vah264enc: Avoid mapping coded buffer twice.

Currently for copying the coded buffer onto a GStreamer buffer, the
coded buffer is mapped two times: one for getting the size, and later
for do the actual copy. We can avoid this by doing directly in the
element rather than in the general encoder object.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/1845>

subprojects/gst-plugins-bad/sys/va/gstvaencoder.c

@@ -1114,90 +1114,6 @@ gst_va_encode_picture_get_raw_surface (GstVaEncodePicture * pic)
   return gst_va_buffer_get_surface (pic->raw_buffer);
 }
 
-gint
-gst_va_encode_picture_get_coded_size (GstVaEncodePicture * pic)
-{
-  VADisplay dpy;
-  VACodedBufferSegment *segment_list;
-  VACodedBufferSegment *segment;
-  VAStatus status;
-  gint size;
-
-  g_return_val_if_fail (pic, -1);
-  g_return_val_if_fail (pic->coded_buffer != VA_INVALID_ID, -1);
-
-  dpy = gst_va_display_get_va_dpy (pic->display);
-
-  status = vaMapBuffer (dpy, pic->coded_buffer, (gpointer *) & segment_list);
-  if (status != VA_STATUS_SUCCESS) {
-    GST_WARNING ("coded buffer vaMapBuffer: %s", vaErrorStr (status));
-    return -1;
-  }
-
-  if (!segment_list) {
-    GST_WARNING ("coded buffer has no segment list");
-    return -1;
-  }
-
-  size = 0;
-  for (segment = segment_list; segment != NULL; segment = segment->next)
-    size += segment->size;
-
-  status = vaUnmapBuffer (dpy, pic->coded_buffer);
-  if (status != VA_STATUS_SUCCESS) {
-    GST_WARNING ("coded buffer vaUnmapBuffer: %s", vaErrorStr (status));
-    return -1;
-  }
-
-  return size;
-}
-
-gboolean
-gst_va_encode_picture_copy_coded_data (GstVaEncodePicture * pic,
-    GstBuffer * dest)
-{
-  VADisplay dpy;
-  VACodedBufferSegment *segment_list;
-  VACodedBufferSegment *segment;
-  VAStatus status;
-  goffset offset;
-  gsize size;
-
-  g_return_val_if_fail (pic, FALSE);
-  g_return_val_if_fail (dest && GST_IS_BUFFER (dest), FALSE);
-  g_return_val_if_fail (pic->coded_buffer != VA_INVALID_ID, FALSE);
-
-  dpy = gst_va_display_get_va_dpy (pic->display);
-
-  status = vaMapBuffer (dpy, pic->coded_buffer, (gpointer *) & segment_list);
-  if (status != VA_STATUS_SUCCESS) {
-    GST_WARNING ("coded buffer vaMapBuffer: %s", vaErrorStr (status));
-    return FALSE;
-  }
-
-  if (!segment_list) {
-    GST_WARNING ("coded buffer has no segment list");
-    return FALSE;
-  }
-
-  offset = 0;
-  for (segment = segment_list; segment != NULL; segment = segment->next) {
-    size = gst_buffer_fill (dest, offset, segment->buf, segment->size);
-    if (size != segment->size) {
-      GST_WARNING ("Segment size is %d, but copied %" G_GSIZE_FORMAT,
-          segment->size, size);
-      break;
-    }
-    offset += segment->size;
-  }
-
-  status = vaUnmapBuffer (dpy, pic->coded_buffer);
-  if (status != VA_STATUS_SUCCESS)
-    GST_WARNING ("coded buffer vaUnmapBuffer: %s", vaErrorStr (status));
-
-  return TRUE;
-}
-
 GstVaEncodePicture *
 gst_va_encode_picture_new (GstVaEncoder * self, GstBuffer * raw_buffer)
 {

subprojects/gst-plugins-bad/sys/va/gstvaencoder.h

@@ -107,8 +107,5 @@ GstVaEncodePicture *  gst_va_encode_picture_new           (GstVaEncoder * self,
 void                  gst_va_encode_picture_free          (GstVaEncodePicture * pic);
 VASurfaceID           gst_va_encode_picture_get_raw_surface (GstVaEncodePicture * pic);
 VASurfaceID           gst_va_encode_picture_get_reconstruct_surface (GstVaEncodePicture * pic);
-gint                  gst_va_encode_picture_get_coded_size (GstVaEncodePicture * pic);
-gboolean              gst_va_encode_picture_copy_coded_data (GstVaEncodePicture * pic,
-                                                             GstBuffer * dest);
 
 G_END_DECLS

subprojects/gst-plugins-bad/sys/va/gstvah264enc.c

@@ -3211,27 +3211,43 @@ _push_buffer_to_downstream (GstVaH264Enc * self, GstVaH264EncFrame * frame_enc)
 {
   GstVideoCodecFrame *frame;
   GstFlowReturn ret;
-  gint coded_size;
+  guint coded_size;
-  GstBuffer *buf = NULL;
+  goffset offset;
+  GstBuffer *buf;
+  VADisplay dpy;
   VASurfaceID surface;
-  VADisplay dpy = gst_va_display_get_va_dpy (self->display);
   VAStatus status;
+  VACodedBufferSegment *seg, *seg_list;
 
   frame = frame_enc->frame;
 
+  dpy = gst_va_display_get_va_dpy (self->display);
+
+  /* Wait for encoding to finish */
   surface = gst_va_encode_picture_get_raw_surface (frame_enc->picture);
   status = vaSyncSurface (dpy, surface);
   if (status != VA_STATUS_SUCCESS) {
-    GST_WARNING ("vaSyncSurface: %s", vaErrorStr (status));
+    GST_WARNING_OBJECT (self, "vaSyncSurface: %s", vaErrorStr (status));
     goto error;
   }
 
-  coded_size = gst_va_encode_picture_get_coded_size (frame_enc->picture);
+  seg_list = NULL;
-  if (coded_size <= 0) {
+  status = vaMapBuffer (dpy, frame_enc->picture->coded_buffer,
-    GST_ERROR_OBJECT (self, "Failed to get the coded size,");
+      (gpointer *) & seg_list);
+  if (status != VA_STATUS_SUCCESS) {
+    GST_WARNING_OBJECT (self, "vaMapBuffer: %s", vaErrorStr (status));
     goto error;
   }
 
+  if (!seg_list) {
+    GST_WARNING_OBJECT (self, "coded buffer has no segment list");
+    goto error;
+  }
+
+  coded_size = 0;
+  for (seg = seg_list; seg; seg = seg->next)
+    coded_size += seg->size;
+
   buf = gst_video_encoder_allocate_output_buffer (GST_VIDEO_ENCODER_CAST (self),
       coded_size);
   if (!buf) {
@@ -3240,12 +3256,23 @@ _push_buffer_to_downstream (GstVaH264Enc * self, GstVaH264EncFrame * frame_enc)
     goto error;
   }
 
-  if (!gst_va_encode_picture_copy_coded_data (frame_enc->picture, buf)) {
+  offset = 0;
-    GST_ERROR_OBJECT (self, "Failed to copy output buffer, size %d",
+  for (seg = seg_list; seg; seg = seg->next) {
-        coded_size);
+    gsize write_size;
-    goto error;
+
+    write_size = gst_buffer_fill (buf, offset, seg->buf, seg->size);
+    if (write_size != seg->size) {
+      GST_WARNING_OBJECT (self, "Segment size is %d, but copied %"
+          G_GSIZE_FORMAT, seg->size, write_size);
+      break;
+    }
+    offset += seg->size;
   }
 
+  status = vaUnmapBuffer (dpy, frame_enc->picture->coded_buffer);
+  if (status != VA_STATUS_SUCCESS)
+    GST_WARNING ("vaUnmapBuffer: %s", vaErrorStr (status));
+
   frame->pts =
       self->start_pts + self->frame_duration * frame_enc->total_frame_count;
   /* The PTS should always be later than the DTS. */