media/filters/ivf_parser.cc

   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 #include "base/logging.h"
   6 #include "base/sys_byteorder.h"
   7 #include "media/filters/ivf_parser.h"
   8
   9 namespace media {
  10
  11 void IvfFileHeader::ByteSwap() {
  12   version = base::ByteSwapToLE16(version);
  13   header_size = base::ByteSwapToLE16(header_size);
  14   fourcc = base::ByteSwapToLE32(fourcc);
  15   width = base::ByteSwapToLE16(width);
  16   height = base::ByteSwapToLE16(height);
  17   timebase_denum = base::ByteSwapToLE32(timebase_denum);
  18   timebase_num = base::ByteSwapToLE32(timebase_num);
  19   num_frames = base::ByteSwapToLE32(num_frames);
  20   unused = base::ByteSwapToLE32(unused);
  21 }
  22
  23 void IvfFrameHeader::ByteSwap() {
  24   frame_size = base::ByteSwapToLE32(frame_size);
  25   timestamp = base::ByteSwapToLE64(timestamp);
  26 }
  27
  28 IvfParser::IvfParser() : ptr_(nullptr), end_(nullptr) {}
  29
  30 bool IvfParser::Initialize(const uint8_t* stream,
  31                            size_t size,
  32                            IvfFileHeader* file_header) {
  33   DCHECK(stream);
  34   DCHECK(file_header);
  35   ptr_ = stream;
  36   end_ = stream + size;
  37
  38   if (size < sizeof(IvfFileHeader)) {
  39     DLOG(ERROR) << "EOF before file header";
  40     return false;
  41   }
  42
  43   memcpy(file_header, ptr_, sizeof(IvfFileHeader));
  44   file_header->ByteSwap();
  45
  46   if (memcmp(file_header->signature, kIvfHeaderSignature,
  47              sizeof(file_header->signature)) != 0) {
  48     DLOG(ERROR) << "IVF signature mismatch";
  49     return false;
  50   }
  51   DLOG_IF(WARNING, file_header->version != 0)
  52       << "IVF version unknown: " << file_header->version
  53       << ", the parser may not be able to parse correctly";
  54   if (file_header->header_size != sizeof(IvfFileHeader)) {
  55     DLOG(ERROR) << "IVF file header size mismatch";
  56     return false;
  57   }
  58
  59   ptr_ += sizeof(IvfFileHeader);
  60
  61   return true;
  62 }
  63
  64 bool IvfParser::ParseNextFrame(IvfFrameHeader* frame_header,
  65                                const uint8_t** payload) {
  66   DCHECK(ptr_);
  67   DCHECK(payload);
  68
  69   if (end_ < ptr_ + sizeof(IvfFrameHeader)) {
  70     DLOG_IF(ERROR, ptr_ != end_) << "Incomplete frame header";
  71     return false;
  72   }
  73
  74   memcpy(frame_header, ptr_, sizeof(IvfFrameHeader));
  75   frame_header->ByteSwap();
  76   ptr_ += sizeof(IvfFrameHeader);
  77
  78   if (end_ < ptr_ + frame_header->frame_size) {
  79     DLOG(ERROR) << "Not enough frame data";
  80     return false;
  81   }
  82
  83   *payload = ptr_;
  84   ptr_ += frame_header->frame_size;
  85
  86   return true;
  87 }
  88
  89 }  // namespace media