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  1. 640 x 480 vs. 720 x 480: The Confusion That Keeps On Giving

    I am aware that there have been similar related questions before this, but I have not found the bottom-line answer.

    BACKGROUND

    I captured old (from the 1980s) VHS video using a Chinese-made analog-to-digital converter, to MP-4.

    I imported the MP-4 file into Adobe Premier Elements (PE) for editing. Adobe Premier Elements establishes the “Project Settings” by the first video clip moved to the Timeline (though this can be overridden and forced to different settings before editing). Given the 4:3 format of my file converted from VHS to MP-4, I assumed that PE would automatically establish a Project Setting of 720x480. In the PE Monitor Screen, the video looks properly formatted (no stretching or squishing); I didn’t even think about the matter and have already completed most of my edits.

    For no particular reason, I looked at my current Project Settings. It says 640x480. Indeed, as I created a short slide show at the end of the video, I used Photoshop to format the pixel dimensions for a perfect 640x480 fit. Looks fine in PE.

    After a good deal of research I understand that format 640x480 has square pixels, while 720x480 has vertically-rectangular pixels of such dimensions that on my computer monitor the two video formats are visually the same.


    QUESTION

    But are they really?

    My end purpose is to save my completed project and burn it to (standard) DVD. I just read that 640x480 is not a “legal” format for DVD. (I’m not sure what “legal” means for other than commercial producers of DVDs.) In any event, I hesitate to put more hours into editing this material if the end product will not work.

    I am aware that PE will not allow a once-started project to be re-set (forced) to new project settings, so I seem to be stuck with 640x480.

    1) Am I stuck? Will my PE project, after initially saved to a disc-burnable format, display properly on both a computer monitor and a TV?

    2) Can someone explain why this captured-and-converted video turned out to be 640x480 rather than 720x480?

    3) If I had known of these issues before I imported my digital file into PE, should I have --- beforehand --- “forced” the Project Settings to 720x480? Would that work, i.e., without distorting the video image? How to handle this matter in the future?

    Thanks for any assistance,

    Howard
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    Was the original capture 640x480? If so, PE set the project setting to match.
    When the file is rendered in PE aren't you able to choose a DVD template ?

    The NTSC DVD standard is 720x480, the authoring programs (those that package the source assets, mpeg-2, audio, subtitles,
    into the Video_ts folder) will not accept 640x480 as input.
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  3. Member dellsam34's Avatar
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    It's neither one, The proper resolution for a video capture is to crop off the 16 horizontal black pixels added by the capture card during capturing then set the pixel aspect ratio to 10/11 for NTSC and 12/11 for PAL/SECAM for a perfect 4:3 frame during encoding to the final playback format, With this you don't need to resize, here is a sample captured from VHS and encoded that way to see if it's compatible with your playback options, if it is then there is no need to resize to a square pixel format, you loose a lot of resolution.

    By the way 704x480 is an official resolution of DVD 4:3 (full screen), 720x480 is anamorphic widescreen not for analog sources such as VHS.

    If you insist on using DVD the proper way of doing it is to capture lossless AVI first, crop to 704x480 then encode to MPEG-2 using the SAR parameters above, from there you can author to DVD, Capturing to mp4 then to mpeg-2 with a resized resolution is a disaster.
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    Last edited by dellsam34; 3rd Aug 2020 at 14:54.
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  4. Originally Posted by Avagadro1 View Post
    I just read that 640x480 is not a “legal” format for DVD. (I’m not sure what “legal” means for other than commercial producers of DVDs.)
    It means it'll be impossible to author a DVD at 640x480.
    ...so I seem to be stuck with 640x480.
    It could be resized yet again to 720x480 and then you could make a DVD of it. But that means unnecessary degradation of the video on the way to the DVD.
    Will my PE project, after initially saved to a disc-burnable format, display properly on both a computer monitor and a TV?
    It won't display at all as you'll never be able to make a DVD directly from a 640x480 video. Now, I'm assuming you want to make a real DVD. You could burn the 640x480 MP4 as a data disc and some players might play it, but it won't be a DVD, which is what I think you want.
    Can someone explain why this captured-and-converted video turned out to be 640x480 rather than 720x480?
    You screwed up something in your editing program. I don't use it so maybe someone else can be more specific.
    Would that work, i.e., without distorting the video image?
    You want a 'distorted' image. Then you encode for MPEG-2 DVD with the DAR set for 4:3 and it'll play 'undistorted' when you're all done. You want to keep it 720x480 all the way through to the end. Unless you crop the black bars and get it down to 704x480. That's okay as well, and probably better.
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  5. Member Cornucopia's Avatar
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    I am concerned that the OP started off on the wrong foot from the beginning, with the "chinese made analog to digital converter, to mp4".

    As mentioned,best practices for vhs: 720x480 (or 704, depending on card & drivers) -> uncompressed/lossless temp format to edit. Edit project using same rez as source. Export to uncompressed/lossless master. Also export as mpeg2 for dvd, BOTH using same rez. Mpeg2 should have option to set AR in codec (either 4:3 or 16:9 as befits the source).

    640x480 shouldn't ever enter into the workflow until you decide to have a streamable/portable/shareable/youtube-friendly avc in mp4 as an optional additional export. Then, the shrinking of the horizontal will be baked into the square-pixelled file. And only ONCE.


    Scott
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  6. Thank you all for your responses, though some of it beyond my understanding.

    Again, I began this project with a VHS tape from the 1980s. I do not know the parameters by which the tape was recorded (other than standard definition, 4:3), but today’s experience (see below) indicates that it was at 640x480.

    I captured the VHS video using an inexpensive USB D-to-A converter, and PotPlayer software. The software allows capture to many formats. I was originally intending to capture to DV-AVI, as my Adobe Premier Elements (an older version) likes that format. However, I read a few weeks ago that now-a-days, for my purposes, I should instead capture to MP-4.

    After the new MP-4 file was on my hard disc, I imported it into Premier Elements and placed it as the first clip (initially the only clip) on the timeline for edit. The intent was to burn the finished product to DVD playable on computer or TV.

    I did not think about the matter, but I assumed that 720x480 was the “correct” format for standard, 4:3 digital video, and thus Premier Elements would set the format as such. However, after hours of editing, when I looked at the “Project Settings” dialog it stated that the video was 640x480. Thus I assume, but don’t know for sure, that 640x480 was how the old VHS camera recorded the video.

    On this website today, I inquired whether all my work on this project was for nothing. Should I ---- could I ---- when beginning the project, have forced the setting to 720x480? What would be the problem or other ramifications of leaving it at 640x480?

    I did not understand all of your responses (resizing and all), but I read your remarks that at 640x480 I would not be able to create a menu or burn to DVD. So I experimented. As a test, I added a DVD menu using the Premier Elements functions (what you commonly call “authoring”), burned the project to a folder, then burned a physical DVD disc.

    Here is what I found:

    1) Despite the video being 640x480, there was no problem adding a DVD Menu or burning to disc.

    2) Playing the video on my computer screen (which is 1080 resolution), the video was somewhat crunchy, especially the lettering in some of the still images that I added.

    3) Playing the DVD in my stand-alone DVD player attached to my TV (1080 flat panel), the video was very good (given, of course, the grossly inferior VHS source). In other words, the project worked as expected. No problem.

    What the heck is going on?

    In the future, even if my project begins with capture of VHS video recorded at 640x480, when setting-up the project (before beginning editing) in Premier Elements, should I "FORCE" the Project Settings to 720x480?

    Thank you.

    Howard
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  7. Originally Posted by davexnet View Post
    Was the original capture 640x480? If so, PE set the project setting to match.
    When the file is rendered in PE aren't you able to choose a DVD template ?

    The NTSC DVD standard is 720x480, the authoring programs (those that package the source assets, mpeg-2, audio, subtitles,
    into the Video_ts folder) will not accept 640x480 as input.
    __________________________________________________ _______________________________

    Thank you, but it did! I don't know what's going on, but Premier Elements recognized the loaded MP-4 as having a 640x480 resolution and kept it that way.

    I WAS able to create a Menu and burn the project to standard DVD.

    The video did not look great on my computer screen, but looked fine on my TV.

    I suppose the bottom-line issue is what to do in the future when I convert VHS tape to digital for editing in Premier Elements and burning a DVD?

    Thanks again.
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  8. Member Cornucopia's Avatar
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    It's actually pretty simple.

    All vhs is analog. Analog NTSC (which is what you have been and would be dealing with here in the US) is ALWAYS ### X 525. The # is variable because it's analog, but due to its limited bandwidth (6MHz) is not truly infinite. But it IS continuous along the scanline, which means that any sample rate used will be as accurate as that rate allows. The 525 is discrete, because there is clearly only that amount of scanlines, as per the spec timing.

    The 525 includes not just visible picture, but also blanking/vertical interval/timecode/closedcaptioning, etc. So to get solely the visible picture scanlines, sampling/digitizing would capture 486 lines. That's what the pro capture cards do. Consumer ones expect to make use of certain compression shortcuts, and one of those requires that the # of lines be evenly divisible by 4. 486 is not, so they compromised by dropping it to 480 (mainly by cutting off the top where those extraordinary line types live). Ta Da!

    The # of horizontal pixels per scanline depends on the sample rate. Very, very old school capture cards (c. mid-late 80s) did sometimes capture 640, but their samplerate was odd.
    The powers that be came to an international common set of sample rates such that both NTSC and PAL and SECAM could be digitized by the same card & they would have similar # pixels per scanline. The agreement document was CCIR (aka ITU) 601. That set the analog sampling to capture 704 pixels (ntsc) or 702 pixels (pal), usually contained in a 720 pixel frame (so leftmost 8 and rightmost 8 are black), per each line.
    Again, the vhs doesn't have pixels (which are digital sample points) because it's analog. But when it gets captured to digital, ntsc should almost always be captured at 704x480 (within 720x480 frame, or not) or 720x480 (ever so slighty stretching the picture), depending on how closely the capture card/device is in compliance with ITU-601. Yes, these all use rectangular pixels.

    No 640x480 there. To get that, these knock-off, non-compliant cards are squeezing (aka rescaling down) the image to fit a 640x480 frame. Just because it thinks that's what some/most consumers might want. But it DOES lose quality in the conversion, not even counting lossy compression.

    Mp4 will accept 640 or 704 or 720 (x 480) so no surprise. But like I said, you were Already at a disadvantage prior to ever even getting into your editor.

    Yes, you were able to export to 640 x 480, and the dvd software was able to "accept" that as a source. But to make a true DVD, it could not keep it like that and it had to recompress and resize it yet again (likely to 720x480, as that is the most common dvd framesize). So that is at least 2 or 3 lossy encodes, and at least 2 resizes to make it to the dvd. As I mentioned, best practices would guide you so that you only have 1 lossy encode and NO resizes. Should be a noticeable difference in perceiveable quality (but there is always variability with bitrates, and with user sensitivity).



    Scott
    Last edited by Cornucopia; 4th Aug 2020 at 00:36.
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  9. Originally Posted by Avagadro1 View Post
    However, I read a few weeks ago that now-a-days, for my purposes, I should instead capture to MP-4.
    You should capture to lossless AVI.
    Thus I assume, but don’t know for sure, that 640x480 was how the old VHS camera recorded the video.
    Can't you just look at your captured MP4 and figure out the resolution? I'm fairly certain your VHS camera didn't capture as 640x480.
    ...that at 640x480 I would not be able to create a menu or burn to DVD.
    You can't, although I mentioned it could be resized back to 720x480.
    ...what you commonly call “authoring”
    Authoring is taking DVD-compliant assets (video, audio, subs, maybe, chapters, maybe) and creating the IFOs, BUPs, and VOBs that make up a DVD.
    1) Despite the video being 640x480, there was no problem adding a DVD Menu or burning to disc.
    Then either it wasn't 640x480 to begin with or it was resized to 720x480. You can easily determine your DVD video isn't 640x480. Here, read "What is DVD?" on this site
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  10. Originally Posted by manono View Post
    Originally Posted by Avagadro1 View Post
    However, I read a few weeks ago that now-a-days, for my purposes, I should instead capture to MP-4.
    You should capture to lossless AVI.
    Thus I assume, but don’t know for sure, that 640x480 was how the old VHS camera recorded the video.
    Can't you just look at your captured MP4 and figure out the resolution? I'm fairly certain your VHS camera didn't capture as 640x480.
    ...that at 640x480 I would not be able to create a menu or burn to DVD.
    You can't, although I mentioned it could be resized back to 720x480.
    ...what you commonly call “authoring”
    Authoring is taking DVD-compliant assets (video, audio, subs, maybe, chapters, maybe) and creating the IFOs, BUPs, and VOBs that make up a DVD.
    1) Despite the video being 640x480, there was no problem adding a DVD Menu or burning to disc.
    Then either it wasn't 640x480 to begin with or it was resized to 720x480. You can easily determine your DVD video isn't 640x480. Here, read "What is DVD?" on this site
    __________________________________________________ ____________________

    manono and others:

    Thank you for your help.

    Based on your comments, I went back to my unedited MP-4 file as captured. (I was not the original VHS videographer.)
    I clicked on PROPERTIES > DETAIL. The MP-4 file, as captured but unedited, is 640x480 (not 720x480).
    What to conclude? As new to these matters I don't know, but I would suggest that it has to be one of two things:
    1) the camera that recorded this video was set to 640x480 resolution --- and that passed through.
    2) The USB digital converter received 720x480 data from the VHS tape and passed out 640x480.
    It would have to be one or the other, would it not?

    Ok. Taking all of your advice, I intend to RECAPTURE this VHS video. I have spent the last several days reading this website and learning VirtualDub. I shall recapture as AVI/Huffyuv. (Am I a quick learner, or what?!) And I just ordered a new (more expensive/non-Chinese) VHS-to-digital capture device; it will be here in a couple of days.

    So . . . upon my recapture, if the resultant AVI is 720x480, then it seems that your kind advice has been addressed.
    But what if the resultant AVI is (still) 640x480, perhaps because that was the setting of the recording camera in the 1980s?
    Should I convert that to 720x480 in VirtualDub (if doable and despite it being a re-encoding), or should I load the 640x480 AVI file into my editing software (Adobe Premier Elements) and let the editing software work with the 640x480 file (as it did earlier).

    All complicated stuff for a person new to video; I appreciate your help.

    Thank you.
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    640x480 or 720x480, it's usually a setting in the capture software

    The VHS tape is analog, it doesn't have a digital resolution. The 480 corresponds to the NTSC scan lines of 525
    (after cropping), while the 720 is the sampling of each line (far beyond any detail that VHS was capable of)
    and of course, it matches the DVD requirements
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  12. davexnet,

    You are implying (absolutley ok, I understand you) that in my initial/practice captures (using PotPlayer, not VirtualDub), I somehow or another INADVERTENTLY had the software set to capture at 640x480. Is that your thought?

    If so, I infer that you suggest that I review my PotPlayer settings (just for purposes of edification, not recapture), to see if, in fact, there was a setting for capture resolution, and it was set for 640x480.

    Is that your suggestion?

    Thanks very much.
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    Originally Posted by Avagadro1 View Post
    davexnet,

    You are implying (absolutley ok, I understand you) that in my initial/practice captures (using PotPlayer, not VirtualDub), I somehow or another INADVERTENTLY had the software set to capture at 640x480. Is that your thought?

    If so, I infer that you suggest that I review my PotPlayer settings (just for purposes of edification, not recapture), to see if, in fact, there was a setting for capture resolution, and it was set for 640x480.

    Is that your suggestion?

    Thanks very much.
    I can't attest to whether Potplayer offers this or not -you'll have to look, but certainly, IuVCR/IuVCS and Virtualdub can capture at 720x480,
    probably also AmarecTV, since this a common capture format
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  14. davexnet:

    Ok, I reviewed all of my inputs for the PotPlayer capture software.

    YES, I did indeed find the selection to which you refer. The title of that drop-down box is “Size”. In that drop-down window are MANY options, including 640x480 and 720x480.

    HOWEVER, what the drop-down box is reading is its default (I did not earlier know about it or touch it), which is the word “ORIGINAL”.

    What should we make of this?

    Should one not assume that “ORIGINAL” means that capture resolution will be whatever was the source, in this case the VHS tape? Or, since you noted that VHS tape, being analog, has no defined resolution, but I had set-up the capture “from analog TV” (which in this case was the correct setting), the software simply defaulted to 640x480.

    Does that ring true to you?

    And this leads to the final thought:

    Although my initial capture was definitely 640x480, it looked perfectly proper when loaded into Premier Elements for editing, and burned to DVD nicely. How come, if the “standard” for standard definition 4:3 video is 720x480?

    For learning purposes, if I were to recapture using the same software, should I set the “SIZE” capture option to 720x480, or leave it at the default of 640x480?

    Of course, going forward I intend to capture using VirtualDub, but I’m trying to learn the theory so that I know how to look for that input resolution selection in VirtualDub.

    Thanks so much.
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    Originally Posted by Avagadro1 View Post
    and burned to DVD nicely.
    This just means the DVD software resized it when creating the DVD; 640x480 is not a valid DVD resolution
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    Originally Posted by Avagadro1 View Post
    HOWEVER, what the drop-down box is reading is its default (I did not earlier know about it or touch it), which is the word “ORIGINAL”.

    What should we make of this?
    All that means is that your capture device was set to output at 640x480. You will need to figure out how to set the output resolution in the capture device.
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  17. Originally Posted by dellsam34 View Post
    By the way 704x480 is an official resolution of DVD 4:3 (full screen), 720x480 is anamorphic widescreen not for analog sources such as VHS.

    If you insist on using DVD the proper way of doing it is to capture lossless AVI first, crop to 704x480 then encode to MPEG-2 using the SAR parameters above, from there you can author to DVD, Capturing to mp4 then to mpeg-2 with a resized resolution is a disaster.

    dellsam (or others who can assist):

    Thanks to everyone's help, I am now able to capture my VHS video to a 720x480 digital file (no longer restricted to 640x480).

    I read your message (above) several times in order to understand it. It now seems to me that what you are referring to is to load my raw capture file (from VHS) into VirtualDub, apply a (any?) filter, then use that filter's "Crop" function. I tested that function and see that in using that dialog, I can crop the 720x480 image file (as captured) to 704x480. Is that what you are suggesting?

    IMPORTANT NOTE: After using VirtualDub, I will not be going straight to DVD. Rather, I intend to save the VirtualDub file and then load the file into Adobe Premier Elements for editing, and then burn to DVD. That being the intended workflow, is the "crop to 704x480" in VirtualDub still recommended? I believe I can import a 704x480 file into Adobe Premier Elements, but I'm almost certain that in Premier Elements I will have to select a (final) resolution format, which (of course?) in this case would be 720x480.

    In summary, in light of my workflow including Adobe Premier Elements for editing and then burning to DVD, should I crop the captured digital file to 704x480 or leave it as 720x480?

    Thank you.

    Addendum: I was just experimenting with my capture software (PotPlayer) and found that there is a function to "resize upon capture". This can be set as one wishes. Would you suggest I not capture at 720x480 and then crop in VirtualDub to 704x480, but instead capture to 704x480? Or is there too much monkey-business going on in such a procedure?
    Last edited by Avagadro1; 25th Aug 2020 at 16:32.
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  18. Originally Posted by Avagadro1 View Post
    Is that what you are suggesting?
    Sort of, although I believe he and most of the rest of us would do the cropping and other filtering in AviSynth and then open the script in VDub to be saved as a lossless AVI.
    I will have to select a (final) resolution format, which (of course?) in this case would be 720x480.
    No, the final resolution for your DVD should be 704x480.
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  19. Member dellsam34's Avatar
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    Yes, vdub allows you to remove the padded 16 pixels from the video that were added by the capture card for safe measures , You can customize your crop individually on each side as long as the total pixels removed is 16, Not sure if it can be done during capturing but the good thing is this process is quick and completely lossless. 704x480 is a legal resolution and recognized by most if not all video codecs. If you don't mind having black bars and rough noisy edges on the frame you don't have to do this, however the aspect ratio will be off by 16 pixels if you leave the side borders but most people would not notice a squeeze of 16 pixels of the active video area.
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  20. Originally Posted by dellsam34 View Post
    Yes, vdub allows you to remove the padded 16 pixels from the video that were added by the capture card for safe measures , You can customize your crop individually on each side as long as the total pixels removed is 16, Not sure if it can be done during capturing but the good thing is this process is quick and completely lossless. 704x480 is a legal resolution and recognized by most if not all video codecs. If you don't mind having black bars and rough noisy edges on the frame you don't have to do this, Also the aspect ratio will be off by 16 pixels if you leave the side borders but most people would not notice a squeeze of 16 pixels.

    dellsam, thank you.

    My original plan (before reading your advice), was to capture at 720x480 and load that into Premier Elements for editing. Of course there will be the "fuzzy bar" at the bottom of a computer screen (I am aware of its origins), but my intended approach (before I learned of this 704x480 matter) was to create a "Clip Mask" in Premier Elements of several pixels all-around, thereby hiding the objectionable fuzzy bar and making it even on all sides.

    In Premier Elements, there is no way that I can see to retain a project file as 704x480, the closest is 720x480. Based on your comments, I assume, therefore, that when I'm through editing, then rendering, my project in Premier Elements, and then I burn a DVD, the program will be re-encoding it to 704x480. Premier Elements is a consumer-level program; to the best of my knowledge and observation, there is no mention whatsoever of 704x480 --- just the several, usual resolutions commonly known as being SD or HD.

    Thanks again.
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  21. dellsam34 and manono ----

    A final question.

    Elsewhere in my learning through this site, I have repeatedly read “do not crop”, “do not crop”, as that forces a resizing/re-encoding, thereby a degrading of the image. Indeed, that is the reason why I had intended, in Premier Elements, to create a “Clip Mask” ---- a black border to cover the “fuzzy” bar (head-switch noise) at the bottom of the computer screen, and then to make that border even all around.

    However, your counsel to take my 720x480 capture from VHS, then, in a VirtualDFub filter, to crop it to 704x480, seems a very different view regarding cropping. Clearly I’m missing something.

    Thank you.
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  22. The advice about not cropping is for when you must resize after cropping. For example, many people want to remove head switching at the bottom of the frame (VHS caps) -- say, 8 lines, for example. If you crop it away you must resize (or add back borders) for DVD because 720x472 is not a legal size for DVD. In your case you are cropping black borders at the left/right of the frame leaving 704x480. That is a legal size for DVD so you don't have to resize or add back borders. And that 704x480 conforms to both the ITU spec (approximately) and the MPEG2/DVD spec for aspect ratios.
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  23. Ok. I now understand the reasoning behind the often quite-strong warnings against cropping in the video-editing software.

    Since I just discovered that I can capture at 720x480, then in VirtualDub's filter dialog crop the 16 lines, or, alternatively, I can set the capture software to 704x480, would there be a preference?

    Thank you.
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  24. One reason for capturing 720x480 is so that you can crop the black borders accurately -- they're not always even on both sides. But if you can capture accurately at 704x480 you might well do so.
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  25. Ok, thank you.
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