Setting up an EDL
If you have enabled the device control feature, you can specify, by timestamp, the exact place within your audio or video content that you want encoding to begin and end. To do so, you must create an edit decision list (EDL), which contains the clips you want to encode. (To enable device control, the device must be connected to the computer either through an port or through a COM port using a VTR that supports the Sony RS422 protocol.)
It is not recommended that you use an EDL for a broadcast because the encoder requires extra time to seek to the EDL points during encoding. During a broadcast, this could cause excessive buffering on a player.
You can add as many EDL entries as you want in any ordernot necessarily in the order in which they occur in the tape. You can also set up an EDL that sources from multiple tapes. During the encoding session, the encoder will prompt you when it is time to change the tape.
You should use a prestriped tape when setting up an EDL. To prestripe a tape, you can record the tape continuously from beginning to end when you first buy the tape. This ensures that the time code in the tape is continuous.
When setting up an EDL, you can control the seeking speed of your device (from slowest to fastest). Your device may not support all of the speeds.
When setting up an EDL, you can control the following:
- Preroll. Specifies the number of frames, relative to the mark-in time, that you want your device to start playing before encoding begins. Prerolling the tape stabilizes the tape so that no lines, jitters, or other artifacts resulting from the startup of the device are encoded. Prerolling should occur before startup latency, so consider the latency of your system as you calculate the number of preroll frames to use.
- Postroll. Specifies the number of frames, relative to the mark-out time, that you want encoding to continue. Postrolling ensures that the encoder captures the last frame of your clip before shutting down.
- Startup latency. Specifies the number of frames, relative to the mark-in time, that you want the encoder to start encoding. This setting compensates for the latency that occurs after the start command is issued but before encoding actually begins. You will have to experiment with your system to determine its latency in frames. After you determine the length of that delay in frames, you can start the encoder early, relative to your mark-in point, by that number of frames. For example, if your computer starts encoding after 10 frames, and you want to start encoding at frame 1, then you would set a startup latency of -9 (9 frames before you actually need it to start).
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