Rebase ring buffer branch to develop

src/internal_modules/roc_netio/target_libuv/roc_netio/udp_receiver_port.cpp

@@ -287,6 +287,7 @@ void UdpReceiverPort::recv_cb_(uv_udp_t* handle,
 
     pp->udp()->src_addr = src_addr;
     pp->udp()->dst_addr = self.config_.bind_address;
+    pp->udp()->receive_timestamp = core::timestamp(core::ClockUnix);
 
     pp->set_data(core::Slice<uint8_t>(*bp, 0, (size_t)nread));
 

src/internal_modules/roc_packet/target_libuv/roc_packet/udp.h

@@ -31,6 +31,9 @@ struct UDP {
 
     //! Sender request state.
     uv_udp_send_t request;
+
+    //! Received Timestamp.
+    core::nanoseconds_t receive_timestamp;
 };
 
 } // namespace packet

src/internal_modules/roc_pipeline/config.h

@@ -159,6 +159,9 @@ struct ReceiverSessionConfig {
     //! Target latency, nanoseconds.
     core::nanoseconds_t target_latency;
 
+    //! Packet prebuffer length, nanoseconds.
+    core::nanoseconds_t prebuf_len;
+
     //! Packet payload type.
     unsigned int payload_type;
 
@@ -185,6 +188,7 @@ struct ReceiverSessionConfig {
 
     ReceiverSessionConfig()
         : target_latency(DefaultLatency)
+        , prebuf_len(DefaultLatency)
         , payload_type(0)
         , resampler_backend(audio::ResamplerBackend_Default)
         , resampler_profile(audio::ResamplerProfile_Medium) {
@@ -225,6 +229,9 @@ struct ReceiverCommonConfig {
     //! Insert weird beeps instead of silence on packet loss.
     bool enable_beeping;
 
+    //! Maximum number of packets per session.
+    size_t max_session_packets;
+
     ReceiverCommonConfig()
         : output_sample_spec(DefaultSampleSpec)
         , enable_timing(false)

src/internal_modules/roc_pipeline/receiver_session_group.cpp

@@ -166,13 +166,56 @@ ReceiverSessionGroup::route_transport_packet_(const packet::PacketPtr& packet) {
     }
 
     if (!can_create_session_(packet)) {
+        enqueue_prebuf_packet_(packet);
         // TODO(gh-183): return status
         return status::StatusOK;
     }
 
     return create_session_(packet);
 }
 
+void ReceiverSessionGroup::enqueue_prebuf_packet_(const packet::PacketPtr& packet_ptr) {
+    prebuf_packets_.push_back(*packet_ptr.get());
+
+    core::nanoseconds_t now = core::timestamp(core::ClockMonotonic);
+
+    while (prebuf_packets_.size() > 0) {
+        core::nanoseconds_t received = prebuf_packets_.front()->udp()->receive_timestamp;
+        if (now - received > receiver_config_.default_session.prebuf_len) {
+            prebuf_packets_.remove(*prebuf_packets_.front());
+        } else {
+            break;
+        }
+    }
+}
+
+void ReceiverSessionGroup::dequeue_prebuf_packets_(ReceiverSession& sess) {
+    packet::PacketPtr curr, next;
+
+    if (prebuf_packets_.size() == 0) {
+        return;
+    }
+
+    core::nanoseconds_t now = core::timestamp(core::ClockMonotonic);
+
+    for (curr = prebuf_packets_.front(); curr; curr = next) {
+        next = prebuf_packets_.nextof(*curr);
+
+        // if packet is too old, remove it from the queue
+        core::nanoseconds_t received = curr->udp()->receive_timestamp;
+        if (now - received > receiver_config_.default_session.prebuf_len) {
+            prebuf_packets_.remove(*curr);
+            continue;
+        }
+
+        // if session handles the packet, remove it from the queue
+        const status::StatusCode code = sess.route(curr);
+        if (code == status::StatusOK) {
+            prebuf_packets_.remove(*curr);
+        }
+    }
+}
+
 status::StatusCode
 ReceiverSessionGroup::route_control_packet_(const packet::PacketPtr& packet) {
     if (!rtcp_composer_) {
@@ -252,6 +295,8 @@ ReceiverSessionGroup::create_session_(const packet::PacketPtr& packet) {
 
     receiver_state_.add_sessions(+1);
 
+    dequeue_prebuf_packets_(*sess);
+
     return status::StatusOK;
 }
 

src/internal_modules/roc_pipeline/receiver_session_group.h

@@ -82,6 +82,8 @@ class ReceiverSessionGroup : public core::NonCopyable<>, private rtcp::IReceiver
 
     status::StatusCode route_transport_packet_(const packet::PacketPtr& packet);
     status::StatusCode route_control_packet_(const packet::PacketPtr& packet);
+    void enqueue_prebuf_packet_(const packet::PacketPtr& packet);
+    void dequeue_prebuf_packets_(ReceiverSession& sess);
 
     bool can_create_session_(const packet::PacketPtr& packet);
 
@@ -108,6 +110,7 @@ class ReceiverSessionGroup : public core::NonCopyable<>, private rtcp::IReceiver
     core::Optional<rtcp::Session> rtcp_session_;
 
     core::List<ReceiverSession> sessions_;
+    core::List<packet::Packet> prebuf_packets_;
 };
 
 } // namespace pipeline

src/public_api/include/roc/config.h

@@ -781,6 +781,14 @@ typedef struct roc_receiver_config {
      * If zero, default value is used. If negative, the timeout is disabled.
      */
     long long choppy_playback_timeout;
+
+    /** Packet prebuffer length, in nanoseconds.
+     * Packets received for sessions that have not yet been created
+     * will be buffered. Any packets older than the prebuf_len
+     * will be discarded.
+     * If zero, default value is used.
+     */
+    unsigned long long prebuf_len;
 } roc_receiver_config;
 
 /** Interface configuration.

src/tests/roc_pipeline/test_receiver_source.cpp

@@ -1792,6 +1792,62 @@ TEST(receiver_source, recv_timestamp_mapping_remixing) {
     CHECK(first_ts);
 }
 
+TEST(receiver_source, packet_buffer) {
+    enum { Rate = SampleRate, Chans = Chans_Stereo, MaxPackets = 10 };
+
+    init(Rate, Chans, Rate, Chans);
+
+    ReceiverConfig config = make_config();
+    config.default_session.prebuf_len = 0;
+    ReceiverSource receiver(config, format_map, packet_factory, byte_buffer_factory,
+                            sample_buffer_factory, arena);
+    CHECK(receiver.is_valid());
+
+    ReceiverSlot* slot = create_slot(receiver);
+    CHECK(slot);
+
+    packet::Queue queue;
+    packet::Queue source_queue;
+    packet::Queue repair_queue;
+
+    packet::IWriter* source_endpoint_writer =
+        create_endpoint(slot, address::Iface_AudioSource, address::Proto_RTP_RS8M_Source);
+    CHECK(source_endpoint_writer);
+
+    packet::IWriter* repair_endpoint_writer =
+        create_endpoint(slot, address::Iface_AudioRepair, address::Proto_RS8M_Repair);
+    CHECK(repair_endpoint_writer);
+
+    fec::WriterConfig fec_config;
+
+    test::PacketWriter packet_writer(
+        arena, queue, queue, format_map, packet_factory, byte_buffer_factory, src1, dst1,
+        dst2, PayloadType_Ch2, packet::FEC_ReedSolomon_M8, fec_config);
+
+    // setup reader
+    test::FrameReader frame_reader(receiver, sample_buffer_factory);
+
+    packet_writer.write_packets(fec_config.n_source_packets, SamplesPerPacket,
+                                output_sample_spec);
+
+    for (int i = 0; i < ManyPackets; ++i) {
+        packet::PacketPtr pp;
+        UNSIGNED_LONGS_EQUAL(status::StatusOK, queue.read(pp));
+        CHECK(pp);
+
+        if (pp->flags() & packet::Packet::FlagAudio) {
+            UNSIGNED_LONGS_EQUAL(status::StatusOK, source_queue.write(pp));
+        }
+        if (pp->flags() & packet::Packet::FlagRepair) {
+            UNSIGNED_LONGS_EQUAL(status::StatusOK, repair_queue.write(pp));
+        }
+    }
+
+    receiver.refresh(frame_reader.refresh_ts());
+    frame_reader.read_nonzero_samples(SamplesPerFrame, output_sample_spec);
+    UNSIGNED_LONGS_EQUAL(1, receiver.num_sessions());
+}
+
 TEST(receiver_source, metrics_sessions) {
     enum { Rate = SampleRate, Chans = Chans_Stereo, MaxSess = 10 };
 

src/tools/roc_recv/cmdline.ggo

@@ -41,6 +41,9 @@ section "Options"
     option "no-play-timeout" - "No playback timeout, TIME units"
         string optional
 
+    option "prebuf-len" - "Length of packet prebuffer, TIME units"
+        string optional
+
     option "choppy-play-timeout" - "Choppy playback timeout, TIME units"
         string optional
 

src/tools/roc_recv/main.cpp

@@ -135,6 +135,19 @@ int main(int argc, char** argv) {
             receiver_config.default_session.target_latency);
     }
 
+    if (args.prebuf_len_given) {
+        core::nanoseconds_t prebuf_len = 0;
+        if (!core::parse_duration(args.prebuf_len_arg, prebuf_len)) {
+            roc_log(LogError, "invalid --prebuf-len");
+            return 1;
+        }
+        receiver_config.default_session.prebuf_len =
+            (core::nanoseconds_t)args.prebuf_len_arg;
+    } else {
+        receiver_config.default_session.prebuf_len =
+            receiver_config.default_session.target_latency;
+    }
+
     if (args.choppy_play_timeout_given) {
         if (!core::parse_duration(
                 args.choppy_play_timeout_arg,