Add framerate to VideoSinkWants and ability to signal on overuse

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 589be63c8021351e9d690f611b12705e9ca088e4..98c8056e3eefffbfb352ff3caf00e4aa285c4834 100644
--- a/webrtc/media/base/videoadapter.cc
+++ b/webrtc/media/base/videoadapter.cc
@@ -106,7 +106,8 @@ VideoAdapter::VideoAdapter(int required_resolution_alignment)
       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()) {}
+      resolution_request_max_pixel_count_(std::numeric_limits<int>::max()),
+      max_framerate_request_(std::numeric_limits<int>::max()) {}
 
 VideoAdapter::VideoAdapter() : VideoAdapter(1) {}
 
@@ -114,21 +115,32 @@ 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;
+
+  if (std::numeric_limits<int>::max() != 0) {

[magjed_webrtc, 2017/02/27 09:30:35]

I think this should be 'max_framerate_request_ != 0' instead. Also, if
'max_framerate_request_ == 0', shouldn't we always return false?

[sprang_webrtc, 2017/02/27 12:51:49]

Whoops. That should be 
max_framerate_request_ != std::numeric_limits<int>::max()
bad copy/paste screwup... These are the tests I mentioned are coming :)
And yes, should return false if max_framerate_request_ <= 0

+    frame_interval_ns = std::max<int64_t>(
+        frame_interval_ns, rtc::kNumNanosecsPerSec / max_framerate_request_);
+  }
+
+  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 +149,7 @@ 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;
 }
 
@@ -249,14 +261,17 @@ void VideoAdapter::OnOutputFormatRequest(const VideoFormat& format) {
   next_frame_timestamp_ns_ = rtc::Optional<int64_t>();
 }
 
-void VideoAdapter::OnResolutionRequest(
+void VideoAdapter::OnResolutionFramerateRequest(
     const rtc::Optional<int>& target_pixel_count,
-    const rtc::Optional<int>& max_pixel_count) {
+    const rtc::Optional<int>& max_pixel_count,
+    const rtc::Optional<int>& 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_);
+  max_framerate_request_ =
+      framerate_fps.value_or(std::numeric_limits<int>::max());
 }
 
 }  // namespace cricket