Troubleshooting Video

1. I can't genlock the signal coming out of the Decoder.
   
   
2. Closed Captioning text looks garbled downstream. What can cause this?
   
   
3. How can I change or lower the video frame rate?
   
   
4. The video bitrate settings seem inconsistent. I type in 5000 Kbps, but it displays as 4.88 Mbps. Why the discrepancy?
   
   
5. Why does my video appear to have frame loss?
   
   

1. I can't genlock the signal coming out of the Decoder.
   Genlock is not provided with an analog Streambox system. Only systems with SDI video have a genlock input and capability. To genlock an analog signal coming out of the Decoder, it would first have to loop through a Time Base Corrector (TBC). An SDI signal can sync directly with a Sync Generator.

   Return to top of page

2. Closed Captioning text looks garbled downstream. What can cause this?
   Normally, the Streambox Decoder handles Line 21/22 Closed Captioning perfectly. However, with excessive signal noise you can experience garbled CC text downstream. The CC decoder software is fairly sensitive to noise, so often it is the first signal component to fail.

   Return to top of page

3. How can I change or lower the video frame rate?
   To go below the default frame rate of 29.97 for NTSC or 25 for PAL/SECAM, change the setting under the Video menu of the Encoder application. Use this guide to help you set the frame rate you desire:

   Setting	NTSC/NTSC-J (fps)	PAL/SECAM (fps)
   Full frame-frame	30	25
   3/4 frame-frame	22.5	18.75
   1/2 frame-frame	15	12.5
   1/3 frame-frame	10	8.3
   1/4 frame-frame	7.5	6.25
   1/5 frame-frame	6	5
   1/10 frame-frame	3	2.5

   Return to top of page

4. The video bitrate settings seem inconsistent. I type in 5000 Kbps, but it displays as 4.88 Mbps. Why is there a discrepancy?
   This is because of the conversion from Megabits per second (Mbps) to Kilobits per second. One Megabit equals 1024 Kilobits, not 1000, so there may appear to be a rounding error but this is due to the conversion being based on hexadecimal rather than decimal, so there is no error.
   
   
5. Why does my video appear to have frame loss?
   If it is consistent frame loss that looks like jitter in the video it could be a field order problem. In this case you would need to change the field order on the Decoder. You can change this in the LCD panel go to Output -> Fields, then experiment with INV2 or Fields Up. For DV based signals the output field order should be set to INV2.

   If it is inconsistent frame loss that looks like digital loss accompanied by blockiness then the problem could be contributed to many other factors: bandwidth set higher than the connection can support, network errors, low VBR buffer time, filtering at high resolution (full D1), and hardware problems. Refer to the Streambox ACT-L3™ manual for help with these settings.

   Return to top of page

   Go Back to FAQ