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// Copyright 2013 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 "content/renderer/media/audio_decoder.h"
#include <stdint.h>
#include <vector>
#include "base/logging.h"
#include "base/strings/string_util.h"
#include "base/time/time.h"
#include "media/base/audio_bus.h"
#include "media/base/limits.h"
#include "media/filters/audio_file_reader.h"
#include "media/filters/in_memory_url_protocol.h"
#include "media/media_buildflags.h"
#include "third_party/blink/public/platform/web_audio_bus.h"
using media::AudioBus;
using media::AudioFileReader;
using media::InMemoryUrlProtocol;
using std::vector;
using blink::WebAudioBus;
namespace content {
// Decode in-memory audio file data.
bool DecodeAudioFileData(
blink::WebAudioBus* destination_bus,
const char* data, size_t data_size) {
DCHECK(destination_bus);
if (!destination_bus)
return false;
#if BUILDFLAG(ENABLE_FFMPEG)
// Uses the FFmpeg library for audio file reading.
InMemoryUrlProtocol url_protocol(reinterpret_cast<const uint8_t*>(data),
data_size, false);
AudioFileReader reader(&url_protocol);
if (!reader.Open())
return false;
size_t number_of_channels = reader.channels();
double file_sample_rate = reader.sample_rate();
// Apply sanity checks to make sure crazy values aren't coming out of
// FFmpeg.
if (!number_of_channels ||
number_of_channels > static_cast<size_t>(media::limits::kMaxChannels) ||
file_sample_rate < media::limits::kMinSampleRate ||
file_sample_rate > media::limits::kMaxSampleRate)
return false;
std::vector<std::unique_ptr<AudioBus>> decoded_audio_packets;
int number_of_frames = reader.Read(&decoded_audio_packets);
if (number_of_frames <= 0)
return false;
// Allocate and configure the output audio channel data and then
// copy the decoded data to the destination.
destination_bus->Initialize(number_of_channels, number_of_frames,
file_sample_rate);
int dest_frame_offset = 0;
for (size_t k = 0; k < decoded_audio_packets.size(); ++k) {
AudioBus* packet = decoded_audio_packets[k].get();
int packet_length = packet->frames();
for (size_t ch = 0; ch < number_of_channels; ++ch) {
float* dst = destination_bus->ChannelData(ch);
float* src = packet->channel(ch);
DCHECK_LE(dest_frame_offset + packet_length, number_of_frames);
memcpy(dst + dest_frame_offset, src, packet_length * sizeof(*dst));
}
dest_frame_offset += packet_length;
}
DVLOG(1) << "Decoded file data (unknown duration)-"
<< " data: " << data << " data size: " << data_size
<< ", decoded duration: " << (number_of_frames / file_sample_rate)
<< ", number of frames: " << number_of_frames
<< ", estimated frames (if available): "
<< (reader.HasKnownDuration() ? reader.GetNumberOfFrames() : 0)
<< ", sample rate: " << file_sample_rate
<< ", number of channels: " << number_of_channels;
return number_of_frames > 0;
#else
return false;
#endif // BUILDFLAG(ENABLE_FFMPEG)
}
} // namespace content
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