The Tor Browser: content/media/VideoUtils.cpp@44a2da4a2ab2 (annotated)

content/media/VideoUtils.cpp@44a2da4a2ab2 (annotated)

content/media/VideoUtils.cpp

Fri, 16 Jan 2015 04:50:19 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Fri, 16 Jan 2015 04:50:19 +0100
branch: TOR_BUG_9701
changeset 13: 44a2da4a2ab2
permissions: -rw-r--r--

Replace accessor implementation with direct member state manipulation, by
request https://trac.torproject.org/projects/tor/ticket/9701#comment:32

 /* 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

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content/media/VideoUtils.cpp@44a2da4a2ab2 (annotated)

content/media/VideoUtils.cpp