On 2015-01-10 13:12, Ingo Korb wrote: >> S-video is the best what you get from the VIC-II. You don't get a >> better signal from it. No component, no RGB, no SDI, ... This means >> you don't jump over its limits. > > But what use is S-Video if you cannot use it because your monitors do > not accept it because it's been phased out? You are right that S-video will disappear earlier than composite, which will follow soon. Upscalers/converters/etc. will still be available for some time - then we should have a proper digital output already. >> Except that I want to make it much cleaner. > > I hope you don't mean that you want to reconstruct which of the 16 > colors was used for the current pixel and output exactly that - although > this could work for Composite/S-Video output, an improved version with > Component/RGB/DVI/HDMI/Displayport output would look like an emulator > and lose everything that relies on the effects of color decoding. Actually I wouldn't mourn that much over this loss but no - I wanted to "accidentally" keep this compatibility too. Accidentally, because I didn't think of deriving pixel colours but rather maximally cleaning up the S-video. Decoding it (anywhere/how) will leave its inherent artefacts in the end. >> I want the solution to reconstruct the sync pulses itself but what you >> say has to be double-checked. If you say that I may run out of the >> VBLANK time to get the proper timing and remain in sync with the source >> then this would indeed pose a problem, solving which would make the >> whole thing more difficult. I think, however that this is not the case. > > The PAL VIC-II outputs 312 lines per frame according to the table shown > at [1], so if you convert those two into fields you end up with 624 > lines per field instead of the 625 that PAL specifies. For NTSC the > result would be 526 lines instead of 525. > > [1] http://hitmen.c02.at/temp/palstuff/ > >>> Are you sure that such a signal is acceptable to modern TVs? No, I am not. And actually if I can't make it fully norm compliant then it won't be worth the non-trivial effort. >> Well - that's the norm. I want to reconstruct the norm signal with >> digital accuracy so that those TVs/upscalers/adapters/etc. don't have >> any excuse for saying "no signal" or displaying garbage. > > I'm tempted to implement a large-memory arbitrary waveform generator on > an FPGA board to replay a sampled and modified C64 image to simulate > this, but unfortunately there are some other things I'd like to finish > first. As always ;-) But that's an interesting domain. And idea too. Maybe we could get an arbitrary waveform generator that would be able to generate one frame repeatedly and then check the influence of various modifications. Maybe we can find something indeed much easier to implement and still considerably improving the compatibility. >>> I haven't tried something like that with >>> interlaced signals yet, but when I accidentally generated a 480p signal >>> where two consecutive frames were differing by one or two lines, I >>> mostly saw the familiar "No Signal" message. >> >> I guess it's understandable in such case as the signal must have seemed >> inconsistent to the receiver. > > Yes, but why should your modified signal seem more consistent? Guessing but I'd say because "my" is expected to be different every other frame, while yours was surely expected to be the same every frame. If it was not - sorry, no zaxxxon.. >> As we all know - it's not what will make me or anyone here a good >> retirement ;-) > > Aren't we all just doing it to have fun anyway? =) And wonder how it can be that not everybody and their dog understand that it is in fact a hell of a fun! :-) >> So yes, cost is an important factor but what I envision is a >> combination of VIC riser and RF modulator replacement. This gives >> ample space for all processing stages I described. > > Good, that also means that you could output standard S-Video signals > from your VIC riser instead of the intermediate levels that the RF > modulator converts to something more standards-compliant. Surely! >> In the end I'd be happy to see an unbeatable quality signal on both >> the original DIN and an HDMI socket located more or less in the middle >> of the former RF modulator's length. > > A type-D HDMI socket should fit into the opening for the original > modulator output without modifying the case, but I'm not sure if these > things can be soldered without using reflow techniques. Reflow is possible @home these days. One gets the Chinese, el cheapo oven, modifies it to actually behave as expected and voila :-) But I wouldn't go that route. I'd just order it soldered. [...] > It would result in a much simpler and cheaper solution though, I suspect > you could get away with a single 8-pin microcontroller plus maybe a bit > of analog components if you need to generate a blanking-level output > signal. It would certainly make for a nice addon to those modulator > replacement/vertical stripe remover boards that people have suddenly > started to design everywhere. Interesting - I haven't seen that many of them but I am probably not frequenting various web forums enough. Have you seen some good examples? -- SD! Message was sent through the cbm-hackers mailing listReceived on 2015-01-12 20:00:03
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