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Use bitrate limits provided by encoder.

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- Use minimum start bitrate to drop frame and adapt resolution in the
beginning of call.

- Use minimum bitrate to decide whether or not resolution should be
increased based on quality in MAINTAIN_FRAMERATE and BALANCED modes.
In BALANCED mode bitrate limits provided by the corresponding field
trial are prioritized over the limits provided by encoder.

Bug: webrtc:10853
Change-Id: I8257eb64565bcafa6ae9887a1af18e90f8400cac
Reviewed-on: https://webrtc-review.googlesource.com/c/src/+/156302
Commit-Queue: Sergey Silkin <ssilkin@webrtc.org>
Reviewed-by: Åsa Persson <asapersson@webrtc.org>
Cr-Commit-Position: refs/heads/master@{#29461}
This commit is contained in:
Sergey Silkin
2019-10-14 13:12:19 +02:00
committed by Commit Bot
parent 5ab79e62f6
commit 41c650bea2
3 changed files with 137 additions and 14 deletions
Download Patch File Download Diff File Expand all files Collapse all files

56
video/video_stream_encoder.cc
View File

@ -320,6 +320,16 @@ class VideoStreamEncoder::VideoSourceProxy {
return RestrictFramerate(framerate_wanted) ? framerate_wanted : -1;
}
int GetHigherResolutionThan(int pixel_count) const {
// On step down we request at most 3/5 the pixel count of the previous
// resolution, so in order to take "one step up" we request a resolution
// as close as possible to 5/3 of the current resolution. The actual pixel
// count selected depends on the capabilities of the source. In order to
// not take a too large step up, we cap the requested pixel count to be at
// most four time the current number of pixels.
return (pixel_count * 5) / 3;
}
bool RequestHigherResolutionThan(int pixel_count) {
// Called on the encoder task queue.
rtc::CritScope lock(&crit_);
@ -340,13 +350,7 @@ class VideoStreamEncoder::VideoSourceProxy {
// Remove any constraints.
sink_wants_.target_pixel_count.reset();
} else {
// On step down we request at most 3/5 the pixel count of the previous
// resolution, so in order to take "one step up" we request a resolution
// as close as possible to 5/3 of the current resolution. The actual pixel
// count selected depends on the capabilities of the source. In order to
// not take a too large step up, we cap the requested pixel count to be at
// most four time the current number of pixels.
sink_wants_.target_pixel_count = (pixel_count * 5) / 3;
sink_wants_.target_pixel_count = GetHigherResolutionThan(pixel_count);
}
RTC_LOG(LS_INFO) << "Scaling up resolution, max pixels: "
<< max_pixels_wanted;
@ -1861,14 +1865,25 @@ void VideoStreamEncoder::OnBitrateUpdated(DataRate target_bitrate,
}
bool VideoStreamEncoder::DropDueToSize(uint32_t pixel_count) const {
if (initial_framedrop_ < kMaxInitialFramedrop &&
encoder_start_bitrate_bps_ > 0) {
if (initial_framedrop_ >= kMaxInitialFramedrop ||
encoder_start_bitrate_bps_ == 0) {
return false;
}
absl::optional<VideoEncoder::ResolutionBitrateLimits> encoder_bitrate_limits =
GetEncoderBitrateLimits(encoder_->GetEncoderInfo(), pixel_count);
if (encoder_bitrate_limits.has_value()) {
// Use bitrate limits provided by encoder.
return encoder_start_bitrate_bps_ <
static_cast<uint32_t>(encoder_bitrate_limits->min_start_bitrate_bps);
}
if (encoder_start_bitrate_bps_ < 300000 /* qvga */) {
return pixel_count > 320 * 240;
} else if (encoder_start_bitrate_bps_ < 500000 /* vga */) {
return pixel_count > 640 * 480;
}
}
return false;
}
@ -2032,6 +2047,14 @@ void VideoStreamEncoder::AdaptUp(AdaptReason reason) {
RTC_FALLTHROUGH();
}
case DegradationPreference::MAINTAIN_FRAMERATE: {
// Check if resolution should be increased based on bitrate and
// limits specified by encoder capabilities.
if (reason == kQuality &&
!CanAdaptUpResolution(last_frame_info_->pixel_count(),
encoder_start_bitrate_bps_)) {
return;
}
// Scale up resolution.
int pixel_count = adaptation_request.input_pixel_count_;
if (adapt_counter.ResolutionCount() == 1) {
@ -2073,6 +2096,19 @@ void VideoStreamEncoder::AdaptUp(AdaptReason reason) {
RTC_LOG(LS_INFO) << adapt_counter.ToString();
}
bool VideoStreamEncoder::CanAdaptUpResolution(int pixels,
uint32_t bitrate_bps) const {
absl::optional<VideoEncoder::ResolutionBitrateLimits> bitrate_limits =
GetEncoderBitrateLimits(encoder_info_,
source_proxy_->GetHigherResolutionThan(pixels));
if (!bitrate_limits.has_value() || bitrate_bps == 0) {
return true; // No limit configured or bitrate provided.
}
RTC_DCHECK_GE(bitrate_limits->frame_size_pixels, pixels);
return bitrate_bps >=
static_cast<uint32_t>(bitrate_limits->min_start_bitrate_bps);
}
// TODO(nisse): Delete, once AdaptReason and AdaptationReason are merged.
void VideoStreamEncoder::UpdateAdaptationStats(AdaptReason reason) {
switch (reason) {

2
video/video_stream_encoder.h
View File

@ -223,6 +223,8 @@ class VideoStreamEncoder : public VideoStreamEncoderInterface,
void UpdateAdaptationStats(AdaptReason reason) RTC_RUN_ON(&encoder_queue_);
VideoStreamEncoderObserver::AdaptationSteps GetActiveCounts(
AdaptReason reason) RTC_RUN_ON(&encoder_queue_);
bool CanAdaptUpResolution(int pixels, uint32_t bitrate_bps) const
RTC_RUN_ON(&encoder_queue_);
void RunPostEncode(EncodedImage encoded_image,
int64_t time_sent_us,
int temporal_index);

85
video/video_stream_encoder_unittest.cc
View File

@ -67,6 +67,10 @@ const int kMaxInitialFramedrop = 4;
const int kDefaultFramerate = 30;
const int64_t kFrameIntervalMs = rtc::kNumMillisecsPerSec / kDefaultFramerate;
const int64_t kProcessIntervalMs = 1000;
const VideoEncoder::ResolutionBitrateLimits
kEncoderBitrateLimits540p(960 * 540, 100 * 1000, 100 * 1000, 2000 * 1000);
const VideoEncoder::ResolutionBitrateLimits
kEncoderBitrateLimits720p(1280 * 720, 200 * 1000, 200 * 1000, 4000 * 1000);
uint8_t optimal_sps[] = {0, 0, 0, 1, H264::NaluType::kSps,
0x00, 0x00, 0x03, 0x03, 0xF4,
@ -2668,6 +2672,87 @@ TEST_F(VideoStreamEncoderTest,
video_stream_encoder_->Stop();
}
TEST_F(VideoStreamEncoderTest, AdaptUpIfBwEstimateIsHigherThanMinBitrate) {
fake_encoder_.SetResolutionBitrateLimits(
{kEncoderBitrateLimits540p, kEncoderBitrateLimits720p});
video_stream_encoder_->OnBitrateUpdated(
DataRate::bps(kEncoderBitrateLimits720p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits720p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits720p.min_start_bitrate_bps), 0, 0);
// Enable MAINTAIN_FRAMERATE preference, no initial limitation.
AdaptingFrameForwarder source;
source.set_adaptation_enabled(true);
video_stream_encoder_->SetSource(
&source, webrtc::DegradationPreference::MAINTAIN_FRAMERATE);
// Insert 720p frame.
int64_t timestamp_ms = kFrameIntervalMs;
source.IncomingCapturedFrame(CreateFrame(timestamp_ms, 1280, 720));
WaitForEncodedFrame(1280, 720);
// Reduce bitrate and trigger adapt down.
video_stream_encoder_->OnBitrateUpdated(
DataRate::bps(kEncoderBitrateLimits540p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits540p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits540p.min_start_bitrate_bps), 0, 0);
video_stream_encoder_->TriggerQualityLow();
// Insert 720p frame. It should be downscaled and encoded.
timestamp_ms += kFrameIntervalMs;
source.IncomingCapturedFrame(CreateFrame(timestamp_ms, 1280, 720));
WaitForEncodedFrame(960, 540);
// Trigger adapt up. Higher resolution should not be requested duo to lack
// of bitrate.
video_stream_encoder_->TriggerQualityHigh();
VerifyFpsMaxResolutionLt(source.sink_wants(), 1280 * 720);
// Increase bitrate.
video_stream_encoder_->OnBitrateUpdated(
DataRate::bps(kEncoderBitrateLimits720p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits720p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits720p.min_start_bitrate_bps), 0, 0);
// Trigger adapt up. Higher resolution should be requested.
video_stream_encoder_->TriggerQualityHigh();
VerifyFpsMaxResolutionMax(source.sink_wants());
video_stream_encoder_->Stop();
}
TEST_F(VideoStreamEncoderTest, DropFirstFramesIfBwEstimateIsTooLow) {
fake_encoder_.SetResolutionBitrateLimits(
{kEncoderBitrateLimits540p, kEncoderBitrateLimits720p});
// Set bitrate equal to min bitrate of 540p.
video_stream_encoder_->OnBitrateUpdated(
DataRate::bps(kEncoderBitrateLimits540p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits540p.min_start_bitrate_bps),
DataRate::bps(kEncoderBitrateLimits540p.min_start_bitrate_bps), 0, 0);
// Enable MAINTAIN_FRAMERATE preference, no initial limitation.
AdaptingFrameForwarder source;
source.set_adaptation_enabled(true);
video_stream_encoder_->SetSource(
&source, webrtc::DegradationPreference::MAINTAIN_FRAMERATE);
// Insert 720p frame. It should be dropped and lower resolution should be
// requested.
int64_t timestamp_ms = kFrameIntervalMs;
source.IncomingCapturedFrame(CreateFrame(timestamp_ms, 1280, 720));
ExpectDroppedFrame();
VerifyFpsMaxResolutionLt(source.sink_wants(), 1280 * 720);
// Insert 720p frame. It should be downscaled and encoded.
timestamp_ms += kFrameIntervalMs;
source.IncomingCapturedFrame(CreateFrame(timestamp_ms, 1280, 720));
WaitForEncodedFrame(960, 540);
video_stream_encoder_->Stop();
}
class BalancedDegradationTest : public VideoStreamEncoderTest {
protected:
void SetupTest() {