405 to 625 converter? - Page 2 - UK Vintage Radio Repair and Restoration Discussion Forum

DoctorWho · 29th Mar 2008, 7:12 pm

Thanks Jeffrey and Darryl, I just wondered. So, basically, it would require a completely new converter from scratch.

Does anyone know how the BBC and ITV convert their surviving 405 line video tapes to 625?

All the best,

Peter.

ppppenguin · 29th Mar 2008, 7:18 pm

I think there was a specialised converter, possibly built by Designs Department, possibly a later one by Snell and Wilcox. May have been a modified ACE 625><525 converter.

DoctorWho · 29th Mar 2008, 7:24 pm

Thanks Jeffrey, I did wonder. I know that some programmes, such as Steptoe and Son survive only as optical standards conversions, I had also heard that there was a method of feeding in 405VT in to the first 405-lines of a 625-line recorder and then interpolating to get it back to 4:3, but I do not know any of the technical details of this. I guess with the archives being transferred over to more recent formats conversions are needed every now and then.

evingar · 29th Mar 2008, 7:38 pm

Quote:

Originally Posted by ppppenguin

I think there was a specialised converter, possibly built by Designs Department, possibly a later one by Snell and Wilcox. May have been a modified ACE 625><525 converter.

You probably know a lot more than I about this Jeffrey, but some of the Hancock stuff screened a few years ago seems to have a very ill defined 405 line structure present . I wondered at the time if the conversion had been done optically.

EDIT

I See the Dr. pre empted me

Kat Manton · 29th Mar 2008, 7:50 pm

Hi,

Quote:

Originally Posted by DoctorWho

So, basically, it would require a completely new converter from scratch.

This is why I'm persuing the computer approach. The hardware already exists and data is available for it; the software already exists and is open-source. So from my POV it's fairly straightforward.

Once the OS supports 405-line capture it'll be possible to do anything with it that can already be done with 525 and 625. That includes recording it, scaling and transcoding to produce DVDs, outputting in real-time as pretty much any standard you like and streaming it over the 'net.

I'd rather do a bit of work that'll mean you can do anything you like with 405-line analogue (including convert it to 625) rather than do even the same amount of work and only end up being able to convert it to 625.

I generally have several projects on the go at any time. One of the projects is to get various bits of my own 405-line gear working anyway.

Cheers, Kat

jjl · 29th Mar 2008, 8:39 pm

Hello Kat

I was involved in a couple of projects using Conexant video capture devices (CX23880, Bt878 etc) and PC hardware a few years ago. I'm not sure that these devices could be persuaded to deal with 405 line video without external hardware support but I have a fair bit of data on these devices. Please send me a PM if you feel that this may be of some help.

John

Dave Moll · 29th Mar 2008, 10:28 pm

Quote:

Originally Posted by Kat Manton

I'd rather do a bit of work that'll mean you can do anything you like with 405-line analogue (including convert it to 625) rather than do even the same amount of work and only end up being able to convert it to 625.

This sounds a bit like what a former colleague of mine called "the energetic pursuit of idleness" (i.e. putting work into the design so that it makes life easier in the long run)

murphyv310 · 29th Mar 2008, 10:40 pm

There is nothing wrong with a properly set up optical converter and I am sure RTE in Ireland did it for a number of years. I have tried it with my V 310 and a Sony DVD camcorder and the results are excellent albeit with a little chopping of the overall field of veiw, a more squared off crt on the 405 set of course would be better and locking the field sync would also improve matters.
Trevor

DoctorWho · 30th Mar 2008, 3:53 pm

As far as I am aware the Steptoe and Son episodes survived only on CV2000 reel to reel episodes that, I think, Ray Galton had recorded off-air at the time. If I remember the story correctly he made an optical standards conversion of them as the tapes were deteriorating, and so this is the only format in which they now survive. If some form of electronic standards conversion had been possible then I am sure the results would have been better, but at least they exist, which, given the huge amount of junking, is something.

29th Mar 2008, 7:12 pm	#21
DoctorWho Rest in Peace Join Date: Apr 2005 Location: Devon Posts: 850	Re: 405 to 625 converter? Thanks Jeffrey and Darryl, I just wondered. So, basically, it would require a completely new converter from scratch. Does anyone know how the BBC and ITV convert their surviving 405 line video tapes to 625? All the best, Peter.

29th Mar 2008, 7:18 pm	#22
ppppenguin Retired Dormant Member Join Date: Dec 2003 Location: North London, UK. Posts: 6,168	Re: 405 to 625 converter? I think there was a specialised converter, possibly built by Designs Department, possibly a later one by Snell and Wilcox. May have been a modified ACE 625><525 converter.

29th Mar 2008, 7:24 pm	#23
DoctorWho Rest in Peace Join Date: Apr 2005 Location: Devon Posts: 850	Re: 405 to 625 converter? Thanks Jeffrey, I did wonder. I know that some programmes, such as Steptoe and Son survive only as optical standards conversions, I had also heard that there was a method of feeding in 405VT in to the first 405-lines of a 625-line recorder and then interpolating to get it back to 4:3, but I do not know any of the technical details of this. I guess with the archives being transferred over to more recent formats conversions are needed every now and then.

29th Mar 2008, 8:39 pm	#26
jjl Octode Join Date: Jan 2003 Location: Ware, Herts. UK. Posts: 1,072	Re: 405 to 625 converter? Hello Kat I was involved in a couple of projects using Conexant video capture devices (CX23880, Bt878 etc) and PC hardware a few years ago. I'm not sure that these devices could be persuaded to deal with 405 line video without external hardware support but I have a fair bit of data on these devices. Please send me a PM if you feel that this may be of some help. John

29th Mar 2008, 10:40 pm	#28
murphyv310 Dekatron Join Date: Sep 2006 Location: Kilmarnock, Ayrshire, UK. Posts: 5,376	Re: 405 to 625 converter? There is nothing wrong with a properly set up optical converter and I am sure RTE in Ireland did it for a number of years. I have tried it with my V 310 and a Sony DVD camcorder and the results are excellent albeit with a little chopping of the overall field of veiw, a more squared off crt on the 405 set of course would be better and locking the field sync would also improve matters. Trevor __________________ Cheers, Trevor. MM0KJJ. RSGB, GQRP, WACRAL, K&LARC. Member

30th Mar 2008, 3:53 pm	#29
DoctorWho Rest in Peace Join Date: Apr 2005 Location: Devon Posts: 850	Re: 405 to 625 converter? As far as I am aware the Steptoe and Son episodes survived only on CV2000 reel to reel episodes that, I think, Ray Galton had recorded off-air at the time. If I remember the story correctly he made an optical standards conversion of them as the tapes were deteriorating, and so this is the only format in which they now survive. If some form of electronic standards conversion had been possible then I am sure the results would have been better, but at least they exist, which, given the huge amount of junking, is something.