Make FrameBuffer support an unlimited number of dependents per frame

Bug: webrtc:10190
Change-Id: I59680ec0dc05bc77dcbef50ddbb83ce2bcd91f7e
Reviewed-on: https://webrtc-review.googlesource.com/c/116788
Reviewed-by: Sergey Silkin <ssilkin@webrtc.org>
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Elad Alon <eladalon@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#26196}

modules/video_coding/BUILD.gn

@@ -197,6 +197,7 @@ rtc_static_library("video_coding") {
     "../../system_wrappers",
     "../rtp_rtcp:rtp_rtcp_format",
     "../utility:utility",
+    "//third_party/abseil-cpp/absl/container:inlined_vector",
     "//third_party/abseil-cpp/absl/types:optional",
     "//third_party/abseil-cpp/absl/types:variant",
   ]

modules/video_coding/frame_buffer2.cc

@@ -479,7 +479,7 @@ void FrameBuffer::PropagateContinuity(FrameMap::iterator start) {
 
     // Loop through all dependent frames, and if that frame no longer has
     // any unfulfilled dependencies then that frame is continuous as well.
-    for (size_t d = 0; d < frame->second.num_dependent_frames; ++d) {
+    for (size_t d = 0; d < frame->second.dependent_frames.size(); ++d) {
       auto frame_ref = frames_.find(frame->second.dependent_frames[d]);
       RTC_DCHECK(frame_ref != frames_.end());
 
@@ -497,8 +497,7 @@ void FrameBuffer::PropagateContinuity(FrameMap::iterator start) {
 
 void FrameBuffer::PropagateDecodability(const FrameInfo& info) {
   TRACE_EVENT0("webrtc", "FrameBuffer::PropagateDecodability");
-  RTC_CHECK(info.num_dependent_frames < FrameInfo::kMaxNumDependentFrames);
+  for (size_t d = 0; d < info.dependent_frames.size(); ++d) {
-  for (size_t d = 0; d < info.num_dependent_frames; ++d) {
     auto ref_info = frames_.find(info.dependent_frames[d]);
     RTC_DCHECK(ref_info != frames_.end());
     // TODO(philipel): Look into why we've seen this happen.
@@ -608,20 +607,7 @@ bool FrameBuffer::UpdateFrameInfoWithIncomingFrame(const EncodedFrame& frame,
     if (dep.continuous)
       --info->second.num_missing_continuous;
 
-    // At this point we know we want to insert this frame, so here we
+    frames_[dep.id].dependent_frames.push_back(id);
-    // intentionally get or create the FrameInfo for this dependency.
-    FrameInfo* dep_info = &frames_[dep.id];
-
-    if (dep_info->num_dependent_frames <
-        (FrameInfo::kMaxNumDependentFrames - 1)) {
-      dep_info->dependent_frames[dep_info->num_dependent_frames] = id;
-      ++dep_info->num_dependent_frames;
-    } else {
-      RTC_LOG(LS_WARNING) << "Frame with (picture_id:spatial_id) ("
-                          << dep.id.picture_id << ":"
-                          << static_cast<int>(dep.id.spatial_layer)
-                          << ") is referenced by too many frames.";
-    }
   }
 
   return true;

modules/video_coding/frame_buffer2.h

@@ -17,6 +17,7 @@
 #include <utility>
 #include <vector>
 
+#include "absl/container/inlined_vector.h"
 #include "api/video/encoded_frame.h"
 #include "modules/video_coding/include/video_coding_defines.h"
 #include "modules/video_coding/inter_frame_delay.h"
@@ -89,15 +90,9 @@ class FrameBuffer {
     FrameInfo(FrameInfo&&);
     ~FrameInfo();
 
-    // The maximum number of frames that can depend on this frame.
-    static constexpr size_t kMaxNumDependentFrames = 8;
-
     // Which other frames that have direct unfulfilled dependencies
     // on this frame.
-    // TODO(philipel): Add simple modify/access functions to prevent adding too
+    absl::InlinedVector<VideoLayerFrameId, 8> dependent_frames;
-    // many |dependent_frames|.
-    VideoLayerFrameId dependent_frames[kMaxNumDependentFrames];
-    size_t num_dependent_frames = 0;
 
     // A frame is continiuous if it has all its referenced/indirectly
     // referenced frames.