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Diffstat (limited to 'src/images/SkImageDecoder_libjpeg.cpp')
| -rw-r--r-- | src/images/SkImageDecoder_libjpeg.cpp | 811 |
1 files changed, 811 insertions, 0 deletions
diff --git a/src/images/SkImageDecoder_libjpeg.cpp b/src/images/SkImageDecoder_libjpeg.cpp new file mode 100644 index 0000000000..492de2374f --- /dev/null +++ b/src/images/SkImageDecoder_libjpeg.cpp @@ -0,0 +1,811 @@ +/* + * Copyright 2007, The Android Open Source Project + * + * Licensed under the Apache License, Version 2.0 (the "License"); + * you may not use this file except in compliance with the License. + * You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, software + * distributed under the License is distributed on an "AS IS" BASIS, + * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. + * See the License for the specific language governing permissions and + * limitations under the License. + */ + +#include "SkImageDecoder.h" +#include "SkColorPriv.h" +#include "SkDither.h" +#include "SkScaledBitmapSampler.h" +#include "SkStream.h" +#include "SkTemplates.h" +#include "SkUtils.h" + +#include <stdio.h> +extern "C" { + #include "jpeglib.h" + #include "jerror.h" +} + +// this enables timing code to report milliseconds for an encode +//#define TIME_ENCODE +//#define TIME_DECODE + +// this enables our rgb->yuv code, which is faster than libjpeg on ARM +// disable for the moment, as we have some glitches when width != multiple of 4 +#define WE_CONVERT_TO_YUV + +////////////////////////////////////////////////////////////////////////// +////////////////////////////////////////////////////////////////////////// + +class SkJPEGImageDecoder : public SkImageDecoder { +public: + virtual Format getFormat() const { + return kJPEG_Format; + } + +protected: + virtual bool onDecode(SkStream* stream, SkBitmap* bm, + SkBitmap::Config pref, Mode); +}; + +SkImageDecoder* SkImageDecoder_JPEG_Factory(SkStream* stream) { + static const char gHeader[] = { 0xFF, 0xD8, 0xFF }; + static const size_t HEADER_SIZE = sizeof(gHeader); + + char buffer[HEADER_SIZE]; + size_t len = stream->read(buffer, HEADER_SIZE); + + if (len != HEADER_SIZE) { + return NULL; // can't read enough + } + + if (memcmp(buffer, gHeader, HEADER_SIZE)) { + return NULL; + } + + return SkNEW(SkJPEGImageDecoder); +} + +////////////////////////////////////////////////////////////////////////// + +#include "SkTime.h" + +class AutoTimeMillis { +public: + AutoTimeMillis(const char label[]) : fLabel(label) { + if (!fLabel) { + fLabel = ""; + } + fNow = SkTime::GetMSecs(); + } + ~AutoTimeMillis() { + SkDebugf("---- Time (ms): %s %d\n", fLabel, SkTime::GetMSecs() - fNow); + } +private: + const char* fLabel; + SkMSec fNow; +}; + +/* our source struct for directing jpeg to our stream object +*/ +struct sk_source_mgr : jpeg_source_mgr { + sk_source_mgr(SkStream* stream, SkImageDecoder* decoder); + + SkStream* fStream; + const void* fMemoryBase; + size_t fMemoryBaseSize; + SkImageDecoder* fDecoder; + enum { + kBufferSize = 1024 + }; + char fBuffer[kBufferSize]; +}; + +/* Automatically clean up after throwing an exception */ +class JPEGAutoClean { +public: + JPEGAutoClean(): cinfo_ptr(NULL) {} + ~JPEGAutoClean() { + if (cinfo_ptr) { + jpeg_destroy_decompress(cinfo_ptr); + } + } + void set(jpeg_decompress_struct* info) { + cinfo_ptr = info; + } +private: + jpeg_decompress_struct* cinfo_ptr; +}; + +static void sk_init_source(j_decompress_ptr cinfo) { + sk_source_mgr* src = (sk_source_mgr*)cinfo->src; + src->next_input_byte = (const JOCTET*)src->fBuffer; + src->bytes_in_buffer = 0; +} + +static boolean sk_fill_input_buffer(j_decompress_ptr cinfo) { + sk_source_mgr* src = (sk_source_mgr*)cinfo->src; + if (src->fDecoder != NULL && src->fDecoder->shouldCancelDecode()) { + return FALSE; + } + size_t bytes = src->fStream->read(src->fBuffer, sk_source_mgr::kBufferSize); + // note that JPEG is happy with less than the full read, + // as long as the result is non-zero + if (bytes == 0) { + return FALSE; + } + + src->next_input_byte = (const JOCTET*)src->fBuffer; + src->bytes_in_buffer = bytes; + return TRUE; +} + +static void sk_skip_input_data(j_decompress_ptr cinfo, long num_bytes) { + SkASSERT(num_bytes > 0); + + sk_source_mgr* src = (sk_source_mgr*)cinfo->src; + + long bytesToSkip = num_bytes - src->bytes_in_buffer; + + // check if the skip amount exceeds the current buffer + if (bytesToSkip > 0) { + size_t bytes = src->fStream->skip(bytesToSkip); + if (bytes != (size_t)bytesToSkip) { +// SkDebugf("xxxxxxxxxxxxxx failure to skip request %d actual %d\n", bytesToSkip, bytes); + cinfo->err->error_exit((j_common_ptr)cinfo); + } + src->next_input_byte = (const JOCTET*)src->fBuffer; + src->bytes_in_buffer = 0; + } else { + src->next_input_byte += num_bytes; + src->bytes_in_buffer -= num_bytes; + } +} + +static boolean sk_resync_to_restart(j_decompress_ptr cinfo, int desired) { + sk_source_mgr* src = (sk_source_mgr*)cinfo->src; + + // what is the desired param for??? + + if (!src->fStream->rewind()) { + SkDebugf("xxxxxxxxxxxxxx failure to rewind\n"); + cinfo->err->error_exit((j_common_ptr)cinfo); + return FALSE; + } + src->next_input_byte = (const JOCTET*)src->fBuffer; + src->bytes_in_buffer = 0; + return TRUE; +} + +static void sk_term_source(j_decompress_ptr /*cinfo*/) {} + +/////////////////////////////////////////////////////////////////////////////// + +static void skmem_init_source(j_decompress_ptr cinfo) { + sk_source_mgr* src = (sk_source_mgr*)cinfo->src; + src->next_input_byte = (const JOCTET*)src->fMemoryBase; + src->bytes_in_buffer = src->fMemoryBaseSize; +} + +static boolean skmem_fill_input_buffer(j_decompress_ptr cinfo) { + SkDebugf("xxxxxxxxxxxxxx skmem_fill_input_buffer called\n"); + return FALSE; +} + +static void skmem_skip_input_data(j_decompress_ptr cinfo, long num_bytes) { + sk_source_mgr* src = (sk_source_mgr*)cinfo->src; +// SkDebugf("xxxxxxxxxxxxxx skmem_skip_input_data called %d\n", num_bytes); + src->next_input_byte = (const JOCTET*)((const char*)src->next_input_byte + num_bytes); + src->bytes_in_buffer -= num_bytes; +} + +static boolean skmem_resync_to_restart(j_decompress_ptr cinfo, int desired) { + SkDebugf("xxxxxxxxxxxxxx skmem_resync_to_restart called\n"); + return TRUE; +} + +static void skmem_term_source(j_decompress_ptr /*cinfo*/) {} + +/////////////////////////////////////////////////////////////////////////////// + +sk_source_mgr::sk_source_mgr(SkStream* stream, SkImageDecoder* decoder) : fStream(stream) { + fDecoder = decoder; + const void* baseAddr = stream->getMemoryBase(); + if (baseAddr && false) { + fMemoryBase = baseAddr; + fMemoryBaseSize = stream->getLength(); + + init_source = skmem_init_source; + fill_input_buffer = skmem_fill_input_buffer; + skip_input_data = skmem_skip_input_data; + resync_to_restart = skmem_resync_to_restart; + term_source = skmem_term_source; + } else { + fMemoryBase = NULL; + fMemoryBaseSize = 0; + + init_source = sk_init_source; + fill_input_buffer = sk_fill_input_buffer; + skip_input_data = sk_skip_input_data; + resync_to_restart = sk_resync_to_restart; + term_source = sk_term_source; + } +// SkDebugf("**************** use memorybase %p %d\n", fMemoryBase, fMemoryBaseSize); +} + +#include <setjmp.h> + +struct sk_error_mgr : jpeg_error_mgr { + jmp_buf fJmpBuf; +}; + +static void sk_error_exit(j_common_ptr cinfo) { + sk_error_mgr* error = (sk_error_mgr*)cinfo->err; + + (*error->output_message) (cinfo); + + /* Let the memory manager delete any temp files before we die */ + jpeg_destroy(cinfo); + + longjmp(error->fJmpBuf, -1); +} + +/////////////////////////////////////////////////////////////////////////////// + +static bool skip_src_rows(jpeg_decompress_struct* cinfo, void* buffer, + int count) { + for (int i = 0; i < count; i++) { + JSAMPLE* rowptr = (JSAMPLE*)buffer; + int row_count = jpeg_read_scanlines(cinfo, &rowptr, 1); + if (row_count != 1) { + return false; + } + } + return true; +} + +// This guy exists just to aid in debugging, as it allows debuggers to just +// set a break-point in one place to see all error exists. +static bool return_false(const jpeg_decompress_struct& cinfo, + const SkBitmap& bm, const char msg[]) { +#if 0 + SkDebugf("libjpeg error %d <%s> from %s [%d %d]", cinfo.err->msg_code, + cinfo.err->jpeg_message_table[cinfo.err->msg_code], msg, + bm.width(), bm.height()); +#endif + return false; // must always return false +} + +bool SkJPEGImageDecoder::onDecode(SkStream* stream, SkBitmap* bm, + SkBitmap::Config prefConfig, Mode mode) { +#ifdef TIME_DECODE + AutoTimeMillis atm("JPEG Decode"); +#endif + + SkAutoMalloc srcStorage; + JPEGAutoClean autoClean; + + jpeg_decompress_struct cinfo; + sk_error_mgr sk_err; + sk_source_mgr sk_stream(stream, this); + + cinfo.err = jpeg_std_error(&sk_err); + sk_err.error_exit = sk_error_exit; + + // All objects need to be instantiated before this setjmp call so that + // they will be cleaned up properly if an error occurs. + if (setjmp(sk_err.fJmpBuf)) { + return return_false(cinfo, *bm, "setjmp"); + } + + jpeg_create_decompress(&cinfo); + autoClean.set(&cinfo); + + //jpeg_stdio_src(&cinfo, file); + cinfo.src = &sk_stream; + + int status = jpeg_read_header(&cinfo, true); + if (status != JPEG_HEADER_OK) { + return return_false(cinfo, *bm, "read_header"); + } + + /* Try to fulfill the requested sampleSize. Since jpeg can do it (when it + can) much faster that we, just use their num/denom api to approximate + the size. + */ + int sampleSize = this->getSampleSize(); + + cinfo.dct_method = JDCT_IFAST; + cinfo.scale_num = 1; + cinfo.scale_denom = sampleSize; + + /* this gives about 30% performance improvement. In theory it may + reduce the visual quality, in practice I'm not seeing a difference + */ + cinfo.do_fancy_upsampling = 0; + + /* this gives another few percents */ + cinfo.do_block_smoothing = 0; + + /* default format is RGB */ + cinfo.out_color_space = JCS_RGB; + + SkBitmap::Config config = prefConfig; + // if no user preference, see what the device recommends + if (config == SkBitmap::kNo_Config) + config = SkImageDecoder::GetDeviceConfig(); + + // only these make sense for jpegs + if (config != SkBitmap::kARGB_8888_Config && + config != SkBitmap::kARGB_4444_Config && + config != SkBitmap::kRGB_565_Config) { + config = SkBitmap::kARGB_8888_Config; + } + +#ifdef ANDROID_RGB + cinfo.dither_mode = JDITHER_NONE; + if (config == SkBitmap::kARGB_8888_Config) { + cinfo.out_color_space = JCS_RGBA_8888; + } else if (config == SkBitmap::kRGB_565_Config) { + if (sampleSize == 1) { + // SkScaledBitmapSampler can't handle RGB_565 yet, + // so don't even try. + cinfo.out_color_space = JCS_RGB_565; + if (this->getDitherImage()) { + cinfo.dither_mode = JDITHER_ORDERED; + } + } + } +#endif + + /* image_width and image_height are the original dimensions, available + after jpeg_read_header(). To see the scaled dimensions, we have to call + jpeg_start_decompress(), and then read output_width and output_height. + */ + if (!jpeg_start_decompress(&cinfo)) { + return return_false(cinfo, *bm, "start_decompress"); + } + + /* If we need to better match the request, we might examine the image and + output dimensions, and determine if the downsampling jpeg provided is + not sufficient. If so, we can recompute a modified sampleSize value to + make up the difference. + + To skip this additional scaling, just set sampleSize = 1; below. + */ + sampleSize = sampleSize * cinfo.output_width / cinfo.image_width; + + + // should we allow the Chooser (if present) to pick a config for us??? + if (!this->chooseFromOneChoice(config, cinfo.output_width, + cinfo.output_height)) { + return return_false(cinfo, *bm, "chooseFromOneChoice"); + } + +#ifdef ANDROID_RGB + /* short-circuit the SkScaledBitmapSampler when possible, as this gives + a significant performance boost. + */ + if (sampleSize == 1 && + ((config == SkBitmap::kARGB_8888_Config && + cinfo.out_color_space == JCS_RGBA_8888) || + (config == SkBitmap::kRGB_565_Config && + cinfo.out_color_space == JCS_RGB_565))) + { + bm->setConfig(config, cinfo.output_width, cinfo.output_height); + bm->setIsOpaque(true); + if (SkImageDecoder::kDecodeBounds_Mode == mode) { + return true; + } + if (!this->allocPixelRef(bm, NULL)) { + return return_false(cinfo, *bm, "allocPixelRef"); + } + SkAutoLockPixels alp(*bm); + JSAMPLE* rowptr = (JSAMPLE*)bm->getPixels(); + INT32 const bpr = bm->rowBytes(); + + while (cinfo.output_scanline < cinfo.output_height) { + int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1); + // if row_count == 0, then we didn't get a scanline, so abort. + // if we supported partial images, we might return true in this case + if (0 == row_count) { + return return_false(cinfo, *bm, "read_scanlines"); + } + if (this->shouldCancelDecode()) { + return return_false(cinfo, *bm, "shouldCancelDecode"); + } + rowptr += bpr; + } + jpeg_finish_decompress(&cinfo); + return true; + } +#endif + + // check for supported formats + SkScaledBitmapSampler::SrcConfig sc; + if (3 == cinfo.out_color_components && JCS_RGB == cinfo.out_color_space) { + sc = SkScaledBitmapSampler::kRGB; +#ifdef ANDROID_RGB + } else if (JCS_RGBA_8888 == cinfo.out_color_space) { + sc = SkScaledBitmapSampler::kRGBX; + //} else if (JCS_RGB_565 == cinfo.out_color_space) { + // sc = SkScaledBitmapSampler::kRGB_565; +#endif + } else if (1 == cinfo.out_color_components && + JCS_GRAYSCALE == cinfo.out_color_space) { + sc = SkScaledBitmapSampler::kGray; + } else { + return return_false(cinfo, *bm, "jpeg colorspace"); + } + + SkScaledBitmapSampler sampler(cinfo.output_width, cinfo.output_height, + sampleSize); + + bm->setConfig(config, sampler.scaledWidth(), sampler.scaledHeight()); + // jpegs are always opauqe (i.e. have no per-pixel alpha) + bm->setIsOpaque(true); + + if (SkImageDecoder::kDecodeBounds_Mode == mode) { + return true; + } + if (!this->allocPixelRef(bm, NULL)) { + return return_false(cinfo, *bm, "allocPixelRef"); + } + + SkAutoLockPixels alp(*bm); + if (!sampler.begin(bm, sc, this->getDitherImage())) { + return return_false(cinfo, *bm, "sampler.begin"); + } + + uint8_t* srcRow = (uint8_t*)srcStorage.alloc(cinfo.output_width * 4); + + // Possibly skip initial rows [sampler.srcY0] + if (!skip_src_rows(&cinfo, srcRow, sampler.srcY0())) { + return return_false(cinfo, *bm, "skip rows"); + } + + // now loop through scanlines until y == bm->height() - 1 + for (int y = 0;; y++) { + JSAMPLE* rowptr = (JSAMPLE*)srcRow; + int row_count = jpeg_read_scanlines(&cinfo, &rowptr, 1); + if (0 == row_count) { + return return_false(cinfo, *bm, "read_scanlines"); + } + if (this->shouldCancelDecode()) { + return return_false(cinfo, *bm, "shouldCancelDecode"); + } + + sampler.next(srcRow); + if (bm->height() - 1 == y) { + // we're done + break; + } + + if (!skip_src_rows(&cinfo, srcRow, sampler.srcDY() - 1)) { + return return_false(cinfo, *bm, "skip rows"); + } + } + + // we formally skip the rest, so we don't get a complaint from libjpeg + if (!skip_src_rows(&cinfo, srcRow, + cinfo.output_height - cinfo.output_scanline)) { + return return_false(cinfo, *bm, "skip rows"); + } + jpeg_finish_decompress(&cinfo); + +// SkDebugf("------------------- bm2 size %d [%d %d] %d\n", bm->getSize(), bm->width(), bm->height(), bm->config()); + return true; +} + +/////////////////////////////////////////////////////////////////////////////// + +#ifdef SK_SUPPORT_IMAGE_ENCODE + +#include "SkColorPriv.h" + +// taken from jcolor.c in libjpeg +#if 0 // 16bit - precise but slow + #define CYR 19595 // 0.299 + #define CYG 38470 // 0.587 + #define CYB 7471 // 0.114 + + #define CUR -11059 // -0.16874 + #define CUG -21709 // -0.33126 + #define CUB 32768 // 0.5 + + #define CVR 32768 // 0.5 + #define CVG -27439 // -0.41869 + #define CVB -5329 // -0.08131 + + #define CSHIFT 16 +#else // 8bit - fast, slightly less precise + #define CYR 77 // 0.299 + #define CYG 150 // 0.587 + #define CYB 29 // 0.114 + + #define CUR -43 // -0.16874 + #define CUG -85 // -0.33126 + #define CUB 128 // 0.5 + + #define CVR 128 // 0.5 + #define CVG -107 // -0.41869 + #define CVB -21 // -0.08131 + + #define CSHIFT 8 +#endif + +static void rgb2yuv_32(uint8_t dst[], SkPMColor c) { + int r = SkGetPackedR32(c); + int g = SkGetPackedG32(c); + int b = SkGetPackedB32(c); + + int y = ( CYR*r + CYG*g + CYB*b ) >> CSHIFT; + int u = ( CUR*r + CUG*g + CUB*b ) >> CSHIFT; + int v = ( CVR*r + CVG*g + CVB*b ) >> CSHIFT; + + dst[0] = SkToU8(y); + dst[1] = SkToU8(u + 128); + dst[2] = SkToU8(v + 128); +} + +static void rgb2yuv_4444(uint8_t dst[], U16CPU c) { + int r = SkGetPackedR4444(c); + int g = SkGetPackedG4444(c); + int b = SkGetPackedB4444(c); + + int y = ( CYR*r + CYG*g + CYB*b ) >> (CSHIFT - 4); + int u = ( CUR*r + CUG*g + CUB*b ) >> (CSHIFT - 4); + int v = ( CVR*r + CVG*g + CVB*b ) >> (CSHIFT - 4); + + dst[0] = SkToU8(y); + dst[1] = SkToU8(u + 128); + dst[2] = SkToU8(v + 128); +} + +static void rgb2yuv_16(uint8_t dst[], U16CPU c) { + int r = SkGetPackedR16(c); + int g = SkGetPackedG16(c); + int b = SkGetPackedB16(c); + + int y = ( 2*CYR*r + CYG*g + 2*CYB*b ) >> (CSHIFT - 2); + int u = ( 2*CUR*r + CUG*g + 2*CUB*b ) >> (CSHIFT - 2); + int v = ( 2*CVR*r + CVG*g + 2*CVB*b ) >> (CSHIFT - 2); + + dst[0] = SkToU8(y); + dst[1] = SkToU8(u + 128); + dst[2] = SkToU8(v + 128); +} + +/////////////////////////////////////////////////////////////////////////////// + +typedef void (*WriteScanline)(uint8_t* SK_RESTRICT dst, + const void* SK_RESTRICT src, int width, + const SkPMColor* SK_RESTRICT ctable); + +static void Write_32_YUV(uint8_t* SK_RESTRICT dst, + const void* SK_RESTRICT srcRow, int width, + const SkPMColor*) { + const uint32_t* SK_RESTRICT src = (const uint32_t*)srcRow; + while (--width >= 0) { +#ifdef WE_CONVERT_TO_YUV + rgb2yuv_32(dst, *src++); +#else + uint32_t c = *src++; + dst[0] = SkGetPackedR32(c); + dst[1] = SkGetPackedG32(c); + dst[2] = SkGetPackedB32(c); +#endif + dst += 3; + } +} + +static void Write_4444_YUV(uint8_t* SK_RESTRICT dst, + const void* SK_RESTRICT srcRow, int width, + const SkPMColor*) { + const SkPMColor16* SK_RESTRICT src = (const SkPMColor16*)srcRow; + while (--width >= 0) { +#ifdef WE_CONVERT_TO_YUV + rgb2yuv_4444(dst, *src++); +#else + SkPMColor16 c = *src++; + dst[0] = SkPacked4444ToR32(c); + dst[1] = SkPacked4444ToG32(c); + dst[2] = SkPacked4444ToB32(c); +#endif + dst += 3; + } +} + +static void Write_16_YUV(uint8_t* SK_RESTRICT dst, + const void* SK_RESTRICT srcRow, int width, + const SkPMColor*) { + const uint16_t* SK_RESTRICT src = (const uint16_t*)srcRow; + while (--width >= 0) { +#ifdef WE_CONVERT_TO_YUV + rgb2yuv_16(dst, *src++); +#else + uint16_t c = *src++; + dst[0] = SkPacked16ToR32(c); + dst[1] = SkPacked16ToG32(c); + dst[2] = SkPacked16ToB32(c); +#endif + dst += 3; + } +} + +static void Write_Index_YUV(uint8_t* SK_RESTRICT dst, + const void* SK_RESTRICT srcRow, int width, + const SkPMColor* SK_RESTRICT ctable) { + const uint8_t* SK_RESTRICT src = (const uint8_t*)srcRow; + while (--width >= 0) { +#ifdef WE_CONVERT_TO_YUV + rgb2yuv_32(dst, ctable[*src++]); +#else + uint32_t c = ctable[*src++]; + dst[0] = SkGetPackedR32(c); + dst[1] = SkGetPackedG32(c); + dst[2] = SkGetPackedB32(c); +#endif + dst += 3; + } +} + +static WriteScanline ChooseWriter(const SkBitmap& bm) { + switch (bm.config()) { + case SkBitmap::kARGB_8888_Config: + return Write_32_YUV; + case SkBitmap::kRGB_565_Config: + return Write_16_YUV; + case SkBitmap::kARGB_4444_Config: + return Write_4444_YUV; + case SkBitmap::kIndex8_Config: + return Write_Index_YUV; + default: + return NULL; + } +} + +struct sk_destination_mgr : jpeg_destination_mgr { + sk_destination_mgr(SkWStream* stream); + + SkWStream* fStream; + + enum { + kBufferSize = 1024 + }; + uint8_t fBuffer[kBufferSize]; +}; + +static void sk_init_destination(j_compress_ptr cinfo) { + sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest; + + dest->next_output_byte = dest->fBuffer; + dest->free_in_buffer = sk_destination_mgr::kBufferSize; +} + +static boolean sk_empty_output_buffer(j_compress_ptr cinfo) { + sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest; + +// if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize - dest->free_in_buffer)) + if (!dest->fStream->write(dest->fBuffer, sk_destination_mgr::kBufferSize)) { + ERREXIT(cinfo, JERR_FILE_WRITE); + return false; + } + + dest->next_output_byte = dest->fBuffer; + dest->free_in_buffer = sk_destination_mgr::kBufferSize; + return TRUE; +} + +static void sk_term_destination (j_compress_ptr cinfo) { + sk_destination_mgr* dest = (sk_destination_mgr*)cinfo->dest; + + size_t size = sk_destination_mgr::kBufferSize - dest->free_in_buffer; + if (size > 0) { + if (!dest->fStream->write(dest->fBuffer, size)) { + ERREXIT(cinfo, JERR_FILE_WRITE); + return; + } + } + dest->fStream->flush(); +} + +sk_destination_mgr::sk_destination_mgr(SkWStream* stream) + : fStream(stream) { + this->init_destination = sk_init_destination; + this->empty_output_buffer = sk_empty_output_buffer; + this->term_destination = sk_term_destination; +} + +class SkJPEGImageEncoder : public SkImageEncoder { +protected: + virtual bool onEncode(SkWStream* stream, const SkBitmap& bm, int quality) { +#ifdef TIME_ENCODE + AutoTimeMillis atm("JPEG Encode"); +#endif + + const WriteScanline writer = ChooseWriter(bm); + if (NULL == writer) { + return false; + } + + SkAutoLockPixels alp(bm); + if (NULL == bm.getPixels()) { + return false; + } + + jpeg_compress_struct cinfo; + sk_error_mgr sk_err; + sk_destination_mgr sk_wstream(stream); + + // allocate these before set call setjmp + SkAutoMalloc oneRow; + SkAutoLockColors ctLocker; + + cinfo.err = jpeg_std_error(&sk_err); + sk_err.error_exit = sk_error_exit; + if (setjmp(sk_err.fJmpBuf)) { + return false; + } + jpeg_create_compress(&cinfo); + + cinfo.dest = &sk_wstream; + cinfo.image_width = bm.width(); + cinfo.image_height = bm.height(); + cinfo.input_components = 3; +#ifdef WE_CONVERT_TO_YUV + cinfo.in_color_space = JCS_YCbCr; +#else + cinfo.in_color_space = JCS_RGB; +#endif + cinfo.input_gamma = 1; + + jpeg_set_defaults(&cinfo); + jpeg_set_quality(&cinfo, quality, TRUE /* limit to baseline-JPEG values */); + cinfo.dct_method = JDCT_IFAST; + + jpeg_start_compress(&cinfo, TRUE); + + const int width = bm.width(); + uint8_t* oneRowP = (uint8_t*)oneRow.alloc(width * 3); + + const SkPMColor* colors = ctLocker.lockColors(bm); + const void* srcRow = bm.getPixels(); + + while (cinfo.next_scanline < cinfo.image_height) { + JSAMPROW row_pointer[1]; /* pointer to JSAMPLE row[s] */ + + writer(oneRowP, srcRow, width, colors); + row_pointer[0] = oneRowP; + (void) jpeg_write_scanlines(&cinfo, row_pointer, 1); + srcRow = (const void*)((const char*)srcRow + bm.rowBytes()); + } + + jpeg_finish_compress(&cinfo); + jpeg_destroy_compress(&cinfo); + + return true; + } +}; + +SkImageEncoder* SkImageEncoder_JPEG_Factory(); +SkImageEncoder* SkImageEncoder_JPEG_Factory() { + return SkNEW(SkJPEGImageEncoder); +} + +#endif /* SK_SUPPORT_IMAGE_ENCODE */ + +////////////////////////////////////////////////////////////////////////// +////////////////////////////////////////////////////////////////////////// + +#ifdef SK_DEBUG + +void SkImageDecoder::UnitTest() { + SkBitmap bm; + + (void)SkImageDecoder::DecodeFile("logo.jpg", &bm); +} + +#endif |