First, the user-preferred language used for mapping is determined using the following steps: The languages are defined for audio streams by an in-band spanning event with an ID of EVENTID_LanguageSpanningEvent. The default stream is a stream that has the Default member set to TRUE in its DVR_STREAM_DESC structure.įor audio streams ( MEDIATYPE_Audio), language-based mapping logic is applied. In default streams mode, the Stream Buffer Source filter uses the following logic to map streams to output pins:įor all streams with media type (major) other than MEDIATYPE_Audio, the Stream Buffer Source filter maps the default stream for each media type to an output pin with a matching media type. If the application does not call EnableDefaultMode, both default streams and default profile modes are enabled. The application cannot change output profiles or specify new stream mappings. The application cannot change stream mappings but must specify a new output profiles.Įnables both profile and streams default mode. The application cannot change output profiles but can specify new stream mappings while the graph is running.Įnables streams default mode, disables profile default mode. The application must set an output profile (using the ISBE2Crossbar::SetOutputProfile method) and stream mappings (using the ISBE2StreamMap::MapStream method).Įnables profile default mode, disables streams default mode. Use either or both of the following flags in the EnableDefaultMode call to explicitly set the default modes that you want to enable: Flagsĭisables both profile and streams default mode. The ISBE2Crossbar interface, which is exposed by the Stream Buffer Source filter, is used to set these two important modes.Īpplications can call the ISBE2Crossbar::EnableDefaultMode method to set profile mode, stream mapping mode, or both. A mode where mapping is controlled by an application.Default streams mode, in which the filter maps streams to output pins automatically, following internal logic.The Stream Buffer Source filter can operate in one of two stream mapping modes: Thus, the stream mapping is essential for the Source Buffer Source to be able to send sample data. When the Stream Buffer Source filter reads streams from a WTV file, it needs to know which pin to use for sending out each stream. As specified in an application-provided output profile.This profile is defined when the WTV file is first created. As described in the default output profile that present in the file.When the Stream Buffer Source filter is initialized with a WTV file, it can expose pins in one of two ways: Setting Defaults, Output Profiles, and Stream Mappings This functionality is achieved through several new interfaces that are exposed by the Stream Buffer Source filter and its output pins. For example, this set can be used in order to limit output pins to audio and video only. The application can define a set of Stream Buffer Source filter output pins, referred to as an output profile, to override the default set. Such matching is referred to as stream mapping. Thus, if a file contains more than one steam of a certain media type, matching between a stream of a specific media type and a pin of the appropriate media type is needed. The Stream Buffer Source filter typically has one output pin per media type (for example, audio or video). This section describes how to manage multiple streams within a WTV file using the new functionality of the Stream Buffer Source filter. Multiple Stream Support in the Stream Buffer Source Filter Manages stream mappings for a Stream Buffer Source filter The Stream Buffer Source filter improvements in SBE2 give developers full access to these features through the following new interfaces, which are discussed in the following sections: InterfaceĮnumerates the streams in a WTV file sets or changes profiles, stream mappings, and default modes for a Stream Buffer Source filterĮnumerates the streams discovered in a WTV file Enhanced recording for files, with more robust recovery.Enhanced metadata that is required for content protection, interactive TV, and dynamic stream support.Multiple streams with interactive TV data.Multiple video angles (for example, for a broadcast soccer game).Dynamic format changes to audio and video streams within a recording, including:.Dynamic addition and removal of audio, video, and data streams.These enhancements allow the filter to handle features that are supported by the new TV Recording File Format (.WTV) that were not available in the. The Stream Buffer Engine (SBE) version 2 (SBE2) in Windows 7 offers several enhancements to the Stream Buffer Source filter that was shipped with previous versions of Windows.
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