summaryrefslogtreecommitdiffstats
path: root/app/gfx/codec/jpeg_codec.cc
diff options
context:
space:
mode:
Diffstat (limited to 'app/gfx/codec/jpeg_codec.cc')
-rw-r--r--app/gfx/codec/jpeg_codec.cc531
1 files changed, 0 insertions, 531 deletions
diff --git a/app/gfx/codec/jpeg_codec.cc b/app/gfx/codec/jpeg_codec.cc
deleted file mode 100644
index 49a72ca..0000000
--- a/app/gfx/codec/jpeg_codec.cc
+++ /dev/null
@@ -1,531 +0,0 @@
-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "app/gfx/codec/jpeg_codec.h"
-
-#include <setjmp.h>
-
-#include "base/logging.h"
-#include "base/scoped_ptr.h"
-#include "third_party/skia/include/core/SkBitmap.h"
-
-extern "C" {
-#if defined(USE_SYSTEM_LIBJPEG)
-#include <jpeglib.h>
-#else
-#include "third_party/libjpeg/jpeglib.h"
-#endif
-}
-
-namespace gfx {
-
-// Encoder/decoder shared stuff ------------------------------------------------
-
-namespace {
-
-// used to pass error info through the JPEG library
-struct CoderErrorMgr {
- jpeg_error_mgr pub;
- jmp_buf setjmp_buffer;
-};
-
-void ErrorExit(jpeg_common_struct* cinfo) {
- CoderErrorMgr *err = reinterpret_cast<CoderErrorMgr*>(cinfo->err);
-
- // Return control to the setjmp point.
- longjmp(err->setjmp_buffer, false);
-}
-
-} // namespace
-
-// Encoder ---------------------------------------------------------------------
-//
-// This code is based on nsJPEGEncoder from Mozilla.
-// Copyright 2005 Google Inc. (Brett Wilson, contributor)
-
-namespace {
-
-// Initial size for the output buffer in the JpegEncoderState below.
-static const int initial_output_buffer_size = 8192;
-
-struct JpegEncoderState {
- explicit JpegEncoderState(std::vector<unsigned char>* o)
- : out(o),
- image_buffer_used(0) {
- }
-
- // Output buffer, of which 'image_buffer_used' bytes are actually used (this
- // will often be less than the actual size of the vector because we size it
- // so that libjpeg can write directly into it.
- std::vector<unsigned char>* out;
-
- // Number of bytes in the 'out' buffer that are actually used (see above).
- size_t image_buffer_used;
-};
-
-// Initializes the JpegEncoderState for encoding, and tells libjpeg about where
-// the output buffer is.
-//
-// From the JPEG library:
-// "Initialize destination. This is called by jpeg_start_compress() before
-// any data is actually written. It must initialize next_output_byte and
-// free_in_buffer. free_in_buffer must be initialized to a positive value."
-void InitDestination(jpeg_compress_struct* cinfo) {
- JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data);
- DCHECK(state->image_buffer_used == 0) << "initializing after use";
-
- state->out->resize(initial_output_buffer_size);
- state->image_buffer_used = 0;
-
- cinfo->dest->next_output_byte = &(*state->out)[0];
- cinfo->dest->free_in_buffer = initial_output_buffer_size;
-}
-
-// Resize the buffer that we give to libjpeg and update our and its state.
-//
-// From the JPEG library:
-// "Callback used by libjpeg whenever the buffer has filled (free_in_buffer
-// reaches zero). In typical applications, it should write out the *entire*
-// buffer (use the saved start address and buffer length; ignore the current
-// state of next_output_byte and free_in_buffer). Then reset the pointer &
-// count to the start of the buffer, and return TRUE indicating that the
-// buffer has been dumped. free_in_buffer must be set to a positive value
-// when TRUE is returned. A FALSE return should only be used when I/O
-// suspension is desired (this operating mode is discussed in the next
-// section)."
-boolean EmptyOutputBuffer(jpeg_compress_struct* cinfo) {
- JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data);
-
- // note the new size, the buffer is full
- state->image_buffer_used = state->out->size();
-
- // expand buffer, just double size each time
- state->out->resize(state->out->size() * 2);
-
- // tell libjpeg where to write the next data
- cinfo->dest->next_output_byte = &(*state->out)[state->image_buffer_used];
- cinfo->dest->free_in_buffer = state->out->size() - state->image_buffer_used;
- return 1;
-}
-
-// Cleans up the JpegEncoderState to prepare for returning in the final form.
-//
-// From the JPEG library:
-// "Terminate destination --- called by jpeg_finish_compress() after all data
-// has been written. In most applications, this must flush any data
-// remaining in the buffer. Use either next_output_byte or free_in_buffer to
-// determine how much data is in the buffer."
-void TermDestination(jpeg_compress_struct* cinfo) {
- JpegEncoderState* state = static_cast<JpegEncoderState*>(cinfo->client_data);
- DCHECK(state->out->size() >= state->image_buffer_used);
-
- // update the used byte based on the next byte libjpeg would write to
- state->image_buffer_used = cinfo->dest->next_output_byte - &(*state->out)[0];
- DCHECK(state->image_buffer_used < state->out->size()) <<
- "JPEG library busted, got a bad image buffer size";
-
- // update our buffer so that it exactly encompases the desired data
- state->out->resize(state->image_buffer_used);
-}
-
-// Converts RGBA to RGB (removing the alpha values) to prepare to send data to
-// libjpeg. This converts one row of data in rgba with the given width in
-// pixels the the given rgb destination buffer (which should have enough space
-// reserved for the final data).
-void StripAlpha(const unsigned char* rgba, int pixel_width, unsigned char* rgb)
-{
- for (int x = 0; x < pixel_width; x++) {
- const unsigned char* pixel_in = &rgba[x * 4];
- unsigned char* pixel_out = &rgb[x * 3];
- pixel_out[0] = pixel_in[0];
- pixel_out[1] = pixel_in[1];
- pixel_out[2] = pixel_in[2];
- }
-}
-
-// Converts BGRA to RGB by reordering the color components and dropping the
-// alpha. This converts one row of data in rgba with the given width in
-// pixels the the given rgb destination buffer (which should have enough space
-// reserved for the final data).
-void BGRAtoRGB(const unsigned char* bgra, int pixel_width, unsigned char* rgb)
-{
- for (int x = 0; x < pixel_width; x++) {
- const unsigned char* pixel_in = &bgra[x * 4];
- unsigned char* pixel_out = &rgb[x * 3];
- pixel_out[0] = pixel_in[2];
- pixel_out[1] = pixel_in[1];
- pixel_out[2] = pixel_in[0];
- }
-}
-
-// This class destroys the given jpeg_compress object when it goes out of
-// scope. It simplifies the error handling in Encode (and even applies to the
-// success case).
-class CompressDestroyer {
- public:
- CompressDestroyer() : cinfo_(NULL) {
- }
- ~CompressDestroyer() {
- DestroyManagedObject();
- }
- void SetManagedObject(jpeg_compress_struct* ci) {
- DestroyManagedObject();
- cinfo_ = ci;
- }
- void DestroyManagedObject() {
- if (cinfo_) {
- jpeg_destroy_compress(cinfo_);
- cinfo_ = NULL;
- }
- }
- private:
- jpeg_compress_struct* cinfo_;
-};
-
-} // namespace
-
-bool JPEGCodec::Encode(const unsigned char* input, ColorFormat format,
- int w, int h, int row_byte_width,
- int quality, std::vector<unsigned char>* output) {
- jpeg_compress_struct cinfo;
- CompressDestroyer destroyer;
- destroyer.SetManagedObject(&cinfo);
- output->clear();
-
- // We set up the normal JPEG error routines, then override error_exit.
- // This must be done before the call to create_compress.
- CoderErrorMgr errmgr;
- cinfo.err = jpeg_std_error(&errmgr.pub);
- errmgr.pub.error_exit = ErrorExit;
- // Establish the setjmp return context for ErrorExit to use.
- if (setjmp(errmgr.setjmp_buffer)) {
- // If we get here, the JPEG code has signaled an error.
- // MSDN notes: "if you intend your code to be portable, do not rely on
- // correct destruction of frame-based objects when executing a nonlocal
- // goto using a call to longjmp." So we delete the CompressDestroyer's
- // object manually instead.
- destroyer.DestroyManagedObject();
- return false;
- }
-
- // The destroyer will destroy() cinfo on exit.
- jpeg_create_compress(&cinfo);
-
- cinfo.image_width = w;
- cinfo.image_height = h;
- cinfo.input_components = 3;
- cinfo.in_color_space = JCS_RGB;
- cinfo.data_precision = 8;
-
- jpeg_set_defaults(&cinfo);
- jpeg_set_quality(&cinfo, quality, 1); // quality here is 0-100
-
- // set up the destination manager
- jpeg_destination_mgr destmgr;
- destmgr.init_destination = InitDestination;
- destmgr.empty_output_buffer = EmptyOutputBuffer;
- destmgr.term_destination = TermDestination;
- cinfo.dest = &destmgr;
-
- JpegEncoderState state(output);
- cinfo.client_data = &state;
-
- jpeg_start_compress(&cinfo, 1);
-
- // feed it the rows, doing necessary conversions for the color format
- if (format == FORMAT_RGB) {
- // no conversion necessary
- while (cinfo.next_scanline < cinfo.image_height) {
- const unsigned char* row = &input[cinfo.next_scanline * row_byte_width];
- jpeg_write_scanlines(&cinfo, const_cast<unsigned char**>(&row), 1);
- }
- } else {
- // get the correct format converter
- void (*converter)(const unsigned char* in, int w, unsigned char* rgb);
- if (format == FORMAT_RGBA) {
- converter = StripAlpha;
- } else if (format == FORMAT_BGRA) {
- converter = BGRAtoRGB;
- } else {
- NOTREACHED() << "Invalid pixel format";
- return false;
- }
-
- // output row after converting
- unsigned char* row = new unsigned char[w * 3];
-
- while (cinfo.next_scanline < cinfo.image_height) {
- converter(&input[cinfo.next_scanline * row_byte_width], w, row);
- jpeg_write_scanlines(&cinfo, &row, 1);
- }
- delete[] row;
- }
-
- jpeg_finish_compress(&cinfo);
- return true;
-}
-
-// Decoder --------------------------------------------------------------------
-
-namespace {
-
-struct JpegDecoderState {
- JpegDecoderState(const unsigned char* in, size_t len)
- : input_buffer(in), input_buffer_length(len) {
- }
-
- const unsigned char* input_buffer;
- size_t input_buffer_length;
-};
-
-// Callback to initialize the source.
-//
-// From the JPEG library:
-// "Initialize source. This is called by jpeg_read_header() before any data is
-// actually read. May leave bytes_in_buffer set to 0 (in which case a
-// fill_input_buffer() call will occur immediately)."
-void InitSource(j_decompress_ptr cinfo) {
- JpegDecoderState* state = static_cast<JpegDecoderState*>(cinfo->client_data);
- cinfo->src->next_input_byte = state->input_buffer;
- cinfo->src->bytes_in_buffer = state->input_buffer_length;
-}
-
-// Callback to fill the buffer. Since our buffer already contains all the data,
-// we should never need to provide more data. If libjpeg thinks it needs more
-// data, our input is probably corrupt.
-//
-// From the JPEG library:
-// "This is called whenever bytes_in_buffer has reached zero and more data is
-// wanted. In typical applications, it should read fresh data into the buffer
-// (ignoring the current state of next_input_byte and bytes_in_buffer), reset
-// the pointer & count to the start of the buffer, and return TRUE indicating
-// that the buffer has been reloaded. It is not necessary to fill the buffer
-// entirely, only to obtain at least one more byte. bytes_in_buffer MUST be
-// set to a positive value if TRUE is returned. A FALSE return should only
-// be used when I/O suspension is desired."
-boolean FillInputBuffer(j_decompress_ptr cinfo) {
- return false;
-}
-
-// Skip data in the buffer. Since we have all the data at once, this operation
-// is easy. It is not clear if this ever gets called because the JPEG library
-// should be able to do the skip itself (it has all the data).
-//
-// From the JPEG library:
-// "Skip num_bytes worth of data. The buffer pointer and count should be
-// advanced over num_bytes input bytes, refilling the buffer as needed. This
-// is used to skip over a potentially large amount of uninteresting data
-// (such as an APPn marker). In some applications it may be possible to
-// optimize away the reading of the skipped data, but it's not clear that
-// being smart is worth much trouble; large skips are uncommon.
-// bytes_in_buffer may be zero on return. A zero or negative skip count
-// should be treated as a no-op."
-void SkipInputData(j_decompress_ptr cinfo, long num_bytes) {
- if (num_bytes > static_cast<long>(cinfo->src->bytes_in_buffer)) {
- // Since all our data should be in the buffer, trying to skip beyond it
- // means that there is some kind of error or corrupt input data. A 0 for
- // bytes left means it will call FillInputBuffer which will then fail.
- cinfo->src->next_input_byte += cinfo->src->bytes_in_buffer;
- cinfo->src->bytes_in_buffer = 0;
- } else if (num_bytes > 0) {
- cinfo->src->bytes_in_buffer -= static_cast<size_t>(num_bytes);
- cinfo->src->next_input_byte += num_bytes;
- }
-}
-
-// Our source doesn't need any cleanup, so this is a NOP.
-//
-// From the JPEG library:
-// "Terminate source --- called by jpeg_finish_decompress() after all data has
-// been read to clean up JPEG source manager. NOT called by jpeg_abort() or
-// jpeg_destroy()."
-void TermSource(j_decompress_ptr cinfo) {
-}
-
-// Converts one row of rgb data to rgba data by adding a fully-opaque alpha
-// value.
-void AddAlpha(const unsigned char* rgb, int pixel_width, unsigned char* rgba) {
- for (int x = 0; x < pixel_width; x++) {
- const unsigned char* pixel_in = &rgb[x * 3];
- unsigned char* pixel_out = &rgba[x * 4];
- pixel_out[0] = pixel_in[0];
- pixel_out[1] = pixel_in[1];
- pixel_out[2] = pixel_in[2];
- pixel_out[3] = 0xff;
- }
-}
-
-// Converts one row of RGB data to BGRA by reordering the color components and
-// adding alpha values of 0xff.
-void RGBtoBGRA(const unsigned char* bgra, int pixel_width, unsigned char* rgb)
-{
- for (int x = 0; x < pixel_width; x++) {
- const unsigned char* pixel_in = &bgra[x * 3];
- unsigned char* pixel_out = &rgb[x * 4];
- pixel_out[0] = pixel_in[2];
- pixel_out[1] = pixel_in[1];
- pixel_out[2] = pixel_in[0];
- pixel_out[3] = 0xff;
- }
-}
-
-// This class destroys the given jpeg_decompress object when it goes out of
-// scope. It simplifies the error handling in Decode (and even applies to the
-// success case).
-class DecompressDestroyer {
- public:
- DecompressDestroyer() : cinfo_(NULL) {
- }
- ~DecompressDestroyer() {
- DestroyManagedObject();
- }
- void SetManagedObject(jpeg_decompress_struct* ci) {
- DestroyManagedObject();
- cinfo_ = ci;
- }
- void DestroyManagedObject() {
- if (cinfo_) {
- jpeg_destroy_decompress(cinfo_);
- cinfo_ = NULL;
- }
- }
- private:
- jpeg_decompress_struct* cinfo_;
-};
-
-} // namespace
-
-bool JPEGCodec::Decode(const unsigned char* input, size_t input_size,
- ColorFormat format, std::vector<unsigned char>* output,
- int* w, int* h) {
- jpeg_decompress_struct cinfo;
- DecompressDestroyer destroyer;
- destroyer.SetManagedObject(&cinfo);
- output->clear();
-
- // We set up the normal JPEG error routines, then override error_exit.
- // This must be done before the call to create_decompress.
- CoderErrorMgr errmgr;
- cinfo.err = jpeg_std_error(&errmgr.pub);
- errmgr.pub.error_exit = ErrorExit;
- // Establish the setjmp return context for ErrorExit to use.
- if (setjmp(errmgr.setjmp_buffer)) {
- // If we get here, the JPEG code has signaled an error.
- // See note in JPEGCodec::Encode() for why we need to destroy the cinfo
- // manually here.
- destroyer.DestroyManagedObject();
- return false;
- }
-
- // The destroyer will destroy() cinfo on exit. We don't want to set the
- // destroyer's object until cinfo is initialized.
- jpeg_create_decompress(&cinfo);
-
- // set up the source manager
- jpeg_source_mgr srcmgr;
- srcmgr.init_source = InitSource;
- srcmgr.fill_input_buffer = FillInputBuffer;
- srcmgr.skip_input_data = SkipInputData;
- srcmgr.resync_to_restart = jpeg_resync_to_restart; // use default routine
- srcmgr.term_source = TermSource;
- cinfo.src = &srcmgr;
-
- JpegDecoderState state(input, input_size);
- cinfo.client_data = &state;
-
- // fill the file metadata into our buffer
- if (jpeg_read_header(&cinfo, true) != JPEG_HEADER_OK)
- return false;
-
- // we want to always get RGB data out
- switch (cinfo.jpeg_color_space) {
- case JCS_GRAYSCALE:
- case JCS_RGB:
- case JCS_YCbCr:
- cinfo.out_color_space = JCS_RGB;
- break;
- case JCS_CMYK:
- case JCS_YCCK:
- default:
- // Mozilla errors out on these color spaces, so I presume that the jpeg
- // library can't do automatic color space conversion for them. We don't
- // care about these anyway.
- return false;
- }
- cinfo.output_components = 3;
-
- jpeg_calc_output_dimensions(&cinfo);
- *w = cinfo.output_width;
- *h = cinfo.output_height;
-
- jpeg_start_decompress(&cinfo);
-
- // FIXME(brettw) we may want to allow the capability for callers to request
- // how to align row lengths as we do for the compressor.
- int row_read_stride = cinfo.output_width * cinfo.output_components;
-
- if (format == FORMAT_RGB) {
- // easy case, row needs no conversion
- int row_write_stride = row_read_stride;
- output->resize(row_write_stride * cinfo.output_height);
-
- for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) {
- unsigned char* rowptr = &(*output)[row * row_write_stride];
- if (!jpeg_read_scanlines(&cinfo, &rowptr, 1))
- return false;
- }
- } else {
- // Rows need conversion to output format: read into a temporary buffer and
- // expand to the final one. Performance: we could avoid the extra
- // allocation by doing the expansion in-place.
- int row_write_stride;
- void (*converter)(const unsigned char* rgb, int w, unsigned char* out);
- if (format == FORMAT_RGBA) {
- row_write_stride = cinfo.output_width * 4;
- converter = AddAlpha;
- } else if (format == FORMAT_BGRA) {
- row_write_stride = cinfo.output_width * 4;
- converter = RGBtoBGRA;
- } else {
- NOTREACHED() << "Invalid pixel format";
- jpeg_destroy_decompress(&cinfo);
- return false;
- }
-
- output->resize(row_write_stride * cinfo.output_height);
-
- scoped_array<unsigned char> row_data(new unsigned char[row_read_stride]);
- unsigned char* rowptr = row_data.get();
- for (int row = 0; row < static_cast<int>(cinfo.output_height); row++) {
- if (!jpeg_read_scanlines(&cinfo, &rowptr, 1))
- return false;
- converter(rowptr, *w, &(*output)[row * row_write_stride]);
- }
- }
-
- jpeg_finish_decompress(&cinfo);
- jpeg_destroy_decompress(&cinfo);
- return true;
-}
-
-// static
-SkBitmap* JPEGCodec::Decode(const unsigned char* input, size_t input_size) {
- int w, h;
- std::vector<unsigned char> data_vector;
- // Use FORMAT_BGRA as that maps to Skia's 32 bit (kARGB_8888_Config) format.
- if (!Decode(input, input_size, FORMAT_BGRA, &data_vector, &w, &h))
- return NULL;
-
- // Skia only handles 32 bit images.
- int data_length = w * h * 4;
-
- SkBitmap* bitmap = new SkBitmap();
- bitmap->setConfig(SkBitmap::kARGB_8888_Config, w, h);
- bitmap->allocPixels();
- memcpy(bitmap->getAddr32(0, 0), &data_vector[0], data_length);
-
- return bitmap;
-}
-
-} // namespace gfx