commit 29a3f928f9ab8b12d19eeb67d25b828148f75bca
author Danil Chapovalov <danilchap@webrtc.org> Thu Dec 12 17:23:23 2024
committer WebRTC LUCI CQ <webrtc-scoped@luci-project-accounts.iam.gserviceaccount.com> Fri Dec 13 12:27:19 2024
tree 85465c8ad65b2b7dc91d41ad8dd89151f148ce12
parent 2bee7845d3ef9f87a46c466a03c9c868fdc0f4e0

In PacketBuffer do not attempt to clear before 1st packet

ClearTo logic relies on clear to sequence number follows first_seq_num_

Bug: chromium:370689424
Change-Id: I12874d5ce7adfdcf9c0691acacdd2b8ae41ce307
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/371320
Commit-Queue: Danil Chapovalov <danilchap@webrtc.org>
Reviewed-by: Rasmus Brandt <brandtr@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#43558}

modules/video_coding/packet_buffer.cc

diff --git a/modules/video_coding/packet_buffer.cc b/modules/video_coding/packet_buffer.cc
index 9d7b6e5..df53e81 100644
--- a/modules/video_coding/packet_buffer.cc
+++ b/modules/video_coding/packet_buffer.cc
@@ -129,8 +129,7 @@
 
 void PacketBuffer::ClearTo(uint16_t seq_num) {
   // We have already cleared past this sequence number, no need to do anything.
-  if (is_cleared_to_first_seq_num_ &&
-      AheadOf<uint16_t>(first_seq_num_, seq_num)) {
+  if (AheadOf<uint16_t>(first_seq_num_, seq_num)) {
     return;
   }
 

modules/video_coding/packet_buffer_unittest.cc

diff --git a/modules/video_coding/packet_buffer_unittest.cc b/modules/video_coding/packet_buffer_unittest.cc
index 925d8f2..6c05d09 100644
--- a/modules/video_coding/packet_buffer_unittest.cc
+++ b/modules/video_coding/packet_buffer_unittest.cc
@@ -839,6 +839,13 @@
       SizeIs(2));
 }
 
+TEST_F(PacketBufferH264FrameGap, DoesntCrashWhenTryToClearBefore1stPacket) {
+  // Test scenario copied from the https://issues.chromium.org/370689424
+  InsertH264(41087, kKeyFrame, kNotFirst, kNotLast, 123, 0, 0, false);
+  packet_buffer_.ClearTo(30896);
+  InsertH264(32896, kKeyFrame, kFirst, kLast, 123, 0, 0, false);
+}
+
 }  // namespace
 }  // namespace video_coding
 }  // namespace webrtc