The Tor Browser / file revision

 /* This Source Code Form is subject to the terms of the Mozilla Public

  * License, v. 2.0. If a copy of the MPL was not distributed with this

  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

 #include "VideoUtils.h"

 #include "MediaResource.h"

 #include "mozilla/dom/TimeRanges.h"

 #include "nsMathUtils.h"

 #include "nsSize.h"

 #include "VorbisUtils.h"

 #include "ImageContainer.h"

 #include <stdint.h>

 namespace mozilla {

 using layers::PlanarYCbCrImage;

 // Converts from number of audio frames to microseconds, given the specified

 // audio rate.

 CheckedInt64 FramesToUsecs(int64_t aFrames, uint32_t aRate) {

   return (CheckedInt64(aFrames) * USECS_PER_S) / aRate;

 }

 // Converts from microseconds to number of audio frames, given the specified

 // audio rate.

 CheckedInt64 UsecsToFrames(int64_t aUsecs, uint32_t aRate) {

   return (CheckedInt64(aUsecs) * aRate) / USECS_PER_S;

 }

 nsresult SecondsToUsecs(double aSeconds, int64_t& aOutUsecs) {

   if (aSeconds * double(USECS_PER_S) > INT64_MAX) {

     return NS_ERROR_FAILURE;

   }

   aOutUsecs = int64_t(aSeconds * double(USECS_PER_S));

   return NS_OK;

 }

 static int32_t ConditionDimension(float aValue)

 {

   // This will exclude NaNs and too-big values.

   if (aValue > 1.0 && aValue <= INT32_MAX)

     return int32_t(NS_round(aValue));

   return 0;

 }

 void ScaleDisplayByAspectRatio(nsIntSize& aDisplay, float aAspectRatio)

 {

   if (aAspectRatio > 1.0) {

     // Increase the intrinsic width

     aDisplay.width = ConditionDimension(aAspectRatio * aDisplay.width);

   } else {

     // Increase the intrinsic height

     aDisplay.height = ConditionDimension(aDisplay.height / aAspectRatio);

   }

 }

 static int64_t BytesToTime(int64_t offset, int64_t length, int64_t durationUs) {

   NS_ASSERTION(length > 0, "Must have positive length");

   double r = double(offset) / double(length);

   if (r > 1.0)

     r = 1.0;

   return int64_t(double(durationUs) * r);

 }

 void GetEstimatedBufferedTimeRanges(mozilla::MediaResource* aStream,

                                     int64_t aDurationUsecs,

                                     mozilla::dom::TimeRanges* aOutBuffered)

 {

   // Nothing to cache if the media takes 0us to play.

   if (aDurationUsecs <= 0 || !aStream || !aOutBuffered)

     return;

   // Special case completely cached files.  This also handles local files.

   if (aStream->IsDataCachedToEndOfResource(0)) {

     aOutBuffered->Add(0, double(aDurationUsecs) / USECS_PER_S);

     return;

   }

   int64_t totalBytes = aStream->GetLength();

   // If we can't determine the total size, pretend that we have nothing

   // buffered. This will put us in a state of eternally-low-on-undecoded-data

   // which is not great, but about the best we can do.

   if (totalBytes <= 0)

     return;

   int64_t startOffset = aStream->GetNextCachedData(0);

   while (startOffset >= 0) {

     int64_t endOffset = aStream->GetCachedDataEnd(startOffset);

     // Bytes [startOffset..endOffset] are cached.

     NS_ASSERTION(startOffset >= 0, "Integer underflow in GetBuffered");

     NS_ASSERTION(endOffset >= 0, "Integer underflow in GetBuffered");

     int64_t startUs = BytesToTime(startOffset, totalBytes, aDurationUsecs);

     int64_t endUs = BytesToTime(endOffset, totalBytes, aDurationUsecs);

     if (startUs != endUs) {

       aOutBuffered->Add(double(startUs) / USECS_PER_S,

                         double(endUs) / USECS_PER_S);

     }

     startOffset = aStream->GetNextCachedData(endOffset);

   }

   return;

 }

 int DownmixAudioToStereo(mozilla::AudioDataValue* buffer,

                          int channels, uint32_t frames)

 {

   int outChannels;

   outChannels = 2;

 #ifdef MOZ_SAMPLE_TYPE_FLOAT32

   // Downmix matrix. Per-row normalization 1 for rows 3,4 and 2 for rows 5-8.

   static const float dmatrix[6][8][2]= {

       /*3*/{{0.5858f,0},{0.4142f,0.4142f},{0,     0.5858f}},

       /*4*/{{0.4226f,0},{0,      0.4226f},{0.366f,0.2114f},{0.2114f,0.366f}},

       /*5*/{{0.6510f,0},{0.4600f,0.4600f},{0,     0.6510f},{0.5636f,0.3254f},{0.3254f,0.5636f}},

       /*6*/{{0.5290f,0},{0.3741f,0.3741f},{0,     0.5290f},{0.4582f,0.2645f},{0.2645f,0.4582f},{0.3741f,0.3741f}},

       /*7*/{{0.4553f,0},{0.3220f,0.3220f},{0,     0.4553f},{0.3943f,0.2277f},{0.2277f,0.3943f},{0.2788f,0.2788f},{0.3220f,0.3220f}},

       /*8*/{{0.3886f,0},{0.2748f,0.2748f},{0,     0.3886f},{0.3366f,0.1943f},{0.1943f,0.3366f},{0.3366f,0.1943f},{0.1943f,0.3366f},{0.2748f,0.2748f}},

   };

   // Re-write the buffer with downmixed data

   for (uint32_t i = 0; i < frames; i++) {

     float sampL = 0.0;

     float sampR = 0.0;

     for (int j = 0; j < channels; j++) {

       sampL+=buffer[i*channels+j]*dmatrix[channels-3][j][0];

       sampR+=buffer[i*channels+j]*dmatrix[channels-3][j][1];

     }

     buffer[i*outChannels]=sampL;

     buffer[i*outChannels+1]=sampR;

   }

 #else

   // Downmix matrix. Per-row normalization 1 for rows 3,4 and 2 for rows 5-8.

   // Coefficients in Q14.

   static const int16_t dmatrix[6][8][2]= {

       /*3*/{{9598, 0},{6786,6786},{0,   9598}},

       /*4*/{{6925, 0},{0,   6925},{5997,3462},{3462,5997}},

       /*5*/{{10663,0},{7540,7540},{0,  10663},{9234,5331},{5331,9234}},

       /*6*/{{8668, 0},{6129,6129},{0,   8668},{7507,4335},{4335,7507},{6129,6129}},

       /*7*/{{7459, 0},{5275,5275},{0,   7459},{6460,3731},{3731,6460},{4568,4568},{5275,5275}},

       /*8*/{{6368, 0},{4502,4502},{0,   6368},{5514,3184},{3184,5514},{5514,3184},{3184,5514},{4502,4502}}

   };

   // Re-write the buffer with downmixed data

   for (uint32_t i = 0; i < frames; i++) {

     int32_t sampL = 0;

     int32_t sampR = 0;

     for (int j = 0; j < channels; j++) {

       sampL+=buffer[i*channels+j]*dmatrix[channels-3][j][0];

       sampR+=buffer[i*channels+j]*dmatrix[channels-3][j][1];

     }

     sampL = (sampL + 8192)>>14;

     buffer[i*outChannels] = static_cast<mozilla::AudioDataValue>(MOZ_CLIP_TO_15(sampL));

     sampR = (sampR + 8192)>>14;

     buffer[i*outChannels+1] = static_cast<mozilla::AudioDataValue>(MOZ_CLIP_TO_15(sampR));

   }

 #endif

   return outChannels;

 }

 bool

 IsVideoContentType(const nsCString& aContentType)

 {

   NS_NAMED_LITERAL_CSTRING(video, "video");

   if (FindInReadable(video, aContentType)) {

     return true;

   }

   return false;

 }

 bool

 IsValidVideoRegion(const nsIntSize& aFrame, const nsIntRect& aPicture,

                    const nsIntSize& aDisplay)

 {

   return

     aFrame.width <= PlanarYCbCrImage::MAX_DIMENSION &&

     aFrame.height <= PlanarYCbCrImage::MAX_DIMENSION &&

     aFrame.width * aFrame.height <= MAX_VIDEO_WIDTH * MAX_VIDEO_HEIGHT &&

     aFrame.width * aFrame.height != 0 &&

     aPicture.width <= PlanarYCbCrImage::MAX_DIMENSION &&

     aPicture.x < PlanarYCbCrImage::MAX_DIMENSION &&

     aPicture.x + aPicture.width < PlanarYCbCrImage::MAX_DIMENSION &&

     aPicture.height <= PlanarYCbCrImage::MAX_DIMENSION &&

     aPicture.y < PlanarYCbCrImage::MAX_DIMENSION &&

     aPicture.y + aPicture.height < PlanarYCbCrImage::MAX_DIMENSION &&

     aPicture.width * aPicture.height <= MAX_VIDEO_WIDTH * MAX_VIDEO_HEIGHT &&

     aPicture.width * aPicture.height != 0 &&

     aDisplay.width <= PlanarYCbCrImage::MAX_DIMENSION &&

     aDisplay.height <= PlanarYCbCrImage::MAX_DIMENSION &&

     aDisplay.width * aDisplay.height <= MAX_VIDEO_WIDTH * MAX_VIDEO_HEIGHT &&

     aDisplay.width * aDisplay.height != 0;

 }

 } // end namespace mozilla