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-rw-r--r--image/decoders/nsPNGDecoder.cpp1035
1 files changed, 1035 insertions, 0 deletions
diff --git a/image/decoders/nsPNGDecoder.cpp b/image/decoders/nsPNGDecoder.cpp
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+++ b/image/decoders/nsPNGDecoder.cpp
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+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ *
+ * This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#include "ImageLogging.h" // Must appear first
+#include "nsPNGDecoder.h"
+
+#include <algorithm>
+#include <cstdint>
+
+#include "gfxColor.h"
+#include "gfxPlatform.h"
+#include "imgFrame.h"
+#include "nsColor.h"
+#include "nsRect.h"
+#include "nspr.h"
+#include "png.h"
+
+#include "RasterImage.h"
+#include "SurfaceCache.h"
+#include "SurfacePipeFactory.h"
+#include "mozilla/DebugOnly.h"
+#include "mozilla/Telemetry.h"
+
+using namespace mozilla::gfx;
+
+using std::min;
+
+namespace mozilla {
+namespace image {
+
+static LazyLogModule sPNGLog("PNGDecoder");
+static LazyLogModule sPNGDecoderAccountingLog("PNGDecoderAccounting");
+
+// limit image dimensions (bug #251381, #591822, #967656, and #1283961)
+#ifndef MOZ_PNG_MAX_WIDTH
+# define MOZ_PNG_MAX_WIDTH 0x7fffffff // Unlimited
+#endif
+#ifndef MOZ_PNG_MAX_HEIGHT
+# define MOZ_PNG_MAX_HEIGHT 0x7fffffff // Unlimited
+#endif
+
+/* Controls the maximum chunk size configuration for libpng. We set this to a
+ * very large number, 256MB specifically. */
+static constexpr png_alloc_size_t kPngMaxChunkSize = 0x10000000;
+
+nsPNGDecoder::AnimFrameInfo::AnimFrameInfo()
+ : mDispose(DisposalMethod::KEEP), mBlend(BlendMethod::OVER), mTimeout(0) {}
+
+#ifdef PNG_APNG_SUPPORTED
+
+int32_t GetNextFrameDelay(png_structp aPNG, png_infop aInfo) {
+ // Delay, in seconds, is delayNum / delayDen.
+ png_uint_16 delayNum = png_get_next_frame_delay_num(aPNG, aInfo);
+ png_uint_16 delayDen = png_get_next_frame_delay_den(aPNG, aInfo);
+
+ if (delayNum == 0) {
+ return 0; // SetFrameTimeout() will set to a minimum.
+ }
+
+ if (delayDen == 0) {
+ delayDen = 100; // So says the APNG spec.
+ }
+
+ // Need to cast delay_num to float to have a proper division and
+ // the result to int to avoid a compiler warning.
+ return static_cast<int32_t>(static_cast<double>(delayNum) * 1000 / delayDen);
+}
+
+nsPNGDecoder::AnimFrameInfo::AnimFrameInfo(png_structp aPNG, png_infop aInfo)
+ : mDispose(DisposalMethod::KEEP), mBlend(BlendMethod::OVER), mTimeout(0) {
+ png_byte dispose_op = png_get_next_frame_dispose_op(aPNG, aInfo);
+ png_byte blend_op = png_get_next_frame_blend_op(aPNG, aInfo);
+
+ if (dispose_op == PNG_DISPOSE_OP_PREVIOUS) {
+ mDispose = DisposalMethod::RESTORE_PREVIOUS;
+ } else if (dispose_op == PNG_DISPOSE_OP_BACKGROUND) {
+ mDispose = DisposalMethod::CLEAR;
+ } else {
+ mDispose = DisposalMethod::KEEP;
+ }
+
+ if (blend_op == PNG_BLEND_OP_SOURCE) {
+ mBlend = BlendMethod::SOURCE;
+ } else {
+ mBlend = BlendMethod::OVER;
+ }
+
+ mTimeout = GetNextFrameDelay(aPNG, aInfo);
+}
+#endif
+
+// First 8 bytes of a PNG file
+const uint8_t nsPNGDecoder::pngSignatureBytes[] = {137, 80, 78, 71,
+ 13, 10, 26, 10};
+
+nsPNGDecoder::nsPNGDecoder(RasterImage* aImage)
+ : Decoder(aImage),
+ mLexer(Transition::ToUnbuffered(State::FINISHED_PNG_DATA, State::PNG_DATA,
+ SIZE_MAX),
+ Transition::TerminateSuccess()),
+ mNextTransition(Transition::ContinueUnbuffered(State::PNG_DATA)),
+ mLastChunkLength(0),
+ mPNG(nullptr),
+ mInfo(nullptr),
+ mCMSLine(nullptr),
+ interlacebuf(nullptr),
+ mFormat(SurfaceFormat::UNKNOWN),
+ mChannels(0),
+ mPass(0),
+ mFrameIsHidden(false),
+ mDisablePremultipliedAlpha(false),
+ mGotInfoCallback(false),
+ mUsePipeTransform(false),
+ mNumFrames(0) {}
+
+nsPNGDecoder::~nsPNGDecoder() {
+ if (mPNG) {
+ png_destroy_read_struct(&mPNG, mInfo ? &mInfo : nullptr, nullptr);
+ }
+ if (mCMSLine) {
+ free(mCMSLine);
+ }
+ if (interlacebuf) {
+ free(interlacebuf);
+ }
+}
+
+nsPNGDecoder::TransparencyType nsPNGDecoder::GetTransparencyType(
+ const OrientedIntRect& aFrameRect) {
+ // Check if the image has a transparent color in its palette.
+ if (HasAlphaChannel()) {
+ return TransparencyType::eAlpha;
+ }
+ if (!aFrameRect.IsEqualEdges(FullFrame())) {
+ MOZ_ASSERT(HasAnimation());
+ return TransparencyType::eFrameRect;
+ }
+
+ return TransparencyType::eNone;
+}
+
+void nsPNGDecoder::PostHasTransparencyIfNeeded(
+ TransparencyType aTransparencyType) {
+ switch (aTransparencyType) {
+ case TransparencyType::eNone:
+ return;
+
+ case TransparencyType::eAlpha:
+ PostHasTransparency();
+ return;
+
+ case TransparencyType::eFrameRect:
+ // If the first frame of animated image doesn't draw into the whole image,
+ // then record that it is transparent. For subsequent frames, this doesn't
+ // affect transparency, because they're composited on top of all previous
+ // frames.
+ if (mNumFrames == 0) {
+ PostHasTransparency();
+ }
+ return;
+ }
+}
+
+// CreateFrame() is used for both simple and animated images.
+nsresult nsPNGDecoder::CreateFrame(const FrameInfo& aFrameInfo) {
+ MOZ_ASSERT(HasSize());
+ MOZ_ASSERT(!IsMetadataDecode());
+
+ // Check if we have transparency, and send notifications if needed.
+ auto transparency = GetTransparencyType(aFrameInfo.mFrameRect);
+ PostHasTransparencyIfNeeded(transparency);
+ mFormat = transparency == TransparencyType::eNone ? SurfaceFormat::OS_RGBX
+ : SurfaceFormat::OS_RGBA;
+
+ // Make sure there's no animation or padding if we're downscaling.
+ MOZ_ASSERT_IF(Size() != OutputSize(), mNumFrames == 0);
+ MOZ_ASSERT_IF(Size() != OutputSize(), !GetImageMetadata().HasAnimation());
+ MOZ_ASSERT_IF(Size() != OutputSize(),
+ transparency != TransparencyType::eFrameRect);
+
+ Maybe<AnimationParams> animParams;
+#ifdef PNG_APNG_SUPPORTED
+ if (!IsFirstFrameDecode() && 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();
+ }
+
+ animParams.emplace(
+ AnimationParams{aFrameInfo.mFrameRect.ToUnknownRect(),
+ FrameTimeout::FromRawMilliseconds(mAnimInfo.mTimeout),
+ mNumFrames, mAnimInfo.mBlend, mAnimInfo.mDispose});
+ }
+#endif
+
+ // If this image is interlaced, we can display better quality intermediate
+ // results to the user by post processing them with ADAM7InterpolatingFilter.
+ SurfacePipeFlags pipeFlags = aFrameInfo.mIsInterlaced
+ ? SurfacePipeFlags::ADAM7_INTERPOLATE
+ : SurfacePipeFlags();
+
+ if (mNumFrames == 0) {
+ // The first frame may be displayed progressively.
+ pipeFlags |= SurfacePipeFlags::PROGRESSIVE_DISPLAY;
+ }
+
+ SurfaceFormat inFormat;
+ if (mTransform && !mUsePipeTransform) {
+ // QCMS will output in the correct format.
+ inFormat = mFormat;
+ } else if (transparency == TransparencyType::eAlpha) {
+ // We are outputting directly as RGBA, so we need to swap at this step.
+ inFormat = SurfaceFormat::R8G8B8A8;
+ } else {
+ // We have no alpha channel, so we need to unpack from RGB to BGRA.
+ inFormat = SurfaceFormat::R8G8B8;
+ }
+
+ // Only apply premultiplication if the frame has true alpha. If we ever
+ // support downscaling animated images, we will need to premultiply for frame
+ // rect transparency when downscaling as well.
+ if (transparency == TransparencyType::eAlpha && !mDisablePremultipliedAlpha) {
+ pipeFlags |= SurfacePipeFlags::PREMULTIPLY_ALPHA;
+ }
+
+ qcms_transform* pipeTransform = mUsePipeTransform ? mTransform : nullptr;
+ Maybe<SurfacePipe> pipe = SurfacePipeFactory::CreateSurfacePipe(
+ this, Size(), OutputSize(), aFrameInfo.mFrameRect, inFormat, mFormat,
+ animParams, pipeTransform, pipeFlags);
+
+ if (!pipe) {
+ mPipe = SurfacePipe();
+ return NS_ERROR_FAILURE;
+ }
+
+ mPipe = std::move(*pipe);
+
+ mFrameRect = aFrameInfo.mFrameRect;
+ mPass = 0;
+
+ MOZ_LOG(sPNGDecoderAccountingLog, LogLevel::Debug,
+ ("PNGDecoderAccounting: nsPNGDecoder::CreateFrame -- created "
+ "image frame with %dx%d pixels for decoder %p",
+ mFrameRect.Width(), mFrameRect.Height(), this));
+
+ return NS_OK;
+}
+
+// set timeout and frame disposal method for the current frame
+void nsPNGDecoder::EndImageFrame() {
+ if (mFrameIsHidden) {
+ return;
+ }
+
+ mNumFrames++;
+
+ Opacity opacity = mFormat == SurfaceFormat::OS_RGBX
+ ? Opacity::FULLY_OPAQUE
+ : Opacity::SOME_TRANSPARENCY;
+
+ PostFrameStop(opacity);
+}
+
+nsresult nsPNGDecoder::InitInternal() {
+ mDisablePremultipliedAlpha =
+ bool(GetSurfaceFlags() & SurfaceFlags::NO_PREMULTIPLY_ALPHA);
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ static png_byte color_chunks[] = {99, 72, 82, 77, '\0', // cHRM
+ 105, 67, 67, 80, '\0'}; // iCCP
+ static png_byte unused_chunks[] = {98, 75, 71, 68, '\0', // bKGD
+ 101, 88, 73, 102, '\0', // eXIf
+ 104, 73, 83, 84, '\0', // hIST
+ 105, 84, 88, 116, '\0', // iTXt
+ 111, 70, 70, 115, '\0', // oFFs
+ 112, 67, 65, 76, '\0', // pCAL
+ 115, 67, 65, 76, '\0', // sCAL
+ 112, 72, 89, 115, '\0', // pHYs
+ 115, 66, 73, 84, '\0', // sBIT
+ 115, 80, 76, 84, '\0', // sPLT
+ 116, 69, 88, 116, '\0', // tEXt
+ 116, 73, 77, 69, '\0', // tIME
+ 122, 84, 88, 116, '\0'}; // zTXt
+#endif
+
+ // Initialize the container's source image header
+ // Always decode to 24 bit pixdepth
+
+ mPNG = png_create_read_struct(PNG_LIBPNG_VER_STRING, nullptr,
+ nsPNGDecoder::error_callback,
+ nsPNGDecoder::warning_callback);
+ if (!mPNG) {
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+ mInfo = png_create_info_struct(mPNG);
+ if (!mInfo) {
+ png_destroy_read_struct(&mPNG, nullptr, nullptr);
+ return NS_ERROR_OUT_OF_MEMORY;
+ }
+
+#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
+ // Ignore unused chunks
+ if (mCMSMode == CMSMode::Off || IsMetadataDecode()) {
+ png_set_keep_unknown_chunks(mPNG, 1, color_chunks, 2);
+ }
+
+ png_set_keep_unknown_chunks(mPNG, 1, unused_chunks,
+ (int)sizeof(unused_chunks) / 5);
+#endif
+
+#ifdef PNG_SET_USER_LIMITS_SUPPORTED
+ png_set_user_limits(mPNG, MOZ_PNG_MAX_WIDTH, MOZ_PNG_MAX_HEIGHT);
+ png_set_chunk_malloc_max(mPNG, kPngMaxChunkSize);
+#endif
+
+#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
+ // Disallow palette-index checking, for speed; we would ignore the warning
+ // anyhow. This feature was added at libpng version 1.5.10 and is disabled
+ // in the embedded libpng but enabled by default in the system libpng. This
+ // call also disables it in the system libpng, for decoding speed.
+ // Bug #745202.
+ png_set_check_for_invalid_index(mPNG, 0);
+#endif
+
+#ifdef PNG_SET_OPTION_SUPPORTED
+# if defined(PNG_sRGB_PROFILE_CHECKS) && PNG_sRGB_PROFILE_CHECKS >= 0
+ // Skip checking of sRGB ICC profiles
+ png_set_option(mPNG, PNG_SKIP_sRGB_CHECK_PROFILE, PNG_OPTION_ON);
+# endif
+
+# ifdef PNG_MAXIMUM_INFLATE_WINDOW
+ // Force a larger zlib inflate window as some images in the wild have
+ // incorrectly set metadata (specifically CMF bits) which prevent us from
+ // decoding them otherwise.
+ png_set_option(mPNG, PNG_MAXIMUM_INFLATE_WINDOW, PNG_OPTION_ON);
+# endif
+#endif
+
+ // use this as libpng "progressive pointer" (retrieve in callbacks)
+ png_set_progressive_read_fn(
+ mPNG, static_cast<png_voidp>(this), nsPNGDecoder::info_callback,
+ nsPNGDecoder::row_callback, nsPNGDecoder::end_callback);
+
+ return NS_OK;
+}
+
+LexerResult nsPNGDecoder::DoDecode(SourceBufferIterator& aIterator,
+ IResumable* aOnResume) {
+ MOZ_ASSERT(!HasError(), "Shouldn't call DoDecode after error!");
+
+ return mLexer.Lex(aIterator, aOnResume,
+ [=](State aState, const char* aData, size_t aLength) {
+ switch (aState) {
+ case State::PNG_DATA:
+ return ReadPNGData(aData, aLength);
+ case State::FINISHED_PNG_DATA:
+ return FinishedPNGData();
+ }
+ MOZ_CRASH("Unknown State");
+ });
+}
+
+LexerTransition<nsPNGDecoder::State> nsPNGDecoder::ReadPNGData(
+ const char* aData, size_t aLength) {
+ // If we were waiting until after returning from a yield to call
+ // CreateFrame(), call it now.
+ if (mNextFrameInfo) {
+ if (NS_FAILED(CreateFrame(*mNextFrameInfo))) {
+ return Transition::TerminateFailure();
+ }
+
+ MOZ_ASSERT(mImageData, "Should have a buffer now");
+ mNextFrameInfo = Nothing();
+ }
+
+ // libpng uses setjmp/longjmp for error handling.
+ if (setjmp(png_jmpbuf(mPNG))) {
+ return Transition::TerminateFailure();
+ }
+
+ // Pass the data off to libpng.
+ mLastChunkLength = aLength;
+ mNextTransition = Transition::ContinueUnbuffered(State::PNG_DATA);
+ png_process_data(mPNG, mInfo,
+ reinterpret_cast<unsigned char*>(const_cast<char*>((aData))),
+ aLength);
+
+ // Make sure that we've reached a terminal state if decoding is done.
+ MOZ_ASSERT_IF(GetDecodeDone(), mNextTransition.NextStateIsTerminal());
+ MOZ_ASSERT_IF(HasError(), mNextTransition.NextStateIsTerminal());
+
+ // Continue with whatever transition the callback code requested. We
+ // initialized this to Transition::ContinueUnbuffered(State::PNG_DATA) above,
+ // so by default we just continue the unbuffered read.
+ return mNextTransition;
+}
+
+LexerTransition<nsPNGDecoder::State> nsPNGDecoder::FinishedPNGData() {
+ // Since we set up an unbuffered read for SIZE_MAX bytes, if we actually read
+ // all that data something is really wrong.
+ MOZ_ASSERT_UNREACHABLE("Read the entire address space?");
+ return Transition::TerminateFailure();
+}
+
+// Sets up gamma pre-correction in libpng before our callback gets called.
+// We need to do this if we don't end up with a CMS profile.
+static void PNGDoGammaCorrection(png_structp png_ptr, png_infop info_ptr) {
+ double aGamma;
+
+ if (png_get_gAMA(png_ptr, info_ptr, &aGamma)) {
+ if ((aGamma <= 0.0) || (aGamma > 21474.83)) {
+ aGamma = 0.45455;
+ png_set_gAMA(png_ptr, info_ptr, aGamma);
+ }
+ png_set_gamma(png_ptr, 2.2, aGamma);
+ } else {
+ png_set_gamma(png_ptr, 2.2, 0.45455);
+ }
+}
+
+// Adapted from http://www.littlecms.com/pngchrm.c example code
+uint32_t nsPNGDecoder::ReadColorProfile(png_structp png_ptr, png_infop info_ptr,
+ int color_type, bool* sRGBTag) {
+ // First try to see if iCCP chunk is present
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_iCCP)) {
+ png_uint_32 profileLen;
+ png_bytep profileData;
+ png_charp profileName;
+ int compression;
+
+ png_get_iCCP(png_ptr, info_ptr, &profileName, &compression, &profileData,
+ &profileLen);
+
+ mInProfile = qcms_profile_from_memory((char*)profileData, profileLen);
+ if (mInProfile) {
+ uint32_t profileSpace = qcms_profile_get_color_space(mInProfile);
+
+ bool mismatch = false;
+ if (color_type & PNG_COLOR_MASK_COLOR) {
+ if (profileSpace != icSigRgbData) {
+ mismatch = true;
+ }
+ } else {
+ if (profileSpace == icSigRgbData) {
+ png_set_gray_to_rgb(png_ptr);
+ } else if (profileSpace != icSigGrayData) {
+ mismatch = true;
+ }
+ }
+
+ if (mismatch) {
+ qcms_profile_release(mInProfile);
+ mInProfile = nullptr;
+ } else {
+ return qcms_profile_get_rendering_intent(mInProfile);
+ }
+ }
+ }
+
+ // Check sRGB chunk
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_sRGB)) {
+ *sRGBTag = true;
+
+ int fileIntent;
+ png_set_gray_to_rgb(png_ptr);
+ png_get_sRGB(png_ptr, info_ptr, &fileIntent);
+ uint32_t map[] = {QCMS_INTENT_PERCEPTUAL, QCMS_INTENT_RELATIVE_COLORIMETRIC,
+ QCMS_INTENT_SATURATION,
+ QCMS_INTENT_ABSOLUTE_COLORIMETRIC};
+ return map[fileIntent];
+ }
+
+ // Check gAMA/cHRM chunks
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_gAMA) &&
+ png_get_valid(png_ptr, info_ptr, PNG_INFO_cHRM)) {
+ qcms_CIE_xyYTRIPLE primaries;
+ qcms_CIE_xyY whitePoint;
+
+ png_get_cHRM(png_ptr, info_ptr, &whitePoint.x, &whitePoint.y,
+ &primaries.red.x, &primaries.red.y, &primaries.green.x,
+ &primaries.green.y, &primaries.blue.x, &primaries.blue.y);
+ whitePoint.Y = primaries.red.Y = primaries.green.Y = primaries.blue.Y = 1.0;
+
+ double gammaOfFile;
+
+ png_get_gAMA(png_ptr, info_ptr, &gammaOfFile);
+
+ mInProfile = qcms_profile_create_rgb_with_gamma(whitePoint, primaries,
+ 1.0 / gammaOfFile);
+
+ if (mInProfile) {
+ png_set_gray_to_rgb(png_ptr);
+ }
+ }
+
+ return QCMS_INTENT_PERCEPTUAL; // Our default
+}
+
+void nsPNGDecoder::info_callback(png_structp png_ptr, png_infop info_ptr) {
+ png_uint_32 width, height;
+ int bit_depth, color_type, interlace_type, compression_type, filter_type;
+ unsigned int channels;
+
+ png_bytep trans = nullptr;
+ int num_trans = 0;
+
+ nsPNGDecoder* decoder =
+ static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+ if (decoder->mGotInfoCallback) {
+ MOZ_LOG(sPNGLog, LogLevel::Warning,
+ ("libpng called info_callback more than once\n"));
+ return;
+ }
+
+ decoder->mGotInfoCallback = true;
+
+ // Always decode to 24-bit RGB or 32-bit RGBA
+ png_get_IHDR(png_ptr, info_ptr, &width, &height, &bit_depth, &color_type,
+ &interlace_type, &compression_type, &filter_type);
+
+ const OrientedIntRect frameRect(0, 0, width, height);
+
+ // Post our size to the superclass
+ decoder->PostSize(frameRect.Width(), frameRect.Height());
+
+ if (width > SurfaceCache::MaximumCapacity() / (bit_depth > 8 ? 16 : 8)) {
+ // libpng needs space to allocate two row buffers
+ png_error(decoder->mPNG, "Image is too wide");
+ }
+
+ if (decoder->HasError()) {
+ // Setting the size led to an error.
+ png_error(decoder->mPNG, "Sizing error");
+ }
+
+ if (color_type == PNG_COLOR_TYPE_PALETTE) {
+ png_set_expand(png_ptr);
+ }
+
+ if (color_type == PNG_COLOR_TYPE_GRAY && bit_depth < 8) {
+ png_set_expand(png_ptr);
+ }
+
+ if (png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
+ png_color_16p trans_values;
+ png_get_tRNS(png_ptr, info_ptr, &trans, &num_trans, &trans_values);
+ // libpng doesn't reject a tRNS chunk with out-of-range samples
+ // so we check it here to avoid setting up a useless opacity
+ // channel or producing unexpected transparent pixels (bug #428045)
+ if (bit_depth < 16) {
+ png_uint_16 sample_max = (1 << bit_depth) - 1;
+ if ((color_type == PNG_COLOR_TYPE_GRAY &&
+ trans_values->gray > sample_max) ||
+ (color_type == PNG_COLOR_TYPE_RGB &&
+ (trans_values->red > sample_max ||
+ trans_values->green > sample_max ||
+ trans_values->blue > sample_max))) {
+ // clear the tRNS valid flag and release tRNS memory
+ png_free_data(png_ptr, info_ptr, PNG_FREE_TRNS, 0);
+ num_trans = 0;
+ }
+ }
+ if (num_trans != 0) {
+ png_set_expand(png_ptr);
+ }
+ }
+
+ if (bit_depth == 16) {
+ png_set_scale_16(png_ptr);
+ }
+
+ // We only need to extract the color profile for non-metadata decodes. It is
+ // fairly expensive to read the profile and create the transform so we should
+ // avoid it if not necessary.
+ uint32_t intent = -1;
+ bool sRGBTag = false;
+ if (!decoder->IsMetadataDecode()) {
+ if (decoder->mCMSMode != CMSMode::Off) {
+ intent = gfxPlatform::GetRenderingIntent();
+ uint32_t pIntent =
+ decoder->ReadColorProfile(png_ptr, info_ptr, color_type, &sRGBTag);
+ // If we're not mandating an intent, use the one from the image.
+ if (intent == uint32_t(-1)) {
+ intent = pIntent;
+ }
+ }
+ if (!decoder->mInProfile || !decoder->GetCMSOutputProfile()) {
+ png_set_gray_to_rgb(png_ptr);
+
+ // only do gamma correction if CMS isn't entirely disabled
+ if (decoder->mCMSMode != CMSMode::Off) {
+ PNGDoGammaCorrection(png_ptr, info_ptr);
+ }
+ }
+ }
+
+ // Let libpng expand interlaced images.
+ const bool isInterlaced = interlace_type == PNG_INTERLACE_ADAM7;
+ if (isInterlaced) {
+ png_set_interlace_handling(png_ptr);
+ }
+
+ // now all of those things we set above are used to update various struct
+ // members and whatnot, after which we can get channels, rowbytes, etc.
+ png_read_update_info(png_ptr, info_ptr);
+ decoder->mChannels = channels = png_get_channels(png_ptr, info_ptr);
+
+ //---------------------------------------------------------------//
+ // copy PNG info into imagelib structs (formerly png_set_dims()) //
+ //---------------------------------------------------------------//
+
+ if (channels < 1 || channels > 4) {
+ png_error(decoder->mPNG, "Invalid number of channels");
+ }
+
+#ifdef PNG_APNG_SUPPORTED
+ bool isAnimated = png_get_valid(png_ptr, info_ptr, PNG_INFO_acTL);
+ if (isAnimated) {
+ int32_t rawTimeout = GetNextFrameDelay(png_ptr, info_ptr);
+ decoder->PostIsAnimated(FrameTimeout::FromRawMilliseconds(rawTimeout));
+
+ if (decoder->Size() != decoder->OutputSize() &&
+ !decoder->IsFirstFrameDecode()) {
+ MOZ_ASSERT_UNREACHABLE(
+ "Doing downscale-during-decode "
+ "for an animated image?");
+ png_error(decoder->mPNG, "Invalid downscale attempt"); // Abort decode.
+ }
+ }
+#endif
+
+ auto transparency = decoder->GetTransparencyType(frameRect);
+ if (decoder->IsMetadataDecode()) {
+ // If we are animated then the first frame rect is either:
+ // 1) the whole image if the IDAT chunk is part of the animation
+ // 2) the frame rect of the first fDAT chunk otherwise.
+ // If we are not animated then we want to make sure to call
+ // PostHasTransparency in the metadata decode if we need to. So it's
+ // okay to pass IntRect(0, 0, width, height) here for animated images;
+ // they will call with the proper first frame rect in the full decode.
+ decoder->PostHasTransparencyIfNeeded(transparency);
+
+ // We have the metadata we're looking for, so stop here, before we allocate
+ // buffers below.
+ return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+ }
+
+ if (decoder->mInProfile && decoder->GetCMSOutputProfile()) {
+ qcms_data_type inType;
+ qcms_data_type outType;
+
+ uint32_t profileSpace = qcms_profile_get_color_space(decoder->mInProfile);
+ decoder->mUsePipeTransform = profileSpace != icSigGrayData;
+ if (decoder->mUsePipeTransform) {
+ // If the transform happens with SurfacePipe, it will be in RGBA if we
+ // have an alpha channel, because the swizzle and premultiplication
+ // happens after color management. Otherwise it will be in BGRA because
+ // the swizzle happens at the start.
+ if (transparency == TransparencyType::eAlpha) {
+ inType = QCMS_DATA_RGBA_8;
+ outType = QCMS_DATA_RGBA_8;
+ } else {
+ inType = gfxPlatform::GetCMSOSRGBAType();
+ outType = inType;
+ }
+ } else {
+ if (color_type & PNG_COLOR_MASK_ALPHA) {
+ inType = QCMS_DATA_GRAYA_8;
+ outType = gfxPlatform::GetCMSOSRGBAType();
+ } else {
+ inType = QCMS_DATA_GRAY_8;
+ outType = gfxPlatform::GetCMSOSRGBAType();
+ }
+ }
+
+ decoder->mTransform = qcms_transform_create(decoder->mInProfile, inType,
+ decoder->GetCMSOutputProfile(),
+ outType, (qcms_intent)intent);
+ } else if ((sRGBTag && decoder->mCMSMode == CMSMode::TaggedOnly) ||
+ decoder->mCMSMode == CMSMode::All) {
+ // If the transform happens with SurfacePipe, it will be in RGBA if we
+ // have an alpha channel, because the swizzle and premultiplication
+ // happens after color management. Otherwise it will be in OS_RGBA because
+ // the swizzle happens at the start.
+ if (transparency == TransparencyType::eAlpha) {
+ decoder->mTransform =
+ decoder->GetCMSsRGBTransform(SurfaceFormat::R8G8B8A8);
+ } else {
+ decoder->mTransform =
+ decoder->GetCMSsRGBTransform(SurfaceFormat::OS_RGBA);
+ }
+ decoder->mUsePipeTransform = true;
+ }
+
+#ifdef PNG_APNG_SUPPORTED
+ if (isAnimated) {
+ png_set_progressive_frame_fn(png_ptr, nsPNGDecoder::frame_info_callback,
+ nullptr);
+ }
+
+ if (png_get_first_frame_is_hidden(png_ptr, info_ptr)) {
+ decoder->mFrameIsHidden = true;
+ } else {
+#endif
+ nsresult rv = decoder->CreateFrame(FrameInfo{frameRect, isInterlaced});
+ if (NS_FAILED(rv)) {
+ png_error(decoder->mPNG, "CreateFrame failed");
+ }
+ MOZ_ASSERT(decoder->mImageData, "Should have a buffer now");
+#ifdef PNG_APNG_SUPPORTED
+ }
+#endif
+
+ if (decoder->mTransform && !decoder->mUsePipeTransform) {
+ decoder->mCMSLine =
+ static_cast<uint8_t*>(malloc(sizeof(uint32_t) * frameRect.Width()));
+ if (!decoder->mCMSLine) {
+ png_error(decoder->mPNG, "malloc of mCMSLine failed");
+ }
+ }
+
+ if (interlace_type == PNG_INTERLACE_ADAM7) {
+ if (frameRect.Height() <
+ INT32_MAX / (frameRect.Width() * int32_t(channels))) {
+ const size_t bufferSize =
+ channels * frameRect.Width() * frameRect.Height();
+
+ if (bufferSize > SurfaceCache::MaximumCapacity()) {
+ png_error(decoder->mPNG, "Insufficient memory to deinterlace image");
+ }
+
+ decoder->interlacebuf = static_cast<uint8_t*>(malloc(bufferSize));
+ }
+ if (!decoder->interlacebuf) {
+ png_error(decoder->mPNG, "malloc of interlacebuf failed");
+ }
+ }
+}
+
+void nsPNGDecoder::PostInvalidationIfNeeded() {
+ Maybe<SurfaceInvalidRect> invalidRect = mPipe.TakeInvalidRect();
+ if (!invalidRect) {
+ return;
+ }
+
+ PostInvalidation(invalidRect->mInputSpaceRect,
+ Some(invalidRect->mOutputSpaceRect));
+}
+
+void nsPNGDecoder::row_callback(png_structp png_ptr, png_bytep new_row,
+ png_uint_32 row_num, int pass) {
+ /* libpng comments:
+ *
+ * This function is called for every row in the image. If the
+ * image is interlacing, and you turned on the interlace handler,
+ * this function will be called for every row in every pass.
+ * Some of these rows will not be changed from the previous pass.
+ * When the row is not changed, the new_row variable will be
+ * nullptr. The rows and passes are called in order, so you don't
+ * really need the row_num and pass, but I'm supplying them
+ * because it may make your life easier.
+ *
+ * For the non-nullptr rows of interlaced images, you must call
+ * png_progressive_combine_row() passing in the row and the
+ * old row. You can call this function for nullptr rows (it will
+ * just return) and for non-interlaced images (it just does the
+ * memcpy for you) if it will make the code easier. Thus, you
+ * can just do this for all cases:
+ *
+ * png_progressive_combine_row(png_ptr, old_row, new_row);
+ *
+ * where old_row is what was displayed for previous rows. Note
+ * that the first pass (pass == 0 really) will completely cover
+ * the old row, so the rows do not have to be initialized. After
+ * the first pass (and only for interlaced images), you will have
+ * to pass the current row, and the function will combine the
+ * old row and the new row.
+ */
+ nsPNGDecoder* decoder =
+ static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+ if (decoder->mFrameIsHidden) {
+ return; // Skip this frame.
+ }
+
+ MOZ_ASSERT_IF(decoder->IsFirstFrameDecode(), decoder->mNumFrames == 0);
+
+ while (pass > decoder->mPass) {
+ // Advance to the next pass. We may have to do this multiple times because
+ // libpng will skip passes if the image is so small that no pixels have
+ // changed on a given pass, but ADAM7InterpolatingFilter needs to be reset
+ // once for every pass to perform interpolation properly.
+ decoder->mPipe.ResetToFirstRow();
+ decoder->mPass++;
+ }
+
+ const png_uint_32 height =
+ static_cast<png_uint_32>(decoder->mFrameRect.Height());
+
+ if (row_num >= height) {
+ // Bail if we receive extra rows. This is especially important because if we
+ // didn't, we might overflow the deinterlacing buffer.
+ MOZ_ASSERT_UNREACHABLE("libpng producing extra rows?");
+ return;
+ }
+
+ // Note that |new_row| may be null here, indicating that this is an interlaced
+ // image and |row_callback| is being called for a row that hasn't changed.
+ MOZ_ASSERT_IF(!new_row, decoder->interlacebuf);
+
+ if (decoder->interlacebuf) {
+ uint32_t width = uint32_t(decoder->mFrameRect.Width());
+
+ // We'll output the deinterlaced version of the row.
+ uint8_t* rowToWrite =
+ decoder->interlacebuf + (row_num * decoder->mChannels * width);
+
+ // Update the deinterlaced version of this row with the new data.
+ png_progressive_combine_row(png_ptr, rowToWrite, new_row);
+
+ decoder->WriteRow(rowToWrite);
+ } else {
+ decoder->WriteRow(new_row);
+ }
+}
+
+void nsPNGDecoder::WriteRow(uint8_t* aRow) {
+ MOZ_ASSERT(aRow);
+
+ uint8_t* rowToWrite = aRow;
+ uint32_t width = uint32_t(mFrameRect.Width());
+
+ // Apply color management to the row, if necessary, before writing it out.
+ // This is only needed for grayscale images.
+ if (mTransform && !mUsePipeTransform) {
+ MOZ_ASSERT(mCMSLine);
+ qcms_transform_data(mTransform, rowToWrite, mCMSLine, width);
+ rowToWrite = mCMSLine;
+ }
+
+ // Write this row to the SurfacePipe.
+ DebugOnly<WriteState> result =
+ mPipe.WriteBuffer(reinterpret_cast<uint32_t*>(rowToWrite));
+ MOZ_ASSERT(WriteState(result) != WriteState::FAILURE);
+
+ PostInvalidationIfNeeded();
+}
+
+void nsPNGDecoder::DoTerminate(png_structp aPNGStruct, TerminalState aState) {
+ // Stop processing data. Note that we intentionally ignore the return value of
+ // png_process_data_pause(), which tells us how many bytes of the data that
+ // was passed to png_process_data() have not been consumed yet, because now
+ // that we've reached a terminal state, we won't do any more decoding or call
+ // back into libpng anymore.
+ png_process_data_pause(aPNGStruct, /* save = */ false);
+
+ mNextTransition = aState == TerminalState::SUCCESS
+ ? Transition::TerminateSuccess()
+ : Transition::TerminateFailure();
+}
+
+void nsPNGDecoder::DoYield(png_structp aPNGStruct) {
+ // Pause data processing. png_process_data_pause() returns how many bytes of
+ // the data that was passed to png_process_data() have not been consumed yet.
+ // We use this information to tell StreamingLexer where to place us in the
+ // input stream when we come back from the yield.
+ png_size_t pendingBytes = png_process_data_pause(aPNGStruct,
+ /* save = */ false);
+
+ MOZ_ASSERT(pendingBytes < mLastChunkLength);
+ size_t consumedBytes = mLastChunkLength - min(pendingBytes, mLastChunkLength);
+
+ mNextTransition =
+ Transition::ContinueUnbufferedAfterYield(State::PNG_DATA, consumedBytes);
+}
+
+nsresult nsPNGDecoder::FinishInternal() {
+ // We shouldn't be called in error cases.
+ MOZ_ASSERT(!HasError(), "Can't call FinishInternal on error!");
+
+ if (IsMetadataDecode()) {
+ return NS_OK;
+ }
+
+ int32_t loop_count = 0;
+#ifdef PNG_APNG_SUPPORTED
+ if (png_get_valid(mPNG, mInfo, PNG_INFO_acTL)) {
+ int32_t num_plays = png_get_num_plays(mPNG, mInfo);
+ loop_count = num_plays - 1;
+ }
+#endif
+
+ if (InFrame()) {
+ EndImageFrame();
+ }
+ PostDecodeDone(loop_count);
+
+ return NS_OK;
+}
+
+#ifdef PNG_APNG_SUPPORTED
+// got the header of a new frame that's coming
+void nsPNGDecoder::frame_info_callback(png_structp png_ptr,
+ png_uint_32 frame_num) {
+ nsPNGDecoder* decoder =
+ static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+ // old frame is done
+ decoder->EndImageFrame();
+
+ const bool previousFrameWasHidden = decoder->mFrameIsHidden;
+
+ if (!previousFrameWasHidden && decoder->IsFirstFrameDecode()) {
+ // We're about to get a second non-hidden frame, but we only want the first.
+ // Stop decoding now. (And avoid allocating the unnecessary buffers below.)
+ return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+ }
+
+ // Only the first frame can be hidden, so unhide unconditionally here.
+ decoder->mFrameIsHidden = false;
+
+ // Save the information necessary to create the frame; we'll actually create
+ // it when we return from the yield.
+ const OrientedIntRect frameRect(
+ png_get_next_frame_x_offset(png_ptr, decoder->mInfo),
+ png_get_next_frame_y_offset(png_ptr, decoder->mInfo),
+ png_get_next_frame_width(png_ptr, decoder->mInfo),
+ png_get_next_frame_height(png_ptr, decoder->mInfo));
+ const bool isInterlaced = bool(decoder->interlacebuf);
+
+# ifndef MOZ_EMBEDDED_LIBPNG
+ // if using system library, check frame_width and height against 0
+ if (frameRect.width == 0) {
+ png_error(png_ptr, "Frame width must not be 0");
+ }
+ if (frameRect.height == 0) {
+ png_error(png_ptr, "Frame height must not be 0");
+ }
+# endif
+
+ const FrameInfo info{frameRect, isInterlaced};
+
+ // If the previous frame was hidden, skip the yield (which will mislead the
+ // caller, who will think the previous frame was real) and just allocate the
+ // new frame here.
+ if (previousFrameWasHidden) {
+ if (NS_FAILED(decoder->CreateFrame(info))) {
+ return decoder->DoTerminate(png_ptr, TerminalState::FAILURE);
+ }
+
+ MOZ_ASSERT(decoder->mImageData, "Should have a buffer now");
+ return; // No yield, so we'll just keep decoding.
+ }
+
+ // Yield to the caller to notify them that the previous frame is now complete.
+ decoder->mNextFrameInfo = Some(info);
+ return decoder->DoYield(png_ptr);
+}
+#endif
+
+void nsPNGDecoder::end_callback(png_structp png_ptr, png_infop info_ptr) {
+ /* libpng comments:
+ *
+ * this function is called when the whole image has been read,
+ * including any chunks after the image (up to and including
+ * the IEND). You will usually have the same info chunk as you
+ * had in the header, although some data may have been added
+ * to the comments and time fields.
+ *
+ * Most people won't do much here, perhaps setting a flag that
+ * marks the image as finished.
+ */
+
+ nsPNGDecoder* decoder =
+ static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
+
+ // We shouldn't get here if we've hit an error
+ MOZ_ASSERT(!decoder->HasError(), "Finishing up PNG but hit error!");
+
+ return decoder->DoTerminate(png_ptr, TerminalState::SUCCESS);
+}
+
+void nsPNGDecoder::error_callback(png_structp png_ptr,
+ png_const_charp error_msg) {
+ MOZ_LOG(sPNGLog, LogLevel::Error, ("libpng error: %s\n", error_msg));
+ png_longjmp(png_ptr, 1);
+}
+
+void nsPNGDecoder::warning_callback(png_structp png_ptr,
+ png_const_charp warning_msg) {
+ MOZ_LOG(sPNGLog, LogLevel::Warning, ("libpng warning: %s\n", warning_msg));
+}
+
+Maybe<Telemetry::HistogramID> nsPNGDecoder::SpeedHistogram() const {
+ return Some(Telemetry::IMAGE_DECODE_SPEED_PNG);
+}
+
+bool nsPNGDecoder::IsValidICOResource() const {
+ // Only 32-bit RGBA PNGs are valid ICO resources; see here:
+ // http://blogs.msdn.com/b/oldnewthing/archive/2010/10/22/10079192.aspx
+
+ // If there are errors in the call to png_get_IHDR, the error_callback in
+ // nsPNGDecoder.cpp is called. In this error callback we do a longjmp, so
+ // we need to save the jump buffer here. Otherwise we'll end up without a
+ // proper callstack.
+ if (setjmp(png_jmpbuf(mPNG))) {
+ // We got here from a longjmp call indirectly from png_get_IHDR
+ return false;
+ }
+
+ png_uint_32 png_width, // Unused
+ png_height; // Unused
+
+ int png_bit_depth, png_color_type;
+
+ if (png_get_IHDR(mPNG, mInfo, &png_width, &png_height, &png_bit_depth,
+ &png_color_type, nullptr, nullptr, nullptr)) {
+ return ((png_color_type == PNG_COLOR_TYPE_RGB_ALPHA ||
+ png_color_type == PNG_COLOR_TYPE_RGB) &&
+ png_bit_depth == 8);
+ } else {
+ return false;
+ }
+}
+
+} // namespace image
+} // namespace mozilla