WebAudioBufferList.cpp [plain text]
#include "config.h"
#include "WebAudioBufferList.h"
#include "CAAudioStreamDescription.h"
#include <wtf/CheckedArithmetic.h>
#include <pal/cf/CoreMediaSoftLink.h>
namespace WebCore {
using namespace PAL;
WebAudioBufferList::WebAudioBufferList(const CAAudioStreamDescription& format)
: m_bytesPerFrame(format.bytesPerFrame())
, m_channelCount(format.numberOfInterleavedChannels())
{
uint32_t bufferCount = format.numberOfChannelStreams();
uint64_t bufferListSize = offsetof(AudioBufferList, mBuffers) + (sizeof(AudioBuffer) * std::max(1U, bufferCount));
ASSERT(bufferListSize <= SIZE_MAX);
m_listBufferSize = static_cast<size_t>(bufferListSize);
m_canonicalList = std::unique_ptr<AudioBufferList>(static_cast<AudioBufferList*>(::operator new (m_listBufferSize)));
memset(m_canonicalList.get(), 0, m_listBufferSize);
m_canonicalList->mNumberBuffers = bufferCount;
for (uint32_t buffer = 0; buffer < bufferCount; ++buffer)
m_canonicalList->mBuffers[buffer].mNumberChannels = m_channelCount;
reset();
}
WebAudioBufferList::WebAudioBufferList(const CAAudioStreamDescription& format, uint32_t sampleCount)
: WebAudioBufferList(format)
{
setSampleCount(sampleCount);
}
static inline Optional<std::pair<size_t, size_t>> computeBufferSizes(uint32_t numberOfInterleavedChannels, uint32_t bytesPerFrame, uint32_t numberOfChannelStreams, uint32_t sampleCount)
{
size_t totalSampleCount;
bool result = WTF::safeMultiply(sampleCount, numberOfInterleavedChannels, totalSampleCount);
if (!result)
return { };
size_t bytesPerBuffer;
result = WTF::safeMultiply(bytesPerFrame, totalSampleCount, bytesPerBuffer);
if (!result)
return { };
size_t flatBufferSize;
result = WTF::safeMultiply(numberOfChannelStreams, bytesPerBuffer, flatBufferSize);
if (!result)
return { };
return std::make_pair(bytesPerBuffer, flatBufferSize);
}
bool WebAudioBufferList::isSupportedDescription(const CAAudioStreamDescription& format, uint32_t sampleCount)
{
return !!computeBufferSizes(format.numberOfInterleavedChannels(), format.bytesPerFrame(), format.numberOfChannelStreams(), sampleCount);
}
void WebAudioBufferList::setSampleCount(uint32_t sampleCount)
{
if (!sampleCount || m_sampleCount == sampleCount)
return;
m_sampleCount = sampleCount;
auto bufferSizes = computeBufferSizes(m_channelCount, m_bytesPerFrame, m_canonicalList->mNumberBuffers, m_sampleCount);
ASSERT(bufferSizes);
m_flatBuffer.resize(bufferSizes->second);
auto* data = m_flatBuffer.data();
for (uint32_t buffer = 0; buffer < m_canonicalList->mNumberBuffers; ++buffer) {
m_canonicalList->mBuffers[buffer].mData = data;
m_canonicalList->mBuffers[buffer].mDataByteSize = bufferSizes->first;
data += bufferSizes->first;
}
reset();
}
WebAudioBufferList::WebAudioBufferList(const CAAudioStreamDescription& format, CMSampleBufferRef sampleBuffer)
: WebAudioBufferList(format)
{
if (!sampleBuffer)
return;
CMBlockBufferRef buffer = nullptr;
if (noErr == CMSampleBufferGetAudioBufferListWithRetainedBlockBuffer(sampleBuffer, nullptr, m_canonicalList.get(), m_listBufferSize, kCFAllocatorSystemDefault, kCFAllocatorSystemDefault, kCMSampleBufferFlag_AudioBufferList_Assure16ByteAlignment, &buffer))
m_blockBuffer = adoptCF(buffer);
reset();
}
void WebAudioBufferList::reset()
{
if (!m_list)
m_list = std::unique_ptr<AudioBufferList>(static_cast<AudioBufferList*>(::operator new (m_listBufferSize)));
memcpy(m_list.get(), m_canonicalList.get(), m_listBufferSize);
}
WTF::IteratorRange<AudioBuffer*> WebAudioBufferList::buffers() const
{
return WTF::makeIteratorRange(&m_list->mBuffers[0], &m_list->mBuffers[m_list->mNumberBuffers]);
}
uint32_t WebAudioBufferList::bufferCount() const
{
return m_list->mNumberBuffers;
}
AudioBuffer* WebAudioBufferList::buffer(uint32_t index) const
{
ASSERT(index < m_list->mNumberBuffers);
if (index < m_list->mNumberBuffers)
return &m_list->mBuffers[index];
return nullptr;
}
void WebAudioBufferList::zeroFlatBuffer()
{
memset(m_flatBuffer.data(), 0, m_flatBuffer.capacity());
}
}