diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-07 19:33:14 +0000 |
commit | 36d22d82aa202bb199967e9512281e9a53db42c9 (patch) | |
tree | 105e8c98ddea1c1e4784a60a5a6410fa416be2de /dom/media/webrtc/SineWaveGenerator.h | |
parent | Initial commit. (diff) | |
download | firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.tar.xz firefox-esr-36d22d82aa202bb199967e9512281e9a53db42c9.zip |
Adding upstream version 115.7.0esr.upstream/115.7.0esrupstream
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.h | 58 |
1 files changed, 58 insertions, 0 deletions
diff --git a/dom/media/webrtc/SineWaveGenerator.h b/dom/media/webrtc/SineWaveGenerator.h new file mode 100644 index 0000000000..73bab53f19 --- /dev/null +++ b/dom/media/webrtc/SineWaveGenerator.h @@ -0,0 +1,58 @@ +/* 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_ */ |