PC Review
Forums
Newsgroups
Hardware
ATI Video Cards
Opinions on the best video port
Forums
Newsgroups
Hardware
ATI Video Cards
Opinions on the best video port
![]() |
Opinions on the best video port |
|
|
Thread Tools | Rate Thread |
|
|
#1 |
|
Guest
Posts: n/a
|
I watch TV video on my PC in two ways. The commonality is that both methods
use a DCT6412 digital/HD dual tuner DVR converter provided by my cable company: 1) Y Pb Pr component cables from the converter to the component input on my Dell 2405fpw. 2) S-video from the converter to the s-video input on an ATI AIW X800XT AGP card. I also have the option of running Video out from the converter to to the video in input on the X800XT. My question is: Which of these methods provides the best picture quality? I'm pretty sure I have to use the Y Pb Pr for High def, but that leaves me with the choice of video out or S-video for the x800xt, unless s-video carrys an HD signal as well. Which method is recommended here? Thanks, mxh |
|
|
|
#2 |
|
Guest
Posts: n/a
|
Y Pb Pr is the best, for it is non-color encoded (sorta - not modulated at
3.58 mhz and mixed with Y yet ), offering the highest bandwidth for color fidelity. With the right encoder, you could get full bandwidth RGB from this format. It is used in frame stores, special effects generators, and character generators of a few years old. (Before Digital Video) (BTW - YPB is a variant from England, where America uses YIQ for NTSC encoding. YBP became popular from international demand for standards) (Care to know the difference between NTSC, PAL, and C-CAM? -NO?) Next best is S-Video. Also known as Y/C. Luminance and Chrominance. The color is encoded to 3.58 mhz vistisual side-band modulation, but not encoded to NTSC video, which limits the luminance channel to around 2.8 meg for low-pass filters, or 4.2 meg for 2 line comb-filters. S-Video can give you luminance bandwidth in excess of 5 meg, and give multi-generation copying of acceptable viewer performance. If you are going Hi-Fi this would be a minimum acceptable format for you. Lowest is Video. Try to use decoders that use 2-line comb filters verses low-pass filters if you can. Your TV will have specks that spell this out. It will affect the sharpness of the video on the screen. Especially when dealing with analogue Hi-def TV. Makes a difference on recorders, video to video movement. And ALWAYS keep the encoding/decoding to a minimum. William "mxh" <mxh@global.net> wrote in message news:G6zYf.11172$FD4.9455@dukeread07... >I watch TV video on my PC in two ways. The commonality is that both methods >use a DCT6412 digital/HD dual tuner DVR converter provided by my cable >company: > > 1) Y Pb Pr component cables from the converter to the component input on > my Dell 2405fpw. > 2) S-video from the converter to the s-video input on an ATI AIW X800XT > AGP card. > > I also have the option of running Video out from the converter to to the > video in input on the X800XT. > > My question is: Which of these methods provides the best picture quality? > I'm pretty sure I have to use the Y Pb Pr for High def, but that leaves me > with the choice of video out or S-video for the x800xt, unless s-video > carrys an HD signal as well. Which method is recommended here? > > Thanks, > mxh > |
|
|
|
#3 |
|
Guest
Posts: n/a
|
William wrote: > Y Pb Pr is the best, for it is non-color encoded (sorta - not modulated at > 3.58 mhz and mixed with Y yet ), offering the highest bandwidth for color > fidelity. With the right encoder, you could get full bandwidth RGB from this > format. It is used in frame stores, special effects generators, and > character generators of a few years old. (Before Digital Video) (BTW - YPB > is a variant from England, where America uses YIQ for NTSC encoding. YBP > became popular from international demand for standards) (Care to know the > difference between NTSC, PAL, and C-CAM? -NO?) > > Next best is S-Video. Also known as Y/C. Luminance and Chrominance. The > color is encoded to 3.58 mhz vistisual side-band modulation, but not encoded > to NTSC video, which limits the luminance channel to around 2.8 meg for > low-pass filters, or 4.2 meg for 2 line comb-filters. S-Video can give you > luminance bandwidth in excess of 5 meg, and give multi-generation copying of > acceptable viewer performance. If you are going Hi-Fi this would be a > minimum acceptable format for you. > > Lowest is Video. Try to use decoders that use 2-line comb filters verses > low-pass filters if you can. Your TV will have specks that spell this out. > It will affect the sharpness of the video on the screen. Especially when > dealing with analogue Hi-def TV. Makes a difference on recorders, video to > video movement. And ALWAYS keep the encoding/decoding to a minimum. > > William > <snip> You're mostly right. Y, Pb, Pr ('component') is simply RGB after going through matrix to convert to Hue, Saturation and Luminance. The constants are a little different betweeen std def and HD. In std def you add 59%G +29.5%R+11.5%B to get Y you then take Y and subtract 100%R to get Pr and do the same for blue to get Pb. Note that so far there is no bandwidth limiting and no loss. You can reverse the algebra to get the original RGB. So, why bother with this? It is very easy to alter color saturation, hue, white and black levels -- and if you get carried away you can control the Hue, Saturation and Luma intensity of individual R,G,B, Yellow, Cyan and Magenta (and even more). When the Pb and Pr components are used to quadrature amplitude modulate the subcarrier, the bandwidth is limited so you are no longer lossless. The signal is 'Y/C' until the subcarrier is added onto the Y signal to become the composite video. This is NOT vestigial sideband. That function is performed on the visual carrier after it has been AM modulated with the composite video. Separating the Luma from the Chroma is the most difficult task from a performance point and your comments about comb (1 line or as you say better 2 line) filters vs trap are right on. The digital world, both std def and HD, transcode the RGB to component but then band limit the color difference components to 1/2 bandwidth, though there are special full bandwidth units used in special effects. Is C-CAM SECAM? GG |
|
|
|
#4 |
|
Guest
Posts: n/a
|
<stratus46@yahoo.com> wrote in message news:1144549023.522779.82170@j33g2000cwa.googlegroups.com... > > <snip> > > You're mostly right. You have not contradicted anything I have said, you have only further explained what I have stated. Did your explanation help the original poster as to his query? Or did you only stroke your ego? Do you feel a need to prove yourself superior to other people? I've been around the block too many times to play this game with you. > Is C-CAM SECAM? Yes. Perhaps I sould have got my notes out. Their a little dusty. William SMPTE / NAB |
|
|
|
#5 |
|
Guest
Posts: n/a
|
Thanks to both of you for the indepth responses. I am trying to record
content from my STB to computer. The two options I have are two machines, one of which has the ATI x800xt (from which I haven't tried capturing from external video sources as of yet), and the other, a Navis Pro capture card (which captures some very high quality video). Both cards have s-video input. Although the X800XT has plenty of input options, it appears that it has no component input, but instead offers a component to s-video adapter, which, I suppose, is s-video quality. So, if I can impose further: I would like to be able to switch between s-video on the x800xt and s-video on the Navis pro (the x800 for when I am just watching and the Navis Pro for recording). Is there some kind of s-video A-B switch that won't cause a reduction in quality? Also, some of the captured content will be from a high def source. Will I experience any problems capturing that via HD to DVD compliant mpeg2? Thanks again for any information, mxh "mxh" <mxh@global.net> wrote in message news:G6zYf.11172$FD4.9455@dukeread07... >I watch TV video on my PC in two ways. The commonality is that both methods >use a DCT6412 digital/HD dual tuner DVR converter provided by my cable >company: > > 1) Y Pb Pr component cables from the converter to the component input on > my Dell 2405fpw. > 2) S-video from the converter to the s-video input on an ATI AIW X800XT > AGP card. > > I also have the option of running Video out from the converter to to the > video in input on the X800XT. > > My question is: Which of these methods provides the best picture quality? > I'm pretty sure I have to use the Y Pb Pr for High def, but that leaves me > with the choice of video out or S-video for the x800xt, unless s-video > carrys an HD signal as well. Which method is recommended here? > > Thanks, > mxh > |
|
|
|
#6 |
|
Guest
Posts: n/a
|
"William" <wlucas@pacifier.com> wrote in message news:123gko8lrjqhd78@corp.supernews.com... >Y Pb Pr is the best, for it is non-color encoded (sorta - not modulated at >3.58 mhz and mixed with Y yet ), offering the highest bandwidth for color >fidelity. With the right encoder, you could get full bandwidth RGB from >this format. It is used in frame stores, special effects generators, and >character generators of a few years old. (Before Digital Video) (BTW - >YPB is a variant from England, where America uses YIQ for NTSC encoding. >YBP became popular from international demand for standards) (Care to know >the difference between NTSC, PAL, and C-CAM? -NO?) > > Next best is S-Video. Also known as Y/C. Luminance and Chrominance. The > color is encoded to 3.58 mhz vistisual side-band modulation, but not > encoded to NTSC video, which limits the luminance channel to around 2.8 > meg for low-pass filters, or 4.2 meg for 2 line comb-filters. S-Video can > give you luminance bandwidth in excess of 5 meg, and give multi-generation > copying of acceptable viewer performance. If you are going Hi-Fi this > would be a minimum acceptable format for you. > > Lowest is Video. Try to use decoders that use 2-line comb filters verses > low-pass filters if you can. Your TV will have specks that spell this > out. It will affect the sharpness of the video on the screen. Especially > when dealing with analogue Hi-def TV. Makes a difference on recorders, > video to video movement. And ALWAYS keep the encoding/decoding to a > minimum. Hi William, Another thought: May I assume that, even though 'video out' is the worst of the 3, it still surpasses the quality of just the 75 ohm coaxial from the STB to the cable input (TV or graphics card)? Thanks, mxh > William > > > > "mxh" <mxh@global.net> wrote in message > news:G6zYf.11172$FD4.9455@dukeread07... >>I watch TV video on my PC in two ways. The commonality is that both >>methods use a DCT6412 digital/HD dual tuner DVR converter provided by my >>cable company: >> >> 1) Y Pb Pr component cables from the converter to the component input on >> my Dell 2405fpw. >> 2) S-video from the converter to the s-video input on an ATI AIW X800XT >> AGP card. >> >> I also have the option of running Video out from the converter to to the >> video in input on the X800XT. >> >> My question is: Which of these methods provides the best picture quality? >> I'm pretty sure I have to use the Y Pb Pr for High def, but that leaves >> me with the choice of video out or S-video for the x800xt, unless s-video >> carrys an HD signal as well. Which method is recommended here? >> >> Thanks, >> mxh >> > > |
|
|
|
#7 |
|
Guest
Posts: n/a
|
"mxh" <mxh@global.net> wrote in message news:4Yc_f.7314$IZ2.5232@dukeread07... > <snip> > > Hi William, > Another thought: May I assume that, even though 'video out' is the worst > of the 3, it still surpasses the quality of just the 75 ohm coaxial from > the STB to the cable input (TV or graphics card)? > > Thanks, > mxh > > STB = Set Top Box? Then yes, to offer Ch 3/4 TV frequency out, an additional step of modulation / demodulation is required. ALSO, unless you have a very expensive STB, you do not have STEREO sound! Dolby, (sp?) the inventor of stereo TV, has patents on stereo TV and charges extra for use of the technology, so most Set Top Box - TV modulators skip stereo out. This includes cable boxes, DVD players, and VCR's - check the specks for stereo on the TV frequency out - it won't be their most of the time. A rule of thumb: The less you molest your analogue signal, the better it will look. This kinda goes to the heart of Digital Rights Management. If digital video degraded as much as analogue video does, their wouldn't be DRM. You can only encode / decode video so many times and it starts to look bad, does the jiggle, tarrying, granny dance for you. I digress. Keep it short, keep it sweat, and beware of lip-sink. (Where the 'moving lips' video corresponds to the sound track.) A common problem with moving video/audio between equipment. BTW this is quite a problem in modern desk top computers. I run into this problem quite often on my own setup. Especially computer recorded TV played back later. William |
|
|
|
#8 |
|
Guest
Posts: n/a
|
"mxh" <mxh@global.net> wrote in message news:9Pc_f.7312$IZ2.4563@dukeread07... > Thanks to both of you for the indepth responses. I am trying to record > content from my STB to computer. The two options I have are two machines, > one of which has the ATI x800xt (from which I haven't tried capturing from > external video sources as of yet), and the other, a Navis Pro capture card > (which captures some very high quality video). Both cards have s-video > input. > > Although the X800XT has plenty of input options, it appears that it has no > component input, but instead offers a component to s-video adapter, which, > I suppose, is s-video quality. So, if I can impose further: > > I would like to be able to switch between s-video on the x800xt and > s-video on the Navis pro (the x800 for when I am just watching and the > Navis Pro for recording). Is there some kind of s-video A-B switch that > won't cause a reduction in quality? > > Also, some of the captured content will be from a high def source. Will I > experience any problems capturing that via HD to DVD compliant mpeg2? > > Thanks again for any information, > mxh > Their are too many variables involved to give you a definitive answer. For one, one encoder is different than another. I would assume (and I use that word with fear) that the Navis Pro has a better decoder built in? Or why did you pay so much money for it. On the other hand, a few years of technology marching forward will make a two dollar chip run circles around what a 200 dollar board used to do. So without seeing the specifications on the two products, including the component to s-video encoder, that call is impossible to give you. (Bandwidth, depth of modulation, cross-modulation, Signal-to-Noise level, etc.) My suggestion: It's time for the grand experiment. Try every way conceivable, take notes. See which works best for you. Then use that method until something changes. You have other problems to be concerned about. S-video needs to be kept short, less than 3 or 4 feet in length, or you start to loose quality. (Their are distribution amps for this purpose.) A/B switches need to be hi-frequency shielded, or you may get cross-modulation, (bleeding ghosting) in the video. Some video from STB's have anti-copy protection methods installed and cause great trouble when you go to capture the video. I think it's called Macrovision. A varying pulse on line 19h that wreaks havoc on decoders that can't scrub this stuff off. So beware, if everything starts to go dark, and pops up bright, and then goes dark, over and over, suspect Macrovision. (They make scrubbers for this infliction.) William |
|
|
|
#9 |
|
Guest
Posts: n/a
|
Hello again, William. Thanks for the response, and please forgive the
delayed response. "William" <wlucas@pacifier.com> wrote in message news:123jfmktmsihk0c@corp.supernews.com... > > "mxh" <mxh@global.net> wrote in message > news:4Yc_f.7314$IZ2.5232@dukeread07... >> > <snip> >> >> Hi William, >> Another thought: May I assume that, even though 'video out' is the worst >> of the 3, it still surpasses the quality of just the 75 ohm coaxial from >> the STB to the cable input (TV or graphics card)? >> >> Thanks, >> mxh >> >> > > STB = Set Top Box? Then yes, to offer Ch 3/4 TV frequency out, an > additional step of modulation / demodulation is required. Unfortunately, yes. I'd really prefer to stream the data via the firewire port, but it seems that Cox STBs don't have the firewire ports enabled, according to them, and all efforts to get XP to recognize it via drivers fail. > ALSO, unless you have a very expensive STB, you do not have STEREO sound! > Dolby, (sp?) the inventor of stereo TV, has patents on stereo TV and > charges extra for use of the technology, so most Set Top Box - TV > modulators skip stereo out. This includes cable boxes, DVD players, and > VCR's - check the specks for stereo on the TV frequency out - it won't be > their most of the time. I'm no expert by any stretch of the imagination, but the STB looks to be of a fairly decent quality. It's a DCT 6416 III HD/Dig DVR with dual tuners (the DVR is nice, but archiving is what I'm after). I haven't had too much time to play with it, but I did some test records (recording from live TV, not the DVR) via s-video to the X800XT. According to TMPGEnc DVD Author, the audio is: mpeg-1 Audio Layer-2 48000 HZ Stereo 224 KBPS. I haven't had the chance to try the s-video to the Navis Pro I mentioned earlier, but it encodes to mpeg-2 and the audio bitrate is 384kbps. The sample file I recorded with the ATI card doesn't sound like mono. > A rule of thumb: The less you molest your analogue signal, the better it > will look. This kinda goes to the heart of Digital Rights Management. If > digital video degraded as much as analogue video does, their wouldn't be > DRM. You can only encode / decode video so many times and it starts to > look bad, does the jiggle, tarrying, granny dance for you. I digress. > > > Keep it short, keep it sweat, and beware of lip-sink. (Where the 'moving > lips' video corresponds to the sound track.) A common problem with moving > video/audio between equipment. BTW this is quite a problem in modern desk > top computers. I run into this problem quite often on my own setup. > Especially computer recorded TV played back later. I've heard of those who have that issue, although I never have myself. I've done a lot of analogue recording (using the Navis Pro and also an AIW 9000 Pro using a straight Moto digital STB converter as the tuner with a 75 ohm cable connection from box to card[s]), but that may change now that I'm fooling with s-video. Thanks, mxh > William > |
|
|
|
#10 |
|
Guest
Posts: n/a
|
"William" <wlucas@pacifier.com> wrote in message news:123jh4e3qa8usb9@corp.supernews.com... > > "mxh" <mxh@global.net> wrote in message > news:9Pc_f.7312$IZ2.4563@dukeread07... >> Thanks to both of you for the indepth responses. I am trying to record >> content from my STB to computer. The two options I have are two machines, >> one of which has the ATI x800xt (from which I haven't tried capturing >> from external video sources as of yet), and the other, a Navis Pro >> capture card (which captures some very high quality video). Both cards >> have s-video input. >> >> Although the X800XT has plenty of input options, it appears that it has >> no component input, but instead offers a component to s-video adapter, >> which, I suppose, is s-video quality. So, if I can impose further: >> >> I would like to be able to switch between s-video on the x800xt and >> s-video on the Navis pro (the x800 for when I am just watching and the >> Navis Pro for recording). Is there some kind of s-video A-B switch that >> won't cause a reduction in quality? >> >> Also, some of the captured content will be from a high def source. Will I >> experience any problems capturing that via HD to DVD compliant mpeg2? >> >> Thanks again for any information, >> mxh >> > > Their are too many variables involved to give you a definitive answer. Yes, I have entirely too many options .> For one, one encoder is different than another. I would assume (and I use > that word with fear) that the Navis Pro has a better decoder built in? Or > why did you pay so much money for it. Yes. It is a unique card, although I considered the price to be quite reasonable, given its quality output. It was only around $400 5 years ago. Oddly, Pentamedia really didn't do much with this card (this is the Navis Pro with the NTSC tuner). There was only one version of the software (although they did produce beta version 1.1...) and it is quite quirky, but most who have had experience with this card will agree that the video quality can be compared to cards costing much more. Although Pentamedia abandoned this card not long after it came out, it can still be found at various sources on the internet. However, there are no software updates since beta 1.1 that I'm aware of. A shame. Great hardware, pathetic software. > On the other hand, a few years of technology marching forward will make a > two dollar chip run circles around what a 200 dollar board used to do. So > without seeing the specifications on the two products, including the > component to s-video encoder, that call is impossible to give you. > (Bandwidth, depth of modulation, cross-modulation, Signal-to-Noise level, > etc.) Here is as much info as I could find: http://www.cestuff.com/hardware_enc...spro_specs.html > My suggestion: It's time for the grand experiment. Try every way > conceivable, take notes. See which works best for you. Then use that > method until something changes. Yes, I agree. I also will try (once again) to find someone at Cox who is knowledgable about the STB I have. As I've said, it has firewire ports (disabled), but there are other ports as well (ethernet, USB, SATA, etc.). I would much rather stream the digital data, even if via USB2. > You have other problems to be concerned about. S-video needs to be kept > short, less than 3 or 4 feet in length, or you start to loose quality. > (Their are distribution amps for this purpose.) A/B switches need to be > hi-frequency shielded, or you may get cross-modulation, (bleeding > ghosting) in the video. I wan't aware of the 3 ft. s-video philosophy, but it makes perfect sense. > Some video from STB's have anti-copy protection methods installed and > cause great trouble when you go to capture the video. I think it's called > Macrovision. A varying pulse on line 19h that wreaks havoc on decoders > that can't scrub this stuff off. So beware, if everything starts to go > dark, and pops up bright, and then goes dark, over and over, suspect > Macrovision. (They make scrubbers for this infliction.) Thanks for all of your input, William. I haven't had as much time as I'd like to dive into this, but am spending time as it becomes available. If you have any other ideas on how to obtain the best quality given my set up, I'd appreciate it. Thanks, mxh > William > > > > > > > |
|
![]() |
|
| Thread Tools | |
| Rate This Thread | |
|
|

Main Page 

.
