Declaration
function GetMediaType(streamIndex: integer; mediaTypeIndex: integer): TIEDictionary;
function GetMediaType(const streamType: WideString; mediaTypeIndex: integer): TIEDictionary;
Description
Returns the media type for the specified stream and media type index.
Each source stream can support several media types (ie. frame size, frame format, etc..) so GetMediaType provides details about them.
| Parameter | Description |
| streamIndex | Index of the stream, in the range of 0 to StreamCount - 1 |
| streamType | A string representing the stream type. Only the first stream of this type will be considered. Can be any one of the values accepted by GetStreamType |
| mediaTypeIndex | Index of the media type, in the range of 0 to GetMediaTypesCount - 1 |
The resulting object is a dictionary which contains following media type attributes:
| Dictionary key | Type | Description |
| IEMAJORTYPE_DICT_KEY | string | Contains major stream type. See GetStreamType for a list of stream types. The Media Foundation Type is MF_MT_MAJOR_TYPE |
| IESUBTYPE_DICT_KEY | string | Contains the media sub type. See below for a list of common values. The Media Foundation Type is MF_MT_SUBTYPE |
| IECOMPRESSED_DICT_KEY | boolean | If this attribute is True, the media type is a compressed format. The Media Foundation Type is MF_MT_COMPRESSED |
| IEAVGBITRATE_DICT_KEY | integer | Approximate data rate of the video stream, in bits per second. The Media Foundation Type is MF_MT_AVG_BITRATE |
| IEDEFAULTSTRIDE_DICT_KEY | integer | The number of bytes needed to go from one row of pixels to the next. The Media Foundation Type is MF_MT_DEFAULT_STRIDE |
| IEFRAMERATE_DICT_KEY | double | Frame rate of a video media type, in frames per second. The Media Foundation Type is MF_MT_FRAME_RATE |
| IEFRAMERATEMAX_DICT_KEY | double | The maximum frame rate that is supported by a video capture device, in frames per second. The Media Foundation Type is MF_MT_FRAME_RATE_RANGE_MAX |
| IEFRAMERATEMIN_DICT_KEY | double | The minimum frame rate that is supported by a video capture device, in frames per second. The Media Foundation Type is MF_MT_FRAME_RATE_RANGE_MIN |
| IEFRAMEWIDTH_DICT_KEY | integer | Width of a video frame, in pixels. The Media Foundation Type is MF_MT_FRAME_SIZE (high dword) |
| IEFRAMEHEIGHT_DICT_KEY | integer | Height of a video frame, in pixels. The Media Foundation Type is MF_MT_FRAME_SIZE (low dword) |
| IEINTERLACEMODE_DICT_KEY | string | Describes how the frames in a video media type are interlaced. The Media Foundation Type is MF_MT_INTERLACE_MODE |
| IEVIDEOLIGHTING_DICT_KEY | string | Specifies the optimal lighting conditions for a video media type. Allowed values are: 'Bright', 'Office', 'Dim' and 'Dark'. The Media Foundation Type is MF_MT_VIDEO_LIGHTING |
| IEAUDIOBITSPERSAMPLE_DICT_KEY | integer | Number of bits per audio sample in an audio media type. The Media Foundation Type is MF_MT_AUDIO_BITS_PER_SAMPLE |
| IEAUDIOFLOATSAMPLESPERSECOND_DICT_KEY | double | Number of audio samples per second. The Media Foundation Type is MF_MT_AUDIO_FLOAT_SAMPLES_PER_SECOND |
| IEAUDIONUMCHANNELS_DICT_KEY | integer | Number of audio channels. The Media Foundation Type is MF_MT_AUDIO_NUM_CHANNELS |
| IEAUDIOSAMPLESPERSECOND_DICT_KEY | integer | Number of audio samples per second. The Media Foundation Type is MF_MT_AUDIO_SAMPLES_PER_SECOND |
| IEAUDIOBLOCKALIGNMENT_DICT_KEY | integer | Block alignment, in bytes. For PCM audio formats, the block alignment is equal to the number of audio channels multiplied by the number of bytes per audio sample. The Media Foundation Type is MF_MT_AUDIO_BLOCK_ALIGNMENT |
| IEALLSAMPLESINDEPENDENT_DICT_KEY | boolean | Specifies for a media type whether each sample is independent of the other samples. The Media Foundation Type is MF_MT_ALL_SAMPLES_INDEPENDENT |
| IEAUDIOAVGBYTESPERSECOND_DICT_KEY | integer | Average number of bytes per second. The Media Foundation Type is MF_MT_AUDIO_AVG_BYTES_PER_SECOND |
The Video media sub types (IESUBTYPE_DICT_KEY) are: 'RGB8', 'RGB555', 'RGB565', 'RGB24', 'RGB32', 'ARGB32', 'AI44', 'AYUV', 'YUY2', 'YVYU', 'YVU9', 'UYVY', 'NV11', 'NV12', 'YV12', 'I420', 'IYUV', 'Y210', 'Y216',
'Y410', 'Y416', 'Y41P', 'Y41T', 'Y42T', 'P210', 'P216', 'P010', 'P016', 'v210', 'v216', 'v410', 'MP43', 'MP4S', 'M4S2', 'MP4V', 'WMV1', 'WMV2', 'WMV3', 'WVC1', 'MSS1', 'MSS2',
'MPG1', 'dvsl', 'dvsd', 'dvhd', 'dv25', 'dv50', 'dvh1', 'dvc ', 'H264', 'MJPG'.
The Audio media sub types (IESUBTYPE_DICT_KEY) are: 'PCM', 'Float', 'DTS', 'Dolby_AC3_SPDIF', 'DRM', 'WMAudioV8', 'WMAudioV9', 'WMAudio_Lossless', 'WMASPDIF', 'MSP1', 'MP3', 'MPEG', 'AAC', 'ADTS'.
The interlace modes (IEINTERLACEMODE_DICT_KEY) are: 'Progressive', 'FieldInterleavedUpperFirst', 'FieldInterleavedLowerFirst', 'FieldSingleUpper', 'FieldSingleLower', 'MixedInterlaceOrProgressive'.
// Fill supported formats listbox
ListBox1.Clear();
with ImageEnView1.IO.MediaFoundationSourceReader do
begin
SetVideoInput(ComboBox1.ItemIndex);
for i := 0 to GetMediaTypesCount(mmf_VIDEO_STREAM) - 1 do
begin
mediaType := GetMediaType(mmf_VIDEO_STREAM, i);
ListBox1.Items.Add(Format('%d x %d %.1f fps (min fps: %.1f max fps: %.1f) %s',
[mediaType.GetInteger(IEFRAMEWIDTH_DICT_KEY), // width
mediaType.GetInteger(IEFRAMEHEIGHT_DICT_KEY), // height
mediaType.GetDouble(IEFRAMERATE_DICT_KEY), // default frame rate
mediaType.GetDouble(IEFRAMERATEMIN_DICT_KEY), // minimum frame rate
mediaType.GetDouble(IEFRAMERATEMAX_DICT_KEY), // maximum frame rate
mediaType.GetString(IESUBTYPE_DICT_KEY) // subtype = color space
]));
end;
end;
See Also
◼StreamCount
◼GetMediaTypesCount