psuvm%iks@psuvax.UUCP (04/30/84)
Thank you one and all for the healthy discussion about the PAL to NTSC conversion. It has greatly helped me in making up my mind. Excuse me for the delay in putting up the summary... I have been rather busy lately. THANKS again. The summary follows: Primary quesion: Does anyone out there know of a way to to convert video cassettes recorded in a country using PAL so that they would playback here ?? and Vice versa ??? Subj: PAL <==> NTSC From: Gary UUCP: ...: decvax | allegra | ucbvax :!decwrl!rhea!mother!hughes ARPA: hughes%mother.DEC @purdue-merlin.ARPA reality?: DEC, ZKO1-2/C07, 110 Spit Brook Rd, Nashua NH 03062 The answer in both cases is yes. There are a number of professional video service companies that will convert from one format to another for a fee. I'm not sure how they do it but my guess is they decode the signal to RGB and the re-encode into the format you require. I don't know whether this introduces a timing problem due to PAL using a 50Hz synch pulse and NTSC using a 60Hz synch. I would expect that to do this officially you would have to own the copyright or prove that the material is not copyright. Getting someone to convert Dr Who tapes sent from the UK by a friend may be difficult. As to playing PAL tapes; I'm glad you asked! I have just purchased the necessary components to do just that (since I have a lot of PAL tapes from Australia etc). SONY make a number of receivers that are multisystem. The one I have is a 20" trinitron 5 system receiver (2072ME5, I think) that understands PAL, SECAM 1 & 2, NTSC 3.38 and NTSC 4.43 (I may have the NTSC numbers slightly wrong). It is also fairly insensitive to power supply - 110-240 volts, 50 or 60 Hz, self adjusting. It will receive broadcast signals in any of the above systems using US or European channel standards. One the tuner locks in a signal, the color decoders decide what colour system is present and decode accordingly. It is about as automatic as you can get, with the ability for manual override. SONY also make three VCRs that are multisystem. The SLT50 is a 5 system VCR that can receive and record all but the NTSC 4.x and play recorded tapes in all 5 formats (beta II and III on NTSC). The other multisystem VCRs in SONY's range do not have all 5 systems and I think the SLT50 is the only one that can handle PAL tapes and record NTSC. It also has a self adjusting universal power supply. In reference to some news items about the noise (audible) made by some SONY VCRs, the SLT50 also has a fairly noisy transport mechanism. The cost of these two items together is about $2600 (about $1300 ea) here in MA. They are not in SONY's consumer product range, so I had to find a professional video supply house. This basically means that the units are hard to find and discounting is rare. SONY restrict the range that their regular dealers can handle to 'consumer' products and not 'professional' or 'industrial' products (SONY categories). I am told that in some states this is illegal so you may be able to get discounts. Panasonic have a smaller receiver for about $750, but the picture quality is not as good. SONY have a 12" monitor that handles all five systems and has two sets of RGB input and output that also sells for about $750. It is a bit small for normal viewing but makes a great monitor and is designed to be used as a terminal monitor (making it tax deductible for some?). If anyone wants more details, mail me. If there is enough interest I will send more info to the net. Gary ========================================================================= From: allegra!decwrl!rhea!orphan!lionel (Steve Lionel) You can't play a PAL tape on an NTSC VCR, no matter what your monitor can do. Steve ========================================================================= From: allegra!decwrl!rhea!orphan!lionel If you're looking for a one-shot deal, just look in your phone book under Video for an industrial video services place. They typically can transfer tapes across formats (VHS,Beta,U-Matic) and standards. At least, one near me in Nashua, NH can. The cost is reasonable, and they usually have fancy picture processors to make the copy as good as the original. As an example of the cost, I recently had a 30 minute Beta tape transferred to VHS at a cost of $29, including the tape. Steve Lionel ======================================================================= From: philabs!rdin!perl PAL cassettes can only be played on PAL-compatible VCR's--regardless of the TV. There are, however, some VCR's that will play PAL tapes and convert the signal so that it can be played on an NTSC TV or copied onto an NTSC tape. PAL tapes can only be made with a VCR designed to record PAL. The camera must also be a PAL camera unless the VCR is designed to accept an NTSC signal and convert it. A PAL camera cannot drive an NTSC-only VCR. Robert Perlberg Resource Dynamics Inc. New York philabs!rdin!rdin2!perl ======================================================================= From the Tardis of Mark Callow msc@qubix.UUCP, decwrl!qubix!msc@Berkeley.ARPA ...{decvax,ucbvax,ihnp4}!decwrl!qubix!msc, ...{ittvax,amd70}!qubix!msc I replied privately to the original question but I just want to clear up how the conversion is done. The suggestion given above would not work due, among many things, to the different number of scan lines in the pictures. The actual black box used is called a field store standards converter. It digitizes one field and stores it. From the digitized image it reconstructs the field in the new format. It does all this in real time and is *expensive*. BTW thanks for the information about the multi-standard tv's and vtr's. -- ======================================================================= From: **** sender's address not in item. ***** Converting a signal from NTSC to PAL or from PAL to NTSC is a major undertaking, and requires some sort of standards converter. These (usually rather large) pieces of equipment cost thousands of dollars. I work at Ampex, where we develop many types of professional video equipment, and I've never seen a standards converter in our labs. They just cost too much to have around. Your Sony TV which will display both NTSC and PAL won't do you any good unless you have a PAL VCR to play the tape with. The PAL and NTSC formats are rather incompatible: NTSC is 525 lines per frame, 30 frames per second, with a 2-frame color sequence. PAL is 625 lines per frame, 25 frames per second, with a 4-frame color sequence. Because of these differences, the recorded tapes, and the VCR's are different. ======================================================================= From the Tardis of Mark Callow msc@qubix.UUCP, decwrl!qubix!msc@Berkeley.ARPA ...{decvax,ucbvax,ihnp4}!decwrl!qubix!msc, ...{ittvax,amd70}!qubix!msc Conversion of films to TV is nothing like as hard as converting NTSC signals to PAL signals or vice-versa. A flying-spot telecine machine is used. This has a "projector" half and a "camera" half. The light source is a CRT (hence the name flying-spot.) scanning just like the TV set. The "camera" used to be a photo-multiplier tube. I don't know what they use these days. By varying the geometry of the image on the scanning CRT all kinds of tricks can be pulled such as showing a cinemascope film without an anamorphic lense. I can't remember exact details of this right now but I once saw it done at the CBC studios in Montreal. Since the film was shot at 24 frames/s and the TV is scanning at either 25 or 30 frames a second, depending on country, various tricks must be played to synchronize the two otherwise you get horizontal black bars moving down the picture. Where TV is 25 frames/s they simply speed up the film. This results in a 100 minute film only lasting 96 minutes. Other than that the speedup is imperceptible. Where TV is 30 frames/s the projector is gimmicked to show every fourth frame twice so that 30 pictures are presented to the TV every second but the film moves at an effective speed of 24 frames/s. Also frame shifting is synchronized with the vertical blanking interval. I have seen "telecine adaptors" advertised in Video magazine. These consist of a box with a hole at one side through which you point your projector. Inside there is a mirror that projects the image onto a ground glass screen at which you have your TV camera aimed. These are a crock for anything but slides. Without the proper synchronization you will get a flickering image with large horizontal lines running up the picture just like you get when you film a TV screen with a movie camera. Seeing an ad for junk like that in what I thought was a reputable magazine makes me wonder about the objectivity of said magazine's test reports. -- ======================================================================== Keep Smiling (=::=) --Indra K. Singhal >> << >> Bitnet: IKS at PSUVM << >> UUCP : :allegra, akgua, ihnp4:!psuvax!IKS@PSUVM.BITNET << >> ARPA : iks%psuvm.BITNET@Berkeley << >> <<