void
MediaEngineGonkVideoSource::ChooseCapability(const VideoTrackConstraintsN& aConstraints,
const MediaEnginePrefs& aPrefs)
{
return GuessCapability(aConstraints, aPrefs);
}
void
MediaEngineWebRTCVideoSource::ChooseCapability(
const VideoTrackConstraintsN &aConstraints,
const MediaEnginePrefs &aPrefs)
{
NS_ConvertUTF16toUTF8 uniqueId(mUniqueId);
int num = mViECapture->NumberOfCapabilities(uniqueId.get(), kMaxUniqueIdLength);
if (num <= 0) {
// Mac doesn't support capabilities.
return GuessCapability(aConstraints, aPrefs);
}
// The rest is the full algorithm for cameras that can list their capabilities.
LOG(("ChooseCapability: prefs: %dx%d @%d-%dfps",
aPrefs.mWidth, aPrefs.mHeight, aPrefs.mFPS, aPrefs.mMinFPS));
typedef nsTArray<uint8_t> SourceSet;
SourceSet candidateSet;
for (int i = 0; i < num; i++) {
candidateSet.AppendElement(i);
}
// Pick among capabilities: First apply required constraints.
for (uint32_t i = 0; i < candidateSet.Length();) {
webrtc::CaptureCapability cap;
mViECapture->GetCaptureCapability(uniqueId.get(), kMaxUniqueIdLength,
candidateSet[i], cap);
if (!SatisfyConstraintSet(aConstraints.mRequired, cap)) {
candidateSet.RemoveElementAt(i);
} else {
++i;
}
}
SourceSet tailSet;
// Then apply advanced (formerly known as optional) constraints.
if (aConstraints.mAdvanced.WasPassed()) {
auto &array = aConstraints.mAdvanced.Value();
for (uint32_t i = 0; i < array.Length(); i++) {
SourceSet rejects;
for (uint32_t j = 0; j < candidateSet.Length();) {
webrtc::CaptureCapability cap;
mViECapture->GetCaptureCapability(uniqueId.get(), kMaxUniqueIdLength,
candidateSet[j], cap);
if (!SatisfyConstraintSet(array[i], cap)) {
rejects.AppendElement(candidateSet[j]);
candidateSet.RemoveElementAt(j);
} else {
++j;
}
}
(candidateSet.Length()? tailSet : candidateSet).MoveElementsFrom(rejects);
}
}
if (!candidateSet.Length()) {
candidateSet.AppendElement(0);
}
int prefWidth = aPrefs.GetWidth();
int prefHeight = aPrefs.GetHeight();
// Default is closest to available capability but equal to or below;
// otherwise closest above. Since we handle the num=0 case above and
// take the first entry always, we can never exit uninitialized.
webrtc::CaptureCapability cap;
bool higher = true;
for (uint32_t i = 0; i < candidateSet.Length(); i++) {
mViECapture->GetCaptureCapability(NS_ConvertUTF16toUTF8(mUniqueId).get(),
kMaxUniqueIdLength, candidateSet[i], cap);
if (higher) {
if (i == 0 ||
(mCapability.width > cap.width && mCapability.height > cap.height)) {
// closer than the current choice
mCapability = cap;
// FIXME: expose expected capture delay?
}
if (cap.width <= (uint32_t) prefWidth && cap.height <= (uint32_t) prefHeight) {
higher = false;
}
} else {
if (cap.width > (uint32_t) prefWidth || cap.height > (uint32_t) prefHeight ||
cap.maxFPS < (uint32_t) aPrefs.mMinFPS) {
continue;
}
if (mCapability.width < cap.width && mCapability.height < cap.height) {
mCapability = cap;
// FIXME: expose expected capture delay?
}
}
// Same resolution, maybe better format or FPS match
if (mCapability.width == cap.width && mCapability.height == cap.height) {
// FPS too low
if (cap.maxFPS < (uint32_t) aPrefs.mMinFPS) {
continue;
}
// Better match
if (cap.maxFPS < mCapability.maxFPS) {
mCapability = cap;
} else if (cap.maxFPS == mCapability.maxFPS) {
// Resolution and FPS the same, check format
if (cap.rawType == webrtc::RawVideoType::kVideoI420
|| cap.rawType == webrtc::RawVideoType::kVideoYUY2
|| cap.rawType == webrtc::RawVideoType::kVideoYV12) {
mCapability = cap;
}
}
}
}
LOG(("chose cap %dx%d @%dfps codec %d raw %d",
mCapability.width, mCapability.height, mCapability.maxFPS,
mCapability.codecType, mCapability.rawType));
}