/*
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* Copyright 2015 Google Inc.
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*
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* Use of this source code is governed by a BSD-style license that can be
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* found in the LICENSE file.
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*/
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#include "SkJpegCodec.h"
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#include "SkCodec.h"
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#include "SkCodecPriv.h"
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#include "SkColorData.h"
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#include "SkJpegDecoderMgr.h"
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#include "SkJpegInfo.h"
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#include "SkStream.h"
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#include "SkTemplates.h"
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#include "SkTo.h"
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#include "SkTypes.h"
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// stdio is needed for libjpeg-turbo
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#include <stdio.h>
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#include "SkJpegUtility.h"
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// This warning triggers false postives way too often in here.
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#if defined(__GNUC__) && !defined(__clang__)
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#pragma GCC diagnostic ignored "-Wclobbered"
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#endif
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extern "C" {
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#include "jerror.h"
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#include "jpeglib.h"
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}
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bool SkJpegCodec::IsJpeg(const void* buffer, size_t bytesRead) {
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constexpr uint8_t jpegSig[] = { 0xFF, 0xD8, 0xFF };
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return bytesRead >= 3 && !memcmp(buffer, jpegSig, sizeof(jpegSig));
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}
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static uint32_t get_endian_int(const uint8_t* data, bool littleEndian) {
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if (littleEndian) {
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return (data[3] << 24) | (data[2] << 16) | (data[1] << 8) | (data[0]);
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}
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return (data[0] << 24) | (data[1] << 16) | (data[2] << 8) | (data[3]);
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}
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const uint32_t kExifHeaderSize = 14;
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const uint32_t kExifMarker = JPEG_APP0 + 1;
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static bool is_orientation_marker(jpeg_marker_struct* marker, SkEncodedOrigin* orientation) {
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if (kExifMarker != marker->marker || marker->data_length < kExifHeaderSize) {
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return false;
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}
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constexpr uint8_t kExifSig[] { 'E', 'x', 'i', 'f', '\0' };
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if (memcmp(marker->data, kExifSig, sizeof(kExifSig))) {
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return false;
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}
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// Account for 'E', 'x', 'i', 'f', '\0', '<fill byte>'.
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constexpr size_t kOffset = 6;
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return is_orientation_marker(marker->data + kOffset, marker->data_length - kOffset,
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orientation);
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}
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bool is_orientation_marker(const uint8_t* data, size_t data_length, SkEncodedOrigin* orientation) {
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bool littleEndian;
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// We need eight bytes to read the endian marker and the offset, below.
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if (data_length < 8 || !is_valid_endian_marker(data, &littleEndian)) {
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return false;
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}
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// Get the offset from the start of the marker.
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// Though this only reads four bytes, use a larger int in case it overflows.
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uint64_t offset = get_endian_int(data + 4, littleEndian);
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// Require that the marker is at least large enough to contain the number of entries.
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if (data_length < offset + 2) {
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return false;
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}
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uint32_t numEntries = get_endian_short(data + offset, littleEndian);
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// Tag (2 bytes), Datatype (2 bytes), Number of elements (4 bytes), Data (4 bytes)
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const uint32_t kEntrySize = 12;
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const auto max = SkTo<uint32_t>((data_length - offset - 2) / kEntrySize);
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numEntries = SkTMin(numEntries, max);
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// Advance the data to the start of the entries.
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data += offset + 2;
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const uint16_t kOriginTag = 0x112;
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const uint16_t kOriginType = 3;
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for (uint32_t i = 0; i < numEntries; i++, data += kEntrySize) {
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uint16_t tag = get_endian_short(data, littleEndian);
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uint16_t type = get_endian_short(data + 2, littleEndian);
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uint32_t count = get_endian_int(data + 4, littleEndian);
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if (kOriginTag == tag && kOriginType == type && 1 == count) {
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uint16_t val = get_endian_short(data + 8, littleEndian);
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if (0 < val && val <= kLast_SkEncodedOrigin) {
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*orientation = (SkEncodedOrigin) val;
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return true;
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}
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}
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}
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return false;
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}
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static SkEncodedOrigin get_exif_orientation(jpeg_decompress_struct* dinfo) {
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SkEncodedOrigin orientation;
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for (jpeg_marker_struct* marker = dinfo->marker_list; marker; marker = marker->next) {
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if (is_orientation_marker(marker, &orientation)) {
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return orientation;
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}
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}
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return kDefault_SkEncodedOrigin;
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}
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static bool is_icc_marker(jpeg_marker_struct* marker) {
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if (kICCMarker != marker->marker || marker->data_length < kICCMarkerHeaderSize) {
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return false;
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}
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return !memcmp(marker->data, kICCSig, sizeof(kICCSig));
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}
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/*
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* ICC profiles may be stored using a sequence of multiple markers. We obtain the ICC profile
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* in two steps:
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* (1) Discover all ICC profile markers and verify that they are numbered properly.
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* (2) Copy the data from each marker into a contiguous ICC profile.
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*/
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static std::unique_ptr<SkEncodedInfo::ICCProfile> read_color_profile(jpeg_decompress_struct* dinfo)
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{
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// Note that 256 will be enough storage space since each markerIndex is stored in 8-bits.
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jpeg_marker_struct* markerSequence[256];
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memset(markerSequence, 0, sizeof(markerSequence));
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uint8_t numMarkers = 0;
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size_t totalBytes = 0;
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// Discover any ICC markers and verify that they are numbered properly.
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for (jpeg_marker_struct* marker = dinfo->marker_list; marker; marker = marker->next) {
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if (is_icc_marker(marker)) {
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// Verify that numMarkers is valid and consistent.
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if (0 == numMarkers) {
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numMarkers = marker->data[13];
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if (0 == numMarkers) {
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SkCodecPrintf("ICC Profile Error: numMarkers must be greater than zero.\n");
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return nullptr;
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}
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} else if (numMarkers != marker->data[13]) {
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SkCodecPrintf("ICC Profile Error: numMarkers must be consistent.\n");
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return nullptr;
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}
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// Verify that the markerIndex is valid and unique. Note that zero is not
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// a valid index.
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uint8_t markerIndex = marker->data[12];
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if (markerIndex == 0 || markerIndex > numMarkers) {
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SkCodecPrintf("ICC Profile Error: markerIndex is invalid.\n");
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return nullptr;
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}
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if (markerSequence[markerIndex]) {
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SkCodecPrintf("ICC Profile Error: Duplicate value of markerIndex.\n");
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return nullptr;
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}
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markerSequence[markerIndex] = marker;
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SkASSERT(marker->data_length >= kICCMarkerHeaderSize);
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totalBytes += marker->data_length - kICCMarkerHeaderSize;
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}
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}
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if (0 == totalBytes) {
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// No non-empty ICC profile markers were found.
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return nullptr;
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}
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// Combine the ICC marker data into a contiguous profile.
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sk_sp<SkData> iccData = SkData::MakeUninitialized(totalBytes);
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void* dst = iccData->writable_data();
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for (uint32_t i = 1; i <= numMarkers; i++) {
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jpeg_marker_struct* marker = markerSequence[i];
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if (!marker) {
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SkCodecPrintf("ICC Profile Error: Missing marker %d of %d.\n", i, numMarkers);
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return nullptr;
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}
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void* src = SkTAddOffset<void>(marker->data, kICCMarkerHeaderSize);
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size_t bytes = marker->data_length - kICCMarkerHeaderSize;
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memcpy(dst, src, bytes);
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dst = SkTAddOffset<void>(dst, bytes);
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}
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return SkEncodedInfo::ICCProfile::Make(std::move(iccData));
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}
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SkCodec::Result SkJpegCodec::ReadHeader(SkStream* stream, SkCodec** codecOut,
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JpegDecoderMgr** decoderMgrOut,
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std::unique_ptr<SkEncodedInfo::ICCProfile> defaultColorProfile) {
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// Create a JpegDecoderMgr to own all of the decompress information
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std::unique_ptr<JpegDecoderMgr> decoderMgr(new JpegDecoderMgr(stream));
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// libjpeg errors will be caught and reported here
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skjpeg_error_mgr::AutoPushJmpBuf jmp(decoderMgr->errorMgr());
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if (setjmp(jmp)) {
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return decoderMgr->returnFailure("ReadHeader", kInvalidInput);
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}
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// Initialize the decompress info and the source manager
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decoderMgr->init();
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auto* dinfo = decoderMgr->dinfo();
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// Instruct jpeg library to save the markers that we care about. Since
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// the orientation and color profile will not change, we can skip this
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// step on rewinds.
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if (codecOut) {
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jpeg_save_markers(dinfo, kExifMarker, 0xFFFF);
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jpeg_save_markers(dinfo, kICCMarker, 0xFFFF);
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}
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// Read the jpeg header
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switch (jpeg_read_header(dinfo, true)) {
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case JPEG_HEADER_OK:
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break;
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case JPEG_SUSPENDED:
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return decoderMgr->returnFailure("ReadHeader", kIncompleteInput);
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default:
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return decoderMgr->returnFailure("ReadHeader", kInvalidInput);
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}
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if (codecOut) {
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// Get the encoded color type
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SkEncodedInfo::Color color;
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if (!decoderMgr->getEncodedColor(&color)) {
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return kInvalidInput;
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}
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SkEncodedOrigin orientation = get_exif_orientation(dinfo);
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auto profile = read_color_profile(dinfo);
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if (profile) {
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auto type = profile->profile()->data_color_space;
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switch (decoderMgr->dinfo()->jpeg_color_space) {
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case JCS_CMYK:
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case JCS_YCCK:
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if (type != skcms_Signature_CMYK) {
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profile = nullptr;
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}
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break;
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case JCS_GRAYSCALE:
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if (type != skcms_Signature_Gray &&
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type != skcms_Signature_RGB)
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{
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profile = nullptr;
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}
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break;
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default:
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if (type != skcms_Signature_RGB) {
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profile = nullptr;
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}
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break;
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}
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}
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if (!profile) {
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profile = std::move(defaultColorProfile);
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}
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SkEncodedInfo info = SkEncodedInfo::Make(dinfo->image_width, dinfo->image_height,
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color, SkEncodedInfo::kOpaque_Alpha, 8,
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std::move(profile));
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SkJpegCodec* codec = new SkJpegCodec(std::move(info), std::unique_ptr<SkStream>(stream),
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decoderMgr.release(), orientation);
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*codecOut = codec;
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} else {
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SkASSERT(nullptr != decoderMgrOut);
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*decoderMgrOut = decoderMgr.release();
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}
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return kSuccess;
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}
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std::unique_ptr<SkCodec> SkJpegCodec::MakeFromStream(std::unique_ptr<SkStream> stream,
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Result* result) {
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return SkJpegCodec::MakeFromStream(std::move(stream), result, nullptr);
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}
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std::unique_ptr<SkCodec> SkJpegCodec::MakeFromStream(std::unique_ptr<SkStream> stream,
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Result* result, std::unique_ptr<SkEncodedInfo::ICCProfile> defaultColorProfile) {
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SkCodec* codec = nullptr;
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*result = ReadHeader(stream.get(), &codec, nullptr, std::move(defaultColorProfile));
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if (kSuccess == *result) {
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// Codec has taken ownership of the stream, we do not need to delete it
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SkASSERT(codec);
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stream.release();
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return std::unique_ptr<SkCodec>(codec);
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}
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return nullptr;
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}
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SkJpegCodec::SkJpegCodec(SkEncodedInfo&& info, std::unique_ptr<SkStream> stream,
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JpegDecoderMgr* decoderMgr, SkEncodedOrigin origin)
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: INHERITED(std::move(info), skcms_PixelFormat_RGBA_8888, std::move(stream), origin)
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, fDecoderMgr(decoderMgr)
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, fReadyState(decoderMgr->dinfo()->global_state)
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, fSwizzleSrcRow(nullptr)
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, fColorXformSrcRow(nullptr)
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, fSwizzlerSubset(SkIRect::MakeEmpty())
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{}
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/*
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* Return the row bytes of a particular image type and width
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*/
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static size_t get_row_bytes(const j_decompress_ptr dinfo) {
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const size_t colorBytes = (dinfo->out_color_space == JCS_RGB565) ? 2 :
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dinfo->out_color_components;
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return dinfo->output_width * colorBytes;
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}
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/*
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* Calculate output dimensions based on the provided factors.
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*
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* Not to be used on the actual jpeg_decompress_struct used for decoding, since it will
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* incorrectly modify num_components.
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*/
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void calc_output_dimensions(jpeg_decompress_struct* dinfo, unsigned int num, unsigned int denom) {
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dinfo->num_components = 0;
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dinfo->scale_num = num;
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dinfo->scale_denom = denom;
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jpeg_calc_output_dimensions(dinfo);
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}
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/*
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* Return a valid set of output dimensions for this decoder, given an input scale
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*/
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SkISize SkJpegCodec::onGetScaledDimensions(float desiredScale) const {
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// libjpeg-turbo supports scaling by 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and 1/1, so we will
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// support these as well
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unsigned int num;
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unsigned int denom = 8;
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if (desiredScale >= 0.9375) {
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num = 8;
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} else if (desiredScale >= 0.8125) {
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num = 7;
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} else if (desiredScale >= 0.6875f) {
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num = 6;
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} else if (desiredScale >= 0.5625f) {
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num = 5;
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} else if (desiredScale >= 0.4375f) {
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num = 4;
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} else if (desiredScale >= 0.3125f) {
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num = 3;
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} else if (desiredScale >= 0.1875f) {
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num = 2;
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} else {
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num = 1;
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}
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// Set up a fake decompress struct in order to use libjpeg to calculate output dimensions
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jpeg_decompress_struct dinfo;
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sk_bzero(&dinfo, sizeof(dinfo));
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dinfo.image_width = this->dimensions().width();
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dinfo.image_height = this->dimensions().height();
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dinfo.global_state = fReadyState;
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calc_output_dimensions(&dinfo, num, denom);
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// Return the calculated output dimensions for the given scale
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return SkISize::Make(dinfo.output_width, dinfo.output_height);
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}
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bool SkJpegCodec::onRewind() {
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JpegDecoderMgr* decoderMgr = nullptr;
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if (kSuccess != ReadHeader(this->stream(), nullptr, &decoderMgr, nullptr)) {
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return fDecoderMgr->returnFalse("onRewind");
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}
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SkASSERT(nullptr != decoderMgr);
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fDecoderMgr.reset(decoderMgr);
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fSwizzler.reset(nullptr);
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fSwizzleSrcRow = nullptr;
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fColorXformSrcRow = nullptr;
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fStorage.reset();
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return true;
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}
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bool SkJpegCodec::conversionSupported(const SkImageInfo& dstInfo, bool srcIsOpaque,
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bool needsColorXform) {
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SkASSERT(srcIsOpaque);
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if (kUnknown_SkAlphaType == dstInfo.alphaType()) {
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return false;
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}
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if (kOpaque_SkAlphaType != dstInfo.alphaType()) {
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SkCodecPrintf("Warning: an opaque image should be decoded as opaque "
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"- it is being decoded as non-opaque, which will draw slower\n");
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}
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J_COLOR_SPACE encodedColorType = fDecoderMgr->dinfo()->jpeg_color_space;
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// Check for valid color types and set the output color space
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switch (dstInfo.colorType()) {
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case kRGBA_8888_SkColorType:
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fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
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break;
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case kBGRA_8888_SkColorType:
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if (needsColorXform) {
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// Always using RGBA as the input format for color xforms makes the
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// implementation a little simpler.
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fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
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} else {
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fDecoderMgr->dinfo()->out_color_space = JCS_EXT_BGRA;
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}
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break;
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case kRGB_565_SkColorType:
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if (needsColorXform) {
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fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
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} else {
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fDecoderMgr->dinfo()->dither_mode = JDITHER_NONE;
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fDecoderMgr->dinfo()->out_color_space = JCS_RGB565;
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}
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break;
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case kGray_8_SkColorType:
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if (JCS_GRAYSCALE != encodedColorType) {
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return false;
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}
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if (needsColorXform) {
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fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
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} else {
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fDecoderMgr->dinfo()->out_color_space = JCS_GRAYSCALE;
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}
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break;
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case kRGBA_F16_SkColorType:
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SkASSERT(needsColorXform);
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fDecoderMgr->dinfo()->out_color_space = JCS_EXT_RGBA;
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break;
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default:
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return false;
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}
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// Check if we will decode to CMYK. libjpeg-turbo does not convert CMYK to RGBA, so
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// we must do it ourselves.
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if (JCS_CMYK == encodedColorType || JCS_YCCK == encodedColorType) {
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fDecoderMgr->dinfo()->out_color_space = JCS_CMYK;
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}
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return true;
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}
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/*
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* Checks if we can natively scale to the requested dimensions and natively scales the
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* dimensions if possible
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*/
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bool SkJpegCodec::onDimensionsSupported(const SkISize& size) {
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skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
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if (setjmp(jmp)) {
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return fDecoderMgr->returnFalse("onDimensionsSupported");
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}
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const unsigned int dstWidth = size.width();
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const unsigned int dstHeight = size.height();
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// Set up a fake decompress struct in order to use libjpeg to calculate output dimensions
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// FIXME: Why is this necessary?
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jpeg_decompress_struct dinfo;
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sk_bzero(&dinfo, sizeof(dinfo));
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dinfo.image_width = this->dimensions().width();
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dinfo.image_height = this->dimensions().height();
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dinfo.global_state = fReadyState;
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// libjpeg-turbo can scale to 1/8, 1/4, 3/8, 1/2, 5/8, 3/4, 7/8, and 1/1
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unsigned int num = 8;
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const unsigned int denom = 8;
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calc_output_dimensions(&dinfo, num, denom);
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while (dinfo.output_width != dstWidth || dinfo.output_height != dstHeight) {
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// Return a failure if we have tried all of the possible scales
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if (1 == num || dstWidth > dinfo.output_width || dstHeight > dinfo.output_height) {
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return false;
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}
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// Try the next scale
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num -= 1;
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calc_output_dimensions(&dinfo, num, denom);
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}
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fDecoderMgr->dinfo()->scale_num = num;
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fDecoderMgr->dinfo()->scale_denom = denom;
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return true;
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}
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int SkJpegCodec::readRows(const SkImageInfo& dstInfo, void* dst, size_t rowBytes, int count,
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const Options& opts) {
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// Set the jump location for libjpeg-turbo errors
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skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
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if (setjmp(jmp)) {
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return 0;
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}
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// When fSwizzleSrcRow is non-null, it means that we need to swizzle. In this case,
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// we will always decode into fSwizzlerSrcRow before swizzling into the next buffer.
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// We can never swizzle "in place" because the swizzler may perform sampling and/or
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// subsetting.
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// When fColorXformSrcRow is non-null, it means that we need to color xform and that
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// we cannot color xform "in place" (many times we can, but not when the src and dst
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// are different sizes).
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// In this case, we will color xform from fColorXformSrcRow into the dst.
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JSAMPLE* decodeDst = (JSAMPLE*) dst;
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uint32_t* swizzleDst = (uint32_t*) dst;
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size_t decodeDstRowBytes = rowBytes;
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size_t swizzleDstRowBytes = rowBytes;
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int dstWidth = opts.fSubset ? opts.fSubset->width() : dstInfo.width();
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if (fSwizzleSrcRow && fColorXformSrcRow) {
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decodeDst = (JSAMPLE*) fSwizzleSrcRow;
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swizzleDst = fColorXformSrcRow;
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decodeDstRowBytes = 0;
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swizzleDstRowBytes = 0;
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dstWidth = fSwizzler->swizzleWidth();
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} else if (fColorXformSrcRow) {
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decodeDst = (JSAMPLE*) fColorXformSrcRow;
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swizzleDst = fColorXformSrcRow;
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decodeDstRowBytes = 0;
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swizzleDstRowBytes = 0;
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} else if (fSwizzleSrcRow) {
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decodeDst = (JSAMPLE*) fSwizzleSrcRow;
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decodeDstRowBytes = 0;
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dstWidth = fSwizzler->swizzleWidth();
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}
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for (int y = 0; y < count; y++) {
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uint32_t lines = jpeg_read_scanlines(fDecoderMgr->dinfo(), &decodeDst, 1);
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if (0 == lines) {
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return y;
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}
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if (fSwizzler) {
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fSwizzler->swizzle(swizzleDst, decodeDst);
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}
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if (this->colorXform()) {
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this->applyColorXform(dst, swizzleDst, dstWidth);
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dst = SkTAddOffset<void>(dst, rowBytes);
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}
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decodeDst = SkTAddOffset<JSAMPLE>(decodeDst, decodeDstRowBytes);
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swizzleDst = SkTAddOffset<uint32_t>(swizzleDst, swizzleDstRowBytes);
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}
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return count;
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}
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/*
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* This is a bit tricky. We only need the swizzler to do format conversion if the jpeg is
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* encoded as CMYK.
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* And even then we still may not need it. If the jpeg has a CMYK color profile and a color
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* xform, the color xform will handle the CMYK->RGB conversion.
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*/
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static inline bool needs_swizzler_to_convert_from_cmyk(J_COLOR_SPACE jpegColorType,
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const skcms_ICCProfile* srcProfile,
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bool hasColorSpaceXform) {
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if (JCS_CMYK != jpegColorType) {
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return false;
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}
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bool hasCMYKColorSpace = srcProfile && srcProfile->data_color_space == skcms_Signature_CMYK;
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return !hasCMYKColorSpace || !hasColorSpaceXform;
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}
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/*
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* Performs the jpeg decode
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*/
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SkCodec::Result SkJpegCodec::onGetPixels(const SkImageInfo& dstInfo,
|
void* dst, size_t dstRowBytes,
|
const Options& options,
|
int* rowsDecoded) {
|
if (options.fSubset) {
|
// Subsets are not supported.
|
return kUnimplemented;
|
}
|
|
// Get a pointer to the decompress info since we will use it quite frequently
|
jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();
|
|
// Set the jump location for libjpeg errors
|
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
|
if (setjmp(jmp)) {
|
return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
|
}
|
|
if (!jpeg_start_decompress(dinfo)) {
|
return fDecoderMgr->returnFailure("startDecompress", kInvalidInput);
|
}
|
|
// The recommended output buffer height should always be 1 in high quality modes.
|
// If it's not, we want to know because it means our strategy is not optimal.
|
SkASSERT(1 == dinfo->rec_outbuf_height);
|
|
if (needs_swizzler_to_convert_from_cmyk(dinfo->out_color_space,
|
this->getEncodedInfo().profile(), this->colorXform())) {
|
this->initializeSwizzler(dstInfo, options, true);
|
}
|
|
this->allocateStorage(dstInfo);
|
|
int rows = this->readRows(dstInfo, dst, dstRowBytes, dstInfo.height(), options);
|
if (rows < dstInfo.height()) {
|
*rowsDecoded = rows;
|
return fDecoderMgr->returnFailure("Incomplete image data", kIncompleteInput);
|
}
|
|
return kSuccess;
|
}
|
|
void SkJpegCodec::allocateStorage(const SkImageInfo& dstInfo) {
|
int dstWidth = dstInfo.width();
|
|
size_t swizzleBytes = 0;
|
if (fSwizzler) {
|
swizzleBytes = get_row_bytes(fDecoderMgr->dinfo());
|
dstWidth = fSwizzler->swizzleWidth();
|
SkASSERT(!this->colorXform() || SkIsAlign4(swizzleBytes));
|
}
|
|
size_t xformBytes = 0;
|
|
if (this->colorXform() && sizeof(uint32_t) != dstInfo.bytesPerPixel()) {
|
xformBytes = dstWidth * sizeof(uint32_t);
|
}
|
|
size_t totalBytes = swizzleBytes + xformBytes;
|
if (totalBytes > 0) {
|
fStorage.reset(totalBytes);
|
fSwizzleSrcRow = (swizzleBytes > 0) ? fStorage.get() : nullptr;
|
fColorXformSrcRow = (xformBytes > 0) ?
|
SkTAddOffset<uint32_t>(fStorage.get(), swizzleBytes) : nullptr;
|
}
|
}
|
|
void SkJpegCodec::initializeSwizzler(const SkImageInfo& dstInfo, const Options& options,
|
bool needsCMYKToRGB) {
|
Options swizzlerOptions = options;
|
if (options.fSubset) {
|
// Use fSwizzlerSubset if this is a subset decode. This is necessary in the case
|
// where libjpeg-turbo provides a subset and then we need to subset it further.
|
// Also, verify that fSwizzlerSubset is initialized and valid.
|
SkASSERT(!fSwizzlerSubset.isEmpty() && fSwizzlerSubset.x() <= options.fSubset->x() &&
|
fSwizzlerSubset.width() == options.fSubset->width());
|
swizzlerOptions.fSubset = &fSwizzlerSubset;
|
}
|
|
SkImageInfo swizzlerDstInfo = dstInfo;
|
if (this->colorXform()) {
|
// The color xform will be expecting RGBA 8888 input.
|
swizzlerDstInfo = swizzlerDstInfo.makeColorType(kRGBA_8888_SkColorType);
|
}
|
|
if (needsCMYKToRGB) {
|
// The swizzler is used to convert to from CMYK.
|
// The swizzler does not use the width or height on SkEncodedInfo.
|
auto swizzlerInfo = SkEncodedInfo::Make(0, 0, SkEncodedInfo::kInvertedCMYK_Color,
|
SkEncodedInfo::kOpaque_Alpha, 8);
|
fSwizzler = SkSwizzler::Make(swizzlerInfo, nullptr, swizzlerDstInfo, swizzlerOptions);
|
} else {
|
int srcBPP = 0;
|
switch (fDecoderMgr->dinfo()->out_color_space) {
|
case JCS_EXT_RGBA:
|
case JCS_EXT_BGRA:
|
case JCS_CMYK:
|
srcBPP = 4;
|
break;
|
case JCS_RGB565:
|
srcBPP = 2;
|
break;
|
case JCS_GRAYSCALE:
|
srcBPP = 1;
|
break;
|
default:
|
SkASSERT(false);
|
break;
|
}
|
fSwizzler = SkSwizzler::MakeSimple(srcBPP, swizzlerDstInfo, swizzlerOptions);
|
}
|
SkASSERT(fSwizzler);
|
}
|
|
SkSampler* SkJpegCodec::getSampler(bool createIfNecessary) {
|
if (!createIfNecessary || fSwizzler) {
|
SkASSERT(!fSwizzler || (fSwizzleSrcRow && fStorage.get() == fSwizzleSrcRow));
|
return fSwizzler.get();
|
}
|
|
bool needsCMYKToRGB = needs_swizzler_to_convert_from_cmyk(
|
fDecoderMgr->dinfo()->out_color_space, this->getEncodedInfo().profile(),
|
this->colorXform());
|
this->initializeSwizzler(this->dstInfo(), this->options(), needsCMYKToRGB);
|
this->allocateStorage(this->dstInfo());
|
return fSwizzler.get();
|
}
|
|
SkCodec::Result SkJpegCodec::onStartScanlineDecode(const SkImageInfo& dstInfo,
|
const Options& options) {
|
// Set the jump location for libjpeg errors
|
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
|
if (setjmp(jmp)) {
|
SkCodecPrintf("setjmp: Error from libjpeg\n");
|
return kInvalidInput;
|
}
|
|
if (!jpeg_start_decompress(fDecoderMgr->dinfo())) {
|
SkCodecPrintf("start decompress failed\n");
|
return kInvalidInput;
|
}
|
|
bool needsCMYKToRGB = needs_swizzler_to_convert_from_cmyk(
|
fDecoderMgr->dinfo()->out_color_space, this->getEncodedInfo().profile(),
|
this->colorXform());
|
if (options.fSubset) {
|
uint32_t startX = options.fSubset->x();
|
uint32_t width = options.fSubset->width();
|
|
// libjpeg-turbo may need to align startX to a multiple of the IDCT
|
// block size. If this is the case, it will decrease the value of
|
// startX to the appropriate alignment and also increase the value
|
// of width so that the right edge of the requested subset remains
|
// the same.
|
jpeg_crop_scanline(fDecoderMgr->dinfo(), &startX, &width);
|
|
SkASSERT(startX <= (uint32_t) options.fSubset->x());
|
SkASSERT(width >= (uint32_t) options.fSubset->width());
|
SkASSERT(startX + width >= (uint32_t) options.fSubset->right());
|
|
// Instruct the swizzler (if it is necessary) to further subset the
|
// output provided by libjpeg-turbo.
|
//
|
// We set this here (rather than in the if statement below), so that
|
// if (1) we don't need a swizzler for the subset, and (2) we need a
|
// swizzler for CMYK, the swizzler will still use the proper subset
|
// dimensions.
|
//
|
// Note that the swizzler will ignore the y and height parameters of
|
// the subset. Since the scanline decoder (and the swizzler) handle
|
// one row at a time, only the subsetting in the x-dimension matters.
|
fSwizzlerSubset.setXYWH(options.fSubset->x() - startX, 0,
|
options.fSubset->width(), options.fSubset->height());
|
|
// We will need a swizzler if libjpeg-turbo cannot provide the exact
|
// subset that we request.
|
if (startX != (uint32_t) options.fSubset->x() ||
|
width != (uint32_t) options.fSubset->width()) {
|
this->initializeSwizzler(dstInfo, options, needsCMYKToRGB);
|
}
|
}
|
|
// Make sure we have a swizzler if we are converting from CMYK.
|
if (!fSwizzler && needsCMYKToRGB) {
|
this->initializeSwizzler(dstInfo, options, true);
|
}
|
|
this->allocateStorage(dstInfo);
|
|
return kSuccess;
|
}
|
|
int SkJpegCodec::onGetScanlines(void* dst, int count, size_t dstRowBytes) {
|
int rows = this->readRows(this->dstInfo(), dst, dstRowBytes, count, this->options());
|
if (rows < count) {
|
// This allows us to skip calling jpeg_finish_decompress().
|
fDecoderMgr->dinfo()->output_scanline = this->dstInfo().height();
|
}
|
|
return rows;
|
}
|
|
bool SkJpegCodec::onSkipScanlines(int count) {
|
// Set the jump location for libjpeg errors
|
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
|
if (setjmp(jmp)) {
|
return fDecoderMgr->returnFalse("onSkipScanlines");
|
}
|
|
return (uint32_t) count == jpeg_skip_scanlines(fDecoderMgr->dinfo(), count);
|
}
|
|
static bool is_yuv_supported(jpeg_decompress_struct* dinfo) {
|
// Scaling is not supported in raw data mode.
|
SkASSERT(dinfo->scale_num == dinfo->scale_denom);
|
|
// I can't imagine that this would ever change, but we do depend on it.
|
static_assert(8 == DCTSIZE, "DCTSIZE (defined in jpeg library) should always be 8.");
|
|
if (JCS_YCbCr != dinfo->jpeg_color_space) {
|
return false;
|
}
|
|
SkASSERT(3 == dinfo->num_components);
|
SkASSERT(dinfo->comp_info);
|
|
// It is possible to perform a YUV decode for any combination of
|
// horizontal and vertical sampling that is supported by
|
// libjpeg/libjpeg-turbo. However, we will start by supporting only the
|
// common cases (where U and V have samp_factors of one).
|
//
|
// The definition of samp_factor is kind of the opposite of what SkCodec
|
// thinks of as a sampling factor. samp_factor is essentially a
|
// multiplier, and the larger the samp_factor is, the more samples that
|
// there will be. Ex:
|
// U_plane_width = image_width * (U_h_samp_factor / max_h_samp_factor)
|
//
|
// Supporting cases where the samp_factors for U or V were larger than
|
// that of Y would be an extremely difficult change, given that clients
|
// allocate memory as if the size of the Y plane is always the size of the
|
// image. However, this case is very, very rare.
|
if ((1 != dinfo->comp_info[1].h_samp_factor) ||
|
(1 != dinfo->comp_info[1].v_samp_factor) ||
|
(1 != dinfo->comp_info[2].h_samp_factor) ||
|
(1 != dinfo->comp_info[2].v_samp_factor))
|
{
|
return false;
|
}
|
|
// Support all common cases of Y samp_factors.
|
// TODO (msarett): As mentioned above, it would be possible to support
|
// more combinations of samp_factors. The issues are:
|
// (1) Are there actually any images that are not covered
|
// by these cases?
|
// (2) How much complexity would be added to the
|
// implementation in order to support these rare
|
// cases?
|
int hSampY = dinfo->comp_info[0].h_samp_factor;
|
int vSampY = dinfo->comp_info[0].v_samp_factor;
|
return (1 == hSampY && 1 == vSampY) ||
|
(2 == hSampY && 1 == vSampY) ||
|
(2 == hSampY && 2 == vSampY) ||
|
(1 == hSampY && 2 == vSampY) ||
|
(4 == hSampY && 1 == vSampY) ||
|
(4 == hSampY && 2 == vSampY);
|
}
|
|
bool SkJpegCodec::onQueryYUV8(SkYUVASizeInfo* sizeInfo, SkYUVColorSpace* colorSpace) const {
|
jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();
|
if (!is_yuv_supported(dinfo)) {
|
return false;
|
}
|
|
jpeg_component_info * comp_info = dinfo->comp_info;
|
for (int i = 0; i < 3; ++i) {
|
sizeInfo->fSizes[i].set(comp_info[i].downsampled_width, comp_info[i].downsampled_height);
|
sizeInfo->fWidthBytes[i] = comp_info[i].width_in_blocks * DCTSIZE;
|
}
|
|
// JPEG never has an alpha channel
|
sizeInfo->fSizes[3].fHeight = sizeInfo->fSizes[3].fWidth = sizeInfo->fWidthBytes[3] = 0;
|
|
sizeInfo->fOrigin = this->getOrigin();
|
|
if (colorSpace) {
|
*colorSpace = kJPEG_SkYUVColorSpace;
|
}
|
|
return true;
|
}
|
|
SkCodec::Result SkJpegCodec::onGetYUV8Planes(const SkYUVASizeInfo& sizeInfo,
|
void* planes[SkYUVASizeInfo::kMaxCount]) {
|
SkYUVASizeInfo defaultInfo;
|
|
// This will check is_yuv_supported(), so we don't need to here.
|
bool supportsYUV = this->onQueryYUV8(&defaultInfo, nullptr);
|
if (!supportsYUV ||
|
sizeInfo.fSizes[0] != defaultInfo.fSizes[0] ||
|
sizeInfo.fSizes[1] != defaultInfo.fSizes[1] ||
|
sizeInfo.fSizes[2] != defaultInfo.fSizes[2] ||
|
sizeInfo.fWidthBytes[0] < defaultInfo.fWidthBytes[0] ||
|
sizeInfo.fWidthBytes[1] < defaultInfo.fWidthBytes[1] ||
|
sizeInfo.fWidthBytes[2] < defaultInfo.fWidthBytes[2]) {
|
return fDecoderMgr->returnFailure("onGetYUV8Planes", kInvalidInput);
|
}
|
|
// Set the jump location for libjpeg errors
|
skjpeg_error_mgr::AutoPushJmpBuf jmp(fDecoderMgr->errorMgr());
|
if (setjmp(jmp)) {
|
return fDecoderMgr->returnFailure("setjmp", kInvalidInput);
|
}
|
|
// Get a pointer to the decompress info since we will use it quite frequently
|
jpeg_decompress_struct* dinfo = fDecoderMgr->dinfo();
|
|
dinfo->raw_data_out = TRUE;
|
if (!jpeg_start_decompress(dinfo)) {
|
return fDecoderMgr->returnFailure("startDecompress", kInvalidInput);
|
}
|
|
// A previous implementation claims that the return value of is_yuv_supported()
|
// may change after calling jpeg_start_decompress(). It looks to me like this
|
// was caused by a bug in the old code, but we'll be safe and check here.
|
SkASSERT(is_yuv_supported(dinfo));
|
|
// Currently, we require that the Y plane dimensions match the image dimensions
|
// and that the U and V planes are the same dimensions.
|
SkASSERT(sizeInfo.fSizes[1] == sizeInfo.fSizes[2]);
|
SkASSERT((uint32_t) sizeInfo.fSizes[0].width() == dinfo->output_width &&
|
(uint32_t) sizeInfo.fSizes[0].height() == dinfo->output_height);
|
|
// Build a JSAMPIMAGE to handle output from libjpeg-turbo. A JSAMPIMAGE has
|
// a 2-D array of pixels for each of the components (Y, U, V) in the image.
|
// Cheat Sheet:
|
// JSAMPIMAGE == JSAMPLEARRAY* == JSAMPROW** == JSAMPLE***
|
JSAMPARRAY yuv[3];
|
|
// Set aside enough space for pointers to rows of Y, U, and V.
|
JSAMPROW rowptrs[2 * DCTSIZE + DCTSIZE + DCTSIZE];
|
yuv[0] = &rowptrs[0]; // Y rows (DCTSIZE or 2 * DCTSIZE)
|
yuv[1] = &rowptrs[2 * DCTSIZE]; // U rows (DCTSIZE)
|
yuv[2] = &rowptrs[3 * DCTSIZE]; // V rows (DCTSIZE)
|
|
// Initialize rowptrs.
|
int numYRowsPerBlock = DCTSIZE * dinfo->comp_info[0].v_samp_factor;
|
for (int i = 0; i < numYRowsPerBlock; i++) {
|
rowptrs[i] = SkTAddOffset<JSAMPLE>(planes[0], i * sizeInfo.fWidthBytes[0]);
|
}
|
for (int i = 0; i < DCTSIZE; i++) {
|
rowptrs[i + 2 * DCTSIZE] =
|
SkTAddOffset<JSAMPLE>(planes[1], i * sizeInfo.fWidthBytes[1]);
|
rowptrs[i + 3 * DCTSIZE] =
|
SkTAddOffset<JSAMPLE>(planes[2], i * sizeInfo.fWidthBytes[2]);
|
}
|
|
// After each loop iteration, we will increment pointers to Y, U, and V.
|
size_t blockIncrementY = numYRowsPerBlock * sizeInfo.fWidthBytes[0];
|
size_t blockIncrementU = DCTSIZE * sizeInfo.fWidthBytes[1];
|
size_t blockIncrementV = DCTSIZE * sizeInfo.fWidthBytes[2];
|
|
uint32_t numRowsPerBlock = numYRowsPerBlock;
|
|
// We intentionally round down here, as this first loop will only handle
|
// full block rows. As a special case at the end, we will handle any
|
// remaining rows that do not make up a full block.
|
const int numIters = dinfo->output_height / numRowsPerBlock;
|
for (int i = 0; i < numIters; i++) {
|
JDIMENSION linesRead = jpeg_read_raw_data(dinfo, yuv, numRowsPerBlock);
|
if (linesRead < numRowsPerBlock) {
|
// FIXME: Handle incomplete YUV decodes without signalling an error.
|
return kInvalidInput;
|
}
|
|
// Update rowptrs.
|
for (int i = 0; i < numYRowsPerBlock; i++) {
|
rowptrs[i] += blockIncrementY;
|
}
|
for (int i = 0; i < DCTSIZE; i++) {
|
rowptrs[i + 2 * DCTSIZE] += blockIncrementU;
|
rowptrs[i + 3 * DCTSIZE] += blockIncrementV;
|
}
|
}
|
|
uint32_t remainingRows = dinfo->output_height - dinfo->output_scanline;
|
SkASSERT(remainingRows == dinfo->output_height % numRowsPerBlock);
|
SkASSERT(dinfo->output_scanline == numIters * numRowsPerBlock);
|
if (remainingRows > 0) {
|
// libjpeg-turbo needs memory to be padded by the block sizes. We will fulfill
|
// this requirement using a dummy row buffer.
|
// FIXME: Should SkCodec have an extra memory buffer that can be shared among
|
// all of the implementations that use temporary/garbage memory?
|
SkAutoTMalloc<JSAMPLE> dummyRow(sizeInfo.fWidthBytes[0]);
|
for (int i = remainingRows; i < numYRowsPerBlock; i++) {
|
rowptrs[i] = dummyRow.get();
|
}
|
int remainingUVRows = dinfo->comp_info[1].downsampled_height - DCTSIZE * numIters;
|
for (int i = remainingUVRows; i < DCTSIZE; i++) {
|
rowptrs[i + 2 * DCTSIZE] = dummyRow.get();
|
rowptrs[i + 3 * DCTSIZE] = dummyRow.get();
|
}
|
|
JDIMENSION linesRead = jpeg_read_raw_data(dinfo, yuv, numRowsPerBlock);
|
if (linesRead < remainingRows) {
|
// FIXME: Handle incomplete YUV decodes without signalling an error.
|
return kInvalidInput;
|
}
|
}
|
|
return kSuccess;
|
}
|
|
// This function is declared in SkJpegInfo.h, used by SkPDF.
|
bool SkGetJpegInfo(const void* data, size_t len,
|
SkISize* size,
|
SkEncodedInfo::Color* colorType,
|
SkEncodedOrigin* orientation) {
|
if (!SkJpegCodec::IsJpeg(data, len)) {
|
return false;
|
}
|
|
SkMemoryStream stream(data, len);
|
JpegDecoderMgr decoderMgr(&stream);
|
// libjpeg errors will be caught and reported here
|
skjpeg_error_mgr::AutoPushJmpBuf jmp(decoderMgr.errorMgr());
|
if (setjmp(jmp)) {
|
return false;
|
}
|
decoderMgr.init();
|
jpeg_decompress_struct* dinfo = decoderMgr.dinfo();
|
jpeg_save_markers(dinfo, kExifMarker, 0xFFFF);
|
jpeg_save_markers(dinfo, kICCMarker, 0xFFFF);
|
if (JPEG_HEADER_OK != jpeg_read_header(dinfo, true)) {
|
return false;
|
}
|
SkEncodedInfo::Color encodedColorType;
|
if (!decoderMgr.getEncodedColor(&encodedColorType)) {
|
return false; // Unable to interpret the color channels as colors.
|
}
|
if (colorType) {
|
*colorType = encodedColorType;
|
}
|
if (orientation) {
|
*orientation = get_exif_orientation(dinfo);
|
}
|
if (size) {
|
*size = {SkToS32(dinfo->image_width), SkToS32(dinfo->image_height)};
|
}
|
return true;
|
}
|
