v4l2codecs: vp9: Allow inter-frames resolution change

When the stream resolution change it is needed to negotiate
a new pools and to update the caps.
Resolution change could occurs on a new sequence or a new
picture so move resolution change detection code in a common
function.
For memory allocation reasons, only allows resolution change
on non keyframe if the driver support remove buffer feature.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gstreamer/-/merge_requests/7684>

subprojects/gst-plugins-bad/sys/v4l2codecs/gstv4l2codecvp9dec.c

@@ -86,6 +86,7 @@ struct _GstV4l2CodecVp9Dec
   gboolean has_videometa;
   gboolean streaming;
   gboolean copy_frames;
+  gboolean need_negotiation;
 
   struct v4l2_ctrl_vp9_frame v4l2_vp9_frame;
   struct v4l2_ctrl_vp9_compressed_hdr v4l2_delta_probs;
@@ -400,9 +401,8 @@ gst_v4l2_codec_vp9_dec_open (GstVideoDecoder * decoder)
       gst_v4l2_decoder_query_control_size (self->decoder,
       V4L2_CID_STATELESS_VP9_COMPRESSED_HDR, NULL);
 
-  /* V4L2 does not support non-keyframe resolution change, this will ask the
+  gst_vp9_decoder_set_non_keyframe_format_change_support (vp9dec,
-   * base class to drop frame until the next keyframe as a workaround. */
+      gst_v4l2_decoder_has_remove_bufs (self->decoder));
-  gst_vp9_decoder_set_non_keyframe_format_change_support (vp9dec, FALSE);
 
   return TRUE;
 }
@@ -477,9 +477,11 @@ gst_v4l2_codec_vp9_dec_negotiate (GstVideoDecoder * decoder)
   GstStaticCaps *static_filter;
 
   /* Ignore downstream renegotiation request. */
-  if (self->streaming)
+  if (!self->need_negotiation)
     goto done;
 
+  self->need_negotiation = FALSE;
+
   GST_DEBUG_OBJECT (self, "Negotiate");
 
   gst_v4l2_codec_vp9_dec_reset_allocation (self);
@@ -571,11 +573,6 @@ gst_v4l2_codec_vp9_dec_decide_allocation (GstVideoDecoder * decoder,
   guint min = 0;
   guint num_bitstream;
 
-  /* If we are streaming here, then it means there is nothing allocation
-   * related in the new state and allocation can be ignored */
-  if (self->streaming)
-    goto no_internal_changes;
-
   g_clear_object (&self->src_pool);
   g_clear_object (&self->src_allocator);
 
@@ -621,7 +618,6 @@ gst_v4l2_codec_vp9_dec_decide_allocation (GstVideoDecoder * decoder,
 
   self->src_pool = gst_v4l2_codec_pool_new (self->src_allocator, &self->vinfo);
 
-no_internal_changes:
   /* Our buffer pool is internal, we will let the base class create a video
    * pool, and use it if we are running out of buffers or if downstream does
    * not support GstVideoMeta */
@@ -629,23 +625,21 @@ no_internal_changes:
       (decoder, query);
 }
 
-static GstFlowReturn
+static gboolean
-gst_v4l2_codec_vp9_dec_new_sequence (GstVp9Decoder * decoder,
+gst_v4l2_codec_vp9_dec_is_format_change (GstV4l2CodecVp9Dec * self,
-    const GstVp9FrameHeader * frame_hdr, gint max_dpb_size)
+    const GstVp9FrameHeader * frame_hdr)
 {
-  GstV4l2CodecVp9Dec *self = GST_V4L2_CODEC_VP9_DEC (decoder);
+  gboolean ret = FALSE;
-  gboolean negotiation_needed = FALSE;
 
   if (self->vinfo.finfo->format == GST_VIDEO_FORMAT_UNKNOWN)
-    negotiation_needed = TRUE;
+    ret = TRUE;
 
-  /* TODO Check if current buffers are large enough, and reuse them */
   if (self->width != frame_hdr->width || self->height != frame_hdr->height) {
     self->width = frame_hdr->width;
     self->height = frame_hdr->height;
-    negotiation_needed = TRUE;
+    GST_DEBUG_OBJECT (self, "Resolution changed to %dx%d",
-    GST_INFO_OBJECT (self, "Resolution changed to %dx%d",
         self->width, self->height);
+    ret = TRUE;
   }
 
   if (self->subsampling_x != frame_hdr->subsampling_x ||
@@ -656,7 +650,7 @@ gst_v4l2_codec_vp9_dec_new_sequence (GstVp9Decoder * decoder,
         frame_hdr->subsampling_x, frame_hdr->subsampling_y);
     self->subsampling_x = frame_hdr->subsampling_x;
     self->subsampling_y = frame_hdr->subsampling_y;
-    negotiation_needed = TRUE;
+    ret = TRUE;
   }
 
   if (frame_hdr->color_space != GST_VP9_CS_UNKNOWN &&
@@ -665,14 +659,14 @@ gst_v4l2_codec_vp9_dec_new_sequence (GstVp9Decoder * decoder,
     GST_DEBUG_OBJECT (self, "colorspace changed from %d to %d",
         self->color_space, frame_hdr->color_space);
     self->color_space = frame_hdr->color_space;
-    negotiation_needed = TRUE;
+    ret = TRUE;
   }
 
   if (frame_hdr->color_range != self->color_range) {
     GST_DEBUG_OBJECT (self, "color range changed from %d to %d",
         self->color_range, frame_hdr->color_range);
     self->color_range = frame_hdr->color_range;
-    negotiation_needed = TRUE;
+    ret = TRUE;
   }
 
   if (frame_hdr->profile != GST_VP9_PROFILE_UNDEFINED &&
@@ -680,23 +674,61 @@ gst_v4l2_codec_vp9_dec_new_sequence (GstVp9Decoder * decoder,
     GST_DEBUG_OBJECT (self, "profile changed from %d to %d", self->profile,
         frame_hdr->profile);
     self->profile = frame_hdr->profile;
-    negotiation_needed = TRUE;
+    ret = TRUE;
   }
 
   if (frame_hdr->bit_depth != self->bit_depth) {
     GST_DEBUG_OBJECT (self, "bit-depth changed from %d to %d",
         self->bit_depth, frame_hdr->bit_depth);
     self->bit_depth = frame_hdr->bit_depth;
-    negotiation_needed = TRUE;
+    ret = TRUE;
   }
 
+  return ret;
+}
+
+static GstFlowReturn
+gst_v4l2_codec_vp9_dec_new_picture (GstVp9Decoder * decoder,
+    GstVideoCodecFrame * frame, GstVp9Picture * picture)
+{
+  GstV4l2CodecVp9Dec *self = GST_V4L2_CODEC_VP9_DEC (decoder);
+
+  self->need_negotiation =
+      gst_v4l2_codec_vp9_dec_is_format_change (self, &picture->frame_hdr);
+
+  if (!self->need_negotiation)
+    return GST_FLOW_OK;
+
+  if (!gst_video_decoder_negotiate (GST_VIDEO_DECODER (self))) {
+    GST_ERROR_OBJECT (self, "Failed to negotiate with downstream");
+    return GST_FLOW_ERROR;
+  }
+
+  return GST_FLOW_OK;
+}
+
+static GstFlowReturn
+gst_v4l2_codec_vp9_dec_new_sequence (GstVp9Decoder * decoder,
+    const GstVp9FrameHeader * frame_hdr, gint max_dpb_size)
+{
+  GstV4l2CodecVp9Dec *self = GST_V4L2_CODEC_VP9_DEC (decoder);
+
+  /* TODO Check if current buffers are large enough, and reuse them */
+  self->need_negotiation =
+      gst_v4l2_codec_vp9_dec_is_format_change (self, frame_hdr);
+
   gst_v4l2_codec_vp9_dec_fill_dec_params (self, frame_hdr, NULL);
 
   if (decoder->parse_compressed_headers)
     gst_v4l2_codec_vp9_dec_fill_prob_updates (self, frame_hdr);
 
-  if (negotiation_needed) {
+  if (self->need_negotiation) {
+    /* If the negotiation request occurs on a key frame or
+     * remove buffer isn't supported do a stream off */
+    if ((frame_hdr->frame_type == GST_VP9_KEY_FRAME)
+        || !gst_v4l2_decoder_has_remove_bufs (self->decoder)) {
       gst_v4l2_codec_vp9_dec_streamoff (self);
+    }
     if (!gst_video_decoder_negotiate (GST_VIDEO_DECODER (self))) {
       GST_ERROR_OBJECT (self, "Failed to negotiate with downstream");
       return GST_FLOW_ERROR;
@@ -1131,6 +1163,7 @@ gst_v4l2_codec_vp9_dec_get_property (GObject * object, guint prop_id,
 static void
 gst_v4l2_codec_vp9_dec_init (GstV4l2CodecVp9Dec * self)
 {
+  self->need_negotiation = TRUE;
 }
 
 static void
@@ -1194,6 +1227,8 @@ gst_v4l2_codec_vp9_dec_subclass_init (GstV4l2CodecVp9DecClass * klass,
 
   vp9decoder_class->new_sequence =
       GST_DEBUG_FUNCPTR (gst_v4l2_codec_vp9_dec_new_sequence);
+  vp9decoder_class->new_picture =
+      GST_DEBUG_FUNCPTR (gst_v4l2_codec_vp9_dec_new_picture);
   vp9decoder_class->start_picture =
       GST_DEBUG_FUNCPTR (gst_v4l2_codec_vp9_dec_start_picture);
   vp9decoder_class->decode_picture =