Media Types

  • Article

DirectShow uses the AM_MEDIA_TYPE structure to describe media samples. This structure includes GUID fields for major type, subtype, and format type, as well as fields specifying other sample features, such as whether the samples are compressed. This article summarizes the major type and subtype options registered by DirectShow. These media types are defined in UUIDS.H.

This article contains the following sections.

  • Media Types with No Subtype
  • Audio Media Types
  • Line 21 Media Types
  • MPEG-2 Media Types
  • Stream Media Types
  • Video Media Types

Media Types with No Subtype

The following table describes the media types with no subtype.

Type Description
MEDIATYPE_AnalogAudio Analog audio connection.
MEDIATYPE_File Media type is a file, used closed captions.
MEDIATYPE_Interleaved Data is interleaved, used by Digital Video (DV).
MEDIATYPE_Midi Data is MIDI format.
MEDIATYPE_ScriptCommand Data is a script command, used by closed captions.
MEDIATYPE_Text Data is text.
MEDIATYPE_Timecode Data is timecode data.

Audio Media Types

The wFormatTag member in the WAVEFORMATEX structure specifies the audio format type. The format type is generally FORMAT_WaveFormatEx. Media samples are generally whole number of samples as specified in the wBitsPerSample member in the WAVEFORMATEX structure. This is not necessarily true for MPEG audio samples that can come from packetized streams and are therefore not necessarily packaged on sample/frame boundaries. For MPEG audio the time stamp in a media sample is the time stamp for the first frame whose first byte is contained in the media sample.

Media subtypes are defined for each wFormatTag as follows:

  • The Data1 subfield of the Media Subtype is the same as the wFormatTag value.
  • The Data 2 field is 0.
  • The Data 3 field is 0x0010.
  • The Data 4 field is 0x80, 0x00, 0x00, 0xAA, 0x00, 0x38, 0x9B, 0x71.

Thus, for PCM audio the subtype GUID would be:

{00000001-0000-0010-8000-00AA00389B71}

Older filters may still use GUID_NULL as the subtype so this should be checked for. However, registration of a filter with the explicit subtype greatly improves the speed of graph loading, especially when the given filter is not required. The CreateAudioMediaType function can be used to create an AM_MEDIA_TYPE structure from a WAVEFORMATEX Structure.

The following table describes the audio media subtypes.

MEDIATYPE_Audio Data is audio
MEDIASUBTYPE_PCMAudio PCM audio
MEDIASUBTYPE_MPEG1Packet MPEG1 Audio Packet
MEDIASUBTYPE_MPEG1Payload MPEG1 Audio Payload

Line 21 Media Types

The following table describes the line 21 closed captioning media subtypes.

MEDIATYPE_AUXLine21Data Data is line 21 type, used by closed captions
MEDIASUBTYPE_Line21_BytePair Line 21 data as byte pairs
MEDIASUBTYPE_Line21_GOPPacket Line 21 data in DVD GOP Packet
MEDIASUBTYPE_Line21_VBIRawData Line 21 data in raw VBI format

MPEG-2 Media Types

The following table describes the MPEG-2 media subtypes.

MEDIATYPE_MPEG2_PES Data is MPEG-2 format, used by DVD
MEDIASUBTYPE_DVD_SUBPICTURE Subpicture data
MEDIASUBTYPE_DOLBY_AC3 Dolby data
MEDIASUBTYPE_MPEG2_AUDIO MPEG-2 audio data
MEDIASUBTYPE_DVD_LPCM_AUDIO DVD audio data

Stream Media Types

Time stamps are byte positions * 10000000 (notionally 1 byte per second) rather than real times.

The following table describes the stream media subtypes.

MEDIATYPE_Stream Data is a non-time stamped byte stream
MEDIASUBTYPE_Avi Data from AVI file
MEDIASUBTYPE_WAVE Data from WAV file
MEDIASUBTYPE_AU Data from AU file
MEDIASUBTYPE_AIFF Data from AIFF file
MEDIASUBTYPE_MPEG1Video MPEG video
MEDIASUBTYPE_MPEG1System MPEG system
MEDIASUBTYPE_MPEG1VideoCD MPEG video CD
MEDIASUBTYPE_MPEG1Audio MPEG audio
MEDIASUBTYPE_DssVideo Dss Video
MEDIASUBTYPE_DssAudio Dss Audio

Video Media Types

The following table describes the video media subtypes.

MEDIATYPE_Video Data is video
MEDIASUBTYPE_YVU9 Standard YVU9 format uncompressed data. A planar YUV format. A Y sample at every pixel, a U and V sample at every fourth pixel horizontally on each line; a Y sample on every vertical line, a U and V sample at every fourth vertical line. 9 bits per pixel.
MEDIASUBTYPE_Y411 YUV 411 format data. Same as Y41P.
MEDIASUBTYPE_Y41P Y41P format data. A packed YUV format. A Y sample at every pixel, a U and V sample at every fourth pixel horizontally on each line; every vertical line sampled. Byte ordering (lowest first) is U0, Y0, V0, Y1, U4, Y2, V4, Y3, Y4, Y5, Y6, Y7, where the suffix 0 is the leftmost pixel and increasing numbers are pixels increasing left to right. Each 12-byte block is 8 image pixels.
MEDIASUBTYPE_YUY2 YUY2 format data. Same as UYVY but with different pixel ordering. Byte ordering (lowest first) is Y0, U0, Y1, V0, Y2, U2, Y3, V2, Y4, U4, Y5, V4, where the suffix 0 is the leftmost pixel and increasing numbers are pixels increasing left to right. Each 4-byte block is 2 image pixels.
MEDIASUBTYPE_YVYU YVYU format data. A packed YUV format. Same as UYVY but with different pixel ordering. Byte ordering (lowest first) is Y0, V0, Y1, U0, Y2, V2, Y3, U2, Y4, V4, Y5, U4, where the suffix 0 is the leftmost pixel and increasing numbers are pixels increasing left to right. Each 4-byte block is 2 image pixels.
MEDIASUBTYPE_UYVY UYVY format data. A packed YUV format. A Y sample at every pixel, a U and V sample at every second pixel horizontally on each line; every vertical line sampled. Probably the most popular of the various YUV 4:2:2 formats. Byte ordering (lowest first) is U0, Y0, V0, Y1, U2, Y2, V2, Y3, U4, Y4, V4, Y5, where the suffix 0 is the leftmost pixel and increasing numbers are pixels increasing left to right. Each 4-byte block is 2 image pixels.
MEDIASUBTYPE_Y211 YUV 211 format data. A packed YUV format. A Y sample at every second pixel, a U and V sample at every fourth pixel horizontally on each line; every vertical line sampled. Byte ordering (lowest first) is Y0, U0, Y2, V0, Y4, U4, Y6, V4, Y8, U8, Y10, V8, where the suffix 0 is the leftmost pixel and increasing numbers are pixels increasing left to right. Each 4-byte block is 4 image pixels.
MEDIASUBTYPE_CLJR Cirrus Logic Jr YUV 411 format with less than 8 bits per Y, U, and V sample. A Y sample at every pixel, a U and V sample at every fourth pixel horizontally on each line; every vertical line sampled.
MEDIASUBTYPE_IF09 Indeo produced YVU9 format with additional information about differences from the last frame. 9.5 bits per pixel but reported as 9.
MEDIASUBTYPE_MJPG Motion JPEG (MJPG) compressed video.
MEDIASUBTYPE_TVMJ TrueVision MJPG format.
MEDIASUBTYPE_WAKE MJPG format produced by some cards.
MEDIASUBTYPE_CFCC MJPG format produced by some cards.
MEDIASUBTYPE_IJPG Intergraph JPEG format.
MEDIASUBTYPE_Plum Plum MJPG format.
MEDIASUBTYPE_RGB1 RGB 1 bit per pixel. Palettized.
MEDIASUBTYPE_RGB4 RGB 4 bits per pixel. Palettized.
MEDIASUBTYPE_RGB8 RGB 8 bits per pixel. Palettized.
MEDIASUBTYPE_RGB565 565 format of RGB, 16 bits per pixel. Uncompressed RGB samples.
MEDIASUBTYPE_RGB555 555 format of RGB, 16 bits per pixel. Uncompressed RGB samples.
MEDIASUBTYPE_RGB24 RGB 24 bits per pixel. Uncompressed RGB samples.
MEDIASUBTYPE_RGB32 RGB 32 bits per pixel. Uncompressed RGB samples.
MEDIASUBTYPE_Overlay Video delivered using hardware overlay.
MEDIASUBTYPE_dvsd Standard DV format.
MEDIASUBTYPE_dvhd High Definition DV format.
MEDIASUBTYPE_dvsl Long Play DV format.
MEDIASUBTYPE_MPEG1Packet MPEG1 Video Packet.
MEDIASUBTYPE_MPEG1Payload MPEG1 Video Payload.
MEDIASUBTYPE_VideoPort Data is video port data, used with DVD.

Last updated on Wednesday, April 13, 2005

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