Try2 of issue 18772. (move jpeg_codec* to base/gfx)

chrome/common/jpeg_codec.cc

-// 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 <setjmp.h>
-
-#include "chrome/common/jpeg_codec.h"
-#include "base/logging.h"
-#include "base/scoped_ptr.h"
-#include "SkBitmap.h"
-
-extern "C" {
-#include "jpeglib.h"
-}
-
-// 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.
-const static int initial_output_buffer_size = 8192;
-
-struct JpegEncoderState {
-  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;
-  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);
-  destroyer.SetManagedObject(&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;
-  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);
-  destroyer.SetManagedObject(&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;
-}
-