IMediaParams::SetTimeFormat method (medparam.h)

Article
4/26/2023

[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 SetTimeFormat method specifies the time format for the object.

Syntax

HRESULT SetTimeFormat(
  [in] GUID        guidTimeFormat,
  [in] MP_TIMEDATA mpTimeData
);

Parameters

[in] guidTimeFormat

Time format GUID that specifies the time format.

[in] mpTimeData

Value of type MP_TIMEDATA that specifies the unit of measure for the new format.

Return value

Returns an HRESULT value. Possible values include the following.

Return code	Description
E_INVALIDARG	Object does not support this time format.
S_OK	Success.

Remarks

Objects can support more than one time format. Every object must support reference time, in which each unit of time is 100 nanoseconds (ns). Other formats are optional. The application must ensure that time stamps on the input buffers match whatever time format was set using this method.

The meaning of the mpTimeData parameter depends on the value of the guidTimeFormat parameter.

Time Format	Meaning of Time Data
GUID_TIME_MUSIC	Parts per quarter note.
GUID_TIME_REFERENCE	Ignored.
GUID_TIME_SAMPLES	Samples per second.

When you call this method, also call the FlushEnvelope method, to flush any envelopes that were set using the previous time format.

To determine what time formats an object supports, call the IMediaParamInfo::GetSupportedTimeFormat method. To retrieve the current format, call the IMediaParamInfo::GetCurrentTimeFormat method.

Requirements

Requirement	Value
Target Platform	Windows
Header	medparam.h
Library	Dmoguids.lib

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