already_AddRefed<VideoPlaybackQuality>
HTMLVideoElement::GetVideoPlaybackQuality() {
DOMHighResTimeStamp creationTime = 0;
uint32_t totalFrames = 0;
uint32_t droppedFrames = 0;
uint32_t corruptedFrames = 0;
if (IsVideoStatsEnabled()) {
if (nsPIDOMWindowInner* window = OwnerDoc()->GetInnerWindow()) {
Performance* perf = window->GetPerformance();
if (perf) {
creationTime = perf->Now();
}
}
if (mDecoder) {
if (nsContentUtils::ShouldResistFingerprinting(OwnerDoc())) {
totalFrames = nsRFPService::GetSpoofedTotalFrames(TotalPlayTime());
droppedFrames = nsRFPService::GetSpoofedDroppedFrames(
TotalPlayTime(), VideoWidth(), VideoHeight());
corruptedFrames = 0;
} else {
FrameStatistics* stats = &mDecoder->GetFrameStatistics();
if (sizeof(totalFrames) >= sizeof(stats->GetParsedFrames())) {
totalFrames = stats->GetTotalFrames();
droppedFrames = stats->GetDroppedFrames();
} else {
uint64_t total = stats->GetTotalFrames();
const auto maxNumber = std::numeric_limits<uint32_t>::max();
if (total <= maxNumber) {
totalFrames = uint32_t(total);
droppedFrames = uint32_t(stats->GetDroppedFrames());
} else {
// Too big number(s) -> Resize everything to fit in 32 bits.
double ratio = double(maxNumber) / double(total);
totalFrames = maxNumber; // === total * ratio
droppedFrames = uint32_t(double(stats->GetDroppedFrames()) * ratio);
}
}
corruptedFrames = 0;
}
}
}
RefPtr<VideoPlaybackQuality> playbackQuality = new VideoPlaybackQuality(
this, creationTime, totalFrames, droppedFrames, corruptedFrames);
return playbackQuality.forget();
}
