// CreateFrame() is used for both simple and animated images
void nsPNGDecoder::CreateFrame(png_uint_32 x_offset, png_uint_32 y_offset,
int32_t width, int32_t height,
gfx::SurfaceFormat format)
{
MOZ_ASSERT(HasSize());
if (format == gfx::SurfaceFormat::B8G8R8A8) {
PostHasTransparency();
}
// Our first full frame is automatically created by the image decoding
// infrastructure. Just use it as long as it matches up.
nsIntRect neededRect(x_offset, y_offset, width, height);
nsRefPtr<imgFrame> currentFrame = GetCurrentFrame();
if (!currentFrame->GetRect().IsEqualEdges(neededRect)) {
if (mNumFrames == 0) {
// We need padding on the first frame, which means that we don't draw into
// part of the image at all. Report that as transparency.
PostHasTransparency();
}
NeedNewFrame(mNumFrames, x_offset, y_offset, width, height, format);
} else if (mNumFrames != 0) {
NeedNewFrame(mNumFrames, x_offset, y_offset, width, height, format);
}
mFrameRect = neededRect;
MOZ_LOG(GetPNGDecoderAccountingLog(), LogLevel::Debug,
("PNGDecoderAccounting: nsPNGDecoder::CreateFrame -- created "
"image frame with %dx%d pixels in container %p",
width, height,
&mImage));
#ifdef PNG_APNG_SUPPORTED
if (png_get_valid(mPNG, mInfo, PNG_INFO_acTL)) {
mAnimInfo = AnimFrameInfo(mPNG, mInfo);
if (mAnimInfo.mDispose == DisposalMethod::CLEAR) {
// We may have to display the background under this image during
// animation playback, so we regard it as transparent.
PostHasTransparency();
}
}
#endif
}
void
Decoder::CompleteDecode()
{
// Implementation-specific finalization
BeforeFinishInternal();
if (!HasError()) {
FinishInternal();
} else {
FinishWithErrorInternal();
}
// If the implementation left us mid-frame, finish that up.
if (mInFrame && !HasError()) {
PostFrameStop();
}
// If PostDecodeDone() has not been called, and this decoder wasn't aborted
// early because of low-memory conditions or losing a race with another
// decoder, we need to send teardown notifications (and report an error to the
// console later).
if (!IsMetadataDecode() && !mDecodeDone && !WasAborted()) {
mShouldReportError = true;
// If we only have a data error, we're usable if we have at least one
// complete frame.
if (!HasDecoderError() && GetCompleteFrameCount() > 0) {
// We're usable, so do exactly what we should have when the decoder
// completed.
// Not writing to the entire frame may have left us transparent.
PostHasTransparency();
if (mInFrame) {
PostFrameStop();
}
PostDecodeDone();
} else {
// We're not usable. Record some final progress indicating the error.
if (!IsMetadataDecode()) {
mProgress |= FLAG_DECODE_COMPLETE;
}
mProgress |= FLAG_HAS_ERROR;
}
}
if (mDecodeDone && !IsMetadataDecode()) {
MOZ_ASSERT(HasError() || mCurrentFrame, "Should have an error or a frame");
// If this image wasn't animated and isn't a transient image, mark its frame
// as optimizable. We don't support optimizing animated images and
// optimizing transient images isn't worth it.
if (!HasAnimation() &&
!(mDecoderFlags & DecoderFlags::IMAGE_IS_TRANSIENT) &&
mCurrentFrame) {
mCurrentFrame->SetOptimizable();
}
}
}
//******************************************************************************
void
nsGIFDecoder2::BeginImageFrame(uint16_t aDepth)
{
MOZ_ASSERT(HasSize());
gfx::SurfaceFormat format;
if (mGIFStruct.is_transparent) {
format = gfx::SurfaceFormat::B8G8R8A8;
PostHasTransparency();
} else {
format = gfx::SurfaceFormat::B8G8R8X8;
}
// Use correct format, RGB for first frame, PAL for following frames
// and include transparency to allow for optimization of opaque images
if (mGIFStruct.images_decoded) {
// Image data is stored with original depth and palette
NeedNewFrame(mGIFStruct.images_decoded, mGIFStruct.x_offset,
mGIFStruct.y_offset, mGIFStruct.width, mGIFStruct.height,
format, aDepth);
} else {
nsRefPtr<imgFrame> currentFrame = GetCurrentFrame();
// Our first full frame is automatically created by the image decoding
// infrastructure. Just use it as long as it matches up.
if (!currentFrame->GetRect().IsEqualEdges(nsIntRect(mGIFStruct.x_offset,
mGIFStruct.y_offset,
mGIFStruct.width,
mGIFStruct.height))) {
// We need padding on the first frame, which means that we don't draw into
// part of the image at all. Report that as transparency.
PostHasTransparency();
// Regardless of depth of input, image is decoded into 24bit RGB
NeedNewFrame(mGIFStruct.images_decoded, mGIFStruct.x_offset,
mGIFStruct.y_offset, mGIFStruct.width, mGIFStruct.height,
format);
}
}
mCurrentFrameIndex = mGIFStruct.images_decoded;
}
//******************************************************************************
nsresult
nsGIFDecoder2::BeginImageFrame(uint16_t aDepth)
{
MOZ_ASSERT(HasSize());
gfx::SurfaceFormat format;
if (mGIFStruct.is_transparent) {
format = gfx::SurfaceFormat::B8G8R8A8;
PostHasTransparency();
} else {
format = gfx::SurfaceFormat::B8G8R8X8;
}
nsIntRect frameRect(mGIFStruct.x_offset, mGIFStruct.y_offset,
mGIFStruct.width, mGIFStruct.height);
// Use correct format, RGB for first frame, PAL for following frames
// and include transparency to allow for optimization of opaque images
nsresult rv = NS_OK;
if (mGIFStruct.images_decoded) {
// Image data is stored with original depth and palette.
rv = AllocateFrame(mGIFStruct.images_decoded, GetSize(),
frameRect, format, aDepth);
} else {
if (!nsIntRect(nsIntPoint(), GetSize()).IsEqualEdges(frameRect)) {
// We need padding on the first frame, which means that we don't draw into
// part of the image at all. Report that as transparency.
PostHasTransparency();
}
// Regardless of depth of input, the first frame is decoded into 24bit RGB.
rv = AllocateFrame(mGIFStruct.images_decoded, GetSize(),
frameRect, format);
}
mCurrentFrameIndex = mGIFStruct.images_decoded;
return rv;
}
LexerTransition<nsIconDecoder::State>
nsIconDecoder::ReadHeader(const char* aData)
{
// Grab the width and height.
uint8_t width = uint8_t(aData[0]);
uint8_t height = uint8_t(aData[1]);
// The input is 32bpp, so we expect 4 bytes of data per pixel.
mBytesPerRow = width * 4;
// Post our size to the superclass.
PostSize(width, height);
// Icons have alpha.
PostHasTransparency();
// If we're doing a metadata decode, we're done.
if (IsMetadataDecode()) {
return Transition::TerminateSuccess();
}
MOZ_ASSERT(!mImageData, "Already have a buffer allocated?");
Maybe<SurfacePipe> pipe =
SurfacePipeFactory::CreateSurfacePipe(this, 0, Size(), OutputSize(),
FullFrame(), SurfaceFormat::B8G8R8A8,
SurfacePipeFlags());
if (!pipe) {
return Transition::TerminateFailure();
}
mPipe = Move(*pipe);
MOZ_ASSERT(mImageData, "Should have a buffer now");
return Transition::To(State::ROW_OF_PIXELS, mBytesPerRow);
}
void
nsICODecoder::WriteInternal(const char* aBuffer, uint32_t aCount)
{
MOZ_ASSERT(!HasError(), "Shouldn't call WriteInternal after error!");
MOZ_ASSERT(aBuffer);
MOZ_ASSERT(aCount > 0);
while (aCount && (mPos < ICONCOUNTOFFSET)) { // Skip to the # of icons.
if (mPos == 2) { // if the third byte is 1: This is an icon, 2: a cursor
if ((*aBuffer != 1) && (*aBuffer != 2)) {
PostDataError();
return;
}
mIsCursor = (*aBuffer == 2);
}
mPos++; aBuffer++; aCount--;
}
if (mPos == ICONCOUNTOFFSET && aCount >= 2) {
mNumIcons =
LittleEndian::readUint16(reinterpret_cast<const uint16_t*>(aBuffer));
aBuffer += 2;
mPos += 2;
aCount -= 2;
}
if (mNumIcons == 0) {
return; // Nothing to do.
}
uint16_t colorDepth = 0;
// If we didn't get a #-moz-resolution, default to PREFICONSIZE.
if (mResolution.width == 0 && mResolution.height == 0) {
mResolution.SizeTo(PREFICONSIZE, PREFICONSIZE);
}
// A measure of the difference in size between the entry we've found
// and the requested size. We will choose the smallest image that is
// >= requested size (i.e. we assume it's better to downscale a larger
// icon than to upscale a smaller one).
int32_t diff = INT_MIN;
// Loop through each entry's dir entry
while (mCurrIcon < mNumIcons) {
if (mPos >= DIRENTRYOFFSET + (mCurrIcon * sizeof(mDirEntryArray)) &&
mPos < DIRENTRYOFFSET + ((mCurrIcon + 1) * sizeof(mDirEntryArray))) {
uint32_t toCopy = sizeof(mDirEntryArray) -
(mPos - DIRENTRYOFFSET - mCurrIcon *
sizeof(mDirEntryArray));
if (toCopy > aCount) {
toCopy = aCount;
}
memcpy(mDirEntryArray + sizeof(mDirEntryArray) - toCopy, aBuffer, toCopy);
mPos += toCopy;
aCount -= toCopy;
aBuffer += toCopy;
}
if (aCount == 0) {
return; // Need more data
}
IconDirEntry e;
if (mPos == (DIRENTRYOFFSET + ICODIRENTRYSIZE) +
(mCurrIcon * sizeof(mDirEntryArray))) {
mCurrIcon++;
ProcessDirEntry(e);
// We can't use GetRealWidth and GetRealHeight here because those operate
// on mDirEntry, here we are going through each item in the directory.
// Calculate the delta between this image's size and the desired size,
// so we can see if it is better than our current-best option.
// In the case of several equally-good images, we use the last one.
int32_t delta = (e.mWidth == 0 ? 256 : e.mWidth) - mResolution.width +
(e.mHeight == 0 ? 256 : e.mHeight) - mResolution.height;
if (e.mBitCount >= colorDepth &&
((diff < 0 && delta >= diff) || (delta >= 0 && delta <= diff))) {
diff = delta;
mImageOffset = e.mImageOffset;
// ensure mImageOffset is >= size of the direntry headers (bug #245631)
uint32_t minImageOffset = DIRENTRYOFFSET +
mNumIcons * sizeof(mDirEntryArray);
if (mImageOffset < minImageOffset) {
PostDataError();
return;
}
colorDepth = e.mBitCount;
memcpy(&mDirEntry, &e, sizeof(IconDirEntry));
}
}
}
if (mPos < mImageOffset) {
// Skip to (or at least towards) the desired image offset
uint32_t toSkip = mImageOffset - mPos;
if (toSkip > aCount) {
toSkip = aCount;
}
mPos += toSkip;
aBuffer += toSkip;
aCount -= toSkip;
}
// If we are within the first PNGSIGNATURESIZE bytes of the image data,
// then we have either a BMP or a PNG. We use the first PNGSIGNATURESIZE
// bytes to determine which one we have.
if (mCurrIcon == mNumIcons && mPos >= mImageOffset &&
mPos < mImageOffset + PNGSIGNATURESIZE) {
uint32_t toCopy = PNGSIGNATURESIZE - (mPos - mImageOffset);
if (toCopy > aCount) {
toCopy = aCount;
}
memcpy(mSignature + (mPos - mImageOffset), aBuffer, toCopy);
mPos += toCopy;
aCount -= toCopy;
aBuffer += toCopy;
mIsPNG = !memcmp(mSignature, nsPNGDecoder::pngSignatureBytes,
PNGSIGNATURESIZE);
if (mIsPNG) {
mContainedDecoder = new nsPNGDecoder(mImage);
mContainedDecoder->SetMetadataDecode(IsMetadataDecode());
mContainedDecoder->SetSendPartialInvalidations(mSendPartialInvalidations);
if (mFirstFrameDecode) {
mContainedDecoder->SetIsFirstFrameDecode();
}
mContainedDecoder->Init();
if (!WriteToContainedDecoder(mSignature, PNGSIGNATURESIZE)) {
return;
}
}
}
// If we have a PNG, let the PNG decoder do all of the rest of the work
if (mIsPNG && mContainedDecoder && mPos >= mImageOffset + PNGSIGNATURESIZE) {
if (!WriteToContainedDecoder(aBuffer, aCount)) {
return;
}
if (!HasSize() && mContainedDecoder->HasSize()) {
PostSize(mContainedDecoder->GetImageMetadata().GetWidth(),
mContainedDecoder->GetImageMetadata().GetHeight());
}
mPos += aCount;
aBuffer += aCount;
aCount = 0;
// Raymond Chen says that 32bpp only are valid PNG ICOs
// http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
if (!IsMetadataDecode() &&
!static_cast<nsPNGDecoder*>(mContainedDecoder.get())->IsValidICO()) {
PostDataError();
}
return;
}
// We've processed all of the icon dir entries and are within the
// bitmap info size
if (!mIsPNG && mCurrIcon == mNumIcons && mPos >= mImageOffset &&
mPos >= mImageOffset + PNGSIGNATURESIZE &&
mPos < mImageOffset + BITMAPINFOSIZE) {
// As we were decoding, we did not know if we had a PNG signature or the
// start of a bitmap information header. At this point we know we had
// a bitmap information header and not a PNG signature, so fill the bitmap
// information header with the data it should already have.
memcpy(mBIHraw, mSignature, PNGSIGNATURESIZE);
// We've found the icon.
uint32_t toCopy = sizeof(mBIHraw) - (mPos - mImageOffset);
if (toCopy > aCount) {
toCopy = aCount;
}
memcpy(mBIHraw + (mPos - mImageOffset), aBuffer, toCopy);
mPos += toCopy;
aCount -= toCopy;
aBuffer += toCopy;
}
// If we have a BMP inside the ICO and we have read the BIH header
if (!mIsPNG && mPos == mImageOffset + BITMAPINFOSIZE) {
// Make sure we have a sane value for the bitmap information header
int32_t bihSize = ExtractBIHSizeFromBitmap(reinterpret_cast<int8_t*>
(mBIHraw));
if (bihSize != BITMAPINFOSIZE) {
PostDataError();
return;
}
// We are extracting the BPP from the BIH header as it should be trusted
// over the one we have from the icon header
mBPP = ExtractBPPFromBitmap(reinterpret_cast<int8_t*>(mBIHraw));
// Init the bitmap decoder which will do most of the work for us
// It will do everything except the AND mask which isn't present in bitmaps
// bmpDecoder is for local scope ease, it will be freed by mContainedDecoder
nsBMPDecoder* bmpDecoder = new nsBMPDecoder(mImage);
mContainedDecoder = bmpDecoder;
bmpDecoder->SetUseAlphaData(true);
mContainedDecoder->SetMetadataDecode(IsMetadataDecode());
mContainedDecoder->SetSendPartialInvalidations(mSendPartialInvalidations);
if (mFirstFrameDecode) {
mContainedDecoder->SetIsFirstFrameDecode();
}
mContainedDecoder->Init();
// The ICO format when containing a BMP does not include the 14 byte
// bitmap file header. To use the code of the BMP decoder we need to
// generate this header ourselves and feed it to the BMP decoder.
int8_t bfhBuffer[BMPFILEHEADERSIZE];
if (!FillBitmapFileHeaderBuffer(bfhBuffer)) {
PostDataError();
return;
}
if (!WriteToContainedDecoder((const char*)bfhBuffer, sizeof(bfhBuffer))) {
return;
}
// Setup the cursor hot spot if one is present
SetHotSpotIfCursor();
// Fix the ICO height from the BIH.
// Fix the height on the BIH to be /2 so our BMP decoder will understand.
if (!FixBitmapHeight(reinterpret_cast<int8_t*>(mBIHraw))) {
PostDataError();
return;
}
// Fix the ICO width from the BIH.
if (!FixBitmapWidth(reinterpret_cast<int8_t*>(mBIHraw))) {
PostDataError();
return;
}
// Write out the BMP's bitmap info header
if (!WriteToContainedDecoder(mBIHraw, sizeof(mBIHraw))) {
return;
}
PostSize(mContainedDecoder->GetImageMetadata().GetWidth(),
mContainedDecoder->GetImageMetadata().GetHeight());
// We have the size. If we're doing a metadata decode, we're done.
if (IsMetadataDecode()) {
return;
}
// Sometimes the ICO BPP header field is not filled out
// so we should trust the contained resource over our own
// information.
mBPP = bmpDecoder->GetBitsPerPixel();
// Check to make sure we have valid color settings
uint16_t numColors = GetNumColors();
if (numColors == (uint16_t)-1) {
PostDataError();
return;
}
}
// If we have a BMP
if (!mIsPNG && mContainedDecoder && mPos >= mImageOffset + BITMAPINFOSIZE) {
uint16_t numColors = GetNumColors();
if (numColors == (uint16_t)-1) {
PostDataError();
return;
}
// Feed the actual image data (not including headers) into the BMP decoder
uint32_t bmpDataOffset = mDirEntry.mImageOffset + BITMAPINFOSIZE;
uint32_t bmpDataEnd = mDirEntry.mImageOffset + BITMAPINFOSIZE +
static_cast<nsBMPDecoder*>(mContainedDecoder.get())->
GetCompressedImageSize() +
4 * numColors;
// If we are feeding in the core image data, but we have not yet
// reached the ICO's 'AND buffer mask'
if (mPos >= bmpDataOffset && mPos < bmpDataEnd) {
// Figure out how much data the BMP decoder wants
uint32_t toFeed = bmpDataEnd - mPos;
if (toFeed > aCount) {
toFeed = aCount;
}
if (!WriteToContainedDecoder(aBuffer, toFeed)) {
return;
}
mPos += toFeed;
aCount -= toFeed;
aBuffer += toFeed;
}
// If the bitmap is fully processed, treat any left over data as the ICO's
// 'AND buffer mask' which appears after the bitmap resource.
if (!mIsPNG && mPos >= bmpDataEnd) {
// There may be an optional AND bit mask after the data. This is
// only used if the alpha data is not already set. The alpha data
// is used for 32bpp bitmaps as per the comment in ICODecoder.h
// The alpha mask should be checked in all other cases.
if (static_cast<nsBMPDecoder*>(mContainedDecoder.get())->
GetBitsPerPixel() != 32 ||
!static_cast<nsBMPDecoder*>(mContainedDecoder.get())->
HasAlphaData()) {
uint32_t rowSize = ((GetRealWidth() + 31) / 32) * 4; // + 31 to round up
if (mPos == bmpDataEnd) {
mPos++;
mRowBytes = 0;
mCurLine = GetRealHeight();
mRow = (uint8_t*)realloc(mRow, rowSize);
if (!mRow) {
PostDecoderError(NS_ERROR_OUT_OF_MEMORY);
return;
}
}
// Ensure memory has been allocated before decoding.
MOZ_ASSERT(mRow, "mRow is null");
if (!mRow) {
PostDataError();
return;
}
uint8_t sawTransparency = 0;
while (mCurLine > 0 && aCount > 0) {
uint32_t toCopy = std::min(rowSize - mRowBytes, aCount);
if (toCopy) {
memcpy(mRow + mRowBytes, aBuffer, toCopy);
aCount -= toCopy;
aBuffer += toCopy;
mRowBytes += toCopy;
}
if (rowSize == mRowBytes) {
mCurLine--;
mRowBytes = 0;
uint32_t* imageData =
static_cast<nsBMPDecoder*>(mContainedDecoder.get())->
GetImageData();
if (!imageData) {
PostDataError();
return;
}
uint32_t* decoded = imageData + mCurLine * GetRealWidth();
uint32_t* decoded_end = decoded + GetRealWidth();
uint8_t* p = mRow;
uint8_t* p_end = mRow + rowSize;
while (p < p_end) {
uint8_t idx = *p++;
sawTransparency |= idx;
for (uint8_t bit = 0x80; bit && decoded<decoded_end; bit >>= 1) {
// Clear pixel completely for transparency.
if (idx & bit) {
*decoded = 0;
}
decoded++;
}
}
}
}
// If any bits are set in sawTransparency, then we know at least one
// pixel was transparent.
if (sawTransparency) {
PostHasTransparency();
}
}
void
nsIconDecoder::WriteInternal(const char* aBuffer, uint32_t aCount,
DecodeStrategy)
{
NS_ABORT_IF_FALSE(!HasError(), "Shouldn't call WriteInternal after error!");
// We put this here to avoid errors about crossing initialization with case
// jumps on linux.
uint32_t bytesToRead = 0;
// Loop until the input data is gone
while (aCount > 0) {
switch (mState) {
case iconStateStart:
// Grab the width
mWidth = (uint8_t)*aBuffer;
// Book Keeping
aBuffer++;
aCount--;
mState = iconStateHaveHeight;
break;
case iconStateHaveHeight:
// Grab the Height
mHeight = (uint8_t)*aBuffer;
// Post our size to the superclass
PostSize(mWidth, mHeight);
PostHasTransparency();
if (HasError()) {
// Setting the size led to an error.
mState = iconStateFinished;
return;
}
// If We're doing a size decode, we're done
if (IsSizeDecode()) {
mState = iconStateFinished;
break;
}
if (!mImageData) {
PostDecoderError(NS_ERROR_OUT_OF_MEMORY);
return;
}
// Book Keeping
aBuffer++;
aCount--;
mState = iconStateReadPixels;
break;
case iconStateReadPixels: {
// How many bytes are we reading?
bytesToRead = std::min(aCount, mImageDataLength - mPixBytesRead);
// Copy the bytes
memcpy(mImageData + mPixBytesRead, aBuffer, bytesToRead);
// Performance isn't critical here, so our update rectangle is
// always the full icon
nsIntRect r(0, 0, mWidth, mHeight);
// Invalidate
PostInvalidation(r);
// Book Keeping
aBuffer += bytesToRead;
aCount -= bytesToRead;
mPixBytesRead += bytesToRead;
// If we've got all the pixel bytes, we're finished
if (mPixBytesRead == mImageDataLength) {
PostFrameStop();
PostDecodeDone();
mState = iconStateFinished;
}
break;
}
case iconStateFinished:
// Consume all excess data silently
aCount = 0;
break;
}
}
}
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;
if (IsSizeDecode()) {
MOZ_ASSERT(!mGIFOpen, "Gif should not be open at this point");
PostSize(mGIFStruct.screen_width, mGIFStruct.screen_height);
return;
}
// 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:
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;
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: {
// 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 size decode, we're done
if (IsSizeDecode()) {
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;
}
}
// 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) {
nsIntRect r(0, 0, mGIFStruct.screen_width, mGIFStruct.y_offset);
PostInvalidation(r);
}
}
if (q[8] & 0x40) {
mGIFStruct.interlaced = true;
mGIFStruct.ipass = 1;
} 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.height;
mGIFStruct.rowp = mImageData;
// 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(!IsSizeDecode(), "Size 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;
}
}
void
nsWEBPDecoder::WriteInternal(const char *aBuffer, uint32_t aCount)
{
MOZ_ASSERT(!HasError(), "Shouldn't call WriteInternal after error!");
const uint8_t* buf = (const uint8_t*)aBuffer;
VP8StatusCode rv = WebPIAppend(mDecoder, buf, aCount);
if (rv == VP8_STATUS_OUT_OF_MEMORY) {
PostDecoderError(NS_ERROR_OUT_OF_MEMORY);
return;
} else if (rv == VP8_STATUS_INVALID_PARAM ||
rv == VP8_STATUS_BITSTREAM_ERROR) {
PostDataError();
return;
} else if (rv == VP8_STATUS_UNSUPPORTED_FEATURE ||
rv == VP8_STATUS_USER_ABORT) {
PostDecoderError(NS_ERROR_FAILURE);
return;
}
// Catch any remaining erroneous return value.
if (rv != VP8_STATUS_OK && rv != VP8_STATUS_SUSPENDED) {
PostDecoderError(NS_ERROR_FAILURE);
return;
}
int lastLineRead = -1;
int height = 0;
int width = 0;
int stride = 0;
mData = WebPIDecGetRGB(mDecoder, &lastLineRead, &width, &height, &stride);
// The only valid format for WebP decoding for both alpha and non-alpha
// images is BGRA, where Opaque images have an A of 255.
// Assume transparency for all images.
// XXX: This could be compositor-optimized by doing a one-time check for
// all-255 alpha pixels, but that might interfere with progressive
// decoding. Probably not worth it?
PostHasTransparency();
if (lastLineRead == -1 || !mData)
return;
if (width <= 0 || height <= 0) {
PostDataError();
return;
}
if (!HasSize())
PostSize(width, height);
if (IsSizeDecode())
return;
if (!mImageData) {
PostDecoderError(NS_ERROR_FAILURE);
return;
}
// Transfer from mData to mImageData
if (lastLineRead > mLastLine) {
for (int line = mLastLine; line < lastLineRead; line++) {
for (int pix = 0; pix < width; pix++) {
// RGBA -> BGRA
uint32_t DataOffset = 4 * (line * width + pix);
mImageData[DataOffset+0] = mData[DataOffset+2];
mImageData[DataOffset+1] = mData[DataOffset+1];
mImageData[DataOffset+2] = mData[DataOffset+0];
mImageData[DataOffset+3] = mData[DataOffset+3];
}
}
// Invalidate
nsIntRect r(0, mLastLine, width, lastLineRead);
PostInvalidation(r);
}
mLastLine = lastLineRead;
return;
}
