/// <summary>
/// Obtains the header data located in the MPEG file and decodes it
/// </summary>
/// <param name="br">The binary reader providing random access to the MPEG file data</param>
private void GetHeaderInfo(BinaryReader br)
{
byte[] buffer = new byte[BUFFER_SIZE];
br.BaseStream.Seek(0, SeekOrigin.Begin);
br.Read(buffer, 0, BUFFER_SIZE);
for (int offset = 0; offset < buffer.Length - 4; offset++)
{
if (IsStreamMarker(ref buffer, offset, HEADER_PACKET))
{
offset += 4; // Move to the data position which follows the stream header
uint headerData = GetData(ref buffer, offset);
// Mask out the bits containing the property we are after, then
// shift the data to the right to get its value
m_pictureWidth = (int)(headerData & 0xFFF00000) >> 20;
m_pictureHeight = (int)(headerData & 0x000FFF00) >> 8;
uint aspectRatioIndex = (headerData & 0x000000F0) >> 4;
uint fpsIndex = headerData & 0x0000000F;
m_aspectRatio = (eAspectRatios)fpsIndex;
m_frameRate = (eFrameRates)fpsIndex;
break;
}
}
}
/// <summary>
/// Obtains the header data located in the MPEG file and decodes it
/// </summary>
/// <param name="br">The binary reader providing random access to the MPEG file data</param>
private void GetHeaderInfo(BinaryReader br)
{
byte[] buffer = new byte[BUFFER_SIZE];
br.BaseStream.Seek(0, SeekOrigin.Begin);
br.Read(buffer, 0, BUFFER_SIZE);
for (int offset = 0; offset < buffer.Length - 4; offset++)
{
if (IsStreamMarker(ref buffer, offset, HEADER_PACKET))
{
offset += 4; // Move to the data position which follows the stream header
uint headerData = GetData(ref buffer, offset);
// Mask out the bits containing the property we are after, then
// shift the data to the right to get its value
m_pictureWidth = (int)(headerData & 0xFFF00000) >> 20;
m_pictureHeight = (int)(headerData & 0x000FFF00) >> 8;
uint aspectRatioIndex = (headerData & 0x000000F0) >> 4;
uint fpsIndex = headerData & 0x0000000F;
m_aspectRatio = (eAspectRatios)fpsIndex;
m_frameRate = (eFrameRates)fpsIndex;
break;
}
}
}
