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

Review URL: http://codereview.chromium.org/18838

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@8699 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 60 insertions, 0 deletions

diff --git a/base/gfx/jpeg_codec.h b/base/gfx/jpeg_codec.h
new file mode 100644
index 0000000..141c00e
--- /dev/null
+++ b/base/gfx/jpeg_codec.h
@@ -0,0 +1,60 @@
+// 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.
+
+#ifndef BASE_GFX_JPEG_CODEC_H_
+#define BASE_GFX_JPEG_CODEC_H_
+
+#include <vector>
+
+class SkBitmap;
+
+// Interface for encoding/decoding JPEG data. This is a wrapper around libjpeg,
+// which has an inconvenient interface for callers. This is only used for UI
+// elements, WebKit has its own more complicated JPEG decoder which handles,
+// among other things, partially downloaded data.
+class JPEGCodec {
+ public:
+  enum ColorFormat {
+    // 3 bytes per pixel (packed), in RGB order regardless of endianness.
+    // This is the native JPEG format.
+    FORMAT_RGB,
+
+    // 4 bytes per pixel, in RGBA order in mem regardless of endianness.
+    FORMAT_RGBA,
+
+    // 4 bytes per pixel, in BGRA order in mem regardless of endianness.
+    // This is the default Windows DIB order.
+    FORMAT_BGRA
+  };
+
+  // Encodes the given raw 'input' data, with each pixel being represented as
+  // given in 'format'. The encoded JPEG data will be written into the supplied
+  // vector and true will be returned on success. On failure (false), the
+  // contents of the output buffer are undefined.
+  //
+  // w, h: dimensions of the image
+  // row_byte_width: the width in bytes of each row. This may be greater than
+  //   w * bytes_per_pixel if there is extra padding at the end of each row
+  //   (often, each row is padded to the next machine word).
+  // quality: an integer in the range 0-100, where 100 is the highest quality.
+  static bool Encode(const unsigned char* input, ColorFormat format,
+                     int w, int h, int row_byte_width,
+                     int quality, std::vector<unsigned char>* output);
+
+  // Decodes the JPEG data contained in input of length input_size. The
+  // decoded data will be placed in *output with the dimensions in *w and *h
+  // on success (returns true). This data will be written in the'format'
+  // format. On failure, the values of these output variables is undefined.
+  static bool Decode(const unsigned char* input, size_t input_size,
+                     ColorFormat format, std::vector<unsigned char>* output,
+                     int* w, int* h);
+
+  // Decodes the JPEG data contained in input of length input_size. If
+  // successful, a SkBitmap is created and returned. It is up to the caller
+  // to delete the returned bitmap.
+  static SkBitmap* Decode(const unsigned char* input, size_t input_size);
+};
+
+#endif  // BASE_GFX_JPEG_CODEC_H_
+