Add default downscale threshold to QualityScaler.
Prevents downscaling below 160x90 or 90x160 to gain more quality.
BUG=4625
R=mflodman@webrtc.org
Review URL: https://codereview.webrtc.org/1160403004.
Cr-Commit-Position: refs/heads/master@{#9480}
diff --git a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
index e5a776e..4370424 100644
--- a/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
+++ b/webrtc/modules/video_coding/codecs/vp8/vp8_impl.cc
@@ -583,7 +583,7 @@
}
rps_.Init();
- quality_scaler_.Init(codec_.qpMax / kDefaultLowQpDenominator);
+ quality_scaler_.Init(codec_.qpMax / QualityScaler::kDefaultLowQpDenominator);
quality_scaler_.ReportFramerate(codec_.maxFramerate);
return InitAndSetControlSettings();
diff --git a/webrtc/modules/video_coding/utility/include/quality_scaler.h b/webrtc/modules/video_coding/utility/include/quality_scaler.h
index 3253435..1d6c917 100644
--- a/webrtc/modules/video_coding/utility/include/quality_scaler.h
+++ b/webrtc/modules/video_coding/utility/include/quality_scaler.h
@@ -15,9 +15,10 @@
#include "webrtc/modules/video_coding/utility/include/moving_average.h"
namespace webrtc {
-const int kDefaultLowQpDenominator = 3;
class QualityScaler {
public:
+ static const int kDefaultLowQpDenominator;
+ static const int kDefaultMinDownscaleDimension;
struct Resolution {
int width;
int height;
diff --git a/webrtc/modules/video_coding/utility/quality_scaler.cc b/webrtc/modules/video_coding/utility/quality_scaler.cc
index 3c9c6c4..7a2a9c0 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler.cc
@@ -15,9 +15,17 @@
static const int kMeasureSeconds = 5;
static const int kFramedropPercentThreshold = 60;
+const int QualityScaler::kDefaultLowQpDenominator = 3;
+// Note that this is the same for width and height to permit 120x90 in both
+// portrait and landscape mode.
+const int QualityScaler::kDefaultMinDownscaleDimension = 90;
+
QualityScaler::QualityScaler()
- : num_samples_(0), low_qp_threshold_(-1), downscale_shift_(0),
- min_width_(0), min_height_(0) {
+ : num_samples_(0),
+ low_qp_threshold_(-1),
+ downscale_shift_(0),
+ min_width_(kDefaultMinDownscaleDimension),
+ min_height_(kDefaultMinDownscaleDimension) {
}
void QualityScaler::Init(int low_qp_threshold) {
@@ -68,18 +76,13 @@
assert(downscale_shift_ >= 0);
for (int shift = downscale_shift_;
- shift > 0 && res.width > 1 && res.height > 1;
+ shift > 0 && (res.width >> 1 >= min_width_) &&
+ (res.height >> 1 >= min_height_);
--shift) {
res.width >>= 1;
res.height >>= 1;
}
- // Set this limitation for VP8 HW encoder to avoid crash.
- if (min_width_ > 0 && res.width * res.height < min_width_ * min_height_) {
- res.width = min_width_;
- res.height = min_height_;
- }
-
return res;
}
diff --git a/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc b/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc
index b93fd96..c09dffb 100644
--- a/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc
+++ b/webrtc/modules/video_coding/utility/quality_scaler_unittest.cc
@@ -31,11 +31,11 @@
QualityScalerTest() {
input_frame_.CreateEmptyFrame(
kWidth, kHeight, kWidth, kHalfWidth, kHalfWidth);
- qs_.Init(kMaxQp / kDefaultLowQpDenominator);
+ qs_.Init(kMaxQp / QualityScaler::kDefaultLowQpDenominator);
qs_.ReportFramerate(kFramerate);
}
- void TriggerScale(ScaleDirection scale_direction) {
+ bool TriggerScale(ScaleDirection scale_direction) {
int initial_width = qs_.GetScaledResolution(input_frame_).width;
for (int i = 0; i < kFramerate * kNumSeconds; ++i) {
switch (scale_direction) {
@@ -48,10 +48,10 @@
}
if (qs_.GetScaledResolution(input_frame_).width != initial_width)
- return;
+ return true;
}
- FAIL() << "No downscale within " << kNumSeconds << " seconds.";
+ return false;
}
void ExpectOriginalFrame() {
@@ -70,6 +70,11 @@
void DoesNotDownscaleFrameDimensions(int width, int height);
+ void DownscaleEndsAt(int input_width,
+ int input_height,
+ int end_width,
+ int end_height);
+
QualityScaler qs_;
VideoFrame input_frame_;
};
@@ -85,7 +90,8 @@
}
TEST_F(QualityScalerTest, DownscalesAfterContinuousFramedrop) {
- TriggerScale(kScaleDown);
+ EXPECT_TRUE(TriggerScale(kScaleDown)) << "No downscale within " << kNumSeconds
+ << " seconds.";
QualityScaler::Resolution res = qs_.GetScaledResolution(input_frame_);
EXPECT_LT(res.width, input_frame_.width());
EXPECT_LT(res.height, input_frame_.height());
@@ -130,8 +136,9 @@
int min_dimension = initial_min_dimension;
int current_shift = 0;
// Drop all frames to force-trigger downscaling.
- while (min_dimension > 16) {
- TriggerScale(kScaleDown);
+ while (min_dimension >= 2 * QualityScaler::kDefaultMinDownscaleDimension) {
+ EXPECT_TRUE(TriggerScale(kScaleDown)) << "No downscale within "
+ << kNumSeconds << " seconds.";
QualityScaler::Resolution res = qs_.GetScaledResolution(input_frame_);
min_dimension = res.width < res.height ? res.width : res.height;
++current_shift;
@@ -142,7 +149,8 @@
// Make sure we can scale back with good-quality frames.
while (min_dimension < initial_min_dimension) {
- TriggerScale(kScaleUp);
+ EXPECT_TRUE(TriggerScale(kScaleUp)) << "No upscale within " << kNumSeconds
+ << " seconds.";
QualityScaler::Resolution res = qs_.GetScaledResolution(input_frame_);
min_dimension = res.width < res.height ? res.width : res.height;
--current_shift;
@@ -195,4 +203,72 @@
DoesNotDownscaleFrameDimensions(1, 1);
}
+TEST_F(QualityScalerTest, DoesNotDownscaleBelow2xDefaultMinDimensionsWidth) {
+ DoesNotDownscaleFrameDimensions(
+ 2 * QualityScaler::kDefaultMinDownscaleDimension - 1, 1000);
+}
+
+TEST_F(QualityScalerTest, DoesNotDownscaleBelow2xDefaultMinDimensionsHeight) {
+ DoesNotDownscaleFrameDimensions(
+ 1000, 2 * QualityScaler::kDefaultMinDownscaleDimension - 1);
+}
+
+void QualityScalerTest::DownscaleEndsAt(int input_width,
+ int input_height,
+ int end_width,
+ int end_height) {
+ // Create a frame with 2x expected end width/height to verify that we can
+ // scale down to expected end width/height.
+ input_frame_.CreateEmptyFrame(input_width, input_height, input_width,
+ (input_width + 1) / 2, (input_width + 1) / 2);
+
+ int last_width = input_width;
+ int last_height = input_height;
+ // Drop all frames to force-trigger downscaling.
+ while (true) {
+ TriggerScale(kScaleDown);
+ QualityScaler::Resolution res = qs_.GetScaledResolution(input_frame_);
+ if (last_width == res.width) {
+ EXPECT_EQ(last_height, res.height);
+ EXPECT_EQ(end_width, res.width);
+ EXPECT_EQ(end_height, res.height);
+ break;
+ }
+ last_width = res.width;
+ last_height = res.height;
+ }
+}
+
+TEST_F(QualityScalerTest, DefaultDownscalesTo160x90) {
+ DownscaleEndsAt(320, 180, 160, 90);
+}
+
+TEST_F(QualityScalerTest, DefaultDownscalesTo90x160) {
+ DownscaleEndsAt(180, 320, 90, 160);
+}
+
+TEST_F(QualityScalerTest, DefaultDownscalesFrom1280x720To160x90) {
+ DownscaleEndsAt(1280, 720, 160, 90);
+}
+
+TEST_F(QualityScalerTest, DefaultDoesntDownscaleBelow160x90) {
+ DownscaleEndsAt(320 - 1, 180 - 1, 320 - 1, 180 - 1);
+}
+
+TEST_F(QualityScalerTest, DefaultDoesntDownscaleBelow90x160) {
+ DownscaleEndsAt(180 - 1, 320 - 1, 180 - 1, 320 - 1);
+}
+
+TEST_F(QualityScalerTest, RespectsMinResolutionWidth) {
+ // Should end at 200x100, as width can't go lower.
+ qs_.SetMinResolution(200, 10);
+ DownscaleEndsAt(1600, 800, 200, 100);
+}
+
+TEST_F(QualityScalerTest, RespectsMinResolutionHeight) {
+ // Should end at 100x200, as height can't go lower.
+ qs_.SetMinResolution(10, 200);
+ DownscaleEndsAt(800, 1600, 100, 200);
+}
+
} // namespace webrtc
