Implement minimum transmit bitrate.

Utilizing minimum transmission bitrate prevents low remote bitrate
estimates (bitrate estimation dips) when encoding non-complex content
such as screenshare of a static image even though there's nothing wrong
with the link.

Requires pacing to be enabled for now, pending issue 3036.

BUG=3014
R=mflodman@webrtc.org, stefan@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/9719004

git-svn-id: http://webrtc.googlecode.com/svn/trunk@5694 4adac7df-926f-26a2-2b94-8c16560cd09d
This commit is contained in:
pbos@webrtc.org 2014-03-13 12:52:27 +00:00
parent 6ea4f6397e
commit 3349ae0cdc
12 changed files with 222 additions and 26 deletions

View File

@ -19,6 +19,7 @@ FakeEncoder::FakeEncoder(Clock* clock)
: clock_(clock),
callback_(NULL),
target_bitrate_kbps_(0),
max_target_bitrate_kbps_(-1),
last_encode_time_ms_(0) {
// Generate some arbitrary not-all-zero data
for (size_t i = 0; i < sizeof(encoded_buffer_); ++i) {
@ -62,6 +63,11 @@ void FakeEncoder::SetCodecSettings(VideoCodec* codec,
strcpy(codec->plName, "FAKE");
}
void FakeEncoder::SetMaxBitrate(int max_kbps) {
assert(max_kbps >= -1); // max_kbps == -1 disables it.
max_target_bitrate_kbps_ = max_kbps;
}
int32_t FakeEncoder::InitEncode(const VideoCodec* config,
int32_t number_of_cores,
uint32_t max_payload_size) {
@ -75,19 +81,22 @@ int32_t FakeEncoder::Encode(
const CodecSpecificInfo* codec_specific_info,
const std::vector<VideoFrameType>* frame_types) {
assert(config_.maxFramerate > 0);
int delta_since_last_encode = 1000 / config_.maxFramerate;
int time_since_last_encode_ms = 1000 / config_.maxFramerate;
int64_t time_now_ms = clock_->TimeInMilliseconds();
if (last_encode_time_ms_ > 0) {
// For all frames but the first we can estimate the display time by looking
// at the display time of the previous frame.
delta_since_last_encode = time_now_ms - last_encode_time_ms_;
time_since_last_encode_ms = time_now_ms - last_encode_time_ms_;
}
int bits_available = target_bitrate_kbps_ * delta_since_last_encode;
int bits_available = target_bitrate_kbps_ * time_since_last_encode_ms;
int min_bits =
config_.simulcastStream[0].minBitrate * delta_since_last_encode;
config_.simulcastStream[0].minBitrate * time_since_last_encode_ms;
if (bits_available < min_bits)
bits_available = min_bits;
int max_bits = max_target_bitrate_kbps_ * time_since_last_encode_ms;
if (max_bits > 0 && max_bits < bits_available)
bits_available = max_bits;
last_encode_time_ms_ = time_now_ms;
for (int i = 0; i < config_.numberOfSimulcastStreams; ++i) {
@ -95,10 +104,10 @@ int32_t FakeEncoder::Encode(
memset(&specifics, 0, sizeof(specifics));
specifics.codecType = kVideoCodecGeneric;
specifics.codecSpecific.generic.simulcast_idx = i;
int min_stream_bits = config_.simulcastStream[i].minBitrate *
delta_since_last_encode;
int max_stream_bits = config_.simulcastStream[i].maxBitrate *
delta_since_last_encode;
int min_stream_bits =
config_.simulcastStream[i].minBitrate * time_since_last_encode_ms;
int max_stream_bits =
config_.simulcastStream[i].maxBitrate * time_since_last_encode_ms;
int stream_bits = (bits_available > max_stream_bits) ? max_stream_bits :
bits_available;
int stream_bytes = (stream_bits + 7) / 8;
@ -110,7 +119,8 @@ int32_t FakeEncoder::Encode(
encoded._timeStamp = input_image.timestamp();
encoded.capture_time_ms_ = input_image.render_time_ms();
encoded._frameType = (*frame_types)[i];
if (min_stream_bits > bits_available) {
// Always encode something on the first frame.
if (min_stream_bits > bits_available && i > 0) {
encoded._length = 0;
encoded._frameType = kSkipFrame;
}
@ -138,5 +148,6 @@ int32_t FakeEncoder::SetRates(uint32_t new_target_bitrate, uint32_t framerate) {
target_bitrate_kbps_ = new_target_bitrate;
return 0;
}
} // namespace test
} // namespace webrtc

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@ -25,23 +25,20 @@ class FakeEncoder : public VideoEncoder {
virtual ~FakeEncoder();
static void SetCodecSettings(VideoCodec* codec, size_t num_streams);
// Sets max bitrate. Not thread-safe, call before registering the encoder.
void SetMaxBitrate(int max_kbps);
virtual int32_t InitEncode(const VideoCodec* config,
int32_t number_of_cores,
uint32_t max_payload_size) OVERRIDE;
virtual int32_t Encode(
const I420VideoFrame& input_image,
const CodecSpecificInfo* codec_specific_info,
const std::vector<VideoFrameType>* frame_types) OVERRIDE;
virtual int32_t RegisterEncodeCompleteCallback(
EncodedImageCallback* callback) OVERRIDE;
virtual int32_t Release() OVERRIDE;
virtual int32_t SetChannelParameters(uint32_t packet_loss, int rtt) OVERRIDE;
virtual int32_t SetRates(uint32_t new_target_bitrate,
uint32_t framerate) OVERRIDE;
@ -50,6 +47,7 @@ class FakeEncoder : public VideoEncoder {
VideoCodec config_;
EncodedImageCallback* callback_;
int target_bitrate_kbps_;
int max_target_bitrate_kbps_;
int64_t last_encode_time_ms_;
uint8_t encoded_buffer_[100000];
};

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@ -33,7 +33,7 @@ class RtpRtcpObserver {
return &receive_transport_;
}
void SetReceivers(PacketReceiver* send_transport_receiver,
virtual void SetReceivers(PacketReceiver* send_transport_receiver,
PacketReceiver* receive_transport_receiver) {
send_transport_.SetReceiver(send_transport_receiver);
receive_transport_.SetReceiver(receive_transport_receiver);

View File

@ -50,6 +50,7 @@ class CallPerfTest : public ::testing::Test {
public:
CallPerfTest()
: send_stream_(NULL), fake_encoder_(Clock::GetRealTimeClock()) {}
protected:
VideoSendStream::Config GetSendTestConfig(Call* call) {
VideoSendStream::Config config = call->GetDefaultSendConfig();
@ -60,6 +61,7 @@ class CallPerfTest : public ::testing::Test {
config.codec.plType = kSendPayloadType;
return config;
}
void RunVideoSendTest(Call* call,
const VideoSendStream::Config& config,
test::RtpRtcpObserver* observer) {
@ -78,6 +80,8 @@ class CallPerfTest : public ::testing::Test {
call->DestroyVideoSendStream(send_stream_);
}
void TestMinTransmitBitrate(bool pad_to_min_bitrate);
VideoSendStream* send_stream_;
test::FakeEncoder fake_encoder_;
};
@ -388,4 +392,133 @@ TEST_F(CallPerfTest, RegisterCpuOveruseObserver) {
VideoSendStream::Config send_config = GetSendTestConfig(call.get());
RunVideoSendTest(call.get(), send_config, &observer);
}
void CallPerfTest::TestMinTransmitBitrate(bool pad_to_min_bitrate) {
static const int kMaxEncodeBitrateKbps = 30;
static const int kMinTransmitBitrateKbps = 150;
static const int kMinAcceptableTransmitBitrate = 130;
static const int kMaxAcceptableTransmitBitrate = 170;
static const int kNumBitrateObservationsInRange = 100;
class BitrateObserver : public test::RtpRtcpObserver, public PacketReceiver {
public:
explicit BitrateObserver(bool using_min_transmit_bitrate)
: test::RtpRtcpObserver(kLongTimeoutMs),
send_stream_(NULL),
send_transport_receiver_(NULL),
using_min_transmit_bitrate_(using_min_transmit_bitrate),
num_bitrate_observations_in_range_(0) {}
virtual void SetReceivers(PacketReceiver* send_transport_receiver,
PacketReceiver* receive_transport_receiver)
OVERRIDE {
send_transport_receiver_ = send_transport_receiver;
test::RtpRtcpObserver::SetReceivers(this, receive_transport_receiver);
}
void SetSendStream(VideoSendStream* send_stream) {
send_stream_ = send_stream;
}
private:
virtual bool DeliverPacket(const uint8_t* packet, size_t length) OVERRIDE {
VideoSendStream::Stats stats = send_stream_->GetStats();
if (stats.substreams.size() > 0) {
assert(stats.substreams.size() == 1);
int bitrate_kbps = stats.substreams.begin()->second.bitrate_bps / 1000;
if (bitrate_kbps > 0) {
test::PrintResult(
"bitrate_stats_",
(using_min_transmit_bitrate_ ? "min_transmit_bitrate"
: "without_min_transmit_bitrate"),
"bitrate_kbps",
static_cast<size_t>(bitrate_kbps),
"kbps",
false);
if (using_min_transmit_bitrate_) {
if (bitrate_kbps > kMinAcceptableTransmitBitrate &&
bitrate_kbps < kMaxAcceptableTransmitBitrate) {
++num_bitrate_observations_in_range_;
}
} else {
// Expect bitrate stats to roughly match the max encode bitrate.
if (bitrate_kbps > kMaxEncodeBitrateKbps - 5 &&
bitrate_kbps < kMaxEncodeBitrateKbps + 5) {
++num_bitrate_observations_in_range_;
}
}
if (num_bitrate_observations_in_range_ ==
kNumBitrateObservationsInRange)
observation_complete_->Set();
}
}
return send_transport_receiver_->DeliverPacket(packet, length);
}
VideoSendStream* send_stream_;
PacketReceiver* send_transport_receiver_;
const bool using_min_transmit_bitrate_;
int num_bitrate_observations_in_range_;
} observer(pad_to_min_bitrate);
scoped_ptr<Call> sender_call(
Call::Create(Call::Config(observer.SendTransport())));
scoped_ptr<Call> receiver_call(
Call::Create(Call::Config(observer.ReceiveTransport())));
VideoSendStream::Config send_config = GetSendTestConfig(sender_call.get());
fake_encoder_.SetMaxBitrate(kMaxEncodeBitrateKbps);
observer.SetReceivers(receiver_call->Receiver(), sender_call->Receiver());
send_config.pacing = true;
if (pad_to_min_bitrate) {
send_config.rtp.min_transmit_bitrate_kbps = kMinTransmitBitrateKbps;
} else {
assert(send_config.rtp.min_transmit_bitrate_kbps == 0);
}
VideoReceiveStream::Config receive_config =
receiver_call->GetDefaultReceiveConfig();
receive_config.codecs.clear();
receive_config.codecs.push_back(send_config.codec);
test::FakeDecoder fake_decoder;
ExternalVideoDecoder decoder;
decoder.decoder = &fake_decoder;
decoder.payload_type = send_config.codec.plType;
receive_config.external_decoders.push_back(decoder);
receive_config.rtp.remote_ssrc = send_config.rtp.ssrcs[0];
receive_config.rtp.local_ssrc = kReceiverLocalSsrc;
VideoSendStream* send_stream =
sender_call->CreateVideoSendStream(send_config);
VideoReceiveStream* receive_stream =
receiver_call->CreateVideoReceiveStream(receive_config);
scoped_ptr<test::FrameGeneratorCapturer> capturer(
test::FrameGeneratorCapturer::Create(send_stream->Input(),
send_config.codec.width,
send_config.codec.height,
30,
Clock::GetRealTimeClock()));
observer.SetSendStream(send_stream);
receive_stream->StartReceiving();
send_stream->StartSending();
capturer->Start();
EXPECT_EQ(kEventSignaled, observer.Wait())
<< "Timeout while waiting for send-bitrate stats.";
send_stream->StopSending();
receive_stream->StopReceiving();
observer.StopSending();
capturer->Stop();
sender_call->DestroyVideoSendStream(send_stream);
receiver_call->DestroyVideoReceiveStream(receive_stream);
}
TEST_F(CallPerfTest, PadsToMinTransmitBitrate) { TestMinTransmitBitrate(true); }
TEST_F(CallPerfTest, NoPadWithoutMinTransmitBitrate) {
TestMinTransmitBitrate(false);
}
} // namespace webrtc

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@ -1475,4 +1475,5 @@ TEST_F(CallTest, ReceiverReferenceTimeReportEnabled) {
TEST_F(CallTest, ReceiverReferenceTimeReportDisabled) {
TestXrReceiverReferenceTimeReport(false);
}
} // namespace webrtc

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@ -49,6 +49,10 @@ VideoSendStream::VideoSendStream(newapi::Transport* transport,
config_.pacing = true;
rtp_rtcp_->SetTransmissionSmoothingStatus(channel_, config_.pacing);
assert(config_.rtp.min_transmit_bitrate_kbps >= 0);
rtp_rtcp_->SetMinTransmitBitrate(channel_,
config_.rtp.min_transmit_bitrate_kbps);
for (size_t i = 0; i < config_.rtp.extensions.size(); ++i) {
const std::string& extension = config_.rtp.extensions[i].name;
int id = config_.rtp.extensions[i].id;

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@ -266,6 +266,15 @@ class WEBRTC_DLLEXPORT ViERTP_RTCP {
virtual int SetTransmissionSmoothingStatus(int video_channel,
bool enable) = 0;
// Sets a minimal bitrate which will be padded to when the encoder doesn't
// produce enough bitrate.
// TODO(pbos): Remove default implementation when libjingle's
// FakeWebRtcVideoEngine is updated.
virtual int SetMinTransmitBitrate(int video_channel,
int min_transmit_bitrate_kbps) {
return -1;
};
// This function returns our locally created statistics of the received RTP
// stream.
virtual int GetReceiveChannelRtcpStatistics(const int video_channel,

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@ -149,6 +149,7 @@ ViEEncoder::ViEEncoder(int32_t engine_id,
bitrate_controller_(bitrate_controller),
time_of_last_incoming_frame_ms_(0),
send_padding_(false),
min_transmit_bitrate_kbps_(0),
target_delay_ms_(0),
network_is_transmitting_(true),
encoder_paused_(false),
@ -459,9 +460,14 @@ int32_t ViEEncoder::SetEncoder(const webrtc::VideoCodec& video_codec) {
kTransmissionMaxBitrateMultiplier *
video_codec.maxBitrate * 1000);
paced_sender_->UpdateBitrate(video_codec.startBitrate,
video_codec.startBitrate,
video_codec.startBitrate);
CriticalSectionScoped crit(data_cs_.get());
int pad_up_to_bitrate_kbps = video_codec.startBitrate;
if (pad_up_to_bitrate_kbps < min_transmit_bitrate_kbps_)
pad_up_to_bitrate_kbps = min_transmit_bitrate_kbps_;
paced_sender_->UpdateBitrate(
video_codec.startBitrate, pad_up_to_bitrate_kbps, pad_up_to_bitrate_kbps);
return 0;
}
@ -527,7 +533,8 @@ int ViEEncoder::TimeToSendPadding(int bytes) {
bool send_padding;
{
CriticalSectionScoped cs(data_cs_.get());
send_padding = send_padding_ || video_suspended_;
send_padding =
send_padding_ || video_suspended_ || min_transmit_bitrate_kbps_ > 0;
}
if (send_padding) {
return default_rtp_rtcp_->TimeToSendPadding(bytes);
@ -1028,6 +1035,12 @@ bool ViEEncoder::SetSsrcs(const std::list<unsigned int>& ssrcs) {
return true;
}
void ViEEncoder::SetMinTransmitBitrate(int min_transmit_bitrate_kbps) {
assert(min_transmit_bitrate_kbps >= 0);
CriticalSectionScoped crit(data_cs_.get());
min_transmit_bitrate_kbps_ = min_transmit_bitrate_kbps;
}
// Called from ViEBitrateObserver.
void ViEEncoder::OnNetworkChanged(const uint32_t bitrate_bps,
const uint8_t fraction_lost,
@ -1091,17 +1104,21 @@ void ViEEncoder::OnNetworkChanged(const uint32_t bitrate_bps,
max_padding_bitrate_kbps = 0;
}
paced_sender_->UpdateBitrate(bitrate_kbps,
max_padding_bitrate_kbps,
pad_up_to_bitrate_kbps);
default_rtp_rtcp_->SetTargetSendBitrate(stream_bitrates);
{
CriticalSectionScoped cs(data_cs_.get());
if (pad_up_to_bitrate_kbps < min_transmit_bitrate_kbps_)
pad_up_to_bitrate_kbps = min_transmit_bitrate_kbps_;
if (max_padding_bitrate_kbps < min_transmit_bitrate_kbps_)
max_padding_bitrate_kbps = min_transmit_bitrate_kbps_;
paced_sender_->UpdateBitrate(
bitrate_kbps, max_padding_bitrate_kbps, pad_up_to_bitrate_kbps);
default_rtp_rtcp_->SetTargetSendBitrate(stream_bitrates);
if (video_suspended_ == video_is_suspended)
return;
video_suspended_ = video_is_suspended;
}
// State changed, inform codec observer.
CriticalSectionScoped crit(callback_cs_.get());
if (codec_observer_) {
WEBRTC_TRACE(webrtc::kTraceInfo, webrtc::kTraceVideo,
ViEId(engine_id_, channel_id_),

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@ -20,6 +20,7 @@
#include "webrtc/modules/video_coding/main/interface/video_coding_defines.h"
#include "webrtc/modules/video_processing/main/interface/video_processing.h"
#include "webrtc/system_wrappers/interface/scoped_ptr.h"
#include "webrtc/system_wrappers/interface/thread_annotations.h"
#include "webrtc/typedefs.h"
#include "webrtc/frame_callback.h"
#include "webrtc/video_engine/vie_defines.h"
@ -154,6 +155,8 @@ class ViEEncoder
// Sets SSRCs for all streams.
bool SetSsrcs(const std::list<unsigned int>& ssrcs);
void SetMinTransmitBitrate(int min_transmit_bitrate_kbps);
// Effect filter.
int32_t RegisterEffectFilter(ViEEffectFilter* effect_filter);
@ -207,6 +210,7 @@ class ViEEncoder
int64_t time_of_last_incoming_frame_ms_;
bool send_padding_;
int min_transmit_bitrate_kbps_ GUARDED_BY(data_cs_);
int target_delay_ms_;
bool network_is_transmitting_;
bool encoder_paused_;
@ -216,7 +220,7 @@ class ViEEncoder
bool fec_enabled_;
bool nack_enabled_;
ViEEncoderObserver* codec_observer_;
ViEEncoderObserver* codec_observer_ GUARDED_BY(callback_cs_);
ViEEffectFilter* effect_filter_;
ProcessThread& module_process_thread_;

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@ -850,6 +850,16 @@ int ViERTP_RTCPImpl::SetTransmissionSmoothingStatus(int video_channel,
return 0;
}
int ViERTP_RTCPImpl::SetMinTransmitBitrate(int video_channel,
int min_transmit_bitrate_kbps) {
ViEChannelManagerScoped cs(*(shared_data_->channel_manager()));
ViEEncoder* vie_encoder = cs.Encoder(video_channel);
if (vie_encoder == NULL)
return -1;
vie_encoder->SetMinTransmitBitrate(min_transmit_bitrate_kbps);
return 0;
}
int ViERTP_RTCPImpl::GetReceiveChannelRtcpStatistics(
const int video_channel,
RtcpStatistics& basic_stats,

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@ -90,6 +90,8 @@ class ViERTP_RTCPImpl
int id);
virtual int SetRtcpXrRrtrStatus(int video_channel, bool enable);
virtual int SetTransmissionSmoothingStatus(int video_channel, bool enable);
virtual int SetMinTransmitBitrate(int video_channel,
int min_transmit_bitrate_kbps);
virtual int GetReceiveChannelRtcpStatistics(const int video_channel,
RtcpStatistics& basic_stats,
int& rtt_ms) const;

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@ -68,13 +68,20 @@ class VideoSendStream {
static const size_t kDefaultMaxPacketSize = 1500 - 40; // TCP over IPv4.
struct Rtp {
Rtp() : max_packet_size(kDefaultMaxPacketSize) {}
Rtp()
: max_packet_size(kDefaultMaxPacketSize),
min_transmit_bitrate_kbps(0) {}
std::vector<uint32_t> ssrcs;
// Max RTP packet size delivered to send transport from VideoEngine.
size_t max_packet_size;
// Padding will be used up to this bitrate regardless of the bitrate
// produced by the encoder. Padding above what's actually produced by the
// encoder helps maintaining a higher bitrate estimate.
int min_transmit_bitrate_kbps;
// RTP header extensions to use for this send stream.
std::vector<RtpExtension> extensions;