media/base/audio_bus.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "media/base/audio_bus.h"
   6
   7 #include "base/logging.h"
   8 #include "base/numerics/safe_conversions.h"
   9 #include "media/audio/audio_parameters.h"
  10 #include "media/base/limits.h"
  11 #include "media/base/vector_math.h"
  12
  13 namespace media {
  14
  15 static const uint8 kUint8Bias = 128;
  16
  17 static bool IsAligned(void* ptr) {
  18   return (reinterpret_cast<uintptr_t>(ptr) &
  19           (AudioBus::kChannelAlignment - 1)) == 0U;
  20 }
  21
  22 // Calculates the required size for an AudioBus with the given params, sets
  23 // |aligned_frames| to the actual frame length of each channel array.
  24 static int CalculateMemorySizeInternal(int channels, int frames,
  25                                        int* out_aligned_frames) {
  26   // Choose a size such that each channel will be aligned by
  27   // kChannelAlignment when stored in a contiguous block.
  28   int aligned_frames =
  29       ((frames * sizeof(float) + AudioBus::kChannelAlignment - 1) &
  30        ~(AudioBus::kChannelAlignment - 1)) / sizeof(float);
  31
  32   if (out_aligned_frames)
  33     *out_aligned_frames = aligned_frames;
  34
  35   return sizeof(float) * channels * aligned_frames;
  36 }
  37
  38 // |Format| is the destination type.  If a bias is present, |Fixed| must be a
  39 // type larger than |Format| such that operations can be made without
  40 // overflowing.  Without a bias |Fixed| must be the same as |Format|.
  41 template<class Format, class Fixed, Format Bias>
  42 static void FromInterleavedInternal(const void* src, int start_frame,
  43                                     int frames, AudioBus* dest,
  44                                     float min, float max) {
  45   COMPILE_ASSERT((Bias == 0 && sizeof(Fixed) == sizeof(Format)) ||
  46                  sizeof(Fixed) > sizeof(Format), invalid_deinterleave_types);
  47   const Format* source = static_cast<const Format*>(src);
  48   const int channels = dest->channels();
  49   for (int ch = 0; ch < channels; ++ch) {
  50     float* channel_data = dest->channel(ch);
  51     for (int i = start_frame, offset = ch; i < start_frame + frames;
  52          ++i, offset += channels) {
  53       const Fixed v = static_cast<Fixed>(source[offset]) - Bias;
  54       channel_data[i] = v * (v < 0 ? -min : max);
  55     }
  56   }
  57 }
  58
  59 // |Format| is the destination type.  If a bias is present, |Fixed| must be a
  60 // type larger than |Format| such that operations can be made without
  61 // overflowing.  Without a bias |Fixed| must be the same as |Format|.
  62 template<class Format, class Fixed, Format Bias>
  63 static void ToInterleavedInternal(const AudioBus* source, int start_frame,
  64                                   int frames, void* dst, Fixed min, Fixed max) {
  65   COMPILE_ASSERT((Bias == 0 && sizeof(Fixed) == sizeof(Format)) ||
  66                  sizeof(Fixed) > sizeof(Format), invalid_interleave_types);
  67   Format* dest = static_cast<Format*>(dst);
  68   const int channels = source->channels();
  69   for (int ch = 0; ch < channels; ++ch) {
  70     const float* channel_data = source->channel(ch);
  71     for (int i = start_frame, offset = ch; i < start_frame + frames;
  72          ++i, offset += channels) {
  73       const float v = channel_data[i];
  74
  75       Fixed sample;
  76       if (v < 0)
  77         sample = v <= -1 ? min : static_cast<Fixed>(-v * min);
  78       else
  79         sample = v >= 1 ? max : static_cast<Fixed>(v * max);
  80
  81       dest[offset] = static_cast<Format>(sample) + Bias;
  82     }
  83   }
  84 }
  85
  86 static void ValidateConfig(int channels, int frames) {
  87   CHECK_GT(frames, 0);
  88   CHECK_GT(channels, 0);
  89   CHECK_LE(channels, static_cast<int>(limits::kMaxChannels));
  90 }
  91
  92 static void CheckOverflow(int start_frame, int frames, int total_frames) {
  93   CHECK_GE(start_frame, 0);
  94   CHECK_GE(frames, 0);
  95   CHECK_GT(total_frames, 0);
  96   int sum = start_frame + frames;
  97   CHECK_LE(sum, total_frames);
  98   CHECK_GE(sum, 0);
  99 }
 100
 101 AudioBus::AudioBus(int channels, int frames)
 102     : frames_(frames),
 103       can_set_channel_data_(false) {
 104   ValidateConfig(channels, frames_);
 105
 106   int aligned_frames = 0;
 107   int size = CalculateMemorySizeInternal(channels, frames, &aligned_frames);
 108
 109   data_.reset(static_cast<float*>(base::AlignedAlloc(
 110       size, AudioBus::kChannelAlignment)));
 111
 112   BuildChannelData(channels, aligned_frames, data_.get());
 113 }
 114
 115 AudioBus::AudioBus(int channels, int frames, float* data)
 116     : frames_(frames),
 117       can_set_channel_data_(false) {
 118   // Since |data| may have come from an external source, ensure it's valid.
 119   CHECK(data);
 120   ValidateConfig(channels, frames_);
 121
 122   int aligned_frames = 0;
 123   CalculateMemorySizeInternal(channels, frames, &aligned_frames);
 124
 125   BuildChannelData(channels, aligned_frames, data);
 126 }
 127
 128 AudioBus::AudioBus(int frames, const std::vector<float*>& channel_data)
 129     : channel_data_(channel_data),
 130       frames_(frames),
 131       can_set_channel_data_(false) {
 132   ValidateConfig(
 133       base::checked_cast<int>(channel_data_.size()), frames_);
 134
 135   // Sanity check wrapped vector for alignment and channel count.
 136   for (size_t i = 0; i < channel_data_.size(); ++i)
 137     DCHECK(IsAligned(channel_data_[i]));
 138 }
 139
 140 AudioBus::AudioBus(int channels)
 141     : channel_data_(channels),
 142       frames_(0),
 143       can_set_channel_data_(true) {
 144   CHECK_GT(channels, 0);
 145   for (size_t i = 0; i < channel_data_.size(); ++i)
 146     channel_data_[i] = NULL;
 147 }
 148
 149 AudioBus::~AudioBus() {}
 150
 151 scoped_ptr<AudioBus> AudioBus::Create(int channels, int frames) {
 152   return scoped_ptr<AudioBus>(new AudioBus(channels, frames));
 153 }
 154
 155 scoped_ptr<AudioBus> AudioBus::Create(const AudioParameters& params) {
 156   return scoped_ptr<AudioBus>(new AudioBus(
 157       params.channels(), params.frames_per_buffer()));
 158 }
 159
 160 scoped_ptr<AudioBus> AudioBus::CreateWrapper(int channels) {
 161   return scoped_ptr<AudioBus>(new AudioBus(channels));
 162 }
 163
 164 scoped_ptr<AudioBus> AudioBus::WrapVector(
 165     int frames, const std::vector<float*>& channel_data) {
 166   return scoped_ptr<AudioBus>(new AudioBus(frames, channel_data));
 167 }
 168
 169 scoped_ptr<AudioBus> AudioBus::WrapMemory(int channels, int frames,
 170                                           void* data) {
 171   // |data| must be aligned by AudioBus::kChannelAlignment.
 172   CHECK(IsAligned(data));
 173   return scoped_ptr<AudioBus>(new AudioBus(
 174       channels, frames, static_cast<float*>(data)));
 175 }
 176
 177 scoped_ptr<AudioBus> AudioBus::WrapMemory(const AudioParameters& params,
 178                                           void* data) {
 179   // |data| must be aligned by AudioBus::kChannelAlignment.
 180   CHECK(IsAligned(data));
 181   return scoped_ptr<AudioBus>(new AudioBus(
 182       params.channels(), params.frames_per_buffer(),
 183       static_cast<float*>(data)));
 184 }
 185
 186 void AudioBus::SetChannelData(int channel, float* data) {
 187   CHECK(can_set_channel_data_);
 188   CHECK(data);
 189   CHECK_GE(channel, 0);
 190   CHECK_LT(static_cast<size_t>(channel), channel_data_.size());
 191   DCHECK(IsAligned(data));
 192   channel_data_[channel] = data;
 193 }
 194
 195 void AudioBus::set_frames(int frames) {
 196   CHECK(can_set_channel_data_);
 197   ValidateConfig(static_cast<int>(channel_data_.size()), frames);
 198   frames_ = frames;
 199 }
 200
 201 void AudioBus::ZeroFramesPartial(int start_frame, int frames) {
 202   CheckOverflow(start_frame, frames, frames_);
 203
 204   if (frames <= 0)
 205     return;
 206
 207   for (size_t i = 0; i < channel_data_.size(); ++i) {
 208     memset(channel_data_[i] + start_frame, 0,
 209            frames * sizeof(*channel_data_[i]));
 210   }
 211 }
 212
 213 void AudioBus::ZeroFrames(int frames) {
 214   ZeroFramesPartial(0, frames);
 215 }
 216
 217 void AudioBus::Zero() {
 218   ZeroFrames(frames_);
 219 }
 220
 221 int AudioBus::CalculateMemorySize(const AudioParameters& params) {
 222   return CalculateMemorySizeInternal(
 223       params.channels(), params.frames_per_buffer(), NULL);
 224 }
 225
 226 int AudioBus::CalculateMemorySize(int channels, int frames) {
 227   return CalculateMemorySizeInternal(channels, frames, NULL);
 228 }
 229
 230 void AudioBus::BuildChannelData(int channels, int aligned_frames, float* data) {
 231   DCHECK(IsAligned(data));
 232   DCHECK_EQ(channel_data_.size(), 0U);
 233   // Separate audio data out into channels for easy lookup later.  Figure out
 234   channel_data_.reserve(channels);
 235   for (int i = 0; i < channels; ++i)
 236     channel_data_.push_back(data + i * aligned_frames);
 237 }
 238
 239 // TODO(dalecurtis): See if intrinsic optimizations help any here.
 240 void AudioBus::FromInterleavedPartial(const void* source, int start_frame,
 241                                       int frames, int bytes_per_sample) {
 242   CheckOverflow(start_frame, frames, frames_);
 243   switch (bytes_per_sample) {
 244     case 1:
 245       FromInterleavedInternal<uint8, int16, kUint8Bias>(
 246           source, start_frame, frames, this,
 247           1.0f / kint8min, 1.0f / kint8max);
 248       break;
 249     case 2:
 250       FromInterleavedInternal<int16, int16, 0>(
 251           source, start_frame, frames, this,
 252           1.0f / kint16min, 1.0f / kint16max);
 253       break;
 254     case 4:
 255       FromInterleavedInternal<int32, int32, 0>(
 256           source, start_frame, frames, this,
 257           1.0f / kint32min, 1.0f / kint32max);
 258       break;
 259     default:
 260       NOTREACHED() << "Unsupported bytes per sample encountered.";
 261       ZeroFramesPartial(start_frame, frames);
 262       return;
 263   }
 264
 265   // Don't clear remaining frames if this is a partial deinterleave.
 266   if (!start_frame) {
 267     // Zero any remaining frames.
 268     ZeroFramesPartial(frames, frames_ - frames);
 269   }
 270 }
 271
 272 void AudioBus::FromInterleaved(const void* source, int frames,
 273                                int bytes_per_sample) {
 274   FromInterleavedPartial(source, 0, frames, bytes_per_sample);
 275 }
 276
 277 void AudioBus::ToInterleaved(int frames, int bytes_per_sample,
 278                              void* dest) const {
 279   ToInterleavedPartial(0, frames, bytes_per_sample, dest);
 280 }
 281
 282 // TODO(dalecurtis): See if intrinsic optimizations help any here.
 283 void AudioBus::ToInterleavedPartial(int start_frame, int frames,
 284                                     int bytes_per_sample, void* dest) const {
 285   CheckOverflow(start_frame, frames, frames_);
 286   switch (bytes_per_sample) {
 287     case 1:
 288       ToInterleavedInternal<uint8, int16, kUint8Bias>(
 289           this, start_frame, frames, dest, kint8min, kint8max);
 290       break;
 291     case 2:
 292       ToInterleavedInternal<int16, int16, 0>(
 293           this, start_frame, frames, dest, kint16min, kint16max);
 294       break;
 295     case 4:
 296       ToInterleavedInternal<int32, int32, 0>(
 297           this, start_frame, frames, dest, kint32min, kint32max);
 298       break;
 299     default:
 300       NOTREACHED() << "Unsupported bytes per sample encountered.";
 301       memset(dest, 0, frames * bytes_per_sample);
 302       return;
 303   }
 304 }
 305
 306 void AudioBus::CopyTo(AudioBus* dest) const {
 307   CopyPartialFramesTo(0, frames(), 0, dest);
 308 }
 309
 310 void AudioBus::CopyPartialFramesTo(int source_start_frame,
 311                                    int frame_count,
 312                                    int dest_start_frame,
 313                                    AudioBus* dest) const {
 314   CHECK_EQ(channels(), dest->channels());
 315   CHECK_LE(source_start_frame + frame_count, frames());
 316   CHECK_LE(dest_start_frame + frame_count, dest->frames());
 317
 318   // Since we don't know if the other AudioBus is wrapped or not (and we don't
 319   // want to care), just copy using the public channel() accessors.
 320   for (int i = 0; i < channels(); ++i) {
 321     memcpy(dest->channel(i) + dest_start_frame,
 322            channel(i) + source_start_frame,
 323            sizeof(*channel(i)) * frame_count);
 324   }
 325 }
 326
 327 void AudioBus::Scale(float volume) {
 328   if (volume > 0 && volume != 1) {
 329     for (int i = 0; i < channels(); ++i)
 330       vector_math::FMUL(channel(i), volume, frames(), channel(i));
 331   } else if (volume == 0) {
 332     Zero();
 333   }
 334 }
 335
 336 void AudioBus::SwapChannels(int a, int b) {
 337   DCHECK(a < channels() && a >= 0);
 338   DCHECK(b < channels() && b >= 0);
 339   DCHECK_NE(a, b);
 340   std::swap(channel_data_[a], channel_data_[b]);
 341 }
 342
 343 }  // namespace media