Several passes through the source data are required to produce an Ultimotion movie file.
During the first pass, the capture routines position the video source device to the starting position in the source video. It then uses OS/2 multimedia to record the desired audio track. If the desired final format for the movie requires both audio and video to be interleaved, MULTITRACKWRITE interleaves them.
During the second pass, capture routines use OS/2 multimedia to position the video source at the desired location. For each frame in the movie, an MCI_STEP message is sent to the MCD controlling the source device. When the resulting image has been "grabbed" or "digitized" by the capture hardware, the video data is retrieved and written to disk through the AVI I/O procedure. This process continues until the required video is captured.
Note: Only the second pass is used if you are recording video without audio.
The following figure illustrates the architecture of the components involved in doing asymmetric capture and compression of video from frame accurate devices.
旼컴컴컴컴컴컴컴컴컴컴�컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴커
� Asymmetric Recorder 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴� �
컴컴컴컴컴컴컴컴컴켸 � �
粕 � Media Control Interface Commands and Notifications � �
넬� 컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴컴좔컴컴컴컴컴컴컴컴커�
납 Media Device Manager 납
냅컴컴컴컴컴컴� 컴컴컴컴컴컴컴컴 컴컴컴컴컴컴컴컴쩡컴컴컴컴컴컴컴컴컴컴컴컴冒
� .WAV data � � � 旼컴�
� 敏쩟쩔 旼컴 컴컴컴컴컴커 旼 컴컴컴컴� 旼 컴컴컴컴컴컴� 旼컴컨커
� 읒좋줄컴퀮mplifier Mixer� 쿣ideo Disc� 쿏igital Media � 쿌VI 첼
� � 쿘edia Driver � 쿏river � 쿏river � 旼IOProc납
� � 읓컴컴컴컴컴� 컴� 읕컴컴컴� 켸 읕컴컴컴 컴컴컫� � 읕� 컴켸�
� � � � � � � � �
� � 旼컴컴� 컴� 旼컴� 컴컴컴컴커 旼� 컴컴컴컴� 旼컴� 커 敏쩟탓 � �
� � 쿌udio � 쿞PI Interfaces� � Laser Disc� 쿣SD � 읒좋줄 읕커 �
� � 쿌dapter � 쿞SM � � � 쿏river� uncompressed� �
� � 읕컴컴컴컴� 읕컴컴컴컴컴컴켸 읕컴컴컴컴컴� 읕컴� 켸 video frame � �
� � audio data 旼컴컴컴컴컴컴컴컴� � 旼켸 �
� � 旼컴컴� 敏쩟쩔 旼컴컴 컴컴컴컴컴� � 旼컴� 컴컴컴컴� 旼컴 컴커�
� 읕 MMIO냐읒좋줄� Multitrack � � 쿣ideo Capture� 쿎ODEC 납
� 읕컴컴� � Stream Handler � � 쿛DD � � 납
읕컴컴컴컴컴컴컴컴�읕컴컴 컴컴컴컴컴� � 읕컴� 컴컴컴컴� 읕컴컴컴冒
� � � �
旼컴컴 컴컴컴컴컴� � 旼컴� 컴컴컴컴� �
� MMIO � � 쿣ideo Adapter� �
� Manager � � 읕컴컴컴컴컴컴� �
읕컴컴 컴컴컴컴컴� 읕컴컴컴컴컴컴컴컴� 敏쩟쩔컴컴�
� 읒좋줄
旼컴컴 컴컴컴컴컴� Compressed
� AVI � Data
� IOProc �
읕컴컴쩡컴컴컴컴켸
�
旼컴컴 컴컴컴컴컴�
� Movie �
� File �
읕컴컴컴컴컴컴컴켸