CWG-G094: Bugfix for Output Order when Frames are Output at a Restricted Switch Frame

Output using av2_output_frame_buffers() in case of restricted_prediction_switch.

**Background:** When we get a switch frame with restricted_prediction_switch == 1, all frames that are going to be set as restricted need to be output first (if eligible for output -- e.g. because implicit_output_frame == 1).

**Issue:** Currently, these reference frames get output in the order they appear in ref_frame_map array -- ignoring their display_order_hint values. This makes it very easy for encoder to make a mistake -- if reference frames in the DPB are NOT in the display order hint order, they will get output in the wrong order.

**Solution:** Instead of calling `assign_output_frame_buffer_p`, call `av2_output_frame_buffers` directly to output previous, current and future eligible frames in correct order.

Fixes #1466

av2/decoder/decodeframe.c

diff --git a/av2/decoder/decodeframe.c b/av2/decoder/decodeframe.c
index f466cf6..13db610 100644
--- a/av2/decoder/decodeframe.c
+++ b/av2/decoder/decodeframe.c
@@ -8075,21 +8075,18 @@
             if (is_mlayer_transitively_dependent(
                     &cm->seq_params, cm->ref_frame_map[i]->mlayer_id,
                     cm->mlayer_id)) {
+              if (is_frame_eligible_for_output(cm->ref_frame_map[i])) {
+                const int doh_error = av2_output_frame_buffers(pbi, i);
+                if (doh_error) {
+                  avm_internal_error(
+                      &cm->error, AVM_CODEC_UNSUP_BITSTREAM,
+                      "Display order hint of an output picture is not unique"
+                      " in the same (xlayer_id %d) layer.",
+                      cm->xlayer_id);
+                }
+              }
               cm->ref_frame_map[i]->is_restricted = true;
               cm->ref_frame_map[i]->display_order_hint = REF_RESTRICTED_DOH;
-              if (is_frame_eligible_for_output(cm->ref_frame_map[i])) {
-                assign_output_frame_buffer_p(
-                    &pbi->output_frames[pbi->num_output_frames++],
-                    cm->ref_frame_map[i]);
-#if CONFIG_BITSTREAM_DEBUG
-                avm_bitstream_queue_set_frame_read(
-                    derive_output_order_idx(cm, cm->ref_frame_map[i]) * 2 + 1);
-#endif  // CONFIG_BITSTREAM_DEBUG
-#if CONFIG_MISMATCH_DEBUG
-                mismatch_move_frame_idx_r(0);
-#endif  // CONFIG_MISMATCH_DEBUG
-              }
-              cm->ref_frame_map[i]->frame_output_done = true;
             }
           }
         }

av2/decoder/decoder.c

diff --git a/av2/decoder/decoder.c b/av2/decoder/decoder.c
index 0f82106..634230f 100644
--- a/av2/decoder/decoder.c
+++ b/av2/decoder/decoder.c
@@ -636,16 +636,7 @@
   return 0;
 }
 
-// This function outputs frames that are ready to be output.
-// The output frames may be the output trigger frame along with
-// past frames that have not yet been output,
-// and/or future frames that are continuous with the output trigger frame.
-// The output trigger frame is the current frame or
-// the frame to be flushed out from the ref_frame_map slot.
-// ref_idx == -1 indicates the output process is trigged by
-// decoding the current frame.
-// Returns 0 on success, 1 if a DOH conformance violation was detected.
-int output_frame_buffers(AV2Decoder *pbi, int ref_idx) {
+int av2_output_frame_buffers(AV2Decoder *pbi, int ref_idx) {
   AV2_COMMON *const cm = &pbi->common;
   RefCntBuffer *trigger_frame = NULL;
   RefCntBuffer *output_candidate = NULL;
@@ -775,7 +766,7 @@
           }
         }
         if (is_frame_eligible_for_output(cm->ref_frame_map[ref_index]))
-          doh_error |= output_frame_buffers(pbi, ref_index);
+          doh_error |= av2_output_frame_buffers(pbi, ref_index);
         decrease_ref_count(cm->ref_frame_map[ref_index], pool);
 
         if (av2_skip_reference_buffer_update(clear_multiple_insert_in_one,
@@ -792,7 +783,7 @@
                         pbi->enable_subgop_stats);
     if (((cm->immediate_output_picture && !cm->cur_frame->frame_output_done) ||
          cm->show_existing_frame)) {
-      doh_error |= output_frame_buffers(pbi, -1);
+      doh_error |= av2_output_frame_buffers(pbi, -1);
       decrease_ref_count(cm->cur_frame, pool);
     } else {
       decrease_ref_count(cm->cur_frame, pool);

av2/decoder/decoder.h

diff --git a/av2/decoder/decoder.h b/av2/decoder/decoder.h
index 242c1cf..f102a0c 100644
--- a/av2/decoder/decoder.h
+++ b/av2/decoder/decoder.h
@@ -811,6 +811,17 @@
                                    PARTITION_TYPE partition, BLOCK_SIZE bsize,
                                    PARTITION_TREE *parent, int index);
 
+// This function outputs frames that are ready to be output.
+// The output frames may be the output trigger frame along with
+// past frames that have not yet been output,
+// and/or future frames that are continuous with the output trigger frame.
+// The output trigger frame is the current frame or
+// the frame to be flushed out from the ref_frame_map slot.
+// ref_idx == -1 indicates the output process is trigged by
+// decoding the current frame.
+// Returns 0 on success, 1 if a DOH conformance violation was detected.
+int av2_output_frame_buffers(AV2Decoder *pbi, int ref_idx);
+
 /*!\endcond */
 
 #if CONFIG_COLLECT_COMPONENT_TIMING