU_HWACCEL   || CONFIG_WMV3_VDPAU_HWACCEL
 int ff_vdpau_mpeg_end_frame(AVCodecContext *avctx)
 {
+    int res = 0;
     AVVDPAUContext *hwctx = avctx->hwaccel_context;
     MpegEncContext *s = avctx->priv_data;
     Picture *pic = s->current_picture_ptr;
     struct vdpau_picture_context *pic_ctx = pic->hwaccel_picture_private;
     VdpVideoSurface surf = ff_vdpau_get_surface_id(pic);
 
+    if (!hwctx->render) {
+        res = hwctx->render2(avctx, &pic->f, (void *)&pic_ctx->info,
+                             pic_ctx->bitstream_buffers_used, pic_ctx->bitstream_buffers);
+    } else
     hwctx->render(hwctx->decoder, surf, (void *)&pic_ctx->info,
                   pic_ctx->bitstream_buffers_used, pic_ctx->bitstream_buffers);
 
     ff_mpeg_draw_horiz_band(s, 0, s->avctx->height);
     av_freep(&pic_ctx->bitstream_buffers);
 
-    return 0;
+    return res;
 }
 #endif
 
diff --git a/libavcodec/vdpau.h b/libavcodec/vdpau.h
index 08116bf..8d89037 100644
--- a/libavcodec/vdpau.h
+++ b/libavcodec/vdpau.h
@@ -70,6 +70,13 @@ union AVVDPAUPictureInfo {
 };
 #endif
 
+struct AVCodecContext;
+struct AVFrame;
+
+typedef int (*AVVDPAU_Render2)(struct AVCodecContext *, struct AVFrame *,
+                               const VdpPictureInfo *, uint32_t,
+                               const VdpBitstreamBuffer *);
+
 /**
  * This structure is used to share data between the libavcodec library and
  * the client video application.
@@ -128,8 +135,13 @@ typedef struct AVVDPAUContext {
     attribute_deprecated
     VdpBitstreamBuffer *bitstream_buffers;
 #endif
+    AVVDPAU_Render2 render2;
 } AVVDPAUContext;
 
+AVVDPAUContext *av_alloc_vdpau_hwaccel(void);
+AVVDPAU_Render2 av_vdpau_hwaccel_get_render2(const AVVDPAUContext *);
+void av_vdpau_hwaccel_set_render2(AVVDPAUContext *, AVVDPAU_Render2);
+
 #if FF_API_CAP_VDPAU
 /** @brief The videoSurface is used for rendering. */
 #define FF_VDPAU_STATE_USED_FOR_RENDER 1
diff --git a/libavcodec/vdpau_h264.c b/libavcodec/vdpau_h264.c
index 06a9582..3f6415d 100644
--- a/libavcodec/vdpau_h264.c
+++ b/libavcodec/vdpau_h264.c
@@ -188,19 +188,24 @@ static int vdpau_h264_decode_slice(AVCodecContext *avctx,
 
 static int vdpau_h264_end_frame(AVCodecContext *avctx)
 {
+    int res = 0;
     AVVDPAUContext *hwctx = avctx->hwaccel_context;
     H264Context *h = avctx->priv_data;
     Picture *pic   = h->cur_pic_ptr;
     struct vdpau_picture_context *pic_ctx = pic->hwaccel_picture_private;
     VdpVideoSurface surf = ff_vdpau_get_surface_id(pic);
 
+    if (!hwctx->render) {
+        res = hwctx->render2(avctx, &pic->f, (void *)&pic_ctx->info,
+                             pic_ctx->bitstream_buffers_used, pic_ctx->bitstream_buffers);
+    } else
     hwctx->render(hwctx->decoder, surf, (void *)&pic_ctx->info,
                   pic_ctx->bitstream_buffers_used, pic_ctx->bitstream_buffers);
 
     ff_h264_draw_horiz_band(h, 0, h->avctx->height);
     av_freep(&pic_ctx->bitstream_buffers);
 
-    return 0;
+    return res;
 }
 
 AVHWAccel ff_h264_vdpau_hwaccel = {
-- 
1.8.3.2