1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/image/src/Decoder.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,281 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +#ifndef MOZILLA_IMAGELIB_DECODER_H_
1.10 +#define MOZILLA_IMAGELIB_DECODER_H_
1.11 +
1.12 +#include "RasterImage.h"
1.13 +#include "imgDecoderObserver.h"
1.14 +#include "mozilla/RefPtr.h"
1.15 +#include "DecodeStrategy.h"
1.16 +#include "ImageMetadata.h"
1.17 +#include "Orientation.h"
1.18 +#include "mozilla/Telemetry.h"
1.19 +
1.20 +namespace mozilla {
1.21 +namespace image {
1.22 +
1.23 +class Decoder
1.24 +{
1.25 +public:
1.26 +
1.27 + Decoder(RasterImage& aImage);
1.28 + virtual ~Decoder();
1.29 +
1.30 + /**
1.31 + * Initialize an image decoder. Decoders may not be re-initialized.
1.32 + *
1.33 + * Notifications Sent: TODO
1.34 + */
1.35 + void Init();
1.36 +
1.37 + /**
1.38 + * Initializes a decoder whose image and observer is already being used by a
1.39 + * parent decoder. Decoders may not be re-initialized.
1.40 + *
1.41 + * Notifications Sent: TODO
1.42 + */
1.43 + void InitSharedDecoder(uint8_t* imageData, uint32_t imageDataLength,
1.44 + uint32_t* colormap, uint32_t colormapSize,
1.45 + imgFrame* currentFrame);
1.46 +
1.47 + /**
1.48 + * Writes data to the decoder.
1.49 + *
1.50 + * @param aBuffer buffer containing the data to be written
1.51 + * @param aCount the number of bytes to write
1.52 + *
1.53 + * Any errors are reported by setting the appropriate state on the decoder.
1.54 + *
1.55 + * Notifications Sent: TODO
1.56 + */
1.57 + void Write(const char* aBuffer, uint32_t aCount, DecodeStrategy aStrategy);
1.58 +
1.59 + /**
1.60 + * Informs the decoder that all the data has been written.
1.61 + *
1.62 + * Notifications Sent: TODO
1.63 + */
1.64 + void Finish(RasterImage::eShutdownIntent aShutdownIntent);
1.65 +
1.66 + /**
1.67 + * Informs the shared decoder that all the data has been written.
1.68 + * Should only be used if InitSharedDecoder was useed
1.69 + *
1.70 + * Notifications Sent: TODO
1.71 + */
1.72 + void FinishSharedDecoder();
1.73 +
1.74 + /**
1.75 + * Tells the decoder to flush any pending invalidations. This informs the image
1.76 + * frame of its decoded region, and sends the appropriate OnDataAvailable call
1.77 + * to consumers.
1.78 + *
1.79 + * This can be called any time when we're midway through decoding a frame,
1.80 + * and must be called after finishing a frame (before starting a new one).
1.81 + */
1.82 + void FlushInvalidations();
1.83 +
1.84 + // We're not COM-y, so we don't get refcounts by default
1.85 + NS_INLINE_DECL_THREADSAFE_REFCOUNTING(Decoder)
1.86 +
1.87 + /*
1.88 + * State.
1.89 + */
1.90 +
1.91 + // If we're doing a "size decode", we more or less pass through the image
1.92 + // data, stopping only to scoop out the image dimensions. A size decode
1.93 + // must be enabled by SetSizeDecode() _before_calling Init().
1.94 + bool IsSizeDecode() { return mSizeDecode; }
1.95 + void SetSizeDecode(bool aSizeDecode)
1.96 + {
1.97 + NS_ABORT_IF_FALSE(!mInitialized, "Can't set size decode after Init()!");
1.98 + mSizeDecode = aSizeDecode;
1.99 + }
1.100 +
1.101 + void SetObserver(imgDecoderObserver* aObserver)
1.102 + {
1.103 + MOZ_ASSERT(aObserver);
1.104 + mObserver = aObserver;
1.105 + }
1.106 +
1.107 + // The number of frames we have, including anything in-progress. Thus, this
1.108 + // is only 0 if we haven't begun any frames.
1.109 + uint32_t GetFrameCount() { return mFrameCount; }
1.110 +
1.111 + // The number of complete frames we have (ie, not including anything in-progress).
1.112 + uint32_t GetCompleteFrameCount() { return mInFrame ? mFrameCount - 1 : mFrameCount; }
1.113 +
1.114 + // Error tracking
1.115 + bool HasError() { return HasDataError() || HasDecoderError(); }
1.116 + bool HasDataError() { return mDataError; }
1.117 + bool HasDecoderError() { return NS_FAILED(mFailCode); }
1.118 + nsresult GetDecoderError() { return mFailCode; }
1.119 + void PostResizeError() { PostDataError(); }
1.120 + bool GetDecodeDone() const {
1.121 + return mDecodeDone;
1.122 + }
1.123 +
1.124 + // flags. Keep these in sync with imgIContainer.idl.
1.125 + // SetDecodeFlags must be called before Init(), otherwise
1.126 + // default flags are assumed.
1.127 + enum {
1.128 + DECODER_NO_PREMULTIPLY_ALPHA = 0x2, // imgIContainer::FLAG_DECODE_NO_PREMULTIPLY_ALPHA
1.129 + DECODER_NO_COLORSPACE_CONVERSION = 0x4 // imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION
1.130 + };
1.131 +
1.132 + enum DecodeStyle {
1.133 + PROGRESSIVE, // produce intermediate frames representing the partial state of the image
1.134 + SEQUENTIAL // decode to final image immediately
1.135 + };
1.136 +
1.137 + void SetDecodeFlags(uint32_t aFlags) { mDecodeFlags = aFlags; }
1.138 + uint32_t GetDecodeFlags() { return mDecodeFlags; }
1.139 +
1.140 + bool HasSize() const { return mImageMetadata.HasSize(); }
1.141 + void SetSizeOnImage();
1.142 +
1.143 + // Use HistogramCount as an invalid Histogram ID
1.144 + virtual Telemetry::ID SpeedHistogram() { return Telemetry::HistogramCount; }
1.145 +
1.146 + ImageMetadata& GetImageMetadata() { return mImageMetadata; }
1.147 +
1.148 + // Tell the decoder infrastructure to allocate a frame. By default, frame 0
1.149 + // is created as an ARGB frame with no offset and with size width * height.
1.150 + // If decoders need something different, they must ask for it.
1.151 + // This is called by decoders when they need a new frame. These decoders
1.152 + // must then save the data they have been sent but not yet processed and
1.153 + // return from WriteInternal. When the new frame is created, WriteInternal
1.154 + // will be called again with nullptr and 0 as arguments.
1.155 + void NeedNewFrame(uint32_t frameNum, uint32_t x_offset, uint32_t y_offset,
1.156 + uint32_t width, uint32_t height,
1.157 + gfxImageFormat format,
1.158 + uint8_t palette_depth = 0);
1.159 +
1.160 + virtual bool NeedsNewFrame() const { return mNeedsNewFrame; }
1.161 +
1.162 + // Try to allocate a frame as described in mNewFrameData and return the
1.163 + // status code from that attempt. Clears mNewFrameData.
1.164 + virtual nsresult AllocateFrame();
1.165 +
1.166 + // Called when a chunk of decoding has been done and the frame needs to be
1.167 + // marked as dirty. Must be called only on the main thread.
1.168 + void MarkFrameDirty();
1.169 +
1.170 + imgFrame* GetCurrentFrame() const { return mCurrentFrame; }
1.171 +
1.172 +protected:
1.173 +
1.174 + /*
1.175 + * Internal hooks. Decoder implementations may override these and
1.176 + * only these methods.
1.177 + */
1.178 + virtual void InitInternal();
1.179 + virtual void WriteInternal(const char* aBuffer, uint32_t aCount, DecodeStrategy aStrategy);
1.180 + virtual void FinishInternal();
1.181 +
1.182 + /*
1.183 + * Progress notifications.
1.184 + */
1.185 +
1.186 + // Called by decoders when they determine the size of the image. Informs
1.187 + // the image of its size and sends notifications.
1.188 + void PostSize(int32_t aWidth,
1.189 + int32_t aHeight,
1.190 + Orientation aOrientation = Orientation());
1.191 +
1.192 + // Called by decoders when they begin a frame. Informs the image, sends
1.193 + // notifications, and does internal book-keeping.
1.194 + void PostFrameStart();
1.195 +
1.196 + // Called by decoders when they end a frame. Informs the image, sends
1.197 + // notifications, and does internal book-keeping.
1.198 + // Specify whether this frame is opaque as an optimization.
1.199 + // For animated images, specify the disposal, blend method and timeout for
1.200 + // this frame.
1.201 + void PostFrameStop(FrameBlender::FrameAlpha aFrameAlpha = FrameBlender::kFrameHasAlpha,
1.202 + FrameBlender::FrameDisposalMethod aDisposalMethod = FrameBlender::kDisposeKeep,
1.203 + int32_t aTimeout = 0,
1.204 + FrameBlender::FrameBlendMethod aBlendMethod = FrameBlender::kBlendOver);
1.205 +
1.206 + // Called by the decoders when they have a region to invalidate. We may not
1.207 + // actually pass these invalidations on right away.
1.208 + void PostInvalidation(nsIntRect& aRect);
1.209 +
1.210 + // Called by the decoders when they have successfully decoded the image. This
1.211 + // may occur as the result of the decoder getting to the appropriate point in
1.212 + // the stream, or by us calling FinishInternal().
1.213 + //
1.214 + // May not be called mid-frame.
1.215 + //
1.216 + // For animated images, specify the loop count. -1 means loop forever, 0
1.217 + // means a single iteration, stopping on the last frame.
1.218 + void PostDecodeDone(int32_t aLoopCount = 0);
1.219 +
1.220 + // Data errors are the fault of the source data, decoder errors are our fault
1.221 + void PostDataError();
1.222 + void PostDecoderError(nsresult aFailCode);
1.223 +
1.224 + /*
1.225 + * Member variables.
1.226 + *
1.227 + */
1.228 + RasterImage &mImage;
1.229 + imgFrame* mCurrentFrame;
1.230 + RefPtr<imgDecoderObserver> mObserver;
1.231 + ImageMetadata mImageMetadata;
1.232 +
1.233 + uint8_t* mImageData; // Pointer to image data in either Cairo or 8bit format
1.234 + uint32_t mImageDataLength;
1.235 + uint32_t* mColormap; // Current colormap to be used in Cairo format
1.236 + uint32_t mColormapSize;
1.237 +
1.238 + uint32_t mDecodeFlags;
1.239 + bool mDecodeDone;
1.240 + bool mDataError;
1.241 +
1.242 +private:
1.243 + uint32_t mFrameCount; // Number of frames, including anything in-progress
1.244 +
1.245 + nsIntRect mInvalidRect; // Tracks an invalidation region in the current frame.
1.246 +
1.247 + nsresult mFailCode;
1.248 +
1.249 + struct NewFrameData
1.250 + {
1.251 + NewFrameData()
1.252 + {}
1.253 +
1.254 + NewFrameData(uint32_t num, uint32_t offsetx, uint32_t offsety,
1.255 + uint32_t width, uint32_t height,
1.256 + gfxImageFormat format, uint8_t paletteDepth)
1.257 + : mFrameNum(num)
1.258 + , mOffsetX(offsetx)
1.259 + , mOffsetY(offsety)
1.260 + , mWidth(width)
1.261 + , mHeight(height)
1.262 + , mFormat(format)
1.263 + , mPaletteDepth(paletteDepth)
1.264 + {}
1.265 + uint32_t mFrameNum;
1.266 + uint32_t mOffsetX;
1.267 + uint32_t mOffsetY;
1.268 + uint32_t mWidth;
1.269 + uint32_t mHeight;
1.270 + gfxImageFormat mFormat;
1.271 + uint8_t mPaletteDepth;
1.272 + };
1.273 + NewFrameData mNewFrameData;
1.274 + bool mNeedsNewFrame;
1.275 + bool mInitialized;
1.276 + bool mSizeDecode;
1.277 + bool mInFrame;
1.278 + bool mIsAnimated;
1.279 +};
1.280 +
1.281 +} // namespace image
1.282 +} // namespace mozilla
1.283 +
1.284 +#endif // MOZILLA_IMAGELIB_DECODER_H_
