Rendering 720x480

Widetrack wrote on 1/25/2020, 8:41 PM

I captured a bunch of Hi8 videos as 720x480 .avi files, and I'd like to render them as .mp4 files, as close to the 720x480 frame size as possible. But I'm unclear on a lot of the options in the render settings box. I tried rendering to a "custom frame size" of 720x480, but it plays back noticeably smaller (and less crisp) than the .avi.

Can anyone suggest the best settings for this?

Thanks for any help.


Former user wrote on 1/25/2020, 8:45 PM

720 x 480 will always be the same size as any other 720 x 480. Your player is probably affecting the playback size. mp4 files are compressed and will never be as crisp as the original AVI files. It is the nature of the beast.

Widetrack wrote on 1/25/2020, 8:51 PM

Dot: That's sure what I thought, but I'm playing them back in VP17, with the Preview window set to 720x480, and the avi and mp4 files in the same positions on track 1 and 2, respectively, and using the mute button to turn track 1 on and off. Also, the info bar at the bottom of the Project media window says both are 720x480. Yet the mp4 is still smaller, with ~3/8" black bars all around it.


Former user wrote on 1/25/2020, 8:54 PM

Can you post a screenshot and also the rendering template settings you are using to make the MP4?

Widetrack wrote on 1/25/2020, 8:58 PM

Also, I would like to ask for recommendations on what codec to use. I've tried the MAGIX AVC/AAC MP4 codec, and set the Custom Frame Size to 720x480.

Former user wrote on 1/25/2020, 9:00 PM

That codec should be fine.

Widetrack wrote on 1/25/2020, 9:10 PM

Dot: Thank you for taking the time to help. Here's the render setting box.

Former user wrote on 1/25/2020, 9:15 PM

Your pixel aspect ratio is incorrect. It should be .9091. You have also made it progressive. Your original was probably interlaced. This will affect the visual quality because you have effectively lowered the resolution.

Widetrack wrote on 1/25/2020, 9:15 PM

Dot: Thank you for taking the time to help. Here's the render setting box.

Widetrack wrote on 1/25/2020, 9:17 PM

OK. Why is this render template set to 1.0000?

Musicvid wrote on 1/25/2020, 9:19 PM

720x480 is a storage dimension, not a delivery dimension.

Multiply 720 by PAR to get the display dimensions. For instance,

(720 x 1.212) x 480 = 854x480


Former user wrote on 1/25/2020, 9:19 PM

It probably defaults to that for HD which is 1 to 1 aspect ratio. NTSC 720 x 480 are non-square pixels. If you want a 1:1 aspect, you should render to 640 x 480.

Widetrack wrote on 1/25/2020, 9:24 PM

Bingo! That fixed the frame problem. Thank you. The image is still visibly less crisp. Is there anything else I can do to help that, or is that just what you get with the compression?

But 640 x 480 will be a yet smaller frame, yes?


Widetrack wrote on 1/25/2020, 9:28 PM

Musicvid: Aha! That explains why I was seeing that framesize in the suggested templates. But where did the figure 1.212 come from? And what is a ""storage dimension"?

And what PAR should I use?

Musicvid wrote on 1/25/2020, 9:28 PM

It probably defaults to that for HD which is 1 to 1 aspect ratio. NTSC 720 x 480 are non-square pixels. If you want a 1:1 aspect, you should render to 640 x 480.

No, 1.2121 is Widescreen 16x9 PAR.

Standard 4:3 is 0.9091 PAR, Both NTSC.

720x480 is not HD, by definition, requiring at least 720 vertical pixels.

Former user wrote on 1/25/2020, 9:36 PM

620 x 480 at 1:1 will be the same size if viewed correctly as 720 x 480 at .9091. The idea was to get as much resolution as possible by changing the aspects of the pixels rather than resolution. Widescreen DV is still 720 x 480 viewed as 1.2121 aspect as Musicvid showed. Still the same amount of pixels, just stretched visually. With normal HD, you don't have the concerns. It is always HD. I have not heard the term storage dimension since aspect ratio is used in final deliveries for standard def. (if TV stations still use SD anymore). SD DVDs are 720 x 480 which is a delivery medium.

Musicvid wrote on 1/25/2020, 9:39 PM


Widetrack wrote on 1/25/2020, 9:40 PM

I tried the .9091 PAR and it appeared somewhat smaller. The 1.0000 smaller yet (about an inch of black on all sides) but much better looking!

Thank you , Gentlemen, for your help, especially at this late time. But I need to leave for the night. I think I'm on the right track.

Best wishes.


Former user wrote on 1/25/2020, 9:41 PM

Nice article of explanation.

john_dennis wrote on 1/26/2020, 12:59 AM

While you're working with old tapes, you should take a look at de-interlacing with Happy Otter Scripts for Vegas Pro.

I'll let you decide which was done with Vegas 17 Smart Adaptive De-interlacing and which was done with Lanczos in HOS.

Edit: Corrected spelling to pay proper tribute to mathematicians that they deserve.

Musicvid wrote on 1/26/2020, 10:03 AM

Lanczos? Do you mean QTGMC?

john_dennis wrote on 1/26/2020, 10:36 AM

RenderPlus/AviSynth/Custom/Frame Size/640x480/Resizer...

Yes, I plan to learn how to spell it.

adis-a3097 wrote on 1/26/2020, 10:44 AM

The one on the right looks denoised to me. #don't shoot me

john_dennis wrote on 1/26/2020, 11:02 AM


"The one on the right looks denoised to me. #don't shoot me"

I won't shoot you. It may be the effect of the de-interlacing and resizing. I rendered it again to make sure I didn't tick the denoise box and the result was the same. It does look flatter or smoother or whatever other touchy-feely word one might use. A little sharpening might be in order when working with these old tapes. My old tapes are mostly gathering dust.

frmax wrote on 1/26/2020, 5:58 PM

I'm a bit surprised. 720x576 PAL 25fps or 720x480 NTSC 29,97fps are typical DVD formats. So I used to encode these Hi8 or Digital8 movies / basically in MPEG-2 format and created a DVD from it.
Which advantages can be expected by rendering in MP4?
(I ask because I still have a lot of old tapes to process)
Thanks for any information in advance.

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