gecko/content/media/wave/nsWaveReader.h

122 lines
4.3 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: */
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla code.
*
* The Initial Developer of the Original Code is the Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2010
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Matthew Gregan <kinetik@flim.org>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#if !defined(nsWaveReader_h_)
#define nsWaveReader_h_
#include "nsBuiltinDecoderReader.h"
class nsBuiltinDecoder;
class nsTimeRanges;
class nsWaveReader : public nsBuiltinDecoderReader
{
public:
nsWaveReader(nsBuiltinDecoder* aDecoder);
~nsWaveReader();
virtual nsresult Init(nsBuiltinDecoderReader* aCloneDonor);
virtual bool DecodeAudioData();
virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
PRInt64 aTimeThreshold);
virtual bool HasAudio()
{
return true;
}
virtual bool HasVideo()
{
return false;
}
virtual nsresult ReadMetadata(nsVideoInfo* aInfo);
virtual nsresult Seek(PRInt64 aTime, PRInt64 aStartTime, PRInt64 aEndTime, PRInt64 aCurrentTime);
virtual nsresult GetBuffered(nsTimeRanges* aBuffered, PRInt64 aStartTime);
private:
bool ReadAll(char* aBuf, PRInt64 aSize, PRInt64* aBytesRead = nsnull);
bool LoadRIFFChunk();
bool ScanForwardUntil(PRUint32 aWantedChunk, PRUint32* aChunkSize);
bool LoadFormatChunk();
bool FindDataOffset();
// 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(PRInt64 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.
PRInt64 TimeToBytes(double aTime) const;
// Rounds aBytes down to the nearest complete audio frame. Assumes
// beginning of byte range is already frame aligned by caller.
PRInt64 RoundDownToFrame(PRInt64 aBytes) const;
PRInt64 GetDataLength();
PRInt64 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.
PRUint32 mSampleRate;
// Number of channels. Limited to range [1, 2] in LoadFormatChunk.
PRUint32 mChannels;
// Size of a single audio frame, which includes a sample for each channel
// (interleaved).
PRUint32 mFrameSize;
// The sample format of the PCM data.
nsAudioStream::SampleFormat mSampleFormat;
// Size of PCM data stored in the WAVE as reported by the data chunk in
// the media.
PRInt64 mWaveLength;
// Start offset of the PCM data in the media stream. Extends mWaveLength
// bytes.
PRInt64 mWavePCMOffset;
};
#endif