The following information summarizes the media types used by Microsoft® DirectShow™ for MPEG data.
Minor type: MEDIASUBTYPE_MPEG1System
Format: None
Sample contents: BYTE stream; no alignment
Minor type: MEDIASUBTYPE_MPEG1VideoCD
Format: None
Sample contents: BYTE stream; no alignment
Minor type: MEDIASUBTYPE_MPEG1Packet
Format: MPEG1WAVEFORMAT
Sample contents: Single MPEG-1 packet including packet header
Minor type: MEDIASUBTYPE_MPEG1Payload
Format: MPEG1WAVEFORMAT
Sample contents: Byte-aligned MPEG-1 audio data
Minor type: MEDIASUBTYPE_MPEG1Packet
Format: VIDEOINFO + Video sequence header
Sample contents: Single MPEG-1 packet including packet header
Minor type: MEDIASUBTYPE_MPEG1Payload
Format: VIDEOINFO + Video sequence header
Sample contents: Byte-aligned MPEG-1 video data
Minor type: MEDIASUBTYPE_ MPEG1Video
Format: None
Sample contents: Array of video stream bytes (no system layer)
Minor type: MEDIASUBTYPE_ MPEG1Audio
Format: None
Sample contents: Array of audio stream bytes (no system layer)
The various filters will support pins as follows:
Filter | Direction | Media type(s) |
System layer splitter | Input | MPEG-1 system stream
MPEG-1 system stream off Video CD |
System layer splitter | Output | MPEG-1 Audio packet or MPEG-1 Audio data |
System layer splitter | Output | MPEG-1 Video packet or MPEG-1 Video data |
Software Audio CODEC | Input | MPEG-1 Audio data or MPEG-1 Audio packet |
Software Video CODEC | Input | MPEG-1 Video data or MPEG-1 Video packet |
Software Audio CODEC | Output | PCM audio mono or stereo, input sampling rate, input sampling rate divided by 2 or input sampling rate divided by 4 |
Software Video CODEC | Output | Uncompressed video in Y41P, YUY2, UYVY, RGB24, RGB32, RGB565, RGB555 and RGB8 formats |
MPEG-1 Video packet and payload media types contain a complete sequence header so that data can be played from the middle of a file without needing a sequence header to initialize the video playback.
The video sequence header is appended to the video data type for MPEG video so that play can begin from the middle of a stream. The length of this field is up to 140 bytes (it includes the sequence header start code—0x000001B3—at the start and any quantization matrices found in the first sequence header encountered).
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