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authorSteve Block <steveblock@google.com>2011-06-08 08:26:01 -0700
committerAndroid (Google) Code Review <android-gerrit@google.com>2011-06-08 08:26:01 -0700
commit3742ac093d35d923c81693096ab6671e9b147700 (patch)
treec2add9100f789dad45ef1ec5328bddde02c47a4c /Source/WebCore/platform/audio/AudioBus.cpp
parent901401d90459bc22580842455d4588b9a697514d (diff)
parente5926f4a0d6adc9ad4a75824129f117181953560 (diff)
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Merge changes I55c6d71a,Ifb3277d4,Ia1b847a2,I7ba9cf3f,Ida2b2a8a,I1280ec90,I72f818d5,I2e3b588b,I9a4e6289,Ia724c78b,Icd8612c8,Ie31b15d7,Ie125edae,I77941a88,I89dae78b,I3516e5ca,I1a4c17b5,I2c4ecc1a,I9c8e6537,Ifac13115,Ie1f80e09,Ia541ed77,I60ce9d78
* changes: Merge WebKit at r82507: Update ThirdPartyProject.prop Merge WebKit at r82507: Cherry-pick change r88166 to add INSPECTOR guards to ScriptProfiler Merge WebKit at r82507: Work around a V8 bug Merge WebKit at r82507: JNIType renamed to JavaType Merge WebKit at r82507: IconDatabaseClient interface expanded Merge WebKit at r82507: Don't use new loss-free code path in HTMLCanvasElement::toDataURL() Merge WebKit at r82507: IcondDatabaseBase::iconForPageURL() renamed Merge WebKit at r82507: IconDatabaseBase::Open() signature changed Merge WebKit at r82507: Node::isContentEditable() renamed Merge WebKit at r82507: Use icon database through IconDatabaseBase Merge WebKit at r82507: toInputElement() is now a member of Node Merge WebKit at r82507: FrameLoaderClient::objectContentType() signature changed Merge WebKit at r82507: StringImpl::computeHash() removed Merge WebKit at r82507: Stub out FontPlatformData::setOrientation() Merge WebKit at r82507: Path::strokeBoundingRect() is now const Merge WebKit at r82507: Add missing UnusedParam.h include in ApplicationCacheGroup.cpp Merge WebKit at r82507: Continue to use Android's version of FontPlatformData.h Merge WebKit at r82507: Update signature of FontCustomPlatformData::fontPlatformData() Merge WebKit at r82507: Fix conflicts due to JNI refactoring Merge WebKit at r82507: Fix conflicts due to new StorageTracker Merge WebKit at r82507: Fix conflicts Merge WebKit at r82507: Fix makefiles Merge WebKit at r82507: Initial merge by git
Diffstat (limited to 'Source/WebCore/platform/audio/AudioBus.cpp')
-rw-r--r--Source/WebCore/platform/audio/AudioBus.cpp87
1 files changed, 87 insertions, 0 deletions
diff --git a/Source/WebCore/platform/audio/AudioBus.cpp b/Source/WebCore/platform/audio/AudioBus.cpp
index dd4746d..6f74471 100644
--- a/Source/WebCore/platform/audio/AudioBus.cpp
+++ b/Source/WebCore/platform/audio/AudioBus.cpp
@@ -32,6 +32,9 @@
#include "AudioBus.h"
+#if !PLATFORM(MAC)
+#include "SincResampler.h"
+#endif
#include "VectorMath.h"
#include <algorithm>
#include <assert.h>
@@ -360,6 +363,90 @@ void AudioBus::sumWithGainFrom(const AudioBus &sourceBus, double* lastMixGain, d
processWithGainFrom(sourceBus, lastMixGain, targetGain, true);
}
+#if !PLATFORM(MAC)
+PassOwnPtr<AudioBus> AudioBus::createBySampleRateConverting(AudioBus* sourceBus, bool mixToMono, double newSampleRate)
+{
+ // sourceBus's sample-rate must be known.
+ ASSERT(sourceBus && sourceBus->sampleRate());
+ if (!sourceBus || !sourceBus->sampleRate())
+ return 0;
+
+ double sourceSampleRate = sourceBus->sampleRate();
+ double destinationSampleRate = newSampleRate;
+ unsigned numberOfSourceChannels = sourceBus->numberOfChannels();
+
+ if (numberOfSourceChannels == 1)
+ mixToMono = false; // already mono
+
+ if (sourceSampleRate == destinationSampleRate) {
+ // No sample-rate conversion is necessary.
+ if (mixToMono)
+ return AudioBus::createByMixingToMono(sourceBus);
+
+ // Return exact copy.
+ return AudioBus::createBufferFromRange(sourceBus, 0, sourceBus->length());
+ }
+
+ // First, mix to mono (if necessary) then sample-rate convert.
+ AudioBus* resamplerSourceBus;
+ OwnPtr<AudioBus> mixedMonoBus;
+ if (mixToMono) {
+ mixedMonoBus = AudioBus::createByMixingToMono(sourceBus);
+ resamplerSourceBus = mixedMonoBus.get();
+ } else {
+ // Directly resample without down-mixing.
+ resamplerSourceBus = sourceBus;
+ }
+
+ // Calculate destination length based on the sample-rates.
+ double sampleRateRatio = sourceSampleRate / destinationSampleRate;
+ int sourceLength = resamplerSourceBus->length();
+ int destinationLength = sourceLength / sampleRateRatio;
+
+ // Create destination bus with same number of channels.
+ unsigned numberOfDestinationChannels = resamplerSourceBus->numberOfChannels();
+ OwnPtr<AudioBus> destinationBus(adoptPtr(new AudioBus(numberOfDestinationChannels, destinationLength)));
+
+ // Sample-rate convert each channel.
+ for (unsigned i = 0; i < numberOfDestinationChannels; ++i) {
+ float* source = resamplerSourceBus->channel(i)->data();
+ float* destination = destinationBus->channel(i)->data();
+
+ SincResampler resampler(sampleRateRatio);
+ resampler.process(source, destination, sourceLength);
+ }
+
+ return destinationBus.release();
+}
+#endif // !PLATFORM(MAC)
+
+PassOwnPtr<AudioBus> AudioBus::createByMixingToMono(AudioBus* sourceBus)
+{
+ switch (sourceBus->numberOfChannels()) {
+ case 1:
+ // Simply create an exact copy.
+ return AudioBus::createBufferFromRange(sourceBus, 0, sourceBus->length());
+ case 2:
+ {
+ unsigned n = sourceBus->length();
+ OwnPtr<AudioBus> destinationBus(adoptPtr(new AudioBus(1, n)));
+
+ float* sourceL = sourceBus->channel(0)->data();
+ float* sourceR = sourceBus->channel(1)->data();
+ float* destination = destinationBus->channel(0)->data();
+
+ // Do the mono mixdown.
+ for (unsigned i = 0; i < n; ++i)
+ destination[i] = 0.5 * (sourceL[i] + sourceR[i]);
+
+ return destinationBus.release();
+ }
+ }
+
+ ASSERT_NOT_REACHED();
+ return 0;
+}
+
} // WebCore
#endif // ENABLE(WEB_AUDIO)