15821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Copyright (c) 2012 The Chromium Authors. All rights reserved. 25821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// Use of this source code is governed by a BSD-style license that can be 35821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// found in the LICENSE file. 45821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// MSVC++ requires this to be set before any other includes to get M_PI. 55821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#define _USE_MATH_DEFINES 65821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <cmath> 75821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 85821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "media/audio/simple_sources.h" 95821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 105821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include <algorithm> 115821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 125821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)#include "base/logging.h" 135821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 145821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)namespace media { 155821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 165821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)////////////////////////////////////////////////////////////////////////////// 175821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// SineWaveAudioSource implementation. 185821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 195821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)SineWaveAudioSource::SineWaveAudioSource(int channels, 205821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) double freq, double sample_freq) 215821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) : channels_(channels), 225821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) f_(freq / sample_freq), 235821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) time_state_(0), 245821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) cap_(0), 255821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) callbacks_(0), 265821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) errors_(0) { 275821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 285821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 295821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// The implementation could be more efficient if a lookup table is constructed 305821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)// but it is efficient enough for our simple needs. 315821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)int SineWaveAudioSource::OnMoreData(AudioBus* audio_bus, 325821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) AudioBuffersState audio_buffers) { 335821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::AutoLock auto_lock(time_lock_); 345821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) callbacks_++; 355821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 365821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // The table is filled with s(t) = kint16max*sin(Theta*t), 375821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // where Theta = 2*PI*fs. 385821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // We store the discrete time value |t| in a member to ensure that the 395821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) // next pass starts at a correct state. 405821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) int max_frames = cap_ > 0 ? 415821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) std::min(audio_bus->frames(), cap_ - time_state_) : audio_bus->frames(); 425821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (int i = 0; i < max_frames; ++i) 435821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) audio_bus->channel(0)[i] = sin(2.0 * M_PI * f_ * time_state_++); 445821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) for (int i = 1; i < audio_bus->channels(); ++i) { 455821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) memcpy(audio_bus->channel(i), audio_bus->channel(0), 465821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) max_frames * sizeof(*audio_bus->channel(i))); 475821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) } 485821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) return max_frames; 495821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 505821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 512a99a7e74a7f215066514fe81d2bfa6639d9edddTorne (Richard Coles)void SineWaveAudioSource::OnError(AudioOutputStream* stream) { 525821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) errors_++; 535821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 545821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 555821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void SineWaveAudioSource::CapSamples(int cap) { 565821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::AutoLock auto_lock(time_lock_); 575821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) DCHECK_GT(cap, 0); 585821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) cap_ = cap; 595821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 605821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 615821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)void SineWaveAudioSource::Reset() { 625821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) base::AutoLock auto_lock(time_lock_); 635821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) time_state_ = 0; 645821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} 655821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles) 665821806d5e7f356e8fa4b058a389a808ea183019Torne (Richard Coles)} // namespace media 67