The D/A converters of ALL Panasonic DMRs work with 52µS/702x576...(they are the same).
The A/D conversion and internal recording is ALWAYS 702(704)x576 on the ES10 and similar devices of this series, but on the Panasonic DMR'S with HDMI output the internal recording is completely in Full-D1 (720x576). With the output via HDMI you have the full 720x576, because the tap takes place before the D/A converters... ...at the analog output of the DMRs with HDMI only 702x576/52µS come out, because the D/A converters of ALL Panasonic DMRs work with 52µS/702x576... If you now have video content with full 720x576, the picture is cut off left and right and filled up with black borders to 720x576 again. Panasonic DMR's with HDMI have the full 720x576 internally, if you now capture the stream via HDMI, you have the full 720x576 range. If you use the analog outputs, you only get a cropped image with filled black borders in 720x576. If you now have a video content whose picture goes over the full 720x576 and you want to use a DVD recorder via S-Video output (analog) as a TBC replacement you need a capture card that can record the resolution 720x576 and use the Pioneer ...30 or a JVC DVD recorder. The analog outputs (D/A conversation) of the Panasonic DMR's cut off the picture and fill it up with black borders on the right and left. I know it's not about the brightness range but that was also a result of all the testing. If you open the uploaded images in virtual dub you can see very well what the active video window is because the video input was over the full 720x576. Also, you should never forget that the active video window is not always exactly centered on either the dvd recorder or the capture card. It's not that simple, so you need to know what the hardware you're using can or can't do. |
Never used a DVD recorder, never will, but the forced cropping if true is kind of sucks. Some tape formats have very thin black border on one side and one big thick border on the opposite side like in some Video8/Hi8 tapes, taking away 16 pixels or so from the active area is not good.
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There is no reason to embarrass the DVD recorders.
It then has something to do with standards such as the ITU-R BT.601. I would like to see how your SDI hardware behaves. Here would be a test file: http://www.digitalfaq.com/forum/report.php?p=66903 Here are some translations of some posts with an online translator. The whole thing is certainly described in much more detail also in English. This means that when capturing with 704x576 AND 720x576, only 702 pixels each in the width contain the content of the PAL 4:3 image. So with 704x576 there are 2 and with 720x576 18 additional pixels that do not belong to the PAL 4:3 format. In any case, several million sampling processes per second (megahertz, MHz) are necessary to digitize a TV picture in a meaningful way. ITU-R BT.601 tells us that we have to sample a scanline at 13.5 MHz. This applies to both PAL and NTSC. This uniform rate produces a resolution close to DVD for both television standards. Unfortunately, the value does not exactly match the 720 horizontal pixels of the DVD. The electron beam of a PAL television needs 52 µs time to draw a scanline. With the ITU sampling rate of 13.5 MHz, we get 52 µs × 13.5 MHz = 702 horizontal pixels, which corresponds to a total active resolution of 702×575 pixels. Active means that the complete image as it was once present in the analog signal is within these 702 pixels. Analog signal: Here there is a fixed "resolution" only for vertical, namely the 576 (or 575) visible lines (the 50 above are blanking interval). Horizontally, however, 52µS are determined for the "image content" of the 64µS lasting line. This image content of the 52µS can now be exactly in 4:3 or 16:9 format to the 576 vertical lines. These for these 52µS are sampled 702 pixels - means nothing else than a "sampling rate" of 13.5 pixels/µS (702/52). This results from the maximum possible bandwidth of a CCIR-B BAS signal. Since the active 52µS (corresponding to 702 pixels) can "slip" a little bit, we have sampled 18 pixels "more" on the left and right side - so we get 720 pixels. So a total of 53.333...µS is sampled (720/13.5) - that means 0.666...µS more on each side. The "reserve" should normally be black (zero level). |
TBC units and internal VCR tbcs often blank the 8 edge pixels too on analog output, it's not something unique to dvd-recorders. They might be doing it less on NTSC but idk. Some make the borders soft, some don't. Maybe the TBCs with SDI output skips it but I don't own one so can't say.
The TBC-3000 I have does the same thing as the panasonic dvrs on PAL input, with sharp borders (though it's off centered a tad for some reason.), black AVT-8710 TBC also blanks, but makes a soft transition between image and border (and is not offset). I think the internal VCR tbc in anything I've tried does too, i.e JVC SVHS decks I've used, Pana NV-HS1000, sony 8mm camcorders, JVC VHSC camcorder. From what I remember, DV camcorders/VCRs also often do this on the analog out. I don't remember my JVC DR-MH300 outputting the full image from the inputs on the analog outs, so maybe it varies between the JVCs. Only one I've used which does in part from what I remember did is an LG, which output full image on component (and HDMI) but not s-video. There often isn't image content in the cropped area, though TBCs adding sharp borders can be a bit annoying as it tends to also cause ringing artifacts around them. |
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However, pthebest19 results show that a capture with the IOData GV-USB of a specific tape give a full 720 active area (which is strange, because its A/D should follow 601 spec), while the DMR capture properly features a 704 area inside the 720 frame. Not clear to me. pthebest19, could you please post a small video of a capture with and without your ES2 of the same segment to compare on the same frame if something is cut (I suspect not)? |
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If you are okay with that extra step good for you, however for many archivists like Lordsmurf they want the entire 720 so they can decide where that 704 sits, to the left, to the right, somewhere in the middle, you got the idea, then crop or mask accordingly, not chop off the sides blindly and hope for the best. It has nothing to do with SDI or what not, it's just a digital port like USB, it's about understanding the process and then use the right gear for the job. A DVD recorder never meant to replace a full frame TBC or a line TBC inside the VCR. Quote:
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Latreche34 why don't you do the test yourself with your hardware? Play a PAL test file with 720x576 where the image content is also visible over the full 720x576 and show us the results.
With analog PAL recordings it might be difficult to find a file that has more picture content than the 702x576. As an example I have added a picture from a purchased DVD. Also here the active image content is 702x576 of 720x576 with black borders left and right and the active imiage content is also not centered. This is how the whole thing is saved on DVD. That all capture cards record in 720x576, you are wrong. Each capture card has its native capture resolution. Attached are some recordings played back from a Sony GX7. The image content goes over the full 720x576 at least in width. Captured with an ATI AIW 7200 at 704x576 and 720x576. Also pictures of a recording with a TV-card with the Philips chipset 7134. Also full picture content played back with the Sony GX7. Captured with 704x576, 720x576, 768x576. Looking at the images and you can see that the native capture resolution of the AIW and the Philips 7134 is 704x576. When capturing at 720x576 or 768x576, only the area from 704 is stretched to 720. You change the pixel aspect ratio. As an example, the same procedure and capture with an Edius/Canopus NX in 720x576, so that you can see that the Sony GX7 also playback the full image content over the 720. |
I see the passthrough barely even makes a difference compared to the capture card I use, especially on this new VCR I'm using which has way better tracking control.
I heard the ES10 was the best at handling tape signals. Wouldn't it be that the JVC or Pioneer recorders perform even worse than my capture card? The reason why I want to keep full 720 is because I want to keep the content the way it was mastered on tape to begin with. Sometimes even the digital masters show only the 702 area because some Digital Betacam VTRs had the 52µS limitation only on the analog outputs, so if they used the YPbPr output to dub them on another tape they'd get the black bars. The older analog masters though sometimes have the picture shifted all the way to the right (or left in rare cases), and the cropping of the DVD recorder removes part of the picture. I think I'll just use the passthrough on some of the bad tapes where the jitter shows up strongly. Most of the time it has to do with the quality of the magnetic tape and not degradation. |
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About Panasonic in passthrough, use it only when needed; if your VCR with lineTBC is good enough it should not be very often. |
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For competently shot video everything the shooter/director intended to be seen was within the action safe area. Thus restricting the digital active area to 702 horizontal pixels and 480 (for NTSC) scan lines did not lose anything artistically important. Given the bandwidth limitations of SD video on VHS the 704 pixels is more that adequate to digitize the a horizontal line. However, this was not the same for computer graphics which came much later in technology evolution. PC graphics did not provide for over-scan although many monitors offered width and height settings to accommodate it. Some TV sets with PC inputs will over-scan video sources and not over scan computer sources. It is something we live with when mixing material that evolved out of different sources. |
I’m pretty sure my VCR doesn’t have a line TBC, but it’s the capture card that has some line sync stabilization which is also specified in the chip datasheet.
For an example with other capture cards I have (like my TV Tuner from 2010 which has the same Conexant chip as the Live USB2), direct captures look terrible, with top screen curling and lots of noise and jitter. At this point I would use the passthrough only in rare cases. I have some beat down tapes, some which I had to clean from mold and such, that play way better on this NV SV120 deck than the combo I had (picture quality looks the same). |
I have VHS captures where the picture isn't perfectly centered and so for example only 4-5 pixels on one edge might not contain good picture information. Do the DMR's center the image before digitizing, or are those pixels lost?
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All my captures, PAL and NTSC have black junk all around four sides of the frame. Here is how the capturing process should work when using a capture device that doesn't crop on the fly: |
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The ATI AIW pictures are digital stills, post few seconds of lossless raw capture so I can get a frame mid stream and examine it. A proper frame grab should look like this:
http://www.digitalfaq.com/forum/atta...1&d=1650104247 |
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How much black there is around vary between recordings, some can extend outside the area where TBCs and the like blank, others dont.
On the first two screens here you can see the TBC in a JVC HR-S8600 can blank out a bit on the left when enabled, all captured via hdmi out of a Panasonic DMR-EH57: TBC off Attachment 15065 TBC on Attachment 15066 On this clip there is less in that area so there is hardly anything that is blanked: TBC off Attachment 15067 TBC on Attachment 15068 |
Indeed, How much black borders around the frame vary from tape to another, though never seen a frame with clean edge on the left like that one. But for capture devices, I know there are cards out there that crop and resize on the fly to 640 or 768, but cropping to 704 and resizing back to 720 while capturing is what I don't understand.
If one knows his capture card is hard locked to cropping it is wise to not choose the output resolution as 720 because the aspect ratio will be slightly altered, instead choose 640 for NTSC and 768 for PAL. |
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Yes, only an issue on cards that crop on the fly or you tell it to crop by selecting a different output resolution. I'm not saying the active area is 720, what I'm saying is the cards sample at 720 the entire line including the timing signals and output it as such unless it was designed with a crop feature that cannot be turned off.
Look at Hodgey samples and my sample, why they are not cropped? |
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Apparently my link went to the Doom9 capture guide Table of Contents instead of this page that I was actually trying to show you: http://www.doom9.org/index.html?/cap...re_window.html
From PDF reference at page bottom: Attachment 15071 Quote:
These oddball capture cards aren't doing a standard 13.5MHz luma sample rate and then cropping to achieve the output. The "cropped" area is part of the signal that isn't being sampled in the first place by the ADC. Quote:
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ImageSource("ENTVNews.avi_snapshot_00.08_[2022.04.15_04.29.23].jpg").ConvertBackToYUY2().Tweak(cont=4) Left: Attachment 15072 Right: Attachment 15073 |
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