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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-19 00:47:55 +0000
commit26a029d407be480d791972afb5975cf62c9360a6 (patch)
treef435a8308119effd964b339f76abb83a57c29483 /dom/media/webrtc/SineWaveGenerator.h
parentInitial commit. (diff)
downloadfirefox-26a029d407be480d791972afb5975cf62c9360a6.tar.xz
firefox-26a029d407be480d791972afb5975cf62c9360a6.zip
Adding upstream version 124.0.1.upstream/124.0.1
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'dom/media/webrtc/SineWaveGenerator.h')
-rw-r--r--dom/media/webrtc/SineWaveGenerator.h58
1 files changed, 58 insertions, 0 deletions
diff --git a/dom/media/webrtc/SineWaveGenerator.h b/dom/media/webrtc/SineWaveGenerator.h
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+++ b/dom/media/webrtc/SineWaveGenerator.h
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+/* 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/. */
+
+#ifndef SINEWAVEGENERATOR_H_
+#define SINEWAVEGENERATOR_H_
+
+#include "MediaSegment.h"
+#include "prtime.h"
+
+namespace mozilla {
+
+// generate 1k sine wave per second
+template <typename Sample>
+class SineWaveGenerator {
+ static_assert(std::is_same<Sample, int16_t>::value ||
+ std::is_same<Sample, float>::value);
+
+ public:
+ static const int bytesPerSample = sizeof(Sample);
+ static const int millisecondsPerSecond = PR_MSEC_PER_SEC;
+ static constexpr float twopi = 2 * M_PI;
+
+ /* If more than 1 channel, generated samples are interleaved. */
+ SineWaveGenerator(uint32_t aSampleRate, uint32_t aFrequency)
+ : mPhase(0.), mPhaseIncrement(twopi * aFrequency / aSampleRate) {}
+
+ // NOTE: only safely called from a single thread (MTG callback)
+ void generate(Sample* aBuffer, TrackTicks aFrameCount,
+ uint32_t aChannelCount = 1) {
+ while (aFrameCount--) {
+ Sample value = sin(mPhase) * Amplitude();
+ for (uint32_t channel = 0; channel < aChannelCount; channel++) {
+ *aBuffer++ = value;
+ }
+ mPhase += mPhaseIncrement;
+ if (mPhase > twopi) {
+ mPhase -= twopi;
+ }
+ }
+ }
+
+ static float Amplitude() {
+ // Set volume to -20db.
+ if (std::is_same<Sample, int16_t>::value) {
+ return 3276.8; // 32768.0 * 10^(-20/20) = 3276.8
+ }
+ return 0.1f; // 1.0 * 10^(-20/20) = 0.1
+ }
+
+ private:
+ double mPhase;
+ const double mPhaseIncrement;
+};
+
+} // namespace mozilla
+
+#endif /* SINEWAVEGENERATOR_H_ */