Update sink wants with ranges for both pixel count and frame rate.

webrtc/media/base/videoadapter.cc

Index: webrtc/media/base/videoadapter.cc
diff --git a/webrtc/media/base/videoadapter.cc b/webrtc/media/base/videoadapter.cc
index 660df8ad673e8f40668d8f150722cb21082073ee..9175ae8cb1558ec2400df6e84d80ab4831a1d895 100644
--- a/webrtc/media/base/videoadapter.cc
+++ b/webrtc/media/base/videoadapter.cc
@@ -21,15 +21,16 @@
 #include "webrtc/base/optional.h"
 #include "webrtc/media/base/mediaconstants.h"
 #include "webrtc/media/base/videocommon.h"
+#include "webrtc/media/base/videosourceinterface.h"
 
 namespace {
 struct Fraction {
-  int numerator;
-  int denominator;
+  uint32_t numerator;
+  uint32_t denominator;
 
   // Determines number of output pixels if both width and height of an input of
   // |input_pixels| pixels is scaled with the fraction numerator / denominator.
-  int scale_pixel_count(int input_pixels) {
+  uint32_t scale_pixel_count(uint32_t input_pixels) {
     return (numerator * numerator * input_pixels) / (denominator * denominator);
   }
 };
@@ -45,7 +46,10 @@ int roundUp(int value_to_round, int multiple, int max_value) {
 
 // Generates a scale factor that makes |input_pixels| close to |target_pixels|,
 // but no higher than |max_pixels|.
-Fraction FindScale(int input_pixels, int target_pixels, int max_pixels) {
+Fraction FindScale(uint32_t input_pixels,
+                   uint32_t target_pixels,
+                   uint32_t max_pixels,
+                   uint32_t min_pixels) {
   // This function only makes sense for a positive target.
   RTC_DCHECK_GT(target_pixels, 0);
   RTC_DCHECK_GT(max_pixels, 0);
@@ -59,10 +63,12 @@ Fraction FindScale(int input_pixels, int target_pixels, int max_pixels) {
   Fraction best_scale = Fraction{1, 1};
   // The minimum (absolute) difference between the number of output pixels and
   // the target pixel count.
-  int min_pixel_diff = std::numeric_limits<int>::max();
+  uint32_t min_pixel_diff = std::numeric_limits<uint32_t>::max();
   if (input_pixels < max_pixels) {
     // Start condition for 1/1 case, if it is less than max.
-    min_pixel_diff = std::abs(input_pixels - target_pixels);
+    min_pixel_diff = target_pixels > input_pixels
+                         ? target_pixels - input_pixels
+                         : input_pixels - target_pixels;
   }
 
   // Alternately scale down by 2/3 and 3/4. This results in fractions which are
@@ -81,9 +87,15 @@ Fraction FindScale(int input_pixels, int target_pixels, int max_pixels) {
       current_scale.denominator *= 4;
     }
 
-    int output_pixels = current_scale.scale_pixel_count(input_pixels);
+    uint32_t output_pixels = current_scale.scale_pixel_count(input_pixels);
+    if (output_pixels < min_pixels) {
+      // Don't violate lower bound;
+      break;
+    }
     if (output_pixels <= max_pixels) {
-      int diff = std::abs(target_pixels - output_pixels);
+      uint32_t diff = target_pixels < output_pixels
+                          ? output_pixels - target_pixels
+                          : target_pixels - output_pixels;
       if (diff < min_pixel_diff) {
         min_pixel_diff = diff;
         best_scale = current_scale;
@@ -104,9 +116,7 @@ VideoAdapter::VideoAdapter(int required_resolution_alignment)
       adaption_changes_(0),
       previous_width_(0),
       previous_height_(0),
-      required_resolution_alignment_(required_resolution_alignment),
-      resolution_request_target_pixel_count_(std::numeric_limits<int>::max()),
-      resolution_request_max_pixel_count_(std::numeric_limits<int>::max()) {}
+      required_resolution_alignment_(required_resolution_alignment) {}
 
 VideoAdapter::VideoAdapter() : VideoAdapter(1) {}
 
@@ -114,21 +124,35 @@ VideoAdapter::~VideoAdapter() {}
 
 bool VideoAdapter::KeepFrame(int64_t in_timestamp_ns) {
   rtc::CritScope cs(&critical_section_);
-  if (!requested_format_ || requested_format_->interval == 0)
+
+  int64_t frame_interval_ns = 0;
+  if (requested_format_ && requested_format_->interval)
+    frame_interval_ns = requested_format_->interval;
+  // TODO(sprang): Take target/min into consideration when implementing smoother
+  // frame dropping.
+  if (requested_framerate_fps_) {
+    frame_interval_ns = std::max<int64_t>(
+        frame_interval_ns,
+        rtc::kNumNanosecsPerSec / requested_framerate_fps_->max);
+  }
+
+  if (frame_interval_ns <= 0) {
+    // Frame rate throttling not enabled.
     return true;
+  }
 
   if (next_frame_timestamp_ns_) {
     // Time until next frame should be outputted.
     const int64_t time_until_next_frame_ns =
         (*next_frame_timestamp_ns_ - in_timestamp_ns);
 
-    // Continue if timestamp is withing expected range.
-    if (std::abs(time_until_next_frame_ns) < 2 * requested_format_->interval) {
+    // Continue if timestamp is within expected range.
+    if (std::abs(time_until_next_frame_ns) < 2 * frame_interval_ns) {
       // Drop if a frame shouldn't be outputted yet.
       if (time_until_next_frame_ns > 0)
         return false;
       // Time to output new frame.
-      *next_frame_timestamp_ns_ += requested_format_->interval;
+      *next_frame_timestamp_ns_ += frame_interval_ns;
       return true;
     }
   }
@@ -137,7 +161,7 @@ bool VideoAdapter::KeepFrame(int64_t in_timestamp_ns) {
   // reset. Set first timestamp target to just half the interval to prefer
   // keeping frames in case of jitter.
   next_frame_timestamp_ns_ =
-      rtc::Optional<int64_t>(in_timestamp_ns + requested_format_->interval / 2);
+      rtc::Optional<int64_t>(in_timestamp_ns + frame_interval_ns / 2);
   return true;
 }
 
@@ -153,13 +177,19 @@ bool VideoAdapter::AdaptFrameResolution(int in_width,
 
   // The max output pixel count is the minimum of the requests from
   // OnOutputFormatRequest and OnResolutionRequest.
-  int max_pixel_count = resolution_request_max_pixel_count_;
+
+  rtc::VideoSinkWants::Range requested_range =
+      requested_pixel_count_.value_or(rtc::VideoSinkWants::Range());
+  RTC_DCHECK_GE(requested_range.target, requested_range.min);
+  RTC_DCHECK_GE(requested_range.max, requested_range.target);
+  uint32_t max_pixel_count = requested_range.max;
   if (requested_format_) {
     max_pixel_count = std::min(
-        max_pixel_count, requested_format_->width * requested_format_->height);
+        max_pixel_count, static_cast<uint32_t>(requested_format_->width *
+                                               requested_format_->height));
   }
-  int target_pixel_count =
-      std::min(resolution_request_target_pixel_count_, max_pixel_count);
+  uint32_t target_pixel_count =
+      std::min(requested_range.target, max_pixel_count);
 
   // Drop the input frame if necessary.
   if (max_pixel_count <= 0 || !KeepFrame(in_timestamp_ns)) {
@@ -201,8 +231,9 @@ bool VideoAdapter::AdaptFrameResolution(int in_width,
     *cropped_height =
         std::min(in_height, static_cast<int>(in_width / requested_aspect));
   }
-  const Fraction scale = FindScale((*cropped_width) * (*cropped_height),
-                                   target_pixel_count, max_pixel_count);
+  const Fraction scale =
+      FindScale((*cropped_width) * (*cropped_height), target_pixel_count,
+                max_pixel_count, requested_range.min);
   // Adjust cropping slightly to get even integer output size and a perfect
   // scale factor. Make sure the resulting dimensions are aligned correctly
   // to be nice to hardware encoders.
@@ -249,14 +280,12 @@ void VideoAdapter::OnOutputFormatRequest(const VideoFormat& format) {
   next_frame_timestamp_ns_ = rtc::Optional<int64_t>();
 }
 
-void VideoAdapter::OnResolutionRequest(
-    const rtc::Optional<int>& target_pixel_count,
-    const rtc::Optional<int>& max_pixel_count) {
+void VideoAdapter::OnResolutionFramerateRequest(
+    const rtc::Optional<rtc::VideoSinkWants::Range>& pixel_count,
+    const rtc::Optional<rtc::VideoSinkWants::Range>& framerate_fps) {
   rtc::CritScope cs(&critical_section_);
-  resolution_request_max_pixel_count_ =
-      max_pixel_count.value_or(std::numeric_limits<int>::max());
-  resolution_request_target_pixel_count_ =
-      target_pixel_count.value_or(resolution_request_max_pixel_count_);
+  requested_pixel_count_ = pixel_count;
+  requested_framerate_fps_ = framerate_fps;
 }
 
 }  // namespace cricket