jason@cbmami.UUCP (Jason Goldberg) (01/30/91)
I am doing some work with a local community colleges Television and Radio department. The chair of the department says that they can afford to purchase (and would very much love the capabilities) a few video toaster w/ Amigas. The problem is that their engineer doesn't feel that the toaster provided "NTSC quality output." Now I am under the impression that broadcast quality is a mythical term, and that NTSC quality would be anything which could be displayed with NTSC equipment, which obviously the toaster can. The real point here, is that the engineer doesn't feel that the toaster has good enough quality output for him. I am hoping to receive two types of information, in response to this post: 1. Technical descriptions of the output of the Toaster which I can rely to him, as to what kind of results he can expect with the toaster. I don't have to understand this stuff (I am guessing I wont...) I just need to be able to give it to him. 2. Examples of places currently using the Toaster in production, the more well known the example the better. I hope to rely this information to chairman of the department. I will gladly post a summary, thanks for your time, -Jason- --------------------------------------------------------------------------- Jason Goldberg UUCP: ucsd!serene!cbmami!jason Del Mar, CA
Gord_Wait@mindlink.UUCP (Gord Wait) (01/31/91)
One possible problem with NTSC that is a requirement for Broadcast Quality Gear, but is no problem for semi-pro and amateur video gear is the RS170-A NTSC spec item which states that the sub-carrier signal must be synchronous with the Horizontal Sync signal, and that it is phase aligned so that at the 11th line of horizontal sync in color frame 1 the subcarrier signal is zero-crossing, and positive going. (This would be at the rising edge of the sync.) Any video source that doesn't meet that requirement will look fine and record fine on just about every type of video gear except 'true' broadcast tape recorders (ie Ampex and Sony 1 inch machines) I don't know what the toaster puts out, but if it A: has NTSC out which doesn't meet this spec, then if it has RGB out AND genlock, you could use an external broadcast NTSC encoder with a sync-pulse generator to obtain broadcast output. Hope this helps... Gord Wait
jerry@truevision.com (Jerry Thompson) (01/31/91)
In article <189a59cc.ARN0dfb@cbmami.UUCP> jason@cbmami.UUCP writes: >The problem is that their engineer doesn't feel that the toaster >provided "NTSC quality output." Now I am under the impression that > The real point here, is that the engineer doesn't feel that the >toaster has good enough quality output for him. I am hoping to receive two ABC has taken the output from a Toaster into their master control. They also use the Toaster on air on the Rick Dee show. Your engineer must be very picky! -- Jerry Thompson | // checks ___________ | "I'm into S&M, I loved the peace and solitude | \\ // and | | | | Sarcasm and so much, I invited my friends. | \X/ balances /_\ | /_\ | Mass Sarcasm."
dewolfe@ug.cs.dal.ca (Colin DeWolfe) (02/01/91)
In article <4630@mindlink.UUCP> Gord_Wait@mindlink.UUCP (Gord Wait) writes: >One possible problem with NTSC that is a requirement for Broadcast Quality >Gear, but is no problem for semi-pro and amateur video gear is the RS170-A NTSC >spec item which states that the sub-carrier signal must be synchronous with the >Horizontal Sync signal, and that it is phase aligned so that at the 11th line >of horizontal sync in color frame 1 the subcarrier signal is zero-crossing, and >positive going. (This would be at the rising edge of the sync.) Any video >source that doesn't meet that requirement will look fine and record fine on >just about every type of video gear except 'true' broadcast tape recorders (ie >Ampex and Sony 1 inch machines) I don't know what the toaster puts out, but if >it A: has NTSC out which doesn't meet this spec, then if it has RGB out AND >genlock, you could use an external broadcast NTSC encoder with a sync-pulse >generator to obtain broadcast output. >Hope this helps... >Gord Wait The toaster IS RS170-A output. At least that's what the guys at NetWorx told me (and was also in the manual) when I went to play with the thing down at their shop.... They were recording to a SONY 1" machine too.... -- Colin DeWolfe dewolfe@ug.cs.dal.ca
hood@cbmvax.commodore.com (Scott Hood) (02/02/91)
In article <1991Jan31.150016.14726@truevision.com> jerry@truevision.com (Jerry Thompson) writes: >In article <189a59cc.ARN0dfb@cbmami.UUCP> jason@cbmami.UUCP writes: >>The problem is that their engineer doesn't feel that the toaster >>provided "NTSC quality output." Now I am under the impression that >> The real point here, is that the engineer doesn't feel that the >>toaster has good enough quality output for him. I am hoping to receive two > >ABC has taken the output from a Toaster into their master control. They also >use the Toaster on air on the Rick Dee show. Your engineer must be very >picky! > >-- >Jerry Thompson | // checks ___________ | "I'm into S&M, >I loved the peace and solitude | \\ // and | | | | Sarcasm and >so much, I invited my friends. | \X/ balances /_\ | /_\ | Mass Sarcasm." Jerry, Hi! What have you been doing with yourself lately? Please tell Keith Masavage I said hello will you! It's very nice to see someone of your experience on the net and using the Toaster. How do you like it? What are its' strengths and weaknesses in your opinion? Regards, Scott Hood -- -- Scott Hood, Hardware Design Engineer (A3000 Crew), Commodore-Amiga, Inc. {uunet|pyramid|rutgers}!cbmvax!hood hood@cbmvax.cbm.commodore.com "The views expressed here are not necessarily those of my employer!"
ltran@pluton.matrox.com (Linh TRAN) (02/02/91)
jason@cbmami.UUCP (Jason Goldberg) writes: > I am doing some work with a local community colleges Television and >Radio department. The chair of the department says that they can afford to >purchase (and would very much love the capabilities) a few video toaster w/ >Amigas. The problem is that their engineer doesn't feel that the toaster >provided "NTSC quality output." Now I am under the impression that >broadcast quality is a mythical term, and that NTSC quality would be >anything which could be displayed with NTSC equipment, which obviously the >toaster can. > The real point here, is that the engineer doesn't feel that the >toaster has good enough quality output for him. I saw that the Video Toaster has problem with unstable source such as normal VCR. May be that is why the engineer said that it does not have Broadcast Quality. Given that Quality, Broadcast or not, is somewhat an arbitrary entity, depending on your applications. If you use VCR as one source of input, then I suggest you to check the output when it display what come from the VCR. You could then judge by yourself if the output is Broadcast Quality or not, and if it suit your purpose. You then could make the trade-off between the price of the VCR and your other video equipement. Remember that video equipements must work well together and the price is the price of the whole system. Inexpensive VCR have jitter because the syncs are stored as is on the tape. At record time or playback, the video sync frequency could change a bit. This is because the servo mechanism and the strectching of the tape. Expensive VCR has its own jitter compensation (or time base correction on the high end). Camera works fine because the output is stable (the whole camera circuitry depends on crystal frequency). The Video Toaster, after what I have heard, sample the video (composite) directly. It seems not to have the ability to resynchronize with the burst signal, making phase discrepencies accumulated. NTSC signal is not robust for phase discrepencies (hue error). That is why the sample frequency of frame-grabbers are multiple of burst frequency (for NTSC: 4 times ~ 3.5MHz). Now, if the sampling frequency is fixed, and the line is abit shorter or longer than the standard line, the sampling points for the I and Q component is no logner in phase with the NTSC burst, making a degraded color output. Finally, although I am pretty sure of what I am talking about, I am not trying to discredit NetWorx (Video Toaster's maker). Maybe the engineers from NetWorx could confirm or explain if the above speculations are well found or not. Linh Tran. This is my opinion. This has nothing to do with my employer. ----------- -- PHU"O"NG NGUYE^N | --/\\ //---- / /---/ -/ email: ltran@pluton.matrox.com | / \\ // /---/ / I USUALLY KNOW WHAT I AM SAYING | -/----\\/--- / / ....PROBABLY NOT THIS TIME........ | _/ \\____ ---/ --/--
dewolfe@ug.cs.dal.ca (Colin DeWolfe) (02/02/91)
In article <1991Feb1.194032.8028@pandora.matrox.com> ltran@pluton.matrox.com (Linh TRAN) writes: >jason@cbmami.UUCP (Jason Goldberg) writes: > Finally, although I am pretty sure of what I am talking about, >I am not trying to discredit NetWorx (Video Toaster's maker). Maybe >the engineers from NetWorx could confirm or explain if the above >speculations are well found or not. > Boy, Im sure the boys down the street at NetWorx would be surprised to find out they make it. Maybe their being a video supply house is a ploy to making us think that they are in topeka, instead of here in Halifax...:-) I HOPE you meant to say, Newtek... Anyway, I would assume that anybody considering a toaster already has a high quality VCR and time base correctors. Our local cable channel has them. >Linh Tran. > > This is my opinion. This has nothing to do with my employer. >----------- >-- >PHU"O"NG NGUYE^N | --/\\ //---- / /---/ -/ >email: ltran@pluton.matrox.com | / \\ // /---/ / >I USUALLY KNOW WHAT I AM SAYING | -/----\\/--- / / > ....PROBABLY NOT THIS TIME........ | _/ \\____ ---/ --/-- -- Colin DeWolfe dewolfe@ug.cs.dal.ca
ltran@pluton.matrox.com (Linh TRAN) (02/05/91)
dewolfe@ug.cs.dal.ca (Colin DeWolfe) writes: >I HOPE you meant to say, Newtek... Yes, it was Newtek... Apology to Networx people. Sorry again. -- PHU"O"NG NGUYE^N | --/\\ //---- / /---/ -/ email: ltran@pluton.matrox.com | / \\ // /---/ / I USUALLY KNOW WHAT I AM SAYING | -/----\\/--- / / ....PROBABLY NOT THIS TIME........ | _/ \\____ ---/ --/--
dewolfe@ug.cs.dal.ca (Colin DeWolfe) (02/06/91)
In article <91036.193927IMS103@psuvm.psu.edu> IMS103@psuvm.psu.edu (Ian Matthew Smith) writes: >ltran@pluton.matrox.com (Linh TRAN) writes: >>dewolfe@ug.cs.dal.ca (Colin DeWolfe) writes: >>>I HOPE you meant to say, Newtek... >> Yes, it was Newtek... Apology to Networx people. Sorry again. > > Just *what* does Networx make that would make them embarased >to put out a peice of equipment like the Toaster? :-) :-) > > - Ian Smith <ims103@psuvm.bitnet> Actually they "make" nothing. They are a Value Added Reseller for Commodore they sell Toaster equipped Amiga 2500s. Humor noted though :-) -- Colin "I love being misqouted" DeWolfe dewolfe@ug.cs.dal.ca
siri@otc.otca.oz (Siri Hewa) (02/13/91)
In article <1991Feb1.194032.8028@pandora.matrox.com> ltran@pluton.matrox.com (Linh TRAN) writes: >jason@cbmami.UUCP (Jason Goldberg) writes: > >>Amigas. The problem is that their engineer doesn't feel that the toaster >>provided "NTSC quality output." Now I am under the impression that >>broadcast quality is a mythical term, and that NTSC quality would be >>anything which could be displayed with NTSC equipment, which obviously the >>toaster can. >> The real point here, is that the engineer doesn't feel that the >>toaster has good enough quality output for him. > > Inexpensive VCR have jitter because the syncs are stored as is >on the tape. At record time or playback, the video sync frequency could >change a bit. This is because the servo mechanism and the strectching >of the tape. Expensive VCR has its own jitter compensation (or time base >correction on the high end). > > The Video Toaster, after what I have heard, sample the video >(composite) directly. It seems not to have the ability to resynchronize >with the burst signal, making phase discrepencies accumulated. NTSC >signal is not robust for phase discrepencies (hue error). That is why >the sample frequency of frame-grabbers are multiple of burst frequency >(for NTSC: 4 times ~ 3.5MHz). > > Now, if the sampling frequency is fixed, and the line is abit >shorter or longer than the standard line, the sampling points for the >I and Q component is no logner in phase with the NTSC burst, making >a degraded color output. > >PHU"O"NG NGUYE^N Re.your comment above if you use a pll with secondary lock such as vcxo,then you should not have any hue errors.This is at front end of the video after the sampling. Re.output of the video,if they have stability problems then this can be cured by redisigning the spg(sync pulse generation).But output video quality come from video coder design. So to the conclusion first rubbish in = rubbish out. Assuming this is not the case,problem may be at the front end of the video.Looking at the toasters price range they may have opt for the cheaper decoding circuitry. By the way Broadcast quality is well define in technical terms. Subjective quality come from years in the field. Iam a broadcast engineer who has design top end equipments in UK. It will be interesting if some one get hold of Tektronic video mesurement unit (Answer or the later one) and do real masurement on toaster. Siri Hewa. ||||OTC|| R&D Visual Communication siri@otc.otca.oz.au