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edf533c3f1
Implements a media.mozGetMetadata() method returning a new javascript object whose properties are key value pairs respresenting metadata tags from the media resource. This data is available after readystate enters METADATA_LOADED. Currently this is only implemented for Ogg Vorbis streams. Media format metadata is parsed out by the media decoders. In the nsCodecStateMachine::ReadMetadata subclasses we fill in an nsDataHashtable pointer using the format-specifc api. The hash pointer is passed up to the media element as part of the MetadataLoaded event. The hash is deleted if the load is aborted. The audio metadata is also reset to zero (as in the constructor), resolving a todo comment.
96 lines
3.0 KiB
C++
96 lines
3.0 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
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/* vim:set ts=2 sw=2 sts=2 et cindent: */
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/* This Source Code Form is subject to the terms of the Mozilla Public
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* License, v. 2.0. If a copy of the MPL was not distributed with this
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* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
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#if !defined(nsWaveReader_h_)
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#define nsWaveReader_h_
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#include "nsBuiltinDecoderReader.h"
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class nsBuiltinDecoder;
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class nsTimeRanges;
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class nsWaveReader : public nsBuiltinDecoderReader
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{
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public:
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nsWaveReader(nsBuiltinDecoder* aDecoder);
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~nsWaveReader();
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virtual nsresult Init(nsBuiltinDecoderReader* aCloneDonor);
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virtual bool DecodeAudioData();
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virtual bool DecodeVideoFrame(bool &aKeyframeSkip,
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PRInt64 aTimeThreshold);
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virtual bool HasAudio()
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{
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return true;
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}
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virtual bool HasVideo()
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{
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return false;
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}
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virtual nsresult ReadMetadata(nsVideoInfo* aInfo,
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nsHTMLMediaElement::MetadataTags** aTags);
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virtual nsresult Seek(PRInt64 aTime, PRInt64 aStartTime, PRInt64 aEndTime, PRInt64 aCurrentTime);
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virtual nsresult GetBuffered(nsTimeRanges* aBuffered, PRInt64 aStartTime);
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// To seek in a buffered range, we just have to seek the stream.
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virtual bool IsSeekableInBufferedRanges() {
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return true;
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}
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private:
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bool ReadAll(char* aBuf, PRInt64 aSize, PRInt64* aBytesRead = nullptr);
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bool LoadRIFFChunk();
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bool ScanForwardUntil(PRUint32 aWantedChunk, PRUint32* aChunkSize);
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bool LoadFormatChunk();
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bool FindDataOffset();
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// Returns the number of seconds that aBytes represents based on the
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// current audio parameters. e.g. 176400 bytes is 1 second at 16-bit
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// stereo 44.1kHz. The time is rounded to the nearest microsecond.
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double BytesToTime(PRInt64 aBytes) const;
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// Returns the number of bytes that aTime represents based on the current
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// audio parameters. e.g. 1 second is 176400 bytes at 16-bit stereo
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// 44.1kHz.
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PRInt64 TimeToBytes(double aTime) const;
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// Rounds aBytes down to the nearest complete audio frame. Assumes
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// beginning of byte range is already frame aligned by caller.
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PRInt64 RoundDownToFrame(PRInt64 aBytes) const;
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PRInt64 GetDataLength();
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PRInt64 GetPosition();
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/*
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Metadata extracted from the WAVE header. Used to initialize the audio
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stream, and for byte<->time domain conversions.
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*/
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// Number of samples per second. Limited to range [100, 96000] in LoadFormatChunk.
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PRUint32 mSampleRate;
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// Number of channels. Limited to range [1, 2] in LoadFormatChunk.
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PRUint32 mChannels;
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// Size of a single audio frame, which includes a sample for each channel
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// (interleaved).
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PRUint32 mFrameSize;
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// The sample format of the PCM data.
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nsAudioStream::SampleFormat mSampleFormat;
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// Size of PCM data stored in the WAVE as reported by the data chunk in
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// the media.
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PRInt64 mWaveLength;
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// Start offset of the PCM data in the media stream. Extends mWaveLength
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// bytes.
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PRInt64 mWavePCMOffset;
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};
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#endif
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