media/filters/jpeg_parser.h

   1 // Copyright 2015 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4 //
   5 #ifndef MEDIA_FILTERS_JPEG_PARSER_H_
   6 #define MEDIA_FILTERS_JPEG_PARSER_H_
   7
   8 #include <stddef.h>
   9 #include <stdint.h>
  10 #include "media/base/media_export.h"
  11
  12 namespace media {
  13
  14 // It's not a full featured JPEG parser implememtation. It only parses JPEG
  15 // baseline sequential process. For explanations of each struct and its
  16 // members, see JPEG specification at
  17 // http://www.w3.org/Graphics/JPEG/itu-t81.pdf.
  18
  19 enum JpegMarker {
  20   JPEG_SOF0 = 0xC0,   // start of frame (baseline)
  21   JPEG_SOF1 = 0xC1,   // start of frame (extended sequential)
  22   JPEG_SOF2 = 0xC2,   // start of frame (progressive)
  23   JPEG_SOF3 = 0xC3,   // start of frame (lossless))
  24   JPEG_DHT = 0xC4,    // define huffman table
  25   JPEG_SOF5 = 0xC5,   // start of frame (differential, sequential)
  26   JPEG_SOF6 = 0xC6,   // start of frame (differential, progressive)
  27   JPEG_SOF7 = 0xC7,   // start of frame (differential, lossless)
  28   JPEG_SOF9 = 0xC9,   // start of frame (arithmetic coding, extended)
  29   JPEG_SOF10 = 0xCA,  // start of frame (arithmetic coding, progressive)
  30   JPEG_SOF11 = 0xCB,  // start of frame (arithmetic coding, lossless)
  31   JPEG_SOF13 = 0xCD,  // start of frame (differential, arithmetic, sequential)
  32   JPEG_SOF14 = 0xCE,  // start of frame (differential, arithmetic, progressive)
  33   JPEG_SOF15 = 0xCF,  // start of frame (differential, arithmetic, lossless)
  34   JPEG_RST0 = 0xD0,   // restart
  35   JPEG_RST1 = 0xD1,   // restart
  36   JPEG_RST2 = 0xD2,   // restart
  37   JPEG_RST3 = 0xD3,   // restart
  38   JPEG_RST4 = 0xD4,   // restart
  39   JPEG_RST5 = 0xD5,   // restart
  40   JPEG_RST6 = 0xD6,   // restart
  41   JPEG_RST7 = 0xD7,   // restart
  42   JPEG_SOI = 0xD8,    // start of image
  43   JPEG_EOI = 0xD9,    // end of image
  44   JPEG_SOS = 0xDA,    // start of scan
  45   JPEG_DQT = 0xDB,    // define quantization table
  46   JPEG_DRI = 0xDD,    // define restart internal
  47   JPEG_MARKER_PREFIX = 0xFF,  // jpeg marker prefix
  48 };
  49
  50 const size_t kJpegMaxHuffmanTableNumBaseline = 2;
  51 const size_t kJpegMaxComponents = 4;
  52 const size_t kJpegMaxQuantizationTableNum = 4;
  53
  54 // Parsing result of JPEG DHT marker.
  55 struct JpegHuffmanTable {
  56   bool valid;
  57   uint8_t code_length[16];
  58   uint8_t code_value[256];
  59 };
  60
  61 // Parsing result of JPEG DQT marker.
  62 struct JpegQuantizationTable {
  63   bool valid;
  64   uint8_t value[64];  // baseline only supports 8 bits quantization table
  65 };
  66
  67 // Parsing result of a JPEG component.
  68 struct JpegComponent {
  69   uint8_t id;
  70   uint8_t horizontal_sampling_factor;
  71   uint8_t vertical_sampling_factor;
  72   uint8_t quantization_table_selector;
  73 };
  74
  75 // Parsing result of a JPEG SOF marker.
  76 struct JpegFrameHeader {
  77   uint16_t visible_width;
  78   uint16_t visible_height;
  79   uint16_t coded_width;
  80   uint16_t coded_height;
  81   uint8_t num_components;
  82   JpegComponent components[kJpegMaxComponents];
  83 };
  84
  85 // Parsing result of JPEG SOS marker.
  86 struct JpegScanHeader {
  87   uint8_t num_components;
  88   struct Component {
  89     uint8_t component_selector;
  90     uint8_t dc_selector;
  91     uint8_t ac_selector;
  92   } components[kJpegMaxComponents];
  93 };
  94
  95 struct JpegParseResult {
  96   JpegFrameHeader frame_header;
  97   JpegHuffmanTable dc_table[kJpegMaxHuffmanTableNumBaseline];
  98   JpegHuffmanTable ac_table[kJpegMaxHuffmanTableNumBaseline];
  99   JpegQuantizationTable q_table[kJpegMaxQuantizationTableNum];
 100   uint16_t restart_interval;
 101   JpegScanHeader scan;
 102   const char* data;
 103   // The size of compressed data of the first image.
 104   size_t data_size;
 105   // The size of the first entire image including header.
 106   size_t image_size;
 107 };
 108
 109 // Parses JPEG picture in |buffer| with |length|.  Returns true iff header is
 110 // valid and JPEG baseline sequential process is present. If parsed
 111 // successfully, |result| is the parsed result.
 112 MEDIA_EXPORT bool ParseJpegPicture(const uint8_t* buffer,
 113                                    size_t length,
 114                                    JpegParseResult* result);
 115
 116 // Parses the first image of JPEG stream in |buffer| with |length|.  Returns
 117 // true iff header is valid and JPEG baseline sequential process is present.
 118 // If parsed successfully, |result| is the parsed result.
 119 MEDIA_EXPORT bool ParseJpegStream(const uint8_t* buffer,
 120                                   size_t length,
 121                                   JpegParseResult* result);
 122
 123 }  // namespace media
 124
 125 #endif  // MEDIA_FILTERS_JPEG_PARSER_H_