d3d11h264dec: Keep track of actually configured DPB size

... instead of the largest we ever seen.
Note that d3d11h264dec element holds previously configured DPB size
for later decoder object re-open decision.

This is to fix below case:
1) Initial SPS, required DPB size is 6
  - decoder object is opened with DPB size 6
  - max_dpb_size is now 6
2) SPS update with resolution change, required DPB size is 1
  - decoder object is re-opened with DPB size 1
  - max_dpb_size should be updated to 1, but it didn't happen (BUG)
3) SPS update without resolution change, only required DPB size is updated to 6
  - decoder object should be re-opened but didn't happen
    because we didn't update max_dpb_size at 2).

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-bad/-/merge_requests/2056>

1 files changed, 6 insertions, 1 deletions

diff --git a/sys/d3d11/gstd3d11h264dec.c b/sys/d3d11/gstd3d11h264dec.c
index 104a5f13d..138dcbec0 100644
--- a/sys/d3d11/gstd3d11h264dec.c
+++ b/sys/d3d11/gstd3d11h264dec.c
@@ -470,7 +470,6 @@ gst_d3d11_h264_dec_new_sequence (GstH264Decoder * decoder,
   if (self->max_dpb_size < max_dpb_size) {
     GST_INFO_OBJECT (self, "Requires larger DPB size (%d -> %d)",
         self->max_dpb_size, max_dpb_size);
-    self->max_dpb_size = max_dpb_size;
     modified = TRUE;
   }
 
@@ -501,6 +500,12 @@ gst_d3d11_h264_dec_new_sequence (GstH264Decoder * decoder,
     gst_video_info_set_format (&info,
         self->out_format, self->width, self->height);
 
+    /* Store configured DPB size here. Then, it will be referenced later
+     * to decide whether we need to re-open decoder object or not.
+     * For instance, if every configuration is same apart from DPB size and
+     * new DPB size is decreased, we can reuse existing decoder object.
+     */
+    self->max_dpb_size = max_dpb_size;
     gst_d3d11_decoder_reset (self->d3d11_decoder);
     if (!gst_d3d11_decoder_open (self->d3d11_decoder, GST_D3D11_CODEC_H264,
             &info, self->coded_width, self->coded_height,