MPEG_STREAM_BUFFER Structure

The MPEG_STREAM_BUFFER structure defines a buffer that receives MPEG-2 data.

Syntax

typedef struct {
    HRESULT hr;
    DWORD   dwDataBufferSize;
    DWORD   dwSizeOfDataRead;
    BYTE*   pDataBuffer;
} MPEG_STREAM_BUFFER, *PMPEG_STREAM_BUFFER;

Members

hr

Specifies a status code. Use this value to check the status of the read request.

dwDataBufferSize

Specifies the size of the buffer, in bytes.

dwSizeOfDataRead

Specifies the amount of valid data in the buffer, in bytes

pDataBuffer

Pointer to a buffer that holds the MPEG-2 data.

Remarks

This structure is used with the IMpeg2Stream::SupplyDataBuffer method to get raw MPEG-2 data.

For PSI tables and sections, set pDataBuffer to point to a SECTION structure. If you also create an MPEG_PACKET_LIST structure to hold a list of buffers, you can pass that list to the ISectionList::InitializeWithRawSections method.

The following code shows how to initialize an MPEG_STREAM_BUFFER structure so that it points to a SECTION structure contained in an MPEG_PACKET_LIST section list:

// Allocate two buffers for section data.
const int cBufferSize = 4096;
BYTE pBuffer1[cBufferSize];
BYTE pBuffer2[cBufferSize];

// Create a packet list to hold both buffers.
MPEG_RQST_PACKET RqstPacket[2];
MPEG_PACKET_LIST Packets;

RqstPacket[0].dwLength = cBufferSize;
RqstPacket[0].pSection = (SECTION*)pBuffer1;
RqstPacket[1].dwLength = cBufferSize;
RqstPacket[1].pSection = (SECTION*)pBuffer2;

Packets.wPacketCount = 2;
Packets.PacketList[0] = &RqstPacket[0];
Packets.PacketList[1] = &RqstPacket[1];

// Set the stream buffer structure to point to the first packet in the list.
MPEG_STREAM_BUFFER StreamBuffer;
ZeroMemory(&StreamBuffer, sizeof(MPEG_STREAM_BUFFER));
StreamBuffer.dwDataBufferSize = Packets.PacketList[0]->dwLength;
StreamBuffer.pDataBuffer = (BYTE*) Packets.PacketList[0]->pSection;

See Also

• MPEG-2 Section and Table Structures