Epiphan VGADVI Recorder - Manual (Page 82)

VGADVI Recorder User Guide 3-2 Fine-tune channel configuration
When adjusting the frame rate, you may need to try different values to achieve the best outcome. The following
table provides the performance expectations when typical settings are used.
Table 16 Performance expectations
Setting H.264 MPEG
Resolution 1920×1200 1920×1080
Video encoding preset: Quality 25-26 fps 13 fps
Video Encoding preset: Speed 27-28 fps 17-18 fps
To change the frame rate:
1. Connect to the admin interface using your preferred connection mechanism. See Connect to the Admin
Interface .
2. Login as admin.
3. From the web interface, click Stream setup; a Stream setup page opens.
4. Enter a value in the Limit frame rate field.
5. Click Apply.
Adjust key frame interval
The key frame interval feature specifies how often a key frame (a frame that contains all the pixels) is used when
streaming the video. This setting also impacts how quickly a video moves through the frames when a viewer
uses the search function of their media player.
Increasing the number of seconds between key frames can significantly reduce your bandwidth and system
resource usage with minor impact to your video quality. A good rule of thumb is to keep the interval between 2
to 3 seconds and decrease the key frame interval as the motion increases. Try different settings and note
changes in the video quality. If your video quality is poor and jittery you may need to decrease the interval
between key frames. If you have unlimited bandwidth and system resources you can choose an option to
stream key frames only.
To adjust the key frame interval:
1. Connect to the admin interface using your preferred connection mechanism. See Connect to the Admin
Interface .
2. Login as admin.
3. From the web interface, click Stream setup; a Stream setup page opens.
4. Scroll to the Key frame interval drop-down menu. Choose the number of seconds before the system
streams a key frame.
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