IMPEG2StreamIdMap::MapStreamId method (strmif.h)

Article
02/22/2024

[The feature associated with this page, DirectShow, is a legacy feature. It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation. Those features have been optimized for Windows 10 and Windows 11. Microsoft strongly recommends that new code use MediaPlayer, IMFMediaEngine and Audio/Video Capture in Media Foundation instead of DirectShow, when possible. Microsoft suggests that existing code that uses the legacy APIs be rewritten to use the new APIs if possible.]

The MapStreamId method maps the Stream ID of an elementary stream within an MPEG-2 program stream to a media content type and substream filtering information.

Syntax

HRESULT MapStreamId(
  [in] ULONG ulStreamId,
  [in] DWORD MediaSampleContent,
  [in] ULONG ulSubstreamFilterValue,
  [in] int   iDataOffset
);

Parameters

[in] ulStreamId

The stream ID of the PES stream.

[in] MediaSampleContent

Specifies the contents of the stream. Currently the only value supported is MPEG2_PROGRAM_ELEMENTARY_STREAM (defined as 0x00000001 in axextend.idl).

[in] ulSubstreamFilterValue

Specifies which substream within this elementary stream to pass on to the downstream decoder. Only the low-order byte can contain a valid filter value. If iDataOffset = 0, this parameter is ignored.

[in] iDataOffset

The byte offset into the payload at which the substream begins.

Return value

Returns S_OK if successful. If the method fails, an error code is returned. If a Stream ID of MEDIA_PROGRAM_STREAM_MAP, MEDIA_PROGRAM_DIRECTORY_PES_PACKET or MEDIA_PROGRAM_PACK_HEADER is attempted, this method returns E_NOTIMPL.

Remarks

The Stream ID mapped by this method is the stream ID in the PES header. Substream filtering is most commonly used to provide multiple channels on a single audio stream.

Requirements

Requirement	Value
Minimum supported client	Windows XP [desktop apps only]
Minimum supported server	Windows Server 2003 [desktop apps only]
Target Platform	Windows
Header	strmif.h (include Dshow.h)
Library	Strmiids.lib