media/filters/ivf_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_IVF_PARSER_H_
   6 #define MEDIA_FILTERS_IVF_PARSER_H_
   7
   8 #include <stddef.h>
   9 #include <stdint.h>
  10
  11 #include "base/macros.h"
  12 #include "media/base/media_export.h"
  13
  14 namespace media {
  15
  16 const char kIvfHeaderSignature[] = "DKIF";
  17
  18 #pragma pack(push, 1)
  19 struct MEDIA_EXPORT IvfFileHeader {
  20   // Byte swap interger fields between native and (on disk) little endian.
  21   void ByteSwap();
  22
  23   char signature[4];        // signature: 'DKIF'
  24   uint16_t version;         // version (should be 0)
  25   uint16_t header_size;     // size of header in bytes
  26   uint32_t fourcc;          // codec FourCC (e.g., 'VP80')
  27   uint16_t width;           // width in pixels
  28   uint16_t height;          // height in pixels
  29   uint32_t timebase_denum;  // timebase denumerator
  30   uint32_t timebase_num;    // timebase numerator. For example, if
  31                             // timebase_denum is 30 and timebase_num is 2, the
  32                             // unit of IvfFrameHeader.timestamp is 2/30
  33                             // seconds.
  34   uint32_t num_frames;      // number of frames in file
  35   uint32_t unused;          // unused
  36 };
  37 static_assert(
  38     sizeof(IvfFileHeader) == 32,
  39     "sizeof(IvfFileHeader) must be fixed since it will be used with file IO");
  40
  41 struct MEDIA_EXPORT IvfFrameHeader {
  42   // Byte swap interger fields between native and (on disk) little endian.
  43   void ByteSwap();
  44
  45   uint32_t frame_size;  // Size of frame in bytes (not including the header)
  46   uint64_t timestamp;   // 64-bit presentation timestamp in unit timebase,
  47                         // which is defined in IvfFileHeader.
  48 };
  49 static_assert(
  50     sizeof(IvfFrameHeader) == 12,
  51     "sizeof(IvfFrameHeader) must be fixed since it will be used with file IO");
  52 #pragma pack(pop)
  53
  54 // IVF is a simple container format for video frame. It is used by libvpx to
  55 // transport VP8 and VP9 bitstream.
  56 class MEDIA_EXPORT IvfParser {
  57  public:
  58   IvfParser();
  59
  60   // Initializes the parser for IVF |stream| with size |size| and parses the
  61   // file header. Returns true on success.
  62   bool Initialize(const uint8_t* stream,
  63                   size_t size,
  64                   IvfFileHeader* file_header);
  65
  66   // Parses the next frame. Returns true if the next frame is parsed without
  67   // error. |frame_header| will be filled with the frame header and |payload|
  68   // will point to frame payload (inside the |stream| buffer given to
  69   // Initialize.)
  70   bool ParseNextFrame(IvfFrameHeader* frame_header, const uint8_t** payload);
  71
  72  private:
  73   bool ParseFileHeader(IvfFileHeader* file_header);
  74
  75   // Current reading position of input stream.
  76   const uint8_t* ptr_;
  77
  78   // The end position of input stream.
  79   const uint8_t* end_;
  80
  81   DISALLOW_COPY_AND_ASSIGN(IvfParser);
  82 };
  83
  84 }  // namespace media
  85
  86 #endif  // MEDIA_FILTERS_IVF_PARSER_H_