gecko/content/media/nsMediaDecoder.h

365 lines
14 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 Corporation.
* Portions created by the Initial Developer are Copyright (C) 2007
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Double <chris.double@double.co.nz>
*
* 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(nsMediaDecoder_h_)
#define nsMediaDecoder_h_
#include "mozilla/XPCOM.h"
#include "nsIPrincipal.h"
#include "nsSize.h"
#include "prlog.h"
#include "gfxContext.h"
#include "gfxRect.h"
#include "nsITimer.h"
#include "ImageLayers.h"
class nsHTMLMediaElement;
class nsMediaStream;
class nsIStreamListener;
class nsTimeRanges;
// The size to use for audio data frames in MozAudioAvailable events.
// This value is per channel, and is chosen to give ~43 fps of events,
// for example, 44100 with 2 channels, 2*1024 = 2048.
#define FRAMEBUFFER_LENGTH_PER_CHANNEL 1024
// The total size of the framebuffer used for MozAudioAvailable events
// has to be within the following range.
#define FRAMEBUFFER_LENGTH_MIN 512
#define FRAMEBUFFER_LENGTH_MAX 16384
// Shuts down a thread asynchronously.
class ShutdownThreadEvent : public nsRunnable
{
public:
ShutdownThreadEvent(nsIThread* aThread) : mThread(aThread) {}
~ShutdownThreadEvent() {}
NS_IMETHOD Run() {
mThread->Shutdown();
return NS_OK;
}
private:
nsCOMPtr<nsIThread> mThread;
};
// All methods of nsMediaDecoder must be called from the main thread only
// with the exception of GetImageContainer, SetVideoData and GetStatistics,
// which can be called from any thread.
class nsMediaDecoder : public nsIObserver
{
public:
typedef mozilla::TimeStamp TimeStamp;
typedef mozilla::TimeDuration TimeDuration;
typedef mozilla::layers::ImageContainer ImageContainer;
typedef mozilla::layers::Image Image;
nsMediaDecoder();
virtual ~nsMediaDecoder();
// Create a new decoder of the same type as this one.
virtual nsMediaDecoder* Clone() = 0;
// Perform any initialization required for the decoder.
// Return PR_TRUE on successful initialisation, PR_FALSE
// on failure.
virtual PRBool Init(nsHTMLMediaElement* aElement);
// Get the current nsMediaStream being used. Its URI will be returned
// by currentSrc.
virtual nsMediaStream* GetCurrentStream() = 0;
// Return the principal of the current URI being played or downloaded.
virtual already_AddRefed<nsIPrincipal> GetCurrentPrincipal() = 0;
// Return the time position in the video stream being
// played measured in seconds.
virtual double GetCurrentTime() = 0;
// Seek to the time position in (seconds) from the start of the video.
virtual nsresult Seek(double aTime) = 0;
// Called by the element when the playback rate has been changed.
// Adjust the speed of the playback, optionally with pitch correction,
// when this is called.
virtual nsresult PlaybackRateChanged() = 0;
// Return the duration of the video in seconds.
virtual double GetDuration() = 0;
// Pause video playback.
virtual void Pause() = 0;
// Set the audio volume. It should be a value from 0 to 1.0.
virtual void SetVolume(double aVolume) = 0;
// Start playback of a video. 'Load' must have previously been
// called.
virtual nsresult Play() = 0;
// Start downloading the media. Decode the downloaded data up to the
// point of the first frame of data.
// aStream is the media stream to use. Ownership of aStream passes to
// the decoder, even if Load returns an error.
// This is called at most once per decoder, after Init().
virtual nsresult Load(nsMediaStream* aStream,
nsIStreamListener **aListener,
nsMediaDecoder* aCloneDonor) = 0;
// Called when the video file has completed downloading.
virtual void ResourceLoaded() = 0;
// Called if the media file encounters a network error.
virtual void NetworkError() = 0;
// Call from any thread safely. Return PR_TRUE if we are currently
// seeking in the media resource.
virtual PRBool IsSeeking() const = 0;
// Return PR_TRUE if the decoder has reached the end of playback.
// Call in the main thread only.
virtual PRBool IsEnded() const = 0;
struct Statistics {
// Estimate of the current playback rate (bytes/second).
double mPlaybackRate;
// Estimate of the current download rate (bytes/second). This
// ignores time that the channel was paused by Gecko.
double mDownloadRate;
// Total length of media stream in bytes; -1 if not known
PRInt64 mTotalBytes;
// Current position of the download, in bytes. This is the offset of
// the first uncached byte after the decoder position.
PRInt64 mDownloadPosition;
// Current position of decoding, in bytes (how much of the stream
// has been consumed)
PRInt64 mDecoderPosition;
// Current position of playback, in bytes
PRInt64 mPlaybackPosition;
// If false, then mDownloadRate cannot be considered a reliable
// estimate (probably because the download has only been running
// a short time).
PRPackedBool mDownloadRateReliable;
// If false, then mPlaybackRate cannot be considered a reliable
// estimate (probably because playback has only been running
// a short time).
PRPackedBool mPlaybackRateReliable;
};
// Return statistics. This is used for progress events and other things.
// This can be called from any thread. It's only a snapshot of the
// current state, since other threads might be changing the state
// at any time.
virtual Statistics GetStatistics() = 0;
// Set the duration of the media resource in units of milliseconds.
// This is called via a channel listener if it can pick up the duration
// from a content header. Must be called from the main thread only.
virtual void SetDuration(PRInt64 aDuration) = 0;
// Set a flag indicating whether seeking is supported
virtual void SetSeekable(PRBool aSeekable) = 0;
// Return PR_TRUE if seeking is supported.
virtual PRBool GetSeekable() = 0;
// Invalidate the frame.
virtual void Invalidate();
// Fire progress events if needed according to the time and byte
// constraints outlined in the specification. aTimer is PR_TRUE
// if the method is called as a result of the progress timer rather
// than the result of downloaded data.
virtual void Progress(PRBool aTimer);
// Fire timeupdate events if needed according to the time constraints
// outlined in the specification.
virtual void FireTimeUpdate();
// Called by nsMediaStream when the "cache suspended" status changes.
// If nsMediaStream::IsSuspendedByCache returns true, then the decoder
// should stop buffering or otherwise waiting for download progress and
// start consuming data, if possible, because the cache is full.
virtual void NotifySuspendedStatusChanged() = 0;
// Called by nsMediaStream when some data has been received.
// Call on the main thread only.
virtual void NotifyBytesDownloaded() = 0;
// Called by nsChannelToPipeListener or nsMediaStream when the
// download has ended. Called on the main thread only. aStatus is
// the result from OnStopRequest.
virtual void NotifyDownloadEnded(nsresult aStatus) = 0;
// Called as data arrives on the stream and is read into the cache. Called
// on the main thread only.
virtual void NotifyDataArrived(const char* aBuffer, PRUint32 aLength, PRUint32 aOffset) = 0;
// Cleanup internal data structures. Must be called on the main
// thread by the owning object before that object disposes of this object.
virtual void Shutdown();
// Suspend any media downloads that are in progress. Called by the
// media element when it is sent to the bfcache, or when we need
// to throttle the download. Call on the main thread only. This can
// be called multiple times, there's an internal "suspend count".
virtual void Suspend() = 0;
// Resume any media downloads that have been suspended. Called by the
// media element when it is restored from the bfcache, or when we need
// to stop throttling the download. Call on the main thread only.
// The download will only actually resume once as many Resume calls
// have been made as Suspend calls. When aForceBuffering is PR_TRUE,
// we force the decoder to go into buffering state before resuming
// playback.
virtual void Resume(PRBool aForceBuffering) = 0;
// Returns a weak reference to the media element we're decoding for,
// if it's available.
nsHTMLMediaElement* GetMediaElement();
// Returns the current size of the framebuffer used in
// MozAudioAvailable events.
PRUint32 GetFrameBufferLength() { return mFrameBufferLength; };
// Sets the length of the framebuffer used in MozAudioAvailable events.
// The new size must be between 512 and 16384.
nsresult RequestFrameBufferLength(PRUint32 aLength);
// Moves any existing channel loads into the background, so that they don't
// block the load event. This is called when we stop delaying the load
// event. Any new loads initiated (for example to seek) will also be in the
// background. Implementations of this must call MoveLoadsToBackground() on
// their nsMediaStream.
virtual void MoveLoadsToBackground()=0;
// Gets the image container for the media element. Will return null if
// the element is not a video element. This can be called from any
// thread; ImageContainers can be used from any thread.
ImageContainer* GetImageContainer() { return mImageContainer; }
// Set the video width, height, pixel aspect ratio, and current image.
// Ownership of the image is transferred to the decoder.
void SetVideoData(const gfxIntSize& aSize,
float aPixelAspectRatio,
Image* aImage);
// Constructs the time ranges representing what segments of the media
// are buffered and playable.
virtual nsresult GetBuffered(nsTimeRanges* aBuffered) = 0;
// Returns PR_TRUE if we can play the entire media through without stopping
// to buffer, given the current download and playback rates.
PRBool CanPlayThrough();
// Called by the nsMediaStream when a read on the stream by the decoder
// is about to block due to insuffient data. Decoders may want to pause
// playback and go into buffering mode when this is called.
virtual void NotifyDataExhausted() = 0;
protected:
// Start timer to update download progress information.
nsresult StartProgress();
// Stop progress information timer.
nsresult StopProgress();
// Ensures our media stream has been pinned.
void PinForSeek();
// Ensures our media stream has been unpinned.
void UnpinForSeek();
protected:
// Timer used for updating progress events
nsCOMPtr<nsITimer> mProgressTimer;
// This should only ever be accessed from the main thread.
// It is set in Init and cleared in Shutdown when the element goes away.
// The decoder does not add a reference the element.
nsHTMLMediaElement* mElement;
PRInt32 mRGBWidth;
PRInt32 mRGBHeight;
nsRefPtr<ImageContainer> mImageContainer;
// Time that the last progress event was fired. Read/Write from the
// main thread only.
TimeStamp mProgressTime;
// Time that data was last read from the media resource. Used for
// computing if the download has stalled and to rate limit progress events
// when data is arriving slower than PROGRESS_MS. A value of null indicates
// that a stall event has already fired and not to fire another one until
// more data is received. Read/Write from the main thread only.
TimeStamp mDataTime;
// Lock around the video RGB, width and size data. This
// is used in the decoder backend threads and the main thread
// to ensure that repainting the video does not use these
// values while they are out of sync (width changed but
// not height yet, etc).
// Backends that are updating the height, width or writing
// to the RGB buffer must obtain this lock first to ensure that
// the video element does not use video data or sizes that are
// in the midst of being changed.
PRLock* mVideoUpdateLock;
// Pixel aspect ratio (ratio of the pixel width to pixel height)
float mPixelAspectRatio;
// The framebuffer size to use for audioavailable events.
PRUint32 mFrameBufferLength;
// PR_TRUE when our media stream has been pinned. We pin the stream
// while seeking.
PRPackedBool mPinnedForSeek;
// Has our size changed since the last repaint?
PRPackedBool mSizeChanged;
// True if the decoder is being shutdown. At this point all events that
// are currently queued need to return immediately to prevent javascript
// being run that operates on the element and decoder during shutdown.
// Read/Write from the main thread only.
PRPackedBool mShuttingDown;
};
#endif