--- /dev/null
+
+/*
+ * Copyright 2007 The Android Open Source Project
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+
+#include "SkImageDecoder.h"
+#include "SkImageEncoder.h"
+#include "SkJpegUtility.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"
+}
+
+#ifdef SK_BUILD_FOR_ANDROID
+#include <cutils/properties.h>
+
+// Key to lookup the size of memory buffer set in system property
+static const char KEY_MEM_CAP[] = "ro.media.dec.jpeg.memcap";
+#endif
+
+// 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, Mode);
+};
+
+//////////////////////////////////////////////////////////////////////////
+
+#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;
+};
+
+/* 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;
+};
+
+#ifdef SK_BUILD_FOR_ANDROID
+/* Check if the memory cap property is set.
+ If so, use the memory size for jpeg decode.
+*/
+static void overwrite_mem_buffer_size(j_decompress_ptr cinfo) {
+#ifdef ANDROID_LARGE_MEMORY_DEVICE
+ cinfo->mem->max_memory_to_use = 30 * 1024 * 1024;
+#else
+ cinfo->mem->max_memory_to_use = 5 * 1024 * 1024;
+#endif
+}
+#endif
+
+
+///////////////////////////////////////////////////////////////////////////////
+
+/* 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.
+ */
+static int recompute_sampleSize(int sampleSize,
+ const jpeg_decompress_struct& cinfo) {
+ return sampleSize * cinfo.output_width / cinfo.image_width;
+}
+
+static bool valid_output_dimensions(const jpeg_decompress_struct& cinfo) {
+ /* These are initialized to 0, so if they have non-zero values, we assume
+ they are "valid" (i.e. have been computed by libjpeg)
+ */
+ return cinfo.output_width != 0 && cinfo.output_height != 0;
+}
+
+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, Mode mode) {
+#ifdef TIME_DECODE
+ AutoTimeMillis atm("JPEG Decode");
+#endif
+
+ SkAutoMalloc srcStorage;
+ JPEGAutoClean autoClean;
+
+ jpeg_decompress_struct cinfo;
+ skjpeg_error_mgr sk_err;
+ skjpeg_source_mgr sk_stream(stream, this);
+
+ cinfo.err = jpeg_std_error(&sk_err);
+ sk_err.error_exit = skjpeg_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);
+
+#ifdef SK_BUILD_FOR_ANDROID
+ overwrite_mem_buffer_size(&cinfo);
+#endif
+
+ //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 = this->getPrefConfig(k32Bit_SrcDepth, false);
+ // 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) {
+ cinfo.out_color_space = JCS_RGB_565;
+ if (this->getDitherImage()) {
+ cinfo.dither_mode = JDITHER_ORDERED;
+ }
+ }
+#endif
+
+ if (sampleSize == 1 && mode == SkImageDecoder::kDecodeBounds_Mode) {
+ bm->setConfig(config, cinfo.image_width, cinfo.image_height);
+ bm->setIsOpaque(true);
+ return true;
+ }
+
+ /* 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)) {
+ /* If we failed here, we may still have enough information to return
+ to the caller if they just wanted (subsampled bounds). If sampleSize
+ was 1, then we would have already returned. Thus we just check if
+ we're in kDecodeBounds_Mode, and that we have valid output sizes.
+
+ One reason to fail here is that we have insufficient stream data
+ to complete the setup. However, output dimensions seem to get
+ computed very early, which is why this special check can pay off.
+ */
+ if (SkImageDecoder::kDecodeBounds_Mode == mode &&
+ valid_output_dimensions(cinfo)) {
+ SkScaledBitmapSampler smpl(cinfo.output_width, cinfo.output_height,
+ recompute_sampleSize(sampleSize, cinfo));
+ bm->setConfig(config, smpl.scaledWidth(), smpl.scaledHeight());
+ bm->setIsOpaque(true);
+ return true;
+ } else {
+ return return_false(cinfo, *bm, "start_decompress");
+ }
+ }
+ sampleSize = recompute_sampleSize(sampleSize, cinfo);
+
+ // 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;
+}
+
+///////////////////////////////////////////////////////////////////////////////
+
+#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;
+ }
+}
+
+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;
+ skjpeg_error_mgr sk_err;
+ skjpeg_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 = skjpeg_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;
+ }
+};
+
+///////////////////////////////////////////////////////////////////////////////
+
+#include "SkTRegistry.h"
+
+static SkImageDecoder* DFactory(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);
+}
+
+static SkImageEncoder* EFactory(SkImageEncoder::Type t) {
+ return (SkImageEncoder::kJPEG_Type == t) ? SkNEW(SkJPEGImageEncoder) : NULL;
+}
+
+static SkTRegistry<SkImageDecoder*, SkStream*> gDReg(DFactory);
+static SkTRegistry<SkImageEncoder*, SkImageEncoder::Type> gEReg(EFactory);