vhs to digital conversion

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jimspost

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vhs to digital conversion

PostMon May 17, 2021 6:51 pm

I have some vhs footage I shot back in the 80s that I would like to convert to a digital format and then edit in Davinci Resolve. Any suggestions on what file format, aspect ratio and other specs would be best? The original tape has numerous camera starts and stops, so I'm assuming in the conversion process I should have it converted as just one clip which I could then bring in to editing and subclip it? Any thoughts, thanks--
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Re: vhs to digital conversion

PostWed May 19, 2021 4:53 am

jimspost wrote:I have some vhs footage I shot back in the 80s that I would like to convert to a digital format and then edit in Davinci Resolve. Any suggestions on what file format, aspect ratio and other specs would be best? The original tape has numerous camera starts and stops, so I'm assuming in the conversion process I should have it converted as just one clip which I could then bring in to editing and subclip it? Any thoughts, thanks--


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Ben Kleschinsky

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Re: vhs to digital conversion

PostWed May 19, 2021 11:10 am

I'm currently struggling through the same predicament right now, since the entire world is HDMI now including Blackmagic cards. I've been staying up all hours of the night attempting to figure out what I should do.

First off it should be noted that analog noise is inherently different from digital noise. There are folks that like to say that the max resolution you will get out of S-Video is 480i. However a 480 resolution that is analog is very different from digital in nature. When you blow up an analog signal you have in theory unlimited resolution. When you blow up digital you get noise in the form of pixelation. I'm really not comfortable taking 480i archives of my family's tapes now that we have 1080P and 4K resolution.

What is the benefit of capturing VHS in high defintion or 4K? No you won't get more information out of the VHS, but by oversampling you avoid pixelation when it's blown up on a large screen. The problem is that almost all S-VIDEO to HDMI adapters that I know of resort to a form of upscaling that is shady at best. I wish there were capture cards that simply took the analog signal and captured it in high defintion, instead of upscaling by adding pixels that are not there in software. I'm really not looking for greater picture quality, but I am looking to avoid pixelation when I blow up the image which you won't get in the analog world.

So I don't really feel comfortable telling you that you should archive your tapes in 360P or 480i resolution with a 4:3 ratio, but I don't have a better option at this point. I am continuing to look. In reality I'm very interested in the concept of oversampling a 480i analog video signal, not upscaling. I have not found the best result yet.
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Uli Plank

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Re: vhs to digital conversion

PostThu May 20, 2021 1:08 am

If these are relatively short recordings with a lot of importance to you, give Video Enhancer AI a try.
But it's slow. If not, use the neural de-interlacer and SuperScale in DR 17.
Maybe AI can help you. Or make you obsolete.

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Ben Kleschinsky

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Re: vhs to digital conversion

PostSat May 22, 2021 11:17 am

Alrighty I thought I should clarify what I wrote now that I've been thinking about it for a week.

I'm going through the same project right now. First and foremost though it should be known that with archiving VHS, no Blackmagic device or capture card will be able to because a composite or s-video connection is analog and an HDMI or component connection is digital. There is going to be frame sync issues so you need to run a TBC device before it enters the capture card.

You can find a restored VCR from the late 1980's early 1990's with TBC, or you can buy an external TBC like a Data Video, Aja FS1/FS2/FS3/FS4, BrightEye by Ensemble Designs.

Next I've found in my research upscaling VHS when you are blowing it up to a high defintion screen can look incredible, but not all upscalers work the same. The better ones I can recommend are Framemeister, Retrotink 5x. The cheaper ones are known for introducing artifacts but certainly an option on a budget.

Then you have the VCR. DigitalFAQ and VideoHelp forums posted VCR buying guides you can google. "VHS Buying Guide". They have a wealth of information over there. Avoid the "pro" units like the plague unless you plan on archive professionally duplicated tape at SP speeds. Then if you want to capture stereo audio you need a two track USB interface, since S-Video only outputs picture unlike HDMI. Something like a Focusrite 2i2, and then you need to sync the audio. When I jumped into this project I thought it was as simple as buying a $15 VCR and $20 capture card. Turns out it's a lot more complicated than that.
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Re: vhs to digital conversion

PostSun May 23, 2021 5:11 pm

Actually I wasn't planning on doing the conversion myself. I have called a couple of companies who do this. While most of these consumer companies do this they put the finished product on a dvd that you can pop into your player and watch. But I told them I wanted it on a hard drive that I could then bring in to my Resolve editing system. They weren't knowledgable about Resolve so they asked me what specs I wanted which prompted my post here in the forum. Thanks--
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Uli Plank

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Re: vhs to digital conversion

PostMon May 24, 2021 1:20 am

Ask them to use ProRes 422 HQ then, not MPEG2 as for DVD.
Maybe AI can help you. Or make you obsolete.

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dpalomaki

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Re: vhs to digital conversion

PostThu Jun 03, 2021 11:17 pm

Note that analog NTSC (e.g., VHS) is a 486i raster scan, and is clearly bandwidth limited in terms of the content of each scan line. Factoring in overscan, the typical 480x720, non-square pixel interlaced scan, (sampled at 13.5 mHz with 10-bit depth) can recover all useful information on in the video, including noise within the video pass band. FWIW, the nominal horizontal luma resolution of VHS is about 240 vertical scan lines, and color is about 40 lines. The VHS recording/playback process amounts to a rather effective low pass filter on the original video signal.

Home video is often noisy, and noise in the image is the bane of lossy codecs such an MPG. That is part of why home video often made ugly DVDs. So use lossless codecs for capture if you have any image processing or restoration in mind. And use them for you archive copies. You can de-noise as part of your restoration process working with lossless originals.

Save any upscaling for the last step; e.g., preparing the distribution form/media.

The long gone Intensity Pro could do fairly nice SD analog capture provide you have a good stable signal. However, the IP4K has some issues, especially with component SD. The Analog to SDI mini converter can do a fair job but does not appear to like super whites (over 100 IRE) or super blacks (under 7.5 IRE) in the analog input.

The economical tape transfer services are hit and miss at best. If the prices are cheap it is likely the result is too. Many seem clueless if you want anythingthing other than a quick dump of VCR output to a DVD recorder on 2-hour recording mode.

The folks at digitalfaq.com are focused on capture and restoration of legacy consumer analog formats, and they obsess about quality.
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Re: vhs to digital conversion

PostSat Jun 12, 2021 9:18 am

dpalomaki wrote:Note that analog NTSC (e.g., VHS) is a 486i raster scan, and is clearly bandwidth limited in terms of the content of each scan line. Factoring in overscan, the typical 480x720, non-square pixel interlaced scan, (sampled at 13.5 mHz with 10-bit depth) can recover all useful information on in the video, including noise within the video pass band. FWIW, the nominal horizontal luma resolution of VHS is about 240 vertical scan lines, and color is about 40 lines. The VHS recording/playback process amounts to a rather effective low pass filter on the original video signal.

Home video is often noisy, and noise in the image is the bane of lossy codecs such an MPG. That is part of why home video often made ugly DVDs. So use lossless codecs for capture if you have any image processing or restoration in mind. And use them for you archive copies. You can de-noise as part of your restoration process working with lossless originals.

I think this all makes sense. I glanced at the Blackmagic product "Capture" page, and I think the only Decklink capture card left that still has an analog input is the DeckLink Studio 4K:

https://www.blackmagicdesign.com/produc ... s/W-DLK-12

This card plus a VHS player with a build-in TBC would be the best way to transfer VHS or S-VHS to digital files. I think ProRes 422 would be fine -- in fact, I doubt there would be a huge difference between 422 and 422LT from a VHS source. The Panasonic AG-7750 and the JVC BR-S822 each have built-in TBCs and would be pretty good decks for this purpose. I would be careful about using any noise reduction or sharpening (which are available on the TBC controls), and try to make the transfer as "flat" as possible.

BTW, some DVDs were (and are) extraordinarily good, depending on the quality of the mastering and how well they did the MPEG encoding. There were -- and still are -- multipass encoding techniques that can yield surprisingly good MPEG DVD encoding, provided they keep the bitrate up to a reasonable level.
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Re: vhs to digital conversion

PostWed Oct 13, 2021 4:32 pm

Thank you all for the information already covered on this topic, it's been quite useful! I've been struggling in obtaining quality VHS captures for some time now and still don't have my issues worked out. Hoping someone might be able to shed some light on where to go from here.

I have a Blackmagic Intensity Shuttle USB 3.0 and a JVC HR-S3800U Super VHS deck. If connecting the JVC directly to the Intensity Shuttle, via S-Video, I have issues with the signal breaking - combination of stuttering video, black flashes or color bars (depending on capture app). This happens both when using the Blackmagic Media Express app or Apple's QuickTime Player. Enabling or disabling "Video Stabilization" in the Menu of the JVC does not seem to make any difference. I obtained an AVT-8710 Multi-system TBC and this definitely seems to smooth out the signal, however I'm noticing the following when looking at the captures. Note, in the two instances below the Intensity Shuttle is the source and I'm capturing to the Apple ProRes 422 format.
• Blackmagic Media Express - At times there appear to be inconsistencies with frame rate and/or field oder which results in stuttering video. Video captured via this method is interlaced, and when running a de-interlace pass via Apple Compressor or Adobe Media Encoder the issue is amplified often resulting in additional artifacts. If skipping the de-interlace pass and using Topaz Labs Video Enhance AI and the model for de-interlacing I run into issues with stuttering again or duplicated frames due to the apparent inconsistencies in the frame rate.
• Apple's QuickTime Player - I do not get any of the fame rate and/or field oder consistencies as mentioned above, and it appears that QuickTime Player de-interlaces the video by default which there seems to be no control over. However, when looking closely at there are soft horizontal lines that appear in the captured video. Assume this has something to do with the auto de-interlacing.

Unsatisfied with the capture quality as detailed above, I've also tried the following:
• Connected the JVC directly to a Sony DCR-TRV520 Digital 8 Handy Cam, again via S-Video, and the camera to my Mac with FireWire 400 and adapters. On the camera enabled A/V to DV and on the Mac in QuickTime Player selected the camera as the A/V source. As far as video capture goes from my tests this has yielded the best quality video capture out of everything I have tried. I do not get any issues with frame rate, field order and the video appears to be de-interlaced well. I also do not need the TBC connected as the camera appears to take care of this. However, the audio does not capture correctly - it clicks, pops, goes out of sync and breaks up. On the camera I've tried switching between both 12-Bit and 16-Bit audio and have the same issue. I tried flipping into camera mode and did a test record using the built in mic - this works fine with no issues. Assuming something is off with the way the analog audio signal is interpreted?
• Within QuickTime Player I've also tried using the Sony camera as the source for the video, and then the Intensity Shuttle as the source for the audio. No issues with audio quality but unfortunately over time the audio drifts and becomes out of sync.

I'm really at a loss here. I just want to be able to have high quality ProRes captures of my VHS tapes to use as a master format for additional encodes or cleanup though Video Enhance AI or other tools. If anyone has any thoughts or suggestions they would be highly appreciated!

Thank you!
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Dmytro Shijan

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Re: vhs to digital conversion

PostThu Oct 14, 2021 10:06 pm

Check this thread viewtopic.php?f=3&t=109259 It may help to understand some specific capture and deinterlace options on macOS and BMD capture cards.

Also see this thread about possible interference moire pattern lines problems with BMD capture cards due overheat.
viewtopic.php?f=3&t=32036
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Re: vhs to digital conversion

PostFri Jan 07, 2022 7:13 pm

I know this is late, but I've been using the BMD Analog to SDI mini converter in to a VIdeo Assist. It combines the analog audio and video and makes a pretty decent copy. It records at NTSC SD. I then convert the files to MP4s and everyone seems happy with the outcome.
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Re: vhs to digital conversion

PostFri Feb 18, 2022 2:07 pm

"I know this is late, but I've been using the BMD Analog to SDI mini converter in to a VIdeo Assist. It combines the analog audio and video and makes a pretty decent copy. It records at NTSC SD. I then convert the files to MP4s and everyone seems happy with the outcome." similar to my first attempted workflow analog to sdi terranex then tried to capture on atamos shogun. the shogun would not see sd res so when i looked at capture devices i saw the 4k extreme 12 g had all the analogue inputs and captured. have had great results with it
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Re: vhs to digital conversion

PostTue Feb 22, 2022 8:14 am

Jsowell wrote:"I know this is late, but I've been using the BMD Analog to SDI mini converter in to a VIdeo Assist. It combines the analog audio and video and makes a pretty decent copy. It records at NTSC SD. I then convert the files to MP4s and everyone seems happy with the outcome." similar to my first attempted workflow analog to sdi terranex then tried to capture on atamos shogun. the shogun would not see sd res so when i looked at capture devices i saw the 4k extreme 12 g had all the analogue inputs and captured. have had great results with it

Now is this a DV converter, or capturing 4:2:2 raw color profile?
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Re: vhs to digital conversion

PostTue Feb 22, 2022 9:02 am

Ben i was just responding to earlier post but did not use the quotes . hopefully treutervid will respond
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Adam Grunseth

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Re: vhs to digital conversion

PostFri Feb 25, 2022 3:27 am

I operate an online service for converting home videos to digital. I started it because I couldn't find a single company that was digitizing NTSC video the "right" way.

Many of the posts here focus on de-interlacing, which is an important part of the process, but you also need to be concerned about how de-interlacing affects the motion cadence of the image. NTSC video is 60i, giving you a nice, smooth, 60hz motion cadence when viewed on a monitor that handles the interlaced signal correctly. Most de-interlacing, however, involves combining fields in some way, resulting in 30 progressive frames per second. You maximize the resolution this way, but you lose half of your temporal resolution. The alternative is usually field doubling, which maintains temporal resolution, but at the expense of spatial resolution.

Then there is also the matter of digitizing the analog signal itself. VHS uses a control track for a timing and image calibration signal (setting 0% and 100% alternatively). However, this control track is at the very edge of the tape and easily damaged, resulting in image issues. For best image quality you should use a TBC to regenerate a good control track signal. Color in NTSC works by carefully controlled chromatic interference, a very clever hack for CRT monitors. But, for digital sampling, there are a couple different ways to calculate the colors- The easy way and the not easy way. The easy way is an approximation, and what most composite video capture devices do. But this results in colors that aren't quite accurate to the original and a loss of chromatic resolution. It is possible to do the brute force math to calculate the physics involved in the chromatic interference, and get colors that are accurate to the original, but this involves a lot of parrel calculations that all must be done in real time during the capture.

To address these issues with the capture service I provide, I developed my own digitizing hardware and deinterlacing algorithm. It corrects the color the accurate, but computationally expensive way upon digitization for superior results. The de-interlacing algorithm maintains both spatial and temporal resolution, generating new fields via a neural network AI to get a full 60p signal.

The website for my service is www.MagicMemoriesBox.com- On the site there is a video comparison showing the results of our capture system versus a typical digitization with off the shelf hardware.
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Re: vhs to digital conversion

PostFri Feb 25, 2022 5:17 am

Adam Grunseth wrote:Then there is also the matter of digitizing the analog signal itself. VHS uses a control track for a timing and image calibration signal (setting 0% and 100% alternatively). However, this control track is at the very edge of the tape and easily damaged, resulting in image issues. For best image quality you should use a TBC to regenerate a good control track signal. Color in NTSC works by carefully controlled chromatic interference, a very clever hack for CRT monitors. But, for digital sampling, there are a couple different ways to calculate the colors- The easy way and the not easy way. The easy way is an approximation, and what most composite video capture devices do. But this results in colors that aren't quite accurate to the original and a loss of chromatic resolution. It is possible to do the brute force math to calculate the physics involved in the chromatic interference, and get colors that are accurate to the original, but this involves a lot of parrel calculations that all must be done in real time during the capture.

To address these issues with the capture service I provide, I developed my own digitizing hardware and deinterlacing algorithm. It corrects the color the accurate, but computationally expensive way upon digitization for superior results. The de-interlacing algorithm maintains both spatial and temporal resolution, generating new fields via a neural network AI to get a full 60p signal.

The website for my service is http://www.MagicMemoriesBox.com- On the site there is a video comparison showing the results of our capture system versus a typical digitization with off the shelf hardware.


It's worth mentioning that the control track is a VERY coarse timing signal and the TBC is recreating the Horizontal and Vertical sync pulses as recorded in the video signal, NOT just the control track.
Also the control track has zero effect on the image calibration. It is purely to make the tape transport run at a speed that will track any variation that occurs during recording, thus providing a stable signal ready for the TBC to process.

The colour difference signals are carried on a subcarrier frequency, not chromatic interference. The design was to ensure compatibility with monochrome TVs which did not detect the 4.43MHz (PAL) colour subcarrier frequency.

These are minor points but are important to understand correctly.
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Adam Grunseth

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Re: vhs to digital conversion

PostSat Feb 26, 2022 6:17 am

Peter Cave wrote:
It's worth mentioning that the control track is a VERY coarse timing signal and the TBC is recreating the Horizontal and Vertical sync pulses as recorded in the video signal, NOT just the control track.
Also the control track has zero effect on the image calibration. It is purely to make the tape transport run at a speed that will track any variation that occurs during recording, thus providing a stable signal ready for the TBC to process.

The colour difference signals are carried on a subcarrier frequency, not chromatic interference. The design was to ensure compatibility with monochrome TVs which did not detect the 4.43MHz (PAL) colour subcarrier frequency.

These are minor points but are important to understand correctly.


1) I never said that a TBC only recreates the control track signal, only that a TBC can help rectify issues caused by a damaged control track.

2) The control track on VHS contains a series of pulses, including the verticle blanking pulse. Most VCR's use the vertical blanking pulse to set the VCR's automatic gain control 0 level. This is also how VHS copy protection worked, having a non-0 level in this pulse would confuse a VCR's AGC, resulting in a copied tape having distortion and weird colors. But, a damaged control track, or poor control track signal, can very much affect image levels at playback depending on how a VCR's AGC is implemented. May things work different in PAL land, but this is very much how things work with NTSC.

3) When it comes to color, NTSC is a bit different than PAL. The PAL format, as I understand, came along as color TV was being introduced. NTSC was originally only for black and white transmission. The PAL format does indeed use an amplitude modulated subcarrier for chroma information. With the NTSC broadcast spec, there wasn't extra bandwidth to add a full chroma signal, and color broadcasts needed to remain backward compatible with black and white televisions. Color NTSC is made up of two signals that are 90 degrees out of phase with each other. These two signals are added together, resulting in the carrier itself being suppressed. The signal that is leftover can be expressed as a sine wave, and is the result of the interference between the two signals. The frequency of this sine wave represents the color hue while the amplitude corresponds to saturation. For color information to be passed in an NTSC signal, the receiver or VCR needs a 0 phase reference to replace the canceled carrier when the signals were added together. Most NTSC VCRs use the blanking area of the control track for this reference. These two NTSC color signals are only 1.5 and 0.5 mhz. By comparison, PAL has a dedicated 4.33 mhz sub carrier for color. These differences are noticeable when viewing the two formats side-by-side, PAL has noticeably more color detail, saturation, and the colors seem to be reproduced more accurately.
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Re: vhs to digital conversion

PostSat Feb 26, 2022 2:41 pm

Looks like a nice service Adam. Absolutely agree with your comment that people confuse timecode with frame rate for NTSC and correct deinterlacing for normal NTSC should be to 60P to maintain temporal motion. I like the smooth motion and now with my GH5 and GH5S shoot 60P as I do not like the visuals of slow frame rates.

For my amateur approach I either use my Sony D8 camcorder for Hi8 or play from my JVC SVHS deck with TBC into my Sony GV-HD700/1 HDV deck then ieee1394 into PC with Vegas deck control to DV. So far not deinterlaced any of them. Topaz looks good in my tests but so slow.
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Re: vhs to digital conversion

PostMon Feb 28, 2022 1:58 am

Adam Grunseth wrote:
Peter Cave wrote:
It's worth mentioning that the control track is a VERY coarse timing signal and the TBC is recreating the Horizontal and Vertical sync pulses as recorded in the video signal, NOT just the control track.
Also the control track has zero effect on the image calibration. It is purely to make the tape transport run at a speed that will track any variation that occurs during recording, thus providing a stable signal ready for the TBC to process.

The colour difference signals are carried on a subcarrier frequency, not chromatic interference. The design was to ensure compatibility with monochrome TVs which did not detect the 4.43MHz (PAL) colour subcarrier frequency.

These are minor points but are important to understand correctly.


1) I never said that a TBC only recreates the control track signal, only that a TBC can help rectify issues caused by a damaged control track.

2) The control track on VHS contains a series of pulses, including the verticle blanking pulse. Most VCR's use the vertical blanking pulse to set the VCR's automatic gain control 0 level. This is also how VHS copy protection worked, having a non-0 level in this pulse would confuse a VCR's AGC, resulting in a copied tape having distortion and weird colors. But, a damaged control track, or poor control track signal, can very much affect image levels at playback depending on how a VCR's AGC is implemented. May things work different in PAL land, but this is very much how things work with NTSC.

3) When it comes to color, NTSC is a bit different than PAL. The PAL format, as I understand, came along as color TV was being introduced. NTSC was originally only for black and white transmission. The PAL format does indeed use an amplitude modulated subcarrier for chroma information. With the NTSC broadcast spec, there wasn't extra bandwidth to add a full chroma signal, and color broadcasts needed to remain backward compatible with black and white televisions. Color NTSC is made up of two signals that are 90 degrees out of phase with each other. These two signals are added together, resulting in the carrier itself being suppressed. The signal that is leftover can be expressed as a sine wave, and is the result of the interference between the two signals. The frequency of this sine wave represents the color hue while the amplitude corresponds to saturation. For color information to be passed in an NTSC signal, the receiver or VCR needs a 0 phase reference to replace the canceled carrier when the signals were added together. Most NTSC VCRs use the blanking area of the control track for this reference. These two NTSC color signals are only 1.5 and 0.5 mhz. By comparison, PAL has a dedicated 4.33 mhz sub carrier for color. These differences are noticeable when viewing the two formats side-by-side, PAL has noticeably more color detail, saturation, and the colors seem to be reproduced more accurately.


Some of your information is misleading.

In NTSC television, a 3.579545MHz color subcarrier is quadrature-modulated by two color-difference signals and added to the luminance signal. The PAL television standard uses a subcarrier frequency of 4.43362MHz. PAL is Phase Alternating Line. PAL is merely an upgraded, revised version of the NTSC standard.
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Re: vhs to digital conversion

PostSat Mar 12, 2022 2:15 pm

I would like to confirm best settings for capture and process. in parentheses is what i am using currently
vhs IRE (7.5)
hi 8 IRE(0)
davinchi color management (off)
clip attributes (auto= video)


I was using color management (on)
clip attribute (full for hi 8) (video for vhs)
adjusting darks down slightly on hdr section in color


just did a bunch of testing straight from a a digi8 camcorder. if i use ire 7.5 the image i record has the side borders and the darkest blacks hovering near 0 however the image looks crushed and i lose very dim objects in the shadow. compared to the image on the camcorder lcd it is clearly darker. if i set it to full in clip attributes the borders and blacks are even but sit 15 high
when recording with 0 ire the borders and the black parts of the image are separated by a 15 gap. set to video when i slide the blacks on the middle of the image to the bottom (near 0) on waveform the sides show -15 in the borders. this looks proper compared to the lcd on camcorder. recording in 0 ire and using video is the same as recording in 7.5 ire then using full in clip attributes. recording in 7.5 ire and using video appears to be right at 0 on waveform but visually crushed blacks. I just went to render the videos to show you guys what was going on and discovered that the clip attributes setting IS NOT WORKING!! you see the change in davinchi but when rendered it will not change anything when using full in clip attributes..this leaves only the option record in 0IRE for hi8 and processes using video since full is not working
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