Add QVGA to thresholds for initial quality.
Makes QualityScaler start at QVGA for <250k initial bitrates. Useful in
combination with overriding max bitrates to a max lower than that for
connections where we know that the max bitrate is capped below where VGA
is useful.
BUG=webrtc:5678
R=glaznev@webrtc.org
Review URL: https://codereview.webrtc.org/1900483004 .
Cr-Commit-Position: refs/heads/master@{#12416}
diff --git a/webrtc/modules/video_coding/utility/quality_scaler.cc b/webrtc/modules/video_coding/utility/quality_scaler.cc
index 0e1f1d4..a5e8c22 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler.cc
@@ -18,11 +18,16 @@
static const int kMeasureSecondsUpscale = 5;
static const int kMeasureSecondsDownscale = 5;
static const int kFramedropPercentThreshold = 60;
-static const int kHdResolutionThreshold = 700 * 500;
-static const int kHdBitrateThresholdKbps = 500;
// Min width/height to downscale to, set to not go below QVGA, but with some
// margin to permit "almost-QVGA" resolutions, such as QCIF.
static const int kMinDownscaleDimension = 140;
+// Initial resolutions corresponding to a bitrate. Aa bit above their actual
+// values to permit near-VGA and near-QVGA resolutions to use the same
+// mechanism.
+static const int kVgaBitrateThresholdKbps = 500;
+static const int kVgaNumPixels = 700 * 500; // 640x480
+static const int kQvgaBitrateThresholdKbps = 250;
+static const int kQvgaNumPixels = 400 * 300; // 320x240
} // namespace
QualityScaler::QualityScaler()
@@ -46,12 +51,13 @@
measure_seconds_upscale_ = kMeasureSecondsFastUpscale;
const int init_width = width;
const int init_height = height;
- // TODO(glaznev): Investigate using thresholds for other resolutions
- // or threshold tables.
- if (initial_bitrate_kbps > 0 &&
- initial_bitrate_kbps < kHdBitrateThresholdKbps) {
- // Start scaling to roughly VGA.
- while (width * height > kHdResolutionThreshold) {
+ if (initial_bitrate_kbps > 0) {
+ int init_num_pixels = width * height;
+ if (initial_bitrate_kbps < kVgaBitrateThresholdKbps)
+ init_num_pixels = kVgaNumPixels;
+ if (initial_bitrate_kbps < kQvgaBitrateThresholdKbps)
+ init_num_pixels = kQvgaNumPixels;
+ while (width * height > init_num_pixels) {
++downscale_shift_;
width /= 2;
height /= 2;
diff --git a/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc b/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc
index 0f761c7..58c41ad 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc
@@ -16,10 +16,8 @@
namespace {
static const int kNumSeconds = 10;
static const int kWidth = 1920;
-static const int kWidthVga = 640;
static const int kHalfWidth = kWidth / 2;
static const int kHeight = 1080;
-static const int kHeightVga = 480;
static const int kFramerate = 30;
static const int kLowQp = 15;
static const int kNormalQp = 30;
@@ -380,13 +378,33 @@
}
TEST_F(QualityScalerTest, DownscaleToVgaOnLowInitialBitrate) {
- qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, true,
- kLowInitialBitrateKbps, kWidth, kHeight, kFramerate);
+ static const int kWidth720p = 1280;
+ static const int kHeight720p = 720;
+ static const int kInitialBitrateKbps = 300;
+ input_frame_.CreateEmptyFrame(kWidth720p, kHeight720p, kWidth720p,
+ kWidth720p / 2, kWidth720p / 2);
+ qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, true, kInitialBitrateKbps,
+ kWidth720p, kHeight720p, kFramerate);
qs_.OnEncodeFrame(input_frame_);
int init_width = qs_.GetScaledResolution().width;
int init_height = qs_.GetScaledResolution().height;
- EXPECT_LE(init_width, kWidthVga);
- EXPECT_LE(init_height, kHeightVga);
+ EXPECT_EQ(640, init_width);
+ EXPECT_EQ(360, init_height);
+}
+
+TEST_F(QualityScalerTest, DownscaleToQvgaOnLowerInitialBitrate) {
+ static const int kWidth720p = 1280;
+ static const int kHeight720p = 720;
+ static const int kInitialBitrateKbps = 200;
+ input_frame_.CreateEmptyFrame(kWidth720p, kHeight720p, kWidth720p,
+ kWidth720p / 2, kWidth720p / 2);
+ qs_.Init(kLowQpThreshold, kDisabledBadQpThreshold, true, kInitialBitrateKbps,
+ kWidth720p, kHeight720p, kFramerate);
+ qs_.OnEncodeFrame(input_frame_);
+ int init_width = qs_.GetScaledResolution().width;
+ int init_height = qs_.GetScaledResolution().height;
+ EXPECT_EQ(320, init_width);
+ EXPECT_EQ(180, init_height);
}
TEST_F(QualityScalerTest, DownscaleAfterMeasuredSecondsThenSlowerBackUp) {
