To Seek By Frame Number Using the Synchronous Reader
To seek for data by frame number using the synchronous reader, you specify a range for playback. A range is defined by a starting frame number in a specific video stream and a number of frames to play.
To seek data in an ASF file by frame number using the synchronous reader, perform the following steps.
- Set the starting frame number and number of frames to read for sample delivery by calling IWMSyncReader::SetRangeByFrame. You must specify the stream number of a frame-indexed video stream. The reader will synchronize the rest of the outputs to the presentation time of the specified frame of the specified stream and begin delivering output samples.
- Begin retrieving samples with calls to IWMSyncReader::GetNextSample. Proceed as you normally would with the synchronous reader.