gecko-dev/content/media/wave/WaveReader.h

110 lines
3.3 KiB
C++

/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim:set ts=2 sw=2 sts=2 et cindent: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#if !defined(WaveReader_h_)
#define WaveReader_h_
#include "MediaDecoderReader.h"
#include "mozilla/dom/HTMLMediaElement.h"
namespace mozilla {
namespace dom {
class TimeRanges;
}
}
namespace mozilla {
class WaveReader : public MediaDecoderReader
{
public:
WaveReader(AbstractMediaDecoder* aDecoder);
~WaveReader();
virtual nsresult Init(MediaDecoderReader* aCloneDonor);
virtual bool DecodeAudioData();
virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
int64_t aTimeThreshold);
virtual bool HasAudio()
{
return true;
}
virtual bool HasVideo()
{
return false;
}
virtual nsresult ReadMetadata(MediaInfo* aInfo,
MetadataTags** aTags);
virtual nsresult Seek(int64_t aTime, int64_t aStartTime, int64_t aEndTime, int64_t aCurrentTime);
virtual nsresult GetBuffered(dom::TimeRanges* aBuffered, int64_t aStartTime);
// To seek in a buffered range, we just have to seek the stream.
virtual bool IsSeekableInBufferedRanges() {
return true;
}
private:
bool ReadAll(char* aBuf, int64_t aSize, int64_t* aBytesRead = nullptr);
bool LoadRIFFChunk();
bool GetNextChunk(uint32_t* aChunk, uint32_t* aChunkSize);
bool LoadFormatChunk(uint32_t aChunkSize);
bool FindDataOffset(uint32_t aChunkSize);
bool LoadListChunk(uint32_t aChunkSize, nsAutoPtr<dom::HTMLMediaElement::MetadataTags> &aTags);
bool LoadAllChunks(nsAutoPtr<dom::HTMLMediaElement::MetadataTags> &aTags);
// Returns the number of seconds that aBytes represents based on the
// current audio parameters. e.g. 176400 bytes is 1 second at 16-bit
// stereo 44.1kHz. The time is rounded to the nearest microsecond.
double BytesToTime(int64_t aBytes) const;
// Returns the number of bytes that aTime represents based on the current
// audio parameters. e.g. 1 second is 176400 bytes at 16-bit stereo
// 44.1kHz.
int64_t TimeToBytes(double aTime) const;
// Rounds aBytes down to the nearest complete audio frame. Assumes
// beginning of byte range is already frame aligned by caller.
int64_t RoundDownToFrame(int64_t aBytes) const;
int64_t GetDataLength();
int64_t GetPosition();
/*
Metadata extracted from the WAVE header. Used to initialize the audio
stream, and for byte<->time domain conversions.
*/
// Number of samples per second. Limited to range [100, 96000] in LoadFormatChunk.
uint32_t mSampleRate;
// Number of channels. Limited to range [1, 2] in LoadFormatChunk.
uint32_t mChannels;
// Size of a single audio frame, which includes a sample for each channel
// (interleaved).
uint32_t mFrameSize;
// The sample format of the PCM data. AudioStream::SampleFormat doesn't
// support U8.
enum {
FORMAT_U8,
FORMAT_S16
} mSampleFormat;
// Size of PCM data stored in the WAVE as reported by the data chunk in
// the media.
int64_t mWaveLength;
// Start offset of the PCM data in the media stream. Extends mWaveLength
// bytes.
int64_t mWavePCMOffset;
};
} // namespace mozilla
#endif