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Continue looking for frames after padding packets

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In H264, reordered packets can cause a frame following padding to become stuck in the packet buffer.
A minimal example:
_, P, 1  - padding packet p and frame 1. Frame 1 has not been returned because of missing packet 0
0, P, 1  - when packet 0 arrives, FindFrames will stop incrementing i when it sees padding packet P, and frame 1 will never be returned

Bug: webrtc:14216
Change-Id: I78b76df9709fa8593c5025d647e2b868af3749f2
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/266465
Reviewed-by: Philip Eliasson <philipel@webrtc.org>
Commit-Queue: Philip Eliasson <philipel@webrtc.org>
Cr-Commit-Position: refs/heads/main@{#37357}
This commit is contained in:
Jared Siskin
2022-06-22 06:35:38 -07:00
committed by WebRTC LUCI CQ
parent db30009304
commit 3f659b1b3c
3 changed files with 39 additions and 6 deletions
Download Patch File Download Diff File Expand all files Collapse all files

31
modules/video_coding/packet_buffer.cc
View File

@ -107,6 +107,10 @@ PacketBuffer::InsertResult PacketBuffer::InsertPacket(
UpdateMissingPackets(seq_num);
received_padding_.erase(
received_padding_.begin(),
received_padding_.lower_bound(seq_num - (buffer_.size() / 4)));
result.packets = FindFrames(seq_num);
return result;
}
@ -140,11 +144,11 @@ void PacketBuffer::ClearTo(uint16_t seq_num) {
first_seq_num_ = seq_num;
is_cleared_to_first_seq_num_ = true;
auto clear_to_it = missing_packets_.upper_bound(seq_num);
if (clear_to_it != missing_packets_.begin()) {
--clear_to_it;
missing_packets_.erase(missing_packets_.begin(), clear_to_it);
}
missing_packets_.erase(missing_packets_.begin(),
missing_packets_.lower_bound(seq_num));
received_padding_.erase(received_padding_.begin(),
received_padding_.lower_bound(seq_num));
}
void PacketBuffer::Clear() {
@ -154,6 +158,7 @@ void PacketBuffer::Clear() {
PacketBuffer::InsertResult PacketBuffer::InsertPadding(uint16_t seq_num) {
PacketBuffer::InsertResult result;
UpdateMissingPackets(seq_num);
received_padding_.insert(seq_num);
result.packets = FindFrames(static_cast<uint16_t>(seq_num + 1));
return result;
}
@ -171,6 +176,7 @@ void PacketBuffer::ClearInternal() {
is_cleared_to_first_seq_num_ = false;
newest_inserted_seq_num_.reset();
missing_packets_.clear();
received_padding_.clear();
}
bool PacketBuffer::ExpandBufferSize() {
@ -219,7 +225,18 @@ bool PacketBuffer::PotentialNewFrame(uint16_t seq_num) const {
std::vector<std::unique_ptr<PacketBuffer::Packet>> PacketBuffer::FindFrames(
uint16_t seq_num) {
std::vector<std::unique_ptr<PacketBuffer::Packet>> found_frames;
for (size_t i = 0; i < buffer_.size() && PotentialNewFrame(seq_num); ++i) {
auto start = seq_num;
for (size_t i = 0; i < buffer_.size(); ++i) {
if (received_padding_.find(seq_num) != received_padding_.end()) {
seq_num += 1;
continue;
}
if (!PotentialNewFrame(seq_num)) {
break;
}
size_t index = seq_num % buffer_.size();
buffer_[index]->continuous = true;
@ -359,6 +376,8 @@ std::vector<std::unique_ptr<PacketBuffer::Packet>> PacketBuffer::FindFrames(
missing_packets_.erase(missing_packets_.begin(),
missing_packets_.upper_bound(seq_num));
received_padding_.erase(received_padding_.lower_bound(start),
received_padding_.upper_bound(seq_num));
}
}
++seq_num;