зеркало из https://github.com/mozilla/gecko-dev.git
1373 строки
44 KiB
C++
1373 строки
44 KiB
C++
/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
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*
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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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/*
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The Graphics Interchange Format(c) is the copyright property of CompuServe
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Incorporated. Only CompuServe Incorporated is authorized to define, redefine,
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enhance, alter, modify or change in any way the definition of the format.
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CompuServe Incorporated hereby grants a limited, non-exclusive, royalty-free
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license for the use of the Graphics Interchange Format(sm) in computer
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software; computer software utilizing GIF(sm) must acknowledge ownership of the
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Graphics Interchange Format and its Service Mark by CompuServe Incorporated, in
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User and Technical Documentation. Computer software utilizing GIF, which is
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distributed or may be distributed without User or Technical Documentation must
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display to the screen or printer a message acknowledging ownership of the
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Graphics Interchange Format and the Service Mark by CompuServe Incorporated; in
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this case, the acknowledgement may be displayed in an opening screen or leading
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banner, or a closing screen or trailing banner. A message such as the following
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may be used:
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"The Graphics Interchange Format(c) is the Copyright property of
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CompuServe Incorporated. GIF(sm) is a Service Mark property of
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CompuServe Incorporated."
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For further information, please contact :
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CompuServe Incorporated
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Graphics Technology Department
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5000 Arlington Center Boulevard
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Columbus, Ohio 43220
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U. S. A.
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CompuServe Incorporated maintains a mailing list with all those individuals and
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organizations who wish to receive copies of this document when it is corrected
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or revised. This service is offered free of charge; please provide us with your
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mailing address.
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*/
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#include <stddef.h>
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#include "nsGIFDecoder2.h"
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#include "nsIInputStream.h"
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#include "RasterImage.h"
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#include "gfxColor.h"
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#include "gfxPlatform.h"
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#include "qcms.h"
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#include <algorithm>
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#include "mozilla/Telemetry.h"
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using namespace mozilla::gfx;
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namespace mozilla {
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namespace image {
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// GETN(n, s) requests at least 'n' bytes available from 'q', at start of state
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// 's'. Colormaps are directly copied in the resp. global_colormap or the
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// local_colormap of the PAL image frame So a fixed buffer in gif_struct is
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// good enough. This buffer is only needed to copy left-over data from one
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// GifWrite call to the next
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#define GETN(n,s) \
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PR_BEGIN_MACRO \
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mGIFStruct.bytes_to_consume = (n); \
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mGIFStruct.state = (s); \
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PR_END_MACRO
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// Get a 16-bit value stored in little-endian format
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#define GETINT16(p) ((p)[1]<<8|(p)[0])
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//////////////////////////////////////////////////////////////////////
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// GIF Decoder Implementation
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nsGIFDecoder2::nsGIFDecoder2(RasterImage* aImage)
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: Decoder(aImage)
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, mCurrentRow(-1)
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, mLastFlushedRow(-1)
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, mOldColor(0)
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, mCurrentFrameIndex(-1)
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, mCurrentPass(0)
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, mLastFlushedPass(0)
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, mGIFOpen(false)
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, mSawTransparency(false)
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{
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// Clear out the structure, excluding the arrays
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memset(&mGIFStruct, 0, sizeof(mGIFStruct));
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// Initialize as "animate once" in case no NETSCAPE2.0 extension is found
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mGIFStruct.loop_count = 1;
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// Start with the version (GIF89a|GIF87a)
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mGIFStruct.state = gif_type;
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mGIFStruct.bytes_to_consume = 6;
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}
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nsGIFDecoder2::~nsGIFDecoder2()
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{
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free(mGIFStruct.local_colormap);
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free(mGIFStruct.hold);
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}
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uint8_t*
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nsGIFDecoder2::GetCurrentRowBuffer()
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{
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if (!mDownscaler) {
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MOZ_ASSERT(!mDeinterlacer, "Deinterlacer without downscaler?");
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uint32_t bpp = mGIFStruct.images_decoded == 0 ? sizeof(uint32_t)
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: sizeof(uint8_t);
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return mImageData + mGIFStruct.irow * mGIFStruct.width * bpp;
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}
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if (!mDeinterlacer) {
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return mDownscaler->RowBuffer();
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}
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return mDeinterlacer->RowBuffer(mGIFStruct.irow);
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}
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uint8_t*
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nsGIFDecoder2::GetRowBuffer(uint32_t aRow)
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{
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MOZ_ASSERT(mGIFStruct.images_decoded == 0,
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"Calling GetRowBuffer on a frame other than the first suggests "
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"we're deinterlacing animated frames");
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MOZ_ASSERT(!mDownscaler || mDeinterlacer,
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"Can't get buffer for a specific row if downscaling "
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"but not deinterlacing");
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if (mDownscaler) {
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return mDeinterlacer->RowBuffer(aRow);
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}
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return mImageData + aRow * mGIFStruct.width * sizeof(uint32_t);
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}
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void
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nsGIFDecoder2::FinishInternal()
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{
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MOZ_ASSERT(!HasError(), "Shouldn't call FinishInternal after error!");
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// If the GIF got cut off, handle it anyway
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if (!IsMetadataDecode() && mGIFOpen) {
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if (mCurrentFrameIndex == mGIFStruct.images_decoded) {
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EndImageFrame();
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}
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PostDecodeDone(mGIFStruct.loop_count - 1);
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mGIFOpen = false;
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}
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}
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// Push any new rows according to mCurrentPass/mLastFlushedPass and
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// mCurrentRow/mLastFlushedRow. Note: caller is responsible for
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// updating mlastFlushed{Row,Pass}.
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void
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nsGIFDecoder2::FlushImageData(uint32_t fromRow, uint32_t rows)
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{
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nsIntRect r(mGIFStruct.x_offset, mGIFStruct.y_offset + fromRow,
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mGIFStruct.width, rows);
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PostInvalidation(r);
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}
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void
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nsGIFDecoder2::FlushImageData()
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{
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if (mDownscaler) {
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if (mDownscaler->HasInvalidation()) {
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DownscalerInvalidRect invalidRect = mDownscaler->TakeInvalidRect();
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PostInvalidation(invalidRect.mOriginalSizeRect,
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Some(invalidRect.mTargetSizeRect));
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}
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return;
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}
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switch (mCurrentPass - mLastFlushedPass) {
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case 0: // same pass
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if (mCurrentRow - mLastFlushedRow) {
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FlushImageData(mLastFlushedRow + 1, mCurrentRow - mLastFlushedRow);
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}
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break;
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case 1: // one pass on - need to handle bottom & top rects
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FlushImageData(0, mCurrentRow + 1);
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FlushImageData(mLastFlushedRow + 1,
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mGIFStruct.clamped_height - (mLastFlushedRow + 1));
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break;
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default: // more than one pass on - push the whole frame
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FlushImageData(0, mGIFStruct.clamped_height);
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}
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}
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//******************************************************************************
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// GIF decoder callback methods. Part of public API for GIF2
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//******************************************************************************
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//******************************************************************************
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void
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nsGIFDecoder2::BeginGIF()
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{
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if (mGIFOpen) {
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return;
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}
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mGIFOpen = true;
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PostSize(mGIFStruct.screen_width, mGIFStruct.screen_height);
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}
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bool
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nsGIFDecoder2::CheckForTransparency(const IntRect& aFrameRect)
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{
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// Check if the image has a transparent color in its palette.
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if (mGIFStruct.is_transparent) {
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PostHasTransparency();
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return true;
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}
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if (mGIFStruct.images_decoded > 0) {
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return false; // We only care about first frame padding below.
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}
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// If we need padding on the first frame, that means we don't draw into part
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// of the image at all. Report that as transparency.
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IntRect imageRect(0, 0, mGIFStruct.screen_width, mGIFStruct.screen_height);
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if (!imageRect.IsEqualEdges(aFrameRect)) {
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PostHasTransparency();
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mSawTransparency = true; // Make sure we don't optimize it away.
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return true;
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}
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return false;
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}
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IntRect
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nsGIFDecoder2::ClampToImageRect(const IntRect& aRect)
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{
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IntRect imageRect(0, 0, mGIFStruct.screen_width, mGIFStruct.screen_height);
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IntRect visibleFrameRect = aRect.Intersect(imageRect);
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// If there's no intersection, |visibleFrameRect| will be an empty rect
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// positioned at the maximum of |imageRect|'s and |aRect|'s coordinates, which
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// is not what we want. Force it to (0, 0) in that case.
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if (visibleFrameRect.IsEmpty()) {
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visibleFrameRect.MoveTo(0, 0);
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}
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return visibleFrameRect;
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}
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//******************************************************************************
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nsresult
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nsGIFDecoder2::BeginImageFrame(uint16_t aDepth)
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{
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MOZ_ASSERT(HasSize());
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IntRect frameRect(mGIFStruct.x_offset, mGIFStruct.y_offset,
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mGIFStruct.width, mGIFStruct.height);
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bool hasTransparency = CheckForTransparency(frameRect);
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gfx::SurfaceFormat format = hasTransparency ? SurfaceFormat::B8G8R8A8
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: SurfaceFormat::B8G8R8X8;
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// Make sure there's no animation if we're downscaling.
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MOZ_ASSERT_IF(mDownscaler, !GetImageMetadata().HasAnimation());
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// Compute the target size and target frame rect. If we're downscaling,
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// Downscaler will automatically strip out first-frame padding, so the target
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// frame rect takes up the entire frame regardless.
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IntSize targetSize = mDownscaler ? mDownscaler->TargetSize()
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: GetSize();
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IntRect targetFrameRect = mDownscaler ? IntRect(IntPoint(), targetSize)
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: frameRect;
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// Use correct format, RGB for first frame, PAL for following frames
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// and include transparency to allow for optimization of opaque images
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nsresult rv = NS_OK;
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if (mGIFStruct.images_decoded) {
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// Image data is stored with original depth and palette.
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rv = AllocateFrame(mGIFStruct.images_decoded, targetSize,
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targetFrameRect, format, aDepth);
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} else {
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// Regardless of depth of input, the first frame is decoded into 24bit RGB.
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rv = AllocateFrame(mGIFStruct.images_decoded, targetSize,
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targetFrameRect, format);
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}
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mCurrentFrameIndex = mGIFStruct.images_decoded;
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if (NS_FAILED(rv)) {
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return rv;
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}
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if (mDownscaler) {
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rv = mDownscaler->BeginFrame(GetSize(), Some(ClampToImageRect(frameRect)),
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mImageData, hasTransparency);
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}
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return rv;
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}
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//******************************************************************************
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void
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nsGIFDecoder2::EndImageFrame()
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{
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Opacity opacity = Opacity::SOME_TRANSPARENCY;
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// First flush all pending image data
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if (!mGIFStruct.images_decoded) {
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// Only need to flush first frame
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FlushImageData();
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// If the first frame is smaller in height than the entire image, send an
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// invalidation for the area it does not have data for.
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// This will clear the remaining bits of the placeholder. (Bug 37589)
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const uint32_t realFrameHeight = mGIFStruct.height + mGIFStruct.y_offset;
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if (realFrameHeight < mGIFStruct.screen_height) {
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if (mDownscaler) {
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IntRect targetRect = IntRect(IntPoint(), mDownscaler->TargetSize());
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PostInvalidation(IntRect(IntPoint(), GetSize()), Some(targetRect));
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} else {
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nsIntRect r(0, realFrameHeight,
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mGIFStruct.screen_width,
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mGIFStruct.screen_height - realFrameHeight);
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PostInvalidation(r);
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}
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}
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// The first frame was preallocated with alpha; if it wasn't transparent, we
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// should fix that. We can also mark it opaque unconditionally if we didn't
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// actually see any transparent pixels - this test is only valid for the
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// first frame.
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if (!mGIFStruct.is_transparent && !mSawTransparency) {
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opacity = Opacity::OPAQUE;
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}
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}
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mCurrentRow = mLastFlushedRow = -1;
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mCurrentPass = mLastFlushedPass = 0;
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// Only add frame if we have any rows at all
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if (mGIFStruct.rows_remaining != mGIFStruct.clamped_height) {
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if (mGIFStruct.rows_remaining && mGIFStruct.images_decoded) {
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// Clear the remaining rows (only needed for the animation frames)
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uint8_t* rowp =
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mImageData + ((mGIFStruct.clamped_height - mGIFStruct.rows_remaining) *
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mGIFStruct.width);
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memset(rowp, 0, mGIFStruct.rows_remaining * mGIFStruct.width);
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}
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}
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// Unconditionally increment images_decoded, because we unconditionally
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// append frames in BeginImageFrame(). This ensures that images_decoded
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// always refers to the frame in mImage we're currently decoding,
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// even if some of them weren't decoded properly and thus are blank.
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mGIFStruct.images_decoded++;
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// Tell the superclass we finished a frame
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PostFrameStop(opacity,
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DisposalMethod(mGIFStruct.disposal_method),
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mGIFStruct.delay_time);
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// Reset the transparent pixel
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if (mOldColor) {
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mColormap[mGIFStruct.tpixel] = mOldColor;
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mOldColor = 0;
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}
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mCurrentFrameIndex = -1;
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}
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//******************************************************************************
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// Send the data to the display front-end.
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uint32_t
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nsGIFDecoder2::OutputRow()
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{
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// Initialize the region in which we're duplicating rows (for the
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// Haeberli-inspired hack below) to |irow|, which is the row we're writing to
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// now.
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int drow_start = mGIFStruct.irow;
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int drow_end = mGIFStruct.irow;
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// Protect against too much image data
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if ((unsigned)drow_start >= mGIFStruct.clamped_height) {
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NS_WARNING("GIF2.cpp::OutputRow - too much image data");
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return 0;
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}
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if (!mGIFStruct.images_decoded) {
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// Haeberli-inspired hack for interlaced GIFs: Replicate lines while
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// displaying to diminish the "venetian-blind" effect as the image is
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// loaded. Adjust pixel vertical positions to avoid the appearance of the
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// image crawling up the screen as successive passes are drawn.
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if (mGIFStruct.progressive_display && mGIFStruct.interlaced &&
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(mGIFStruct.ipass < 4)) {
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// ipass = 1,2,3 results in resp. row_dup = 7,3,1 and row_shift = 3,1,0
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const uint32_t row_dup = 15 >> mGIFStruct.ipass;
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const uint32_t row_shift = row_dup >> 1;
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drow_start -= row_shift;
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drow_end = drow_start + row_dup;
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// Extend if bottom edge isn't covered because of the shift upward.
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if (((mGIFStruct.clamped_height - 1) - drow_end) <= row_shift) {
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drow_end = mGIFStruct.clamped_height - 1;
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}
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// Clamp first and last rows to upper and lower edge of image.
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if (drow_start < 0) {
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drow_start = 0;
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}
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if ((unsigned)drow_end >= mGIFStruct.clamped_height) {
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drow_end = mGIFStruct.clamped_height - 1;
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}
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}
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// Row to process
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uint8_t* rowp = GetCurrentRowBuffer();
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// Convert color indices to Cairo pixels
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uint8_t* from = rowp + mGIFStruct.clamped_width;
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uint32_t* to = ((uint32_t*)rowp) + mGIFStruct.clamped_width;
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uint32_t* cmap = mColormap;
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for (uint32_t c = mGIFStruct.clamped_width; c > 0; c--) {
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*--to = cmap[*--from];
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}
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// check for alpha (only for first frame)
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if (mGIFStruct.is_transparent && !mSawTransparency) {
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const uint32_t* rgb = (uint32_t*)rowp;
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for (uint32_t i = mGIFStruct.clamped_width; i > 0; i--) {
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if (*rgb++ == 0) {
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mSawTransparency = true;
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break;
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}
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}
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}
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// If we're downscaling but not deinterlacing, we're done with this row and
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// can commit it now. Otherwise, we'll let Deinterlacer do the committing
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// when we call PropagatePassToDownscaler() at the end of this pass.
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if (mDownscaler && !mDeinterlacer) {
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mDownscaler->CommitRow();
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}
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if (drow_end > drow_start) {
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// Duplicate rows if needed to reduce the "venetian blind" effect mentioned
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// above. This writes out scanlines of the image in a way that isn't ordered
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// vertically, which is incompatible with the filter that we use for
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// downscale-during-decode, so we can't do this if we're downscaling.
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MOZ_ASSERT_IF(mDownscaler, mDeinterlacer);
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const uint32_t bpr = sizeof(uint32_t) * mGIFStruct.clamped_width;
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for (int r = drow_start; r <= drow_end; r++) {
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// Skip the row we wrote to above; that's what we're copying *from*.
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if (r != int(mGIFStruct.irow)) {
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memcpy(GetRowBuffer(r), rowp, bpr);
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}
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}
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}
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}
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mCurrentRow = drow_end;
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mCurrentPass = mGIFStruct.ipass;
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if (mGIFStruct.ipass == 1) {
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mLastFlushedPass = mGIFStruct.ipass; // interlaced starts at 1
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}
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if (!mGIFStruct.interlaced) {
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MOZ_ASSERT(!mDeinterlacer);
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mGIFStruct.irow++;
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} else {
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static const uint8_t kjump[5] = { 1, 8, 8, 4, 2 };
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int currentPass = mGIFStruct.ipass;
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do {
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// Row increments resp. per 8,8,4,2 rows
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mGIFStruct.irow += kjump[mGIFStruct.ipass];
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if (mGIFStruct.irow >= mGIFStruct.clamped_height) {
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// Next pass starts resp. at row 4,2,1,0
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mGIFStruct.irow = 8 >> mGIFStruct.ipass;
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mGIFStruct.ipass++;
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}
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} while (mGIFStruct.irow >= mGIFStruct.clamped_height);
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// We've finished a pass. If we're downscaling, it's time to propagate the
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// rows we've decoded so far from our Deinterlacer to our Downscaler.
|
|
if (mGIFStruct.ipass > currentPass && mDownscaler) {
|
|
MOZ_ASSERT(mDeinterlacer);
|
|
mDeinterlacer->PropagatePassToDownscaler(*mDownscaler);
|
|
FlushImageData();
|
|
mDownscaler->ResetForNextProgressivePass();
|
|
}
|
|
}
|
|
|
|
return --mGIFStruct.rows_remaining;
|
|
}
|
|
|
|
//******************************************************************************
|
|
// Perform Lempel-Ziv-Welch decoding
|
|
bool
|
|
nsGIFDecoder2::DoLzw(const uint8_t* q)
|
|
{
|
|
if (!mGIFStruct.rows_remaining) {
|
|
return true;
|
|
}
|
|
if (MOZ_UNLIKELY(mDownscaler && mDownscaler->IsFrameComplete())) {
|
|
return true;
|
|
}
|
|
|
|
// Copy all the decoder state variables into locals so the compiler
|
|
// won't worry about them being aliased. The locals will be homed
|
|
// back into the GIF decoder structure when we exit.
|
|
int avail = mGIFStruct.avail;
|
|
int bits = mGIFStruct.bits;
|
|
int codesize = mGIFStruct.codesize;
|
|
int codemask = mGIFStruct.codemask;
|
|
int count = mGIFStruct.count;
|
|
int oldcode = mGIFStruct.oldcode;
|
|
const int clear_code = ClearCode();
|
|
uint8_t firstchar = mGIFStruct.firstchar;
|
|
int32_t datum = mGIFStruct.datum;
|
|
uint16_t* prefix = mGIFStruct.prefix;
|
|
uint8_t* stackp = mGIFStruct.stackp;
|
|
uint8_t* suffix = mGIFStruct.suffix;
|
|
uint8_t* stack = mGIFStruct.stack;
|
|
uint8_t* rowp = mGIFStruct.rowp;
|
|
|
|
uint8_t* rowend = GetCurrentRowBuffer() + mGIFStruct.clamped_width;
|
|
|
|
#define OUTPUT_ROW() \
|
|
PR_BEGIN_MACRO \
|
|
if (!OutputRow()) \
|
|
goto END; \
|
|
rowp = GetCurrentRowBuffer(); \
|
|
rowend = rowp + mGIFStruct.clamped_width; \
|
|
PR_END_MACRO
|
|
|
|
for (const uint8_t* ch = q; count-- > 0; ch++) {
|
|
// Feed the next byte into the decoder's 32-bit input buffer.
|
|
datum += ((int32_t)* ch) << bits;
|
|
bits += 8;
|
|
|
|
// Check for underflow of decoder's 32-bit input buffer.
|
|
while (bits >= codesize) {
|
|
// Get the leading variable-length symbol from the data stream
|
|
int code = datum & codemask;
|
|
datum >>= codesize;
|
|
bits -= codesize;
|
|
|
|
// Reset the dictionary to its original state, if requested
|
|
if (code == clear_code) {
|
|
codesize = mGIFStruct.datasize + 1;
|
|
codemask = (1 << codesize) - 1;
|
|
avail = clear_code + 2;
|
|
oldcode = -1;
|
|
continue;
|
|
}
|
|
|
|
// Check for explicit end-of-stream code
|
|
if (code == (clear_code + 1)) {
|
|
// end-of-stream should only appear after all image data
|
|
return (mGIFStruct.rows_remaining == 0);
|
|
}
|
|
|
|
if (MOZ_UNLIKELY(mDownscaler && mDownscaler->IsFrameComplete())) {
|
|
goto END;
|
|
}
|
|
|
|
if (oldcode == -1) {
|
|
if (code >= MAX_BITS) {
|
|
return false;
|
|
}
|
|
*rowp++ = suffix[code] & mColorMask; // ensure index is within colormap
|
|
if (rowp == rowend) {
|
|
OUTPUT_ROW();
|
|
}
|
|
|
|
firstchar = oldcode = code;
|
|
continue;
|
|
}
|
|
|
|
int incode = code;
|
|
if (code >= avail) {
|
|
*stackp++ = firstchar;
|
|
code = oldcode;
|
|
|
|
if (stackp >= stack + MAX_BITS) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
while (code >= clear_code) {
|
|
if ((code >= MAX_BITS) || (code == prefix[code])) {
|
|
return false;
|
|
}
|
|
|
|
*stackp++ = suffix[code];
|
|
code = prefix[code];
|
|
|
|
if (stackp == stack + MAX_BITS) {
|
|
return false;
|
|
}
|
|
}
|
|
|
|
*stackp++ = firstchar = suffix[code];
|
|
|
|
// Define a new codeword in the dictionary.
|
|
if (avail < 4096) {
|
|
prefix[avail] = oldcode;
|
|
suffix[avail] = firstchar;
|
|
avail++;
|
|
|
|
// If we've used up all the codewords of a given length
|
|
// increase the length of codewords by one bit, but don't
|
|
// exceed the specified maximum codeword size of 12 bits.
|
|
if (((avail & codemask) == 0) && (avail < 4096)) {
|
|
codesize++;
|
|
codemask += avail;
|
|
}
|
|
}
|
|
oldcode = incode;
|
|
|
|
// Copy the decoded data out to the scanline buffer.
|
|
do {
|
|
*rowp++ = *--stackp & mColorMask; // ensure index is within colormap
|
|
if (rowp == rowend) {
|
|
OUTPUT_ROW();
|
|
|
|
// Consume decoded data that falls past the end of the clamped width.
|
|
stackp -= mGIFStruct.width - mGIFStruct.clamped_width;
|
|
stackp = std::max(stackp, stack);
|
|
}
|
|
} while (stackp > stack);
|
|
}
|
|
}
|
|
|
|
END:
|
|
|
|
// Home the local copies of the GIF decoder state variables
|
|
mGIFStruct.avail = avail;
|
|
mGIFStruct.bits = bits;
|
|
mGIFStruct.codesize = codesize;
|
|
mGIFStruct.codemask = codemask;
|
|
mGIFStruct.count = count;
|
|
mGIFStruct.oldcode = oldcode;
|
|
mGIFStruct.firstchar = firstchar;
|
|
mGIFStruct.datum = datum;
|
|
mGIFStruct.stackp = stackp;
|
|
mGIFStruct.rowp = rowp;
|
|
|
|
return true;
|
|
}
|
|
|
|
/// Expand the colormap from RGB to Packed ARGB as needed by Cairo.
|
|
/// And apply any LCMS transformation.
|
|
static void
|
|
ConvertColormap(uint32_t* aColormap, uint32_t aColors)
|
|
{
|
|
// Apply CMS transformation if enabled and available
|
|
if (gfxPlatform::GetCMSMode() == eCMSMode_All) {
|
|
qcms_transform* transform = gfxPlatform::GetCMSRGBTransform();
|
|
if (transform) {
|
|
qcms_transform_data(transform, aColormap, aColormap, aColors);
|
|
}
|
|
}
|
|
// Convert from the GIF's RGB format to the Cairo format.
|
|
// Work from end to begin, because of the in-place expansion
|
|
uint8_t* from = ((uint8_t*)aColormap) + 3 * aColors;
|
|
uint32_t* to = aColormap + aColors;
|
|
|
|
// Convert color entries to Cairo format
|
|
|
|
// set up for loops below
|
|
if (!aColors) {
|
|
return;
|
|
}
|
|
uint32_t c = aColors;
|
|
|
|
// copy as bytes until source pointer is 32-bit-aligned
|
|
// NB: can't use 32-bit reads, they might read off the end of the buffer
|
|
for (; (NS_PTR_TO_UINT32(from) & 0x3) && c; --c) {
|
|
from -= 3;
|
|
*--to = gfxPackedPixel(0xFF, from[0], from[1], from[2]);
|
|
}
|
|
|
|
// bulk copy of pixels.
|
|
while (c >= 4) {
|
|
from -= 12;
|
|
to -= 4;
|
|
c -= 4;
|
|
GFX_BLOCK_RGB_TO_FRGB(from,to);
|
|
}
|
|
|
|
// copy remaining pixel(s)
|
|
// NB: can't use 32-bit reads, they might read off the end of the buffer
|
|
while (c--) {
|
|
from -= 3;
|
|
*--to = gfxPackedPixel(0xFF, from[0], from[1], from[2]);
|
|
}
|
|
}
|
|
|
|
void
|
|
nsGIFDecoder2::WriteInternal(const char* aBuffer, uint32_t aCount)
|
|
{
|
|
MOZ_ASSERT(!HasError(), "Shouldn't call WriteInternal after error!");
|
|
|
|
// These variables changed names; renaming would make a much bigger patch :(
|
|
const uint8_t* buf = (const uint8_t*)aBuffer;
|
|
uint32_t len = aCount;
|
|
|
|
const uint8_t* q = buf;
|
|
|
|
// Add what we have sofar to the block
|
|
// If previous call to me left something in the hold first complete current
|
|
// block, or if we are filling the colormaps, first complete the colormap
|
|
uint8_t* p =
|
|
(mGIFStruct.state ==
|
|
gif_global_colormap) ? (uint8_t*) mGIFStruct.global_colormap :
|
|
(mGIFStruct.state == gif_image_colormap) ? (uint8_t*) mColormap :
|
|
(mGIFStruct.bytes_in_hold) ? mGIFStruct.hold : nullptr;
|
|
|
|
if (len == 0 && buf == nullptr) {
|
|
// We've just gotten the frame we asked for. Time to use the data we
|
|
// stashed away.
|
|
len = mGIFStruct.bytes_in_hold;
|
|
q = buf = p;
|
|
} else if (p) {
|
|
// Add what we have sofar to the block
|
|
uint32_t l = std::min(len, mGIFStruct.bytes_to_consume);
|
|
memcpy(p+mGIFStruct.bytes_in_hold, buf, l);
|
|
|
|
if (l < mGIFStruct.bytes_to_consume) {
|
|
// Not enough in 'buf' to complete current block, get more
|
|
mGIFStruct.bytes_in_hold += l;
|
|
mGIFStruct.bytes_to_consume -= l;
|
|
return;
|
|
}
|
|
// Point 'q' to complete block in hold (or in colormap)
|
|
q = p;
|
|
}
|
|
|
|
// Invariant:
|
|
// 'q' is start of current to be processed block (hold, colormap or buf)
|
|
// 'bytes_to_consume' is number of bytes to consume from 'buf'
|
|
// 'buf' points to the bytes to be consumed from the input buffer
|
|
// 'len' is number of bytes left in input buffer from position 'buf'.
|
|
// At entrance of the for loop will 'buf' will be moved 'bytes_to_consume'
|
|
// to point to next buffer, 'len' is adjusted accordingly.
|
|
// So that next round in for loop, q gets pointed to the next buffer.
|
|
|
|
for (;len >= mGIFStruct.bytes_to_consume; q=buf, mGIFStruct.bytes_in_hold = 0)
|
|
{
|
|
// Eat the current block from the buffer, q keeps pointed at current block
|
|
buf += mGIFStruct.bytes_to_consume;
|
|
len -= mGIFStruct.bytes_to_consume;
|
|
|
|
switch (mGIFStruct.state) {
|
|
case gif_lzw:
|
|
if (!DoLzw(q)) {
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
}
|
|
GETN(1, gif_sub_block);
|
|
break;
|
|
|
|
case gif_lzw_start: {
|
|
// Make sure the transparent pixel is transparent in the colormap
|
|
if (mGIFStruct.is_transparent) {
|
|
// Save old value so we can restore it later
|
|
if (mColormap == mGIFStruct.global_colormap) {
|
|
mOldColor = mColormap[mGIFStruct.tpixel];
|
|
}
|
|
mColormap[mGIFStruct.tpixel] = 0;
|
|
}
|
|
|
|
// Initialize LZW parser/decoder
|
|
mGIFStruct.datasize = *q;
|
|
const int clear_code = ClearCode();
|
|
if (mGIFStruct.datasize > MAX_LZW_BITS ||
|
|
clear_code >= MAX_BITS) {
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
}
|
|
|
|
mGIFStruct.avail = clear_code + 2;
|
|
mGIFStruct.oldcode = -1;
|
|
mGIFStruct.codesize = mGIFStruct.datasize + 1;
|
|
mGIFStruct.codemask = (1 << mGIFStruct.codesize) - 1;
|
|
mGIFStruct.datum = mGIFStruct.bits = 0;
|
|
|
|
// init the tables
|
|
for (int i = 0; i < clear_code; i++) {
|
|
mGIFStruct.suffix[i] = i;
|
|
}
|
|
|
|
mGIFStruct.stackp = mGIFStruct.stack;
|
|
|
|
GETN(1, gif_sub_block);
|
|
}
|
|
break;
|
|
|
|
// All GIF files begin with "GIF87a" or "GIF89a"
|
|
case gif_type:
|
|
if (!strncmp((char*)q, "GIF89a", 6)) {
|
|
mGIFStruct.version = 89;
|
|
} else if (!strncmp((char*)q, "GIF87a", 6)) {
|
|
mGIFStruct.version = 87;
|
|
} else {
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
}
|
|
GETN(7, gif_global_header);
|
|
break;
|
|
|
|
case gif_global_header:
|
|
// This is the height and width of the "screen" or
|
|
// frame into which images are rendered. The
|
|
// individual images can be smaller than the
|
|
// screen size and located with an origin anywhere
|
|
// within the screen.
|
|
|
|
mGIFStruct.screen_width = GETINT16(q);
|
|
mGIFStruct.screen_height = GETINT16(q + 2);
|
|
mGIFStruct.global_colormap_depth = (q[4]&0x07) + 1;
|
|
|
|
// screen_bgcolor is not used
|
|
//mGIFStruct.screen_bgcolor = q[5];
|
|
// q[6] = Pixel Aspect Ratio
|
|
// Not used
|
|
// float aspect = (float)((q[6] + 15) / 64.0);
|
|
|
|
if (q[4] & 0x80) {
|
|
// Get the global colormap
|
|
const uint32_t size = (3 << mGIFStruct.global_colormap_depth);
|
|
if (len < size) {
|
|
// Use 'hold' pattern to get the global colormap
|
|
GETN(size, gif_global_colormap);
|
|
break;
|
|
}
|
|
// Copy everything, go to colormap state to do CMS correction
|
|
memcpy(mGIFStruct.global_colormap, buf, size);
|
|
buf += size;
|
|
len -= size;
|
|
GETN(0, gif_global_colormap);
|
|
break;
|
|
}
|
|
|
|
GETN(1, gif_image_start);
|
|
break;
|
|
|
|
case gif_global_colormap:
|
|
// Everything is already copied into global_colormap
|
|
// Convert into Cairo colors including CMS transformation
|
|
ConvertColormap(mGIFStruct.global_colormap,
|
|
1<<mGIFStruct.global_colormap_depth);
|
|
GETN(1, gif_image_start);
|
|
break;
|
|
|
|
case gif_image_start:
|
|
switch (*q) {
|
|
case GIF_TRAILER:
|
|
if (IsMetadataDecode()) {
|
|
return;
|
|
}
|
|
mGIFStruct.state = gif_done;
|
|
break;
|
|
|
|
case GIF_EXTENSION_INTRODUCER:
|
|
GETN(2, gif_extension);
|
|
break;
|
|
|
|
case GIF_IMAGE_SEPARATOR:
|
|
GETN(9, gif_image_header);
|
|
break;
|
|
|
|
default:
|
|
// If we get anything other than GIF_IMAGE_SEPARATOR,
|
|
// GIF_EXTENSION_INTRODUCER, or GIF_TRAILER, there is extraneous data
|
|
// between blocks. The GIF87a spec tells us to keep reading
|
|
// until we find an image separator, but GIF89a says such
|
|
// a file is corrupt. We follow GIF89a and bail out.
|
|
if (mGIFStruct.images_decoded > 0) {
|
|
// The file is corrupt, but one or more images have
|
|
// been decoded correctly. In this case, we proceed
|
|
// as if the file were correctly terminated and set
|
|
// the state to gif_done, so the GIF will display.
|
|
mGIFStruct.state = gif_done;
|
|
} else {
|
|
// No images decoded, there is nothing to display.
|
|
mGIFStruct.state = gif_error;
|
|
}
|
|
}
|
|
break;
|
|
|
|
case gif_extension:
|
|
mGIFStruct.bytes_to_consume = q[1];
|
|
if (mGIFStruct.bytes_to_consume) {
|
|
switch (*q) {
|
|
case GIF_GRAPHIC_CONTROL_LABEL:
|
|
// The GIF spec mandates that the GIFControlExtension header block
|
|
// length is 4 bytes, and the parser for this block reads 4 bytes,
|
|
// so we must enforce that the buffer contains at least this many
|
|
// bytes. If the GIF specifies a different length, we allow that, so
|
|
// long as it's larger; the additional data will simply be ignored.
|
|
mGIFStruct.state = gif_control_extension;
|
|
mGIFStruct.bytes_to_consume =
|
|
std::max(mGIFStruct.bytes_to_consume, 4u);
|
|
break;
|
|
|
|
// The GIF spec also specifies the lengths of the following two
|
|
// extensions' headers (as 12 and 11 bytes, respectively). Because
|
|
// we ignore the plain text extension entirely and sanity-check the
|
|
// actual length of the application extension header before reading it,
|
|
// we allow GIFs to deviate from these values in either direction. This
|
|
// is important for real-world compatibility, as GIFs in the wild exist
|
|
// with application extension headers that are both shorter and longer
|
|
// than 11 bytes.
|
|
case GIF_APPLICATION_EXTENSION_LABEL:
|
|
mGIFStruct.state = gif_application_extension;
|
|
break;
|
|
|
|
case GIF_PLAIN_TEXT_LABEL:
|
|
mGIFStruct.state = gif_skip_block;
|
|
break;
|
|
|
|
case GIF_COMMENT_LABEL:
|
|
mGIFStruct.state = gif_consume_comment;
|
|
break;
|
|
|
|
default:
|
|
mGIFStruct.state = gif_skip_block;
|
|
}
|
|
} else {
|
|
GETN(1, gif_image_start);
|
|
}
|
|
break;
|
|
|
|
case gif_consume_block:
|
|
if (!*q) {
|
|
GETN(1, gif_image_start);
|
|
} else {
|
|
GETN(*q, gif_skip_block);
|
|
}
|
|
break;
|
|
|
|
case gif_skip_block:
|
|
GETN(1, gif_consume_block);
|
|
break;
|
|
|
|
case gif_control_extension:
|
|
mGIFStruct.is_transparent = *q & 0x1;
|
|
mGIFStruct.tpixel = q[3];
|
|
mGIFStruct.disposal_method = ((*q) >> 2) & 0x7;
|
|
|
|
if (mGIFStruct.disposal_method == 4) {
|
|
// Some specs say 3rd bit (value 4), other specs say value 3.
|
|
// Let's choose 3 (the more popular).
|
|
mGIFStruct.disposal_method = 3;
|
|
} else if (mGIFStruct.disposal_method > 4) {
|
|
// This GIF is using a disposal method which is undefined in the spec.
|
|
// Treat it as DisposalMethod::NOT_SPECIFIED.
|
|
mGIFStruct.disposal_method = 0;
|
|
}
|
|
|
|
{
|
|
DisposalMethod method = DisposalMethod(mGIFStruct.disposal_method);
|
|
if (method == DisposalMethod::CLEAR_ALL ||
|
|
method == DisposalMethod::CLEAR) {
|
|
// We may have to display the background under this image during
|
|
// animation playback, so we regard it as transparent.
|
|
PostHasTransparency();
|
|
}
|
|
}
|
|
|
|
mGIFStruct.delay_time = GETINT16(q + 1) * 10;
|
|
|
|
if (mGIFStruct.delay_time > 0) {
|
|
PostIsAnimated(mGIFStruct.delay_time);
|
|
}
|
|
|
|
GETN(1, gif_consume_block);
|
|
break;
|
|
|
|
case gif_comment_extension:
|
|
if (*q) {
|
|
GETN(*q, gif_consume_comment);
|
|
} else {
|
|
GETN(1, gif_image_start);
|
|
}
|
|
break;
|
|
|
|
case gif_consume_comment:
|
|
GETN(1, gif_comment_extension);
|
|
break;
|
|
|
|
case gif_application_extension:
|
|
// Check for netscape application extension
|
|
if (mGIFStruct.bytes_to_consume == 11 &&
|
|
(!strncmp((char*)q, "NETSCAPE2.0", 11) ||
|
|
!strncmp((char*)q, "ANIMEXTS1.0", 11))) {
|
|
GETN(1, gif_netscape_extension_block);
|
|
} else {
|
|
GETN(1, gif_consume_block);
|
|
}
|
|
break;
|
|
|
|
// Netscape-specific GIF extension: animation looping
|
|
case gif_netscape_extension_block:
|
|
if (*q) {
|
|
// We might need to consume 3 bytes in
|
|
// gif_consume_netscape_extension, so make sure we have at least that.
|
|
GETN(std::max(3, static_cast<int>(*q)), gif_consume_netscape_extension);
|
|
} else {
|
|
GETN(1, gif_image_start);
|
|
}
|
|
break;
|
|
|
|
// Parse netscape-specific application extensions
|
|
case gif_consume_netscape_extension:
|
|
switch (q[0] & 7) {
|
|
case 1:
|
|
// Loop entire animation specified # of times. Only read the
|
|
// loop count during the first iteration.
|
|
mGIFStruct.loop_count = GETINT16(q + 1);
|
|
GETN(1, gif_netscape_extension_block);
|
|
break;
|
|
|
|
case 2:
|
|
// Wait for specified # of bytes to enter buffer
|
|
|
|
// Don't do this, this extension doesn't exist (isn't used at all)
|
|
// and doesn't do anything, as our streaming/buffering takes care
|
|
// of it all...
|
|
// See: http://semmix.pl/color/exgraf/eeg24.htm
|
|
GETN(1, gif_netscape_extension_block);
|
|
break;
|
|
|
|
default:
|
|
// 0,3-7 are yet to be defined netscape extension codes
|
|
mGIFStruct.state = gif_error;
|
|
}
|
|
break;
|
|
|
|
case gif_image_header: {
|
|
if (mGIFStruct.images_decoded == 1) {
|
|
if (!HasAnimation()) {
|
|
// We should've already called PostIsAnimated(); this must be a
|
|
// corrupt animated image with a first frame timeout of zero. Signal
|
|
// that we're animated now, before the first-frame decode early exit
|
|
// below, so that RasterImage can detect that this happened.
|
|
PostIsAnimated(/* aFirstFrameTimeout = */ 0);
|
|
}
|
|
|
|
if (IsFirstFrameDecode()) {
|
|
// We're about to get a second frame, but we only want the first. Stop
|
|
// decoding now.
|
|
mGIFStruct.state = gif_done;
|
|
break;
|
|
}
|
|
|
|
if (mDownscaler) {
|
|
MOZ_ASSERT_UNREACHABLE("Doing downscale-during-decode "
|
|
"for an animated image?");
|
|
mDownscaler.reset();
|
|
}
|
|
}
|
|
|
|
// Get image offsets, with respect to the screen origin
|
|
mGIFStruct.x_offset = GETINT16(q);
|
|
mGIFStruct.y_offset = GETINT16(q + 2);
|
|
|
|
// Get image width and height.
|
|
mGIFStruct.width = GETINT16(q + 4);
|
|
mGIFStruct.height = GETINT16(q + 6);
|
|
|
|
if (!mGIFStruct.images_decoded) {
|
|
// Work around broken GIF files where the logical screen
|
|
// size has weird width or height. We assume that GIF87a
|
|
// files don't contain animations.
|
|
if ((mGIFStruct.screen_height < mGIFStruct.height) ||
|
|
(mGIFStruct.screen_width < mGIFStruct.width) ||
|
|
(mGIFStruct.version == 87)) {
|
|
mGIFStruct.screen_height = mGIFStruct.height;
|
|
mGIFStruct.screen_width = mGIFStruct.width;
|
|
mGIFStruct.x_offset = 0;
|
|
mGIFStruct.y_offset = 0;
|
|
}
|
|
// Create the image container with the right size.
|
|
BeginGIF();
|
|
if (HasError()) {
|
|
// Setting the size led to an error.
|
|
mGIFStruct.state = gif_error;
|
|
return;
|
|
}
|
|
|
|
// If we were doing a metadata decode, we're done.
|
|
if (IsMetadataDecode()) {
|
|
IntRect frameRect(mGIFStruct.x_offset, mGIFStruct.y_offset,
|
|
mGIFStruct.width, mGIFStruct.height);
|
|
CheckForTransparency(frameRect);
|
|
return;
|
|
}
|
|
}
|
|
|
|
// Work around more broken GIF files that have zero image width or height
|
|
if (!mGIFStruct.height || !mGIFStruct.width) {
|
|
mGIFStruct.height = mGIFStruct.screen_height;
|
|
mGIFStruct.width = mGIFStruct.screen_width;
|
|
if (!mGIFStruct.height || !mGIFStruct.width) {
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
}
|
|
}
|
|
|
|
// Hack around GIFs with frame rects outside the given screen bounds.
|
|
IntRect clampedRect =
|
|
ClampToImageRect(IntRect(mGIFStruct.x_offset, mGIFStruct.y_offset,
|
|
mGIFStruct.width, mGIFStruct.height));
|
|
if (clampedRect.IsEmpty()) {
|
|
// XXX Bug 1227546 - Maybe we should treat this as valid?
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
}
|
|
mGIFStruct.clamped_width = clampedRect.width;
|
|
mGIFStruct.clamped_height = clampedRect.height;
|
|
|
|
MOZ_ASSERT(mGIFStruct.clamped_width <= mGIFStruct.width);
|
|
MOZ_ASSERT(mGIFStruct.clamped_height <= mGIFStruct.height);
|
|
|
|
// Depth of colors is determined by colormap
|
|
// (q[8] & 0x80) indicates local colormap
|
|
// bits per pixel is (q[8]&0x07 + 1) when local colormap is set
|
|
uint32_t depth = mGIFStruct.global_colormap_depth;
|
|
if (q[8] & 0x80) {
|
|
depth = (q[8]&0x07) + 1;
|
|
}
|
|
uint32_t realDepth = depth;
|
|
while (mGIFStruct.tpixel >= (1 << realDepth) && (realDepth < 8)) {
|
|
realDepth++;
|
|
}
|
|
// Mask to limit the color values within the colormap
|
|
mColorMask = 0xFF >> (8 - realDepth);
|
|
|
|
if (NS_FAILED(BeginImageFrame(realDepth))) {
|
|
mGIFStruct.state = gif_error;
|
|
return;
|
|
}
|
|
|
|
// FALL THROUGH
|
|
}
|
|
|
|
case gif_image_header_continue: {
|
|
// While decoders can reuse frames, we unconditionally increment
|
|
// mGIFStruct.images_decoded when we're done with a frame, so we both can
|
|
// and need to zero out the colormap and image data after every new frame.
|
|
memset(mImageData, 0, mImageDataLength);
|
|
if (mColormap) {
|
|
memset(mColormap, 0, mColormapSize);
|
|
}
|
|
|
|
if (!mGIFStruct.images_decoded) {
|
|
// Send a onetime invalidation for the first frame if it has a y-axis
|
|
// offset. Otherwise, the area may never be refreshed and the
|
|
// placeholder will remain on the screen. (Bug 37589)
|
|
if (mGIFStruct.y_offset > 0) {
|
|
if (mDownscaler) {
|
|
IntRect targetRect = IntRect(IntPoint(), mDownscaler->TargetSize());
|
|
PostInvalidation(IntRect(IntPoint(), GetSize()), Some(targetRect));
|
|
} else {
|
|
nsIntRect r(0, 0, mGIFStruct.screen_width, mGIFStruct.y_offset);
|
|
PostInvalidation(r);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (q[8] & 0x40) {
|
|
mGIFStruct.interlaced = true;
|
|
mGIFStruct.ipass = 1;
|
|
if (mDownscaler) {
|
|
mDeinterlacer.emplace(mDownscaler->FrameSize());
|
|
|
|
if (!mDeinterlacer->IsValid()) {
|
|
mDeinterlacer.reset();
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
}
|
|
}
|
|
} else {
|
|
mGIFStruct.interlaced = false;
|
|
mGIFStruct.ipass = 0;
|
|
}
|
|
|
|
// Only apply the Haeberli display hack on the first frame
|
|
mGIFStruct.progressive_display = (mGIFStruct.images_decoded == 0);
|
|
|
|
// Clear state from last image
|
|
mGIFStruct.irow = 0;
|
|
mGIFStruct.rows_remaining = mGIFStruct.clamped_height;
|
|
mGIFStruct.rowp = GetCurrentRowBuffer();
|
|
|
|
// Depth of colors is determined by colormap
|
|
// (q[8] & 0x80) indicates local colormap
|
|
// bits per pixel is (q[8]&0x07 + 1) when local colormap is set
|
|
uint32_t depth = mGIFStruct.global_colormap_depth;
|
|
if (q[8] & 0x80) {
|
|
depth = (q[8]&0x07) + 1;
|
|
}
|
|
uint32_t realDepth = depth;
|
|
while (mGIFStruct.tpixel >= (1 << realDepth) && (realDepth < 8)) {
|
|
realDepth++;
|
|
}
|
|
// has a local colormap?
|
|
if (q[8] & 0x80) {
|
|
mGIFStruct.local_colormap_size = 1 << depth;
|
|
if (!mGIFStruct.images_decoded) {
|
|
// First frame has local colormap, allocate space for it
|
|
// as the image frame doesn't have its own palette
|
|
mColormapSize = sizeof(uint32_t) << realDepth;
|
|
if (!mGIFStruct.local_colormap) {
|
|
mGIFStruct.local_colormap = (uint32_t*)moz_xmalloc(mColormapSize);
|
|
}
|
|
mColormap = mGIFStruct.local_colormap;
|
|
}
|
|
const uint32_t size = 3 << depth;
|
|
if (mColormapSize > size) {
|
|
// Clear the notfilled part of the colormap
|
|
memset(((uint8_t*)mColormap) + size, 0, mColormapSize - size);
|
|
}
|
|
if (len < size) {
|
|
// Use 'hold' pattern to get the image colormap
|
|
GETN(size, gif_image_colormap);
|
|
break;
|
|
}
|
|
// Copy everything, go to colormap state to do CMS correction
|
|
memcpy(mColormap, buf, size);
|
|
buf += size;
|
|
len -= size;
|
|
GETN(0, gif_image_colormap);
|
|
break;
|
|
} else {
|
|
// Switch back to the global palette
|
|
if (mGIFStruct.images_decoded) {
|
|
// Copy global colormap into the palette of current frame
|
|
memcpy(mColormap, mGIFStruct.global_colormap, mColormapSize);
|
|
} else {
|
|
mColormap = mGIFStruct.global_colormap;
|
|
}
|
|
}
|
|
GETN(1, gif_lzw_start);
|
|
}
|
|
break;
|
|
|
|
case gif_image_colormap:
|
|
// Everything is already copied into local_colormap
|
|
// Convert into Cairo colors including CMS transformation
|
|
ConvertColormap(mColormap, mGIFStruct.local_colormap_size);
|
|
GETN(1, gif_lzw_start);
|
|
break;
|
|
|
|
case gif_sub_block:
|
|
mGIFStruct.count = *q;
|
|
if (mGIFStruct.count) {
|
|
// Still working on the same image: Process next LZW data block
|
|
// Make sure there are still rows left. If the GIF data
|
|
// is corrupt, we may not get an explicit terminator.
|
|
if (!mGIFStruct.rows_remaining) {
|
|
#ifdef DONT_TOLERATE_BROKEN_GIFS
|
|
mGIFStruct.state = gif_error;
|
|
break;
|
|
#else
|
|
// This is an illegal GIF, but we remain tolerant.
|
|
GETN(1, gif_sub_block);
|
|
#endif
|
|
if (mGIFStruct.count == GIF_TRAILER) {
|
|
// Found a terminator anyway, so consider the image done
|
|
GETN(1, gif_done);
|
|
break;
|
|
}
|
|
}
|
|
GETN(mGIFStruct.count, gif_lzw);
|
|
} else {
|
|
// See if there are any more images in this sequence.
|
|
EndImageFrame();
|
|
GETN(1, gif_image_start);
|
|
}
|
|
break;
|
|
|
|
case gif_done:
|
|
MOZ_ASSERT(!IsMetadataDecode(),
|
|
"Metadata decodes shouldn't reach gif_done");
|
|
FinishInternal();
|
|
goto done;
|
|
|
|
case gif_error:
|
|
PostDataError();
|
|
return;
|
|
|
|
// We shouldn't ever get here.
|
|
default:
|
|
MOZ_ASSERT_UNREACHABLE("Unexpected mGIFStruct.state");
|
|
PostDecoderError(NS_ERROR_UNEXPECTED);
|
|
return;
|
|
}
|
|
}
|
|
|
|
// if an error state is set but no data remains, code flow reaches here
|
|
if (mGIFStruct.state == gif_error) {
|
|
PostDataError();
|
|
return;
|
|
}
|
|
|
|
// Copy the leftover into mGIFStruct.hold
|
|
if (len) {
|
|
// Add what we have sofar to the block
|
|
if (mGIFStruct.state != gif_global_colormap &&
|
|
mGIFStruct.state != gif_image_colormap) {
|
|
if (!SetHold(buf, len)) {
|
|
PostDataError();
|
|
return;
|
|
}
|
|
} else {
|
|
uint8_t* p = (mGIFStruct.state == gif_global_colormap) ?
|
|
(uint8_t*)mGIFStruct.global_colormap :
|
|
(uint8_t*)mColormap;
|
|
memcpy(p, buf, len);
|
|
mGIFStruct.bytes_in_hold = len;
|
|
}
|
|
|
|
mGIFStruct.bytes_to_consume -= len;
|
|
}
|
|
|
|
// We want to flush before returning if we're on the first frame
|
|
done:
|
|
if (!mGIFStruct.images_decoded) {
|
|
FlushImageData();
|
|
mLastFlushedRow = mCurrentRow;
|
|
mLastFlushedPass = mCurrentPass;
|
|
}
|
|
}
|
|
|
|
bool
|
|
nsGIFDecoder2::SetHold(const uint8_t* buf1, uint32_t count1,
|
|
const uint8_t* buf2 /* = nullptr */,
|
|
uint32_t count2 /* = 0 */)
|
|
{
|
|
// We have to handle the case that buf currently points to hold
|
|
uint8_t* newHold = (uint8_t*) malloc(std::max(uint32_t(MIN_HOLD_SIZE),
|
|
count1 + count2));
|
|
if (!newHold) {
|
|
mGIFStruct.state = gif_error;
|
|
return false;
|
|
}
|
|
|
|
memcpy(newHold, buf1, count1);
|
|
if (buf2) {
|
|
memcpy(newHold + count1, buf2, count2);
|
|
}
|
|
|
|
free(mGIFStruct.hold);
|
|
mGIFStruct.hold = newHold;
|
|
mGIFStruct.bytes_in_hold = count1 + count2;
|
|
return true;
|
|
}
|
|
|
|
Telemetry::ID
|
|
nsGIFDecoder2::SpeedHistogram()
|
|
{
|
|
return Telemetry::IMAGE_DECODE_SPEED_GIF;
|
|
}
|
|
|
|
} // namespace image
|
|
} // namespace mozilla
|