Input Streams

DVD input streams are provided to the minidriver as arrays of encrypted DVD PACKs. PACKs are as defined in the DVD specification. Note that the system clock reference (SCR) field of the PACK is set to zero because Microsoft's DVD architecture uses the "master clock" paradigm for audio and video synchronization. Typically, the audio stream of the DVD decoder minidriver provides the master clock. For more information, see Master Clock.

DVD data streams are sent to the minidriver through the SRB_WRITE_DATA request. For more information about SRB requests, see Handling Stream Request Blocks and Stream Class SRB Reference. Hardware should support scatter/gather DMA, because several DVD PACKs may be present in a single request packet.

The following table describes the MPEG2 video input stream media types used by DVD movies:

Attribute	Value
Major Format GUID	KSDATAFORMAT_TYPE_DVD_ENCRYPTED_PACK
Minor Format GUID	KSDATAFORMAT_SUBTYPE_MPEG2_VIDEO
Format Block Specifier GUID	KSDATAFORMAT_SPECIFIER_MPEG2_VIDEO
Format Block Structure	MPEG2VIDEOINFO (Superset of VIDEOINFO2 structure. Also indicates MPEG profile and level.)

The following table describes the AC-3 audio input stream media types used by DVD movies:

Attribute	Value
Major Format GUID	KSDATAFORMAT_TYPE_DVD_ENCRYPTED_PACK
Minor Format GUID	KSDATAFORMAT_SUBTYPE_AC3_AUDIO
Format Block Specifier GUID	KSDATAFORMAT_SPECIFIER_WAVEFORMATEX (Note that this is expected to change.)
Format Block Structure	KSDATAFORMAT_WAVEFORMATEX Superset of WaveFormatEx (More than two channels. Down-mix descriptor.)

The following table describes the LPCM audio input stream media types used by DVD movies:

Attribute	Value
Major Format GUID	KSDATAFORMAT_TYPE_DVD_ENCRYPTED_PACK
Minor Format GUID	KSDATAFORMAT_SUBTYPE_LPCM_AUDIO
Format Block Specifier GUID	KSDATAFORMAT_SPECIFIER_WAVEFORMATEX
Format Block Structure	KSDATAFORMAT_WAVEFORMATEX

The following table describes the DTS audio input stream media types used by DVD movies:

Attribute	Value
Major Format GUID	KSDATAFORMAT_TYPE_DVD_ENCRYPTED_PACK
Minor Format GUID	KSDATAFORMAT_SUBTYPE_DTS_AUDIO
Format Block Specifier GUID	KSDATAFORMAT_SPECIFIER_WAVEFORMATEX (Note that this is expected to change.)
Format Block Structure	KSDATAFORMAT_WAVEFORMATEX Superset of WaveFormatEx (More than two channels. Down-mix descriptor.)

The following table describes the SDDS audio input stream media types used by DVD movies:

Attribute	Value
Major Format GUID	KSDATAFORMAT_TYPE_DVD_ENCRYPTED_PACK
Minor Format GUID	KSDATAFORMAT_SUBTYPE_SDDS_AUDIO
Format Block Specifier GUID	KSDATAFORMAT_SPECIFIER_WAVEFORMATEX (Note that this is expected to change.)
Format Block Structure	KSDATAFORMAT_WAVEFORMATEX Superset of WaveFormatEx (More than two channels. Down-mix descriptor.)

The following table describes the subpicture stream media types used by DVD movies:

Attribute	Value
Major Format GUID	KSDATAFORMAT_TYPE_DVD_ENCRYPTED_PACK
Minor Format GUID	KSDATAFORMAT_SUBTYPE_SUBPICTURE
Format Block Specifier GUID	KSDATAFORMAT_SPECIFIER_NONE
Format Block Structure	None

For subpicture highlighting, palette information and highlight information are passed as properties. The subpicture data stream consists of packets of data, as provided by the DVD specification. Although the PACK header is stripped off, it is still provided.

The Microsoft supplied DVD navigator filter parses all button and keyboard information and only passes one highlight rectangle down to the subpicture decoder at any given time. As a result, highlight information is sent to the decoder more often than it is present in the DVD stream. This is different from the DVD specification.

The DVD navigator/splitter filter processes all keystroke information and sends new highlight information each time a button state changes. The information describes only one mode of one button at a time. It includes a display rectangle in pixel coordinates of the screen, or a display of the subpicture, if present. The KSPROPERTY_SPHLI structure also contains color and contrast information but only for the present state of the currently selected button. The format is defined in the DVD specification.

The highlight information arrives asynchronously to the data stream. The DVD decoder minidriver must use the highlight Start and End time stamps to correlate the highlight information to the relevant subpicture information, if any. If the DVD decoder minidriver has not received any subpicture stream information for the requested time stamps, the decoder assumes that the highlight information is stand-alone and does not apply to a subpicture. In this case, the color and contrast information can be assumed to be all the same color.

Highlight information contains Start and End time-stamps. These are in the same units as other time stamps, with two exceptions: A Start time-stamp of 0xFFFFFFFF means the highlight property is effective upon receipt, and an End time-stamp of 0xFFFFFFFF means the highlight property is valid until the next highlight is received.