Bug 1755332 - VideoDecoderConfig.framerate is a double. r=alwu,webidl,smaug

Spec change: https://github.com/w3c/media-capabilities/issues/96#issuecomment-537364759
Spec text: https://w3c.github.io/media-capabilities/#dom-videoconfiguration-framerate

Differential Revision: https://phabricator.services.mozilla.com/D138780

dom/media/MediaMIMETypes.cpp

@@ -145,43 +145,6 @@ MediaExtendedMIMEType::MediaExtendedMIMEType(const MediaMIMEType& aType)
 MediaExtendedMIMEType::MediaExtendedMIMEType(MediaMIMEType&& aType)
     : mOriginalString(aType.AsString()), mMIMEType(std::move(aType)) {}
 
-/* static */
-Maybe<double> MediaExtendedMIMEType::ComputeFractionalString(
-    const nsAString& aFrac) {
-  nsAutoString frac(aFrac);
-  nsresult error;
-  double result = frac.ToDouble(&error);
-  if (NS_SUCCEEDED(error)) {
-    if (result <= 0) {
-      return Nothing();
-    }
-    return Some(result);
-  }
-
-  int32_t slashPos = frac.Find(u"/"_ns);
-  if (slashPos == kNotFound) {
-    return Nothing();
-  }
-
-  nsAutoString firstPart(Substring(frac, 0, slashPos - 1));
-  double first = firstPart.ToDouble(&error);
-  if (NS_FAILED(error)) {
-    return Nothing();
-  }
-  nsAutoString secondPart(Substring(frac, slashPos + 1));
-  double second = secondPart.ToDouble(&error);
-  if (NS_FAILED(error) || second == 0) {
-    return Nothing();
-  }
-
-  result = first / second;
-  if (result <= 0) {
-    return Nothing();
-  }
-
-  return Some(result);
-}
-
 Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(const nsAString& aType) {
   nsContentTypeParser parser(aType);
   nsAutoString mime;
@@ -230,15 +193,13 @@ Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(
   rv = parser.GetParameter("codecs", codecs);
   bool haveCodecs = NS_SUCCEEDED(rv);
 
-  auto framerate =
-      MediaExtendedMIMEType::ComputeFractionalString(aConfig.mFramerate);
-  if (!framerate) {
+  if (!IsFinite(aConfig.mFramerate) || aConfig.mFramerate <= 0.0) {
     return Nothing();
   }
 
   return Some(MediaExtendedMIMEType(
       NS_ConvertUTF16toUTF8(aConfig.mContentType), mime8, haveCodecs, codecs,
-      aConfig.mWidth, aConfig.mHeight, framerate.ref(), aConfig.mBitrate));
+      aConfig.mWidth, aConfig.mHeight, aConfig.mFramerate, aConfig.mBitrate));
 }
 
 Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(

dom/media/MediaMIMETypes.h

@@ -172,10 +172,6 @@ class MediaExtendedMIMEType {
 
   size_t SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const;
 
-  // aFrac is either a floating-point number or a fraction made of two
-  // floating-point numbers.
-  static Maybe<double> ComputeFractionalString(const nsAString& aFrac);
-
  private:
   friend Maybe<MediaExtendedMIMEType> MakeMediaExtendedMIMEType(
       const nsAString& aType);

dom/media/mediacapabilities/MediaCapabilities.cpp

@@ -63,11 +63,10 @@ static nsCString VideoConfigurationToStr(const VideoConfiguration* aConfig) {
 
   auto str = nsPrintfCString(
       "[contentType:%s width:%d height:%d bitrate:%" PRIu64
-      " framerate:%s hasAlphaChannel:%s hdrMetadataType:%s colorGamut:%s "
+      " framerate:%lf hasAlphaChannel:%s hdrMetadataType:%s colorGamut:%s "
       "transferFunction:%s scalabilityMode:%s]",
       NS_ConvertUTF16toUTF8(aConfig->mContentType).get(), aConfig->mWidth,
-      aConfig->mHeight, aConfig->mBitrate,
-      NS_ConvertUTF16toUTF8(aConfig->mFramerate).get(),
+      aConfig->mHeight, aConfig->mBitrate, aConfig->mFramerate,
       aConfig->mHasAlphaChannel.WasPassed()
           ? aConfig->mHasAlphaChannel.Value() ? "true" : "false"
           : "?",

dom/webidl/MediaCapabilities.webidl

@@ -37,7 +37,7 @@ dictionary VideoConfiguration {
   required unsigned long width;
   required unsigned long height;
   required unsigned long long bitrate;
-  required DOMString framerate;
+  required double framerate;
   boolean hasAlphaChannel;
   HdrMetadataType hdrMetadataType;
   ColorGamut colorGamut;

testing/web-platform/meta/media-capabilities/decodingInfo.any.js.ini

@@ -8,9 +8,6 @@
   [Test that decodingInfo rejects if the video configuration contentType has more than one parameter]
     expected: FAIL
 
-  [Test that decodingInfo() rejects framerate in the form of x/y]
-    expected: FAIL
-
   [Test that decodingInfo with spatialRendering set returns a valid MediaCapabilitiesInfo objects]
     expected: FAIL
 
@@ -37,9 +34,6 @@
   [Test that decodingInfo rejects if the video configuration contentType has more than one parameter]
     expected: FAIL
 
-  [Test that decodingInfo() rejects framerate in the form of x/y]
-    expected: FAIL
-
   [Test that decodingInfo with spatialRendering set returns a valid MediaCapabilitiesInfo objects]
     expected: FAIL