01-04-2019, 12:05 AM
Hello Frank, et al,
As I am into vintage TV formats I just bought a French TV9-90UM. I am a little crazy I know...
.
That is the French version of the Sony TV9-90UB which instead of 405 can receive 819 line TV signals on VHF. I got this for later developments in the standards conversion arena... Of course 819 lines is a higher format than 625 so converting up would be only one option but what I would really like to do is convert an HD signal i.e 720p or 1080i to 819 lines.
For an "HD Hedghog" this kind of conversion would need a different approach though.
- An HD input capability for the Hedghog from an HDMI or HD-SDI input interface
- A different scaling approach as we would be going from a higher to a lower resolution format
- Perhaps a different output chip as the current one has an LPF with 9MHz cut off (the French 819 line system has a vision bandwidth of 14Mhz)
For 720p inputs this could be done by generating odd and even fields from the 720p frames with an algorithm that shifts up/down by half a line with respect to the original position to get the interlaced image. For 1080i simply the 1080x540 fields would be converted to 819 line fields.
My question is; could this be done with the Hedghog hardware base by replacing the input TVP5051 decoder by an HDMI or HD-SDI front end? I realize that HDMI my pose some additional problems due to HDCP but I would go for a non HDCP input or HD-SDI which would be my preference...
I realize this is a new subject and just wanted to get some feedback about whether this is feasible. Nothing I am planning in the next few weeks though, just to get a discussion started perhaps in a new thread?
Cheers
Semir
As I am into vintage TV formats I just bought a French TV9-90UM. I am a little crazy I know...
. That is the French version of the Sony TV9-90UB which instead of 405 can receive 819 line TV signals on VHF. I got this for later developments in the standards conversion arena... Of course 819 lines is a higher format than 625 so converting up would be only one option but what I would really like to do is convert an HD signal i.e 720p or 1080i to 819 lines.
For an "HD Hedghog" this kind of conversion would need a different approach though.
- An HD input capability for the Hedghog from an HDMI or HD-SDI input interface
- A different scaling approach as we would be going from a higher to a lower resolution format
- Perhaps a different output chip as the current one has an LPF with 9MHz cut off (the French 819 line system has a vision bandwidth of 14Mhz)
For 720p inputs this could be done by generating odd and even fields from the 720p frames with an algorithm that shifts up/down by half a line with respect to the original position to get the interlaced image. For 1080i simply the 1080x540 fields would be converted to 819 line fields.
My question is; could this be done with the Hedghog hardware base by replacing the input TVP5051 decoder by an HDMI or HD-SDI front end? I realize that HDMI my pose some additional problems due to HDCP but I would go for a non HDCP input or HD-SDI which would be my preference...
I realize this is a new subject and just wanted to get some feedback about whether this is feasible. Nothing I am planning in the next few weeks though, just to get a discussion started perhaps in a new thread?
Cheers
Semir
