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AM_SAMPLE2_PROPERTIES structure (strmif.h)

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[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 It has been superseded by MediaPlayer, IMFMediaEngine, and Audio/Video Capture in Media Foundation.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 AM_SAMPLE2_PROPERTIES structure describes the properties of a media sample. The IMediaSample2 interface uses this structure.

Syntax

typedef struct tagAM_SAMPLE2_PROPERTIES {
  DWORD          cbData;
  DWORD          dwTypeSpecificFlags;
  DWORD          dwSampleFlags;
  LONG           lActual;
  REFERENCE_TIME tStart;
  REFERENCE_TIME tStop;
  DWORD          dwStreamId;
  AM_MEDIA_TYPE  *pMediaType;
  BYTE           *pbBuffer;
  LONG           cbBuffer;
} AM_SAMPLE2_PROPERTIES;

Members

cbData

Length of property data, in bytes. This structure member is for extensibility.

dwTypeSpecificFlags

Type-specific flags. Flags are defined separately for each media type. The default value is AM_VIDEO_FLAG_INTERLEAVED_FRAME (zero). The following flags are used for video streams. They are defined in the header file dvdmedia.h.

Flag Meaning
AM_VIDEO_FLAG_FIELD_MASK
0x0003
 Use this mask to check whether the sample is a field or a frame.
AM_VIDEO_FLAG_INTERLEAVED_FRAME
0x0000
 The sample is a frame. (Use the AM_VIDEO_FLAG_FIELD_MASK bitmask to test for this value.)
AM_VIDEO_FLAG_FIELD1
0x0001
 The sample is field 1. (Use the AM_VIDEO_FLAG_FIELD_MASK bitmask to test for this value.)
AM_VIDEO_FLAG_FIELD2
0x0002
 The sample is the field 2. (Use the AM_VIDEO_FLAG_FIELD_MASK bitmask to test for this value.)
AM_VIDEO_FLAG_FIELD1FIRST
0x0004
 If this flag is set, display field 1 first. Otherwise, display field 2 first. (Applies only when there are two fields per sample.)
AM_VIDEO_FLAG_WEAVE
0x0008
 If this flag is set, use weave mode (that is, do not deinterlace the sample). Otherwise, use bob mode. This flag applies only when there are two fields per sample.
AM_VIDEO_FLAG_REPEAT_FIELD
0x0040
 If this flag is set, display the first field again after displaying the second field. (Applies only when there are two fields per sample.)
AM_ReverseBlockStart
0x2
 Signals the start of a VOBU during reverse playback of DVD video. For more information, see DVD Playback Enhancements in Windows Vista.
AM_ReverseBlockEnd
0x4
 Signals the end of a VOBU during reverse playback of DVD video. The DVD Navigator sets this flag on an empty sample to signal the end of a VOBU. For more information, see DVD Playback Enhancements in Windows Vista.
AM_UseNewCSSKey
0x1
 For DVD playback, indicates the point in the stream when the decoder should apply a new Content Scramble System (CSS) key.

The DVD Navigator sets this flag on an empty media sample just before it renegotiate a CSS title key.

Previously, the DVD Navigator incorrectly sent this key before negotiating the disc key. Starting in Windows 7, if the decoder's AM_PROPERTY_DVDCOPY_SUPPORTS_NEW_KEYCOUNT property returns TRUE, the DVD Navigator does not send this flag before negotiating the disc key. See DVD Copy Protection Property Set.
 

Other flags are defined but not currently used. See dvdmedia.h.

dwSampleFlags

Bitwise combination of flags the AM_SAMPLE_PROPERTY_FLAGS enumerated data type. Undefined bits are reserved and must be zero.

lActual

Length of the valid data in the buffer.

tStart

Start time, if valid. The dwSampleFlags member specifies whether this member is valid.

tStop

Stop time, if valid. The dwSampleFlags member specifies whether this member is valid.

dwStreamId

Stream identifier. If the value is AM_STREAM_MEDIA, the stream contains media data. If the value is AM_STREAM_CONTROL, the stream contains control information. Applications can define values of 0x80000000 or greater for their own use. (See AM_SAMPLE_PROPERTY_FLAGS.)

pMediaType

Pointer to an AM_MEDIA_TYPE structure that specifies the media type if the format has changed. If this format has not changed, this member is NULL.

pbBuffer

Pointer to the sample buffer.

cbBuffer

Size of the sample buffer, in bytes.

Requirements

Requirement Value
Header strmif.h (include Dshow.h)

See also

DirectShow Structures