C++ memory_cptr::get_buffer方法代码示例

memory_cptr
header_removal_compressor_c::do_compress(memory_cptr const &buffer) {
  if (!m_bytes || (0 == m_bytes->get_size()))
    return buffer;

  size_t size = m_bytes->get_size();
  if (buffer->get_size() < size)
    throw mtx::compression_x(boost::format(Y("Header removal compression not possible because the buffer contained %1% bytes "
                                             "which is less than the size of the headers that should be removed, %2%.")) % buffer->get_size() % size);

  unsigned char *buffer_ptr = buffer->get_buffer();
  unsigned char *bytes_ptr  = m_bytes->get_buffer();

  if (memcmp(buffer_ptr, bytes_ptr, size)) {
    std::string b_buffer, b_bytes;
    size_t i;

    for (i = 0; size > i; ++i) {
      b_buffer += (boost::format(" %|1$02x|") % static_cast<unsigned int>(buffer_ptr[i])).str();
      b_bytes  += (boost::format(" %|1$02x|") % static_cast<unsigned int>(bytes_ptr[i])).str();
    }
    throw mtx::compression_x(boost::format(Y("Header removal compression not possible because the buffer did not start with the bytes that should be removed. "
                                             "Wanted bytes:%1%; found:%2%.")) % b_bytes % b_buffer);
  }

  return memory_c::clone(buffer->get_buffer() + size, buffer->get_size() - size);
}

void
vc1::es_parser_c::handle_packet(memory_cptr packet) {
  uint32_t marker = get_uint32_be(packet->get_buffer());

  switch (marker) {
    case VC1_MARKER_SEQHDR:
      handle_sequence_header_packet(packet);
      break;

    case VC1_MARKER_ENTRYPOINT:
      handle_entrypoint_packet(packet);
      break;

    case VC1_MARKER_FRAME:
      handle_frame_packet(packet);
      break;

    case VC1_MARKER_SLICE:
      handle_slice_packet(packet);
      break;

    case VC1_MARKER_FIELD:
      handle_field_packet(packet);
      break;

    case VC1_MARKER_ENDOFSEQ:
      handle_end_of_sequence_packet(packet);
      break;

    default:
      handle_unknown_packet(marker, packet);
      break;
  }
}

void
wav_pcm_demuxer_c::process(int64_t len) {
  if (0 >= len)
    return;

  m_ptzr->process(new packet_t(new memory_c(m_buffer->get_buffer(), len, false)));
}

void
xtr_oggvorbis_c::handle_frame(memory_cptr &frame,
                              KaxBlockAdditions *,
                              int64_t,
                              int64_t,
                              int64_t,
                              int64_t,
                              bool,
                              bool,
                              bool) {
  m_content_decoder.reverse(frame, CONTENT_ENCODING_SCOPE_BLOCK);

  ogg_packet op;
  op.packet               = frame->get_buffer();
  op.bytes                = frame->get_size();
  int64_t this_block_size = vorbis_packet_blocksize(&m_vorbis_info, &op);

  if (-1 != m_previous_block_size) {
    m_queued_granulepos   = m_samples;
    m_samples            += (this_block_size + m_previous_block_size) / 4;
  }

  m_previous_end        = m_samples * 1000000000 / m_sfreq;
  m_previous_block_size = this_block_size;

  queue_frame(frame, 0);
}

void
xtr_ivf_c::handle_frame(memory_cptr &frame,
                        KaxBlockAdditions *,
                        int64_t timecode,
                        int64_t,
                        int64_t,
                        int64_t,
                        bool,
                        bool,
                        bool) {
  m_content_decoder.reverse(frame, CONTENT_ENCODING_SCOPE_BLOCK);

  uint64_t frame_number = timecode * m_frame_rate_num / m_frame_rate_den / 1000000000ull;

  mxverb(2, boost::format("timecode %1% num %2% den %3% frame_number %4% calculated back %5%\n")
         % timecode % m_frame_rate_num % m_frame_rate_den % frame_number
         % (frame_number * 1000000000ull * m_frame_rate_den / m_frame_rate_num));

  ivf::frame_header_t frame_header;
  put_uint32_le(&frame_header.frame_size, frame->get_size());
  put_uint32_le(&frame_header.timestamp,  frame_number);

  m_out->write(&frame_header,       sizeof(frame_header));
  m_out->write(frame->get_buffer(), frame->get_size());

  ++m_frame_count;
}

std::string
vc1_info_c::create_checksum_info(memory_cptr packet) {
  if (!g_opt_checksum)
    return "";

  return (boost::format(Y(" checksum 0x%|1$08x|")) % calc_adler32(packet->get_buffer(), packet->get_size())).str();
}

static std::shared_ptr<std::vector<std::string> >
extract_vorbis_comments(const memory_cptr &mem) {
  std::shared_ptr<std::vector<std::string> > comments(new std::vector<std::string>);
  mm_mem_io_c in(mem->get_buffer(), mem->get_size());
  uint32_t i, n, len;

  try {
    in.skip(7);                 // 0x03 "vorbis"
    n = in.read_uint32_le();    // vendor_length
    in.skip(n);                 // vendor_string
    n = in.read_uint32_le();    // user_comment_list_length

    comments->reserve(n);

    for (i = 0; i < n; i++) {
      len = in.read_uint32_le();
      memory_cptr buffer(new memory_c((unsigned char *)safemalloc(len + 1), len + 1));

      if (in.read(buffer->get_buffer(), len) != len)
        throw false;

      comments->push_back(std::string((char *)buffer->get_buffer(), len));
    }
  } catch(...) {
  }

  return comments;
}

std::vector<memory_cptr>
unlace_memory_xiph(memory_cptr &buffer) {
  if (1 > buffer->get_size())
    throw mtx::mem::lacing_x("Buffer too small");

  std::vector<int> sizes;
  unsigned char *ptr = buffer->get_buffer();
  unsigned char *end = buffer->get_buffer() + buffer->get_size();
  size_t last_size   = buffer->get_size();
  size_t num_blocks  = ptr[0] + 1;
  size_t i;
  ++ptr;

  for (i = 0; (num_blocks - 1) > i; ++i) {
    int size = 0;
    while ((ptr < end) && (*ptr == 255)) {
      size += 255;
      ++ptr;
    }

    if (ptr >= end)
      throw mtx::mem::lacing_x("End-of-buffer while reading the block sizes");

    size += *ptr;
    ++ptr;

    sizes.push_back(size);
    last_size -= size;
  }

  sizes.push_back(last_size - (ptr - buffer->get_buffer()));

  std::vector<memory_cptr> blocks;

  for (i = 0; sizes.size() > i; ++i) {
    if ((ptr + sizes[i]) > end)
      throw mtx::mem::lacing_x("End-of-buffer while assigning the blocks");

    blocks.push_back(memory_cptr(new memory_c(ptr, sizes[i], false)));
    ptr += sizes[i];
  }

  return blocks;
}

size_t
mm_io_c::write(const memory_cptr &buffer,
               size_t size,
               size_t offset) {
  size = std::min(buffer->get_size() - offset, size);

  if (write(buffer->get_buffer() + offset, size) != size)
    throw mtx::mm_io::end_of_file_x();
  return size;
}

void
header_removal_compressor_c::decompress(memory_cptr &buffer) {
  if (!m_bytes.is_set() || (0 == m_bytes->get_size()))
    return;

  memory_cptr new_buffer = memory_c::alloc(buffer->get_size() + m_bytes->get_size());

  memcpy(new_buffer->get_buffer(),                       m_bytes->get_buffer(), m_bytes->get_size());
  memcpy(new_buffer->get_buffer() + m_bytes->get_size(), buffer->get_buffer(),  buffer->get_size());

  buffer = new_buffer;
}

memory_cptr
header_removal_compressor_c::do_decompress(memory_cptr const &buffer) {
  if (!m_bytes || (0 == m_bytes->get_size()))
    return buffer;

  memory_cptr new_buffer = memory_c::alloc(buffer->get_size() + m_bytes->get_size());

  memcpy(new_buffer->get_buffer(),                       m_bytes->get_buffer(), m_bytes->get_size());
  memcpy(new_buffer->get_buffer() + m_bytes->get_size(), buffer->get_buffer(),  buffer->get_size());

  return new_buffer;
}

void
xtr_oggkate_c::handle_frame(memory_cptr &frame,
                            KaxBlockAdditions *,
                            int64_t timecode,
                            int64_t,
                            int64_t,
                            int64_t,
                            bool,
                            bool,
                            bool) {
  m_content_decoder.reverse(frame, CONTENT_ENCODING_SCOPE_BLOCK);

  ogg_packet op;
  op.b_o_s    = 0;
  op.e_o_s    = (frame->get_size() == 1) && (frame->get_buffer()[0] == 0x7f);
  op.packetno = m_packetno;
  op.packet   = frame->get_buffer();
  op.bytes    = frame->get_size();

  /* we encode the backlink in the granulepos */
  float f_timecode   = timecode / 1000000000.0;
  int64_t g_backlink = 0;

  if (op.bytes >= static_cast<long>(1 + 3 * sizeof(int64_t)))
    g_backlink = get_uint64_le(op.packet + 1 + 2 * sizeof(int64_t));

  float f_backlink = g_backlink * (float)m_kate_id_header.gden / m_kate_id_header.gnum;
  float f_base     = f_timecode - f_backlink;
  float f_offset   = f_timecode - f_base;
  int64_t g_base   = (int64_t)(f_base   * m_kate_id_header.gnum / m_kate_id_header.gden);
  int64_t g_offset = (int64_t)(f_offset * m_kate_id_header.gnum / m_kate_id_header.gden);
  op.granulepos    = (g_base << m_kate_id_header.kfgshift) | g_offset;

  ogg_stream_packetin(&m_os, &op);
  flush_pages(); /* Kate is a data packet per page */

  ++m_packetno;
}

void
vc1_info_c::handle_sequence_header_packet(memory_cptr packet) {
  std::string checksum = create_checksum_info(packet);
  mxinfo(boost::format(Y("Sequence header at %1% size %2%%3%\n")) % m_stream_pos % packet->get_size() % checksum);

  m_seqhdr_found = vc1::parse_sequence_header(packet->get_buffer(), packet->get_size(), m_seqhdr);

  if (g_opt_sequence_headers) {
    if (m_seqhdr_found)
      dump_sequence_header(m_seqhdr);
    else
      mxinfo(Y("  parsing failed\n"));
  }
}

void
analyze_header_removal_compressor_c::compress(memory_cptr &buffer) {
  ++m_packet_counter;

  if (!m_bytes.is_set()) {
    m_bytes = memory_cptr(buffer->clone());
    return;
  }

  unsigned char *current = buffer->get_buffer();
  unsigned char *saved   = m_bytes->get_buffer();
  size_t i, new_size     = 0;

  for (i = 0; i < std::min(buffer->get_size(), m_bytes->get_size()); ++i, ++new_size)
    if (current[i] != saved[i])
      break;

  m_bytes->set_size(new_size);
}

void
vc1::es_parser_c::handle_sequence_header_packet(memory_cptr packet) {
  flush_frame();

  add_pre_frame_extra_data(packet);

  vc1::sequence_header_t seqhdr;
  if (!vc1::parse_sequence_header(packet->get_buffer(), packet->get_size(), seqhdr))
    return;

  m_seqhdr_changed = !m_seqhdr_found || (packet->get_size() != m_raw_seqhdr->get_size()) || memcmp(packet->get_buffer(), m_raw_seqhdr->get_buffer(), packet->get_size());

  memcpy(&m_seqhdr, &seqhdr, sizeof(vc1::sequence_header_t));
  m_raw_seqhdr   = memory_cptr(packet->clone());
  m_seqhdr_found = true;

  if (!m_default_duration_forced && m_seqhdr.framerate_flag && (0 != m_seqhdr.framerate_num) && (0 != m_seqhdr.framerate_den))
    m_default_duration = 1000000000ll * m_seqhdr.framerate_num / m_seqhdr.framerate_den;
}