gecko/image/decoders/nsPNGDecoder.cpp
Jeff Muizelaar 738a667bbd Bug 1131446. mFrameHasNoAlpha is mostly pointless. r=seth
Starting with bug 391583 we detect whether a png image has any transparency
during decode. I don't think this is worth doing anymore. We choose the format
of image based on the png header, that should be sufficient for the performance
improvement we desire from opaque images. This gets us faster image decoding.
2015-02-10 13:26:14 +08:00

903 lines
27 KiB
C++

/* -*- 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 "gfxColor.h"
#include "gfxPlatform.h"
#include "nsColor.h"
#include "nsIInputStream.h"
#include "nsMemory.h"
#include "nsPNGDecoder.h"
#include "nsRect.h"
#include "nspr.h"
#include "png.h"
#include "RasterImage.h"
#include "mozilla/Telemetry.h"
#include <algorithm>
namespace mozilla {
namespace image {
#ifdef PR_LOGGING
static PRLogModuleInfo*
GetPNGLog()
{
static PRLogModuleInfo* sPNGLog;
if (!sPNGLog) {
sPNGLog = PR_NewLogModule("PNGDecoder");
}
return sPNGLog;
}
static PRLogModuleInfo*
GetPNGDecoderAccountingLog()
{
static PRLogModuleInfo* sPNGDecoderAccountingLog;
if (!sPNGDecoderAccountingLog) {
sPNGDecoderAccountingLog = PR_NewLogModule("PNGDecoderAccounting");
}
return sPNGDecoderAccountingLog;
}
#endif
// Limit image dimensions (bug #251381, #591822, and #967656)
#ifndef MOZ_PNG_MAX_DIMENSION
# define MOZ_PNG_MAX_DIMENSION 32767
#endif
// For size decodes
#define WIDTH_OFFSET 16
#define HEIGHT_OFFSET (WIDTH_OFFSET + 4)
#define BYTES_NEEDED_FOR_DIMENSIONS (HEIGHT_OFFSET + 4)
nsPNGDecoder::AnimFrameInfo::AnimFrameInfo()
: mDispose(DisposalMethod::KEEP)
, mBlend(BlendMethod::OVER)
, mTimeout(0)
{ }
#ifdef PNG_APNG_SUPPORTED
nsPNGDecoder::AnimFrameInfo::AnimFrameInfo(png_structp aPNG, png_infop aInfo)
: mDispose(DisposalMethod::KEEP)
, mBlend(BlendMethod::OVER)
, mTimeout(0)
{
png_uint_16 delay_num, delay_den;
// delay, in seconds is delay_num/delay_den
png_byte dispose_op;
png_byte blend_op;
delay_num = png_get_next_frame_delay_num(aPNG, aInfo);
delay_den = png_get_next_frame_delay_den(aPNG, aInfo);
dispose_op = png_get_next_frame_dispose_op(aPNG, aInfo);
blend_op = png_get_next_frame_blend_op(aPNG, aInfo);
if (delay_num == 0) {
mTimeout = 0; // SetFrameTimeout() will set to a minimum
} else {
if (delay_den == 0) {
delay_den = 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 compiler warning
mTimeout = static_cast<int32_t>(static_cast<double>(delay_num) *
1000 / delay_den);
}
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;
}
}
#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),
mPNG(nullptr), mInfo(nullptr),
mCMSLine(nullptr), interlacebuf(nullptr),
mInProfile(nullptr), mTransform(nullptr),
mHeaderBytesRead(0), mCMSMode(0),
mChannels(0), mFrameIsHidden(false),
mDisablePremultipliedAlpha(false),
mNumFrames(0)
{
}
nsPNGDecoder::~nsPNGDecoder()
{
if (mPNG) {
png_destroy_read_struct(&mPNG, mInfo ? &mInfo : nullptr, nullptr);
}
if (mCMSLine) {
nsMemory::Free(mCMSLine);
}
if (interlacebuf) {
nsMemory::Free(interlacebuf);
}
if (mInProfile) {
qcms_profile_release(mInProfile);
// mTransform belongs to us only if mInProfile is non-null
if (mTransform) {
qcms_transform_release(mTransform);
}
}
}
// 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;
PR_LOG(GetPNGDecoderAccountingLog(), PR_LOG_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
}
// set timeout and frame disposal method for the current frame
void
nsPNGDecoder::EndImageFrame()
{
if (mFrameIsHidden) {
return;
}
mNumFrames++;
Opacity opacity = Opacity::SOME_TRANSPARENCY;
if (format == gfx::SurfaceFormat::B8G8R8X8) {
opacity = Opacity::OPAQUE;
}
#ifdef PNG_APNG_SUPPORTED
uint32_t numFrames = GetFrameCount();
// We can't use mPNG->num_frames_read as it may be one ahead.
if (numFrames > 1) {
PostInvalidation(mFrameRect);
}
#endif
PostFrameStop(opacity, mAnimInfo.mDispose, mAnimInfo.mTimeout,
mAnimInfo.mBlend);
}
void
nsPNGDecoder::InitInternal()
{
// For size decodes, we don't need to initialize the png decoder
if (IsSizeDecode()) {
return;
}
mCMSMode = gfxPlatform::GetCMSMode();
if (GetDecodeFlags() & imgIContainer::FLAG_DECODE_NO_COLORSPACE_CONVERSION) {
mCMSMode = eCMSMode_Off;
}
mDisablePremultipliedAlpha =
GetDecodeFlags() & imgIContainer::FLAG_DECODE_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
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
// For full decodes, do png init stuff
// 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) {
PostDecoderError(NS_ERROR_OUT_OF_MEMORY);
return;
}
mInfo = png_create_info_struct(mPNG);
if (!mInfo) {
PostDecoderError(NS_ERROR_OUT_OF_MEMORY);
png_destroy_read_struct(&mPNG, nullptr, nullptr);
return;
}
#ifdef PNG_HANDLE_AS_UNKNOWN_SUPPORTED
// Ignore unused chunks
if (mCMSMode == eCMSMode_Off) {
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_CHUNK_MALLOC_LIMIT_SUPPORTED
if (mCMSMode != eCMSMode_Off) {
png_set_chunk_malloc_max(mPNG, 4000000L);
}
#endif
#ifdef PNG_READ_CHECK_FOR_INVALID_INDEX_SUPPORTED
#ifndef PR_LOGGING
// Disallow palette-index checking, for speed; we would ignore the warning
// anyhow unless we have defined PR_LOGGING. 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
#endif
#if defined(PNG_SET_OPTION_SUPPORTED) && 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
// 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);
}
void
nsPNGDecoder::WriteInternal(const char* aBuffer, uint32_t aCount)
{
MOZ_ASSERT(!HasError(), "Shouldn't call WriteInternal after error!");
// If we only want width/height, we don't need to go through libpng
if (IsSizeDecode()) {
// Are we done?
if (mHeaderBytesRead == BYTES_NEEDED_FOR_DIMENSIONS) {
return;
}
// Scan the header for the width and height bytes
uint32_t pos = 0;
const uint8_t* bptr = (uint8_t*)aBuffer;
while (pos < aCount && mHeaderBytesRead < BYTES_NEEDED_FOR_DIMENSIONS) {
// Verify the signature bytes
if (mHeaderBytesRead < sizeof(pngSignatureBytes)) {
if (bptr[pos] != nsPNGDecoder::pngSignatureBytes[mHeaderBytesRead]) {
PostDataError();
return;
}
}
// Get width and height bytes into the buffer
if ((mHeaderBytesRead >= WIDTH_OFFSET) &&
(mHeaderBytesRead < BYTES_NEEDED_FOR_DIMENSIONS)) {
mSizeBytes[mHeaderBytesRead - WIDTH_OFFSET] = bptr[pos];
}
pos ++;
mHeaderBytesRead ++;
}
// If we're done now, verify the data and set up the container
if (mHeaderBytesRead == BYTES_NEEDED_FOR_DIMENSIONS) {
// Grab the width and height, accounting for endianness (thanks libpng!)
uint32_t width = png_get_uint_32(mSizeBytes);
uint32_t height = png_get_uint_32(mSizeBytes + 4);
// Too big?
if ((width > MOZ_PNG_MAX_DIMENSION) || (height > MOZ_PNG_MAX_DIMENSION)) {
PostDataError();
return;
}
// Post our size to the superclass
PostSize(width, height);
}
// Otherwise, we're doing a standard decode
} else {
// libpng uses setjmp/longjmp for error handling - set the buffer
if (setjmp(png_jmpbuf(mPNG))) {
// We might not really know what caused the error, but it makes more
// sense to blame the data.
if (!HasError()) {
PostDataError();
}
png_destroy_read_struct(&mPNG, &mInfo, nullptr);
return;
}
// Pass the data off to libpng
png_process_data(mPNG, mInfo, (unsigned char*)aBuffer, aCount);
}
}
// 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
static qcms_profile*
PNGGetColorProfile(png_structp png_ptr, png_infop info_ptr,
int color_type, qcms_data_type* inType, uint32_t* intent)
{
qcms_profile* profile = nullptr;
*intent = QCMS_INTENT_PERCEPTUAL; // Our default
// 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);
profile = qcms_profile_from_memory((char*)profileData, profileLen);
if (profile) {
uint32_t profileSpace = qcms_profile_get_color_space(profile);
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(profile);
profile = nullptr;
} else {
*intent = qcms_profile_get_rendering_intent(profile);
}
}
}
// Check sRGB chunk
if (!profile && png_get_valid(png_ptr, info_ptr, PNG_INFO_sRGB)) {
profile = qcms_profile_sRGB();
if (profile) {
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 };
*intent = map[fileIntent];
}
}
// Check gAMA/cHRM chunks
if (!profile &&
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);
profile = qcms_profile_create_rgb_with_gamma(whitePoint, primaries,
1.0/gammaOfFile);
if (profile) {
png_set_gray_to_rgb(png_ptr);
}
}
if (profile) {
uint32_t profileSpace = qcms_profile_get_color_space(profile);
if (profileSpace == icSigGrayData) {
if (color_type & PNG_COLOR_MASK_ALPHA) {
*inType = QCMS_DATA_GRAYA_8;
} else {
*inType = QCMS_DATA_GRAY_8;
}
} else {
if (color_type & PNG_COLOR_MASK_ALPHA ||
png_get_valid(png_ptr, info_ptr, PNG_INFO_tRNS)) {
*inType = QCMS_DATA_RGBA_8;
} else {
*inType = QCMS_DATA_RGB_8;
}
}
}
return profile;
}
void
nsPNGDecoder::info_callback(png_structp png_ptr, png_infop info_ptr)
{
// int number_passes; NOT USED
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));
// 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);
// Are we too big?
if (width > MOZ_PNG_MAX_DIMENSION || height > MOZ_PNG_MAX_DIMENSION) {
png_longjmp(decoder->mPNG, 1);
}
// Post our size to the superclass
decoder->PostSize(width, height);
if (decoder->HasError()) {
// Setting the size led to an error.
png_longjmp(decoder->mPNG, 1);
}
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);
}
qcms_data_type inType = QCMS_DATA_RGBA_8;
uint32_t intent = -1;
uint32_t pIntent;
if (decoder->mCMSMode != eCMSMode_Off) {
intent = gfxPlatform::GetRenderingIntent();
decoder->mInProfile = PNGGetColorProfile(png_ptr, info_ptr,
color_type, &inType, &pIntent);
// If we're not mandating an intent, use the one from the image.
if (intent == uint32_t(-1)) {
intent = pIntent;
}
}
if (decoder->mInProfile && gfxPlatform::GetCMSOutputProfile()) {
qcms_data_type outType;
if (color_type & PNG_COLOR_MASK_ALPHA || num_trans) {
outType = QCMS_DATA_RGBA_8;
} else {
outType = QCMS_DATA_RGB_8;
}
decoder->mTransform = qcms_transform_create(decoder->mInProfile,
inType,
gfxPlatform::GetCMSOutputProfile(),
outType,
(qcms_intent)intent);
} else {
png_set_gray_to_rgb(png_ptr);
// only do gamma correction if CMS isn't entirely disabled
if (decoder->mCMSMode != eCMSMode_Off) {
PNGDoGammaCorrection(png_ptr, info_ptr);
}
if (decoder->mCMSMode == eCMSMode_All) {
if (color_type & PNG_COLOR_MASK_ALPHA || num_trans) {
decoder->mTransform = gfxPlatform::GetCMSRGBATransform();
} else {
decoder->mTransform = gfxPlatform::GetCMSRGBTransform();
}
}
}
// let libpng expand interlaced images
if (interlace_type == PNG_INTERLACE_ADAM7) {
// number_passes =
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 == 3) {
decoder->format = gfx::SurfaceFormat::B8G8R8X8;
} else if (channels == 2 || channels == 4) {
decoder->format = gfx::SurfaceFormat::B8G8R8A8;
}
#ifdef PNG_APNG_SUPPORTED
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_acTL)) {
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
decoder->CreateFrame(0, 0, width, height, decoder->format);
#ifdef PNG_APNG_SUPPORTED
}
#endif
if (decoder->mTransform &&
(channels <= 2 || interlace_type == PNG_INTERLACE_ADAM7)) {
uint32_t bpp[] = { 0, 3, 4, 3, 4 };
decoder->mCMSLine =
(uint8_t*)moz_malloc(bpp[channels] * width);
if (!decoder->mCMSLine) {
png_longjmp(decoder->mPNG, 5); // NS_ERROR_OUT_OF_MEMORY
}
}
if (interlace_type == PNG_INTERLACE_ADAM7) {
if (height < INT32_MAX / (width * channels)) {
decoder->interlacebuf = (uint8_t*)moz_malloc(channels * width * height);
}
if (!decoder->interlacebuf) {
png_longjmp(decoder->mPNG, 5); // NS_ERROR_OUT_OF_MEMORY
}
}
if (decoder->NeedsNewFrame()) {
// We know that we need a new frame, so pause input so the decoder
// infrastructure can give it to us.
png_process_data_pause(png_ptr, /* save = */ 1);
}
}
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));
// skip this frame
if (decoder->mFrameIsHidden) {
return;
}
if (row_num >= (png_uint_32) decoder->mFrameRect.height) {
return;
}
if (new_row) {
int32_t width = decoder->mFrameRect.width;
uint32_t iwidth = decoder->mFrameRect.width;
png_bytep line = new_row;
if (decoder->interlacebuf) {
line = decoder->interlacebuf + (row_num * decoder->mChannels * width);
png_progressive_combine_row(png_ptr, line, new_row);
}
uint32_t bpr = width * sizeof(uint32_t);
uint32_t* cptr32 = (uint32_t*)(decoder->mImageData + (row_num*bpr));
if (decoder->mTransform) {
if (decoder->mCMSLine) {
qcms_transform_data(decoder->mTransform, line, decoder->mCMSLine,
iwidth);
// copy alpha over
uint32_t channels = decoder->mChannels;
if (channels == 2 || channels == 4) {
for (uint32_t i = 0; i < iwidth; i++)
decoder->mCMSLine[4 * i + 3] = line[channels * i + channels - 1];
}
line = decoder->mCMSLine;
} else {
qcms_transform_data(decoder->mTransform, line, line, iwidth);
}
}
switch (decoder->format) {
case gfx::SurfaceFormat::B8G8R8X8: {
// counter for while() loops below
uint32_t idx = iwidth;
// copy as bytes until source pointer is 32-bit-aligned
for (; (NS_PTR_TO_UINT32(line) & 0x3) && idx; --idx) {
*cptr32++ = gfxPackedPixel(0xFF, line[0], line[1], line[2]);
line += 3;
}
// copy pixels in blocks of 4
while (idx >= 4) {
GFX_BLOCK_RGB_TO_FRGB(line, cptr32);
idx -= 4;
line += 12;
cptr32 += 4;
}
// copy remaining pixel(s)
while (idx--) {
// 32-bit read of final pixel will exceed buffer, so read bytes
*cptr32++ = gfxPackedPixel(0xFF, line[0], line[1], line[2]);
line += 3;
}
}
break;
case gfx::SurfaceFormat::B8G8R8A8: {
if (!decoder->mDisablePremultipliedAlpha) {
for (uint32_t x=width; x>0; --x) {
*cptr32++ = gfxPackedPixel(line[3], line[0], line[1], line[2]);
line += 4;
}
} else {
for (uint32_t x=width; x>0; --x) {
*cptr32++ = gfxPackedPixelNoPreMultiply(line[3], line[0], line[1],
line[2]);
line += 4;
}
}
}
break;
default:
png_longjmp(decoder->mPNG, 1);
}
if (decoder->mNumFrames <= 1) {
// Only do incremental image display for the first frame
// XXXbholley - this check should be handled in the superclass
nsIntRect r(0, row_num, width, 1);
decoder->PostInvalidation(r);
}
}
}
#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)
{
png_uint_32 x_offset, y_offset;
int32_t width, height;
nsPNGDecoder* decoder =
static_cast<nsPNGDecoder*>(png_get_progressive_ptr(png_ptr));
// old frame is done
decoder->EndImageFrame();
// Only the first frame can be hidden, so unhide unconditionally here.
decoder->mFrameIsHidden = false;
x_offset = png_get_next_frame_x_offset(png_ptr, decoder->mInfo);
y_offset = png_get_next_frame_y_offset(png_ptr, decoder->mInfo);
width = png_get_next_frame_width(png_ptr, decoder->mInfo);
height = png_get_next_frame_height(png_ptr, decoder->mInfo);
decoder->CreateFrame(x_offset, y_offset, width, height, decoder->format);
if (decoder->NeedsNewFrame()) {
// We know that we need a new frame, so pause input so the decoder
// infrastructure can give it to us.
png_process_data_pause(png_ptr, /* save = */ 1);
}
}
#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!");
int32_t loop_count = 0;
#ifdef PNG_APNG_SUPPORTED
if (png_get_valid(png_ptr, info_ptr, PNG_INFO_acTL)) {
int32_t num_plays = png_get_num_plays(png_ptr, info_ptr);
loop_count = num_plays - 1;
}
#endif
// Send final notifications
decoder->EndImageFrame();
decoder->PostDecodeDone(loop_count);
}
void
nsPNGDecoder::error_callback(png_structp png_ptr, png_const_charp error_msg)
{
PR_LOG(GetPNGLog(), PR_LOG_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)
{
PR_LOG(GetPNGLog(), PR_LOG_WARNING, ("libpng warning: %s\n", warning_msg));
}
Telemetry::ID
nsPNGDecoder::SpeedHistogram()
{
return Telemetry::IMAGE_DECODE_SPEED_PNG;
}
} // namespace image
} // namespace mozilla