TI E2E Community
Legacy Video Converters Forum
How to generate a blue screen through tvp5158
I'm using tvp5158 for four channel video capturing. When video source wasn't inserted into one video channel, is it possible to generate a blue screen signal automatically from the tvp5158?
I writed 0x44 to register 0xa9, then writed 0x1 to register 0x24..
But , blue screen signal wasn't generated through tvp5158.
The first thing you need to do is select some other color than black so that you can easily see when it’s working.
To select the color blue, modify the following register settings.
- Write 29h to register 90h
- Write F0h to register 91h
- Write 6Eh to register 92h
Lastly, you need to enable the blue screen mode as follows.
- Write 44h to register A9h to enable the automatic blue screen mode, or
- Write 48h to register A9h to enable the force blue screen mode
In the automatic blue screen mode, the blue screen will be enabled whenever the TVP5158 loses horizontal and/or vertical lock.
There is one known issue with using the automatic blue screen mode with a weak signal or any other input that’s hard to lock too. If the TVP5158 horizontal and/or vertical lock is intermittent (i.e. not stable), then the blue screen may continually flash on and off.
When I encoded D1_PAL video, I found the size of blue screen was 736X2100. Could tvp5158 output four blue screens which size is 720x576? So,If one video channel of tvp5158 couldn't receive video signal, tvp5158 would create a blue screen to instead of normal video output.
Each video channel has an independent blue screen output mode. If one video channel is placed in the blue screen mode, it will have no effect on the other 3 channels.
The blue screen mode only affects active video. For unscaled D1 outputs, the size of active video and hence the blue screen is 720x576 for PAL.
What output format (e.g. 4-Ch D1 line-interleaved) are you trying to use?
The value of register 0xb0 is 0xa0. So I'm using 4-Ch D1 line-interleaved output format . If I disconnect the video connection on tvp5158, the TVP5158_VDET flag will alway be false. Although I've set register 0xa9 to 0x48. tvp5158 wouldn't output bluescreen .
What values are you writing to registers 90h, 91h and 92h?
Hi Jim ,
register 0x90 = 0x10
register 0x91 = 0x80
register 0x92 = 0x80
register 0x93 = 0x00
You need to select some other color than black so that you can more easily see when it’s working.
The problem have been resolved, Thanks.
All content and materials on this site are provided "as is". TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with regard to these materials, including but not limited to all implied warranties and conditions of merchantability, fitness for a particular purpose, title and non-infringement of any third party intellectual property right. TI and its respective suppliers and providers of content make no representations about the suitability of these materials for any purpose and disclaim all warranties and conditions with respect to these materials. No license, either express or implied, by estoppel or otherwise, is granted by TI. Use of the information on this site may require a license from a third party, or a license from TI.
TI is a global semiconductor design and manufacturing company. Innovate with 100,000+ analog ICs andembedded processors, along with software, tools and the industry’s largest sales/support staff.