DV Splitter Filter
|Microsoft DirectShow 9.0|
DV Splitter Filter
This filter splits an interleaved digital video (DV) stream into its component video and audio streams.
|Filter Interfaces||IBaseFilter, IDVSplitter|
|Input Pin Media Types||MEDIATYPE_Interleaved, MEDIASUBTYPE_dvsd, FORMAT_DvInfo|
|Input Pin Interfaces||IMemInputPin, IPin, IQualityControl|
|Output Pin Media Types||Video: MEDIATYPE_Video, FORMAT_DvInfo
Audio: MEDIATYPE_Audio, MEDIASUBTYPE_PCM, FORMAT_WaveFormatEx
|Output Pin Interfaces||IMediaPosition, IMediaSeeking, IPin, IQualityControl|
|Property Page CLSID||No property page.|
DV frames contain audio and video in the same frame. The DV Splitter filter extracts the audio data and delivers it as one or two audio streams, from the audio output pins. The original DV frame is delivered from the video output pin, as a video frame. The media type on the video frame is changed from MEDIATYPE_Interleaved to MEDIATYPE_Video, but otherwise the data is not modified. The media type is changed to signal that the audio data into the frame should be ignored. The DV Splitter does not set a media time on its output samples; if you are writing a downstream filter that requires the media times, then you can derive the times from the frame count.
The DV Splitter filter can accept dynamic format changes in the audio stream. However, if the AVI Mux filter is downstream, it will reject the format change. If this happens, the DV Splitter stops producing an audio stream. This limitation only affects type-2 file capture. For type-1 files, the interleaved stream is not split in the first place. For preview, there is no AVI Mux filter downstream.
If the DV source is a live camera, there is normally no reason for the audio format to change. However, the format might change if you transmit from a VTR tape that contains several heterogeneous sources.
Each DV frame contains metadata, in addition to the audio and video data. This metadata can change from frame to frame. Applications can parse the metadata by examining either the input samples or the video output samples. However, DirectShow does not provide any direct support for parsing DV metadata. Consult IEC 61834-4 for more information.