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// Copyright (c) 2010 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "media/audio/simple_sources.h"
#include <algorithm>
#include <math.h>
#include "base/basictypes.h"
#include "base/logging.h"
#include "base/ref_counted.h"
#include "media/audio/audio_io.h"
#include "media/base/data_buffer.h"
//////////////////////////////////////////////////////////////////////////////
// SineWaveAudioSource implementation.
SineWaveAudioSource::SineWaveAudioSource(Format format, int channels,
double freq, double sample_freq)
: format_(format),
channels_(channels),
freq_(freq),
sample_freq_(sample_freq) {
// TODO(cpu): support other formats.
DCHECK((format_ == FORMAT_16BIT_LINEAR_PCM) && (channels_ == 1));
}
// The implementation could be more efficient if a lookup table is constructed
// but it is efficient enough for our simple needs.
uint32 SineWaveAudioSource::OnMoreData(
AudioOutputStream* stream, uint8* dest, uint32 max_size,
AudioBuffersState audio_buffers) {
const double kTwoPi = 2.0 * 3.141592653589;
double f = freq_ / sample_freq_;
int16* sin_tbl = reinterpret_cast<int16*>(dest);
uint32 len = max_size / sizeof(int16);
// The table is filled with s(t) = 32768*sin(2PI*f*t).
for (uint32 ix = 0; ix != len; ++ix) {
double th = kTwoPi * ix * f;
sin_tbl[ix] = static_cast<int16>((1 << 15) * sin(th));
}
return max_size;
}
void SineWaveAudioSource::OnError(AudioOutputStream* stream, int code) {
NOTREACHED();
}
//////////////////////////////////////////////////////////////////////////////
// PushSource implementation.
PushSource::PushSource()
: buffer_(0, 0) {
}
PushSource::~PushSource() { }
uint32 PushSource::OnMoreData(
AudioOutputStream* stream, uint8* dest, uint32 max_size,
AudioBuffersState buffers_state) {
return buffer_.Read(dest, max_size);
}
void PushSource::OnError(AudioOutputStream* stream, int code) {
NOTREACHED();
}
// TODO(cpu): Manage arbitrary large sizes.
bool PushSource::Write(const void *data, uint32 len) {
if (len == 0) {
NOTREACHED();
return false;
}
buffer_.Append(static_cast<const uint8*>(data), len);
return true;
}
uint32 PushSource::UnProcessedBytes() {
return buffer_.forward_bytes();
}
void PushSource::ClearAll() {
// Cleanup() will discard all the data.
CleanUp();
}
void PushSource::CleanUp() {
buffer_.Clear();
}
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