Different Image size exporting on MAC than on Windows - Davinvci Resolve

I don't know what media-player you are using but i would start using something better/more flexible than the standard Windows player.
I personally use Media Player Classic Home Cinema(MPC-HC)

Originally Posted by Neil-Betamax

I'm exporting loads of VHS I've captured as AVI, using davinci resolve.
Pixel Aspect ratio - 16:9 Anamorphic (4:3 doesn't display big enough)

By not big enough, i hope you not meaning the so called "pillarboxing"?
Why would you display your 4:3 VHS captures in stretched 16:9?

Thanks Hello_Hello,

The information I listed is everything I see in the render settings in davinci resolve. Under advanced settings on the Mac (davinci 15), it says 'Pixel Aspect Ratio' - From the header you can select between either 16:9 anamorphic or 4:3 standard definition.

The computer which tends to always play back the files smaller (only if they were exported on the windows laptop), is the only computer which does this, which makes me think it could be down to something within the OS or graphics card on playback, but it does play back bigger when its a file exported from the mac on that machine. I've played with the graphics card settings and resolution etc, but couldn't figure out why it plays back smaller on that desktop PC, but bigger if the files were exported on the mac.
I guess from what we can see, its nothing to do with pixel aspect ratio as to why I notice this difference.

There's another thing, when I export on the windows laptop, anything around 3 hours long always turns out at least 20GB, which is another reason I'm moving the files across to the mac to export them there.

[/QUOTE]
Fullscreen mode should only display the video without the player's own window (without menu and navigation bars etc).[/QUOTE]

When I play it back on the desktop PC, there's always a boarder, as it's trying to keep dimensions accurate & not stretched etc. I was using VLC and windows media player, but I've just downloaded MPC HC and I have the same results. It creates a boarder (I think) when you choose 16:9, but from the options available this is all I'm aware I have available to work with when exporting from the Windows Laptop. Otherwise, 4:3 SD turns out small every time on playback, unless I export the file on the Mac as 4:3.

I've taken some screenshots and detailed the results in photoshop so it looks clearer. The details I listed on the OP was everything I could detail from the render settings in a list. Hopefully this will look a bit clearer.

If I can export these files on the windows laptop, in a way the size will be displayed on every device, just as big as they do on the Mac, that'd be really great.
Also, if I can keep the file size around 5-6GB too, since when I export these files on the windows laptop, they end up around 20GB for 3 hours, so perhaps I may need to tweak my preferences around in Davinci Resolve so I can keep the file size down without sacrificing too much quality. I could experiment with restricting the quality by kp/s in the 'restrict to' section, but the image size would still play back smaller & at present, the mac seems to be giving a big enough image size & file size without sacrificing any quality noticably. It'd be interesting to see if anything's possible to change on the windows laptop to achieve similar results as I get on the mac, hoping that's possible. (sorry if I've been repeating myself a bit, its a little difficult to explain)....

https://forum.videohelp.com/attachment.php?attachmentid=78619&stc=1&d=1714046128

https://forum.videohelp.com/attachment.php?attachmentid=78621&stc=1&d=1714046267

Ps, apologies. I'm struggling to upload the picture. Hopefully the links work. Thanks

What were the project settings ? Certainly wrong projects settings can cause this

Why is the frame rate 24 for a PAL sequence on the MAC , but 25 on the PC in the screenshots , but 24 in mediainfo in the 1st post ?

Originally Posted by poisondeathray

What were the project settings ? Certainly wrong projects settings can cause this

Why is the frame rate 24 for a PAL sequence on the MAC , but 25 on the PC in the screenshots , but 24 in mediainfo in the 1st post ?

Hi, Thanks for your input. Untill you mentioned this, I had no idea it was set to 25 FPS on that export from the PC. Well spotted. I've always exported at 24 FPS, perhaps there's a chance for some reason davinci had automatically set it to 25 whilst I was playing around with different settings, & then I hadn't noticed. In the 1st post I was writing down everything I usually see when it comes to exporting, I had a different project open for reference, so when I took that screenshot I must have accidentally changed it to 25 somehow.

I'll put up a screen shot of the project settings shortly, both machines are currently in use (one rendering, other on capture. Theres a lot to get through)

Originally Posted by Neil-Betamax

From the header you can select between either 16:9 anamorphic or 4:3 standard definition.

First of al you should be very clear about your source video capture file you are trying to convert?
It looks awfully stretched to me so i expect it is regular 4:3, so you should keep it that way in your editing/processing chain.

Originally Posted by Neil-Betamax

When I play it back on the desktop PC, there's always a boarder, as it's trying to keep dimensions accurate & not stretched etc.

Well, that is how players should play it as as default, keeping the correct aspect ratio and letter/pillar boxing if needed.
But you can change/override that in the player settings if you want to do that.

Hi The_Doman,

The source file is captured at 625i50 PAL AVI 8-bit YUV, captured on the windows laptop using media express. I'll edit the OP so its clear, sorry about that.

I'm starting to realize that having not paid attention to the project settings, this could be where I've gone wrong. I thought everything I needed to focus on was under render settings. Here are screenshots of project settings for both machines:

https://forum.videohelp.com/attachment.php?attachmentid=78627&stc=1&d=1714060436

Apologies for the reems of detail here. I've been working at this for a long time, but I never thought to check the project settings.
If there's anything which stands out I'm doing wrong, please say. As far as I were aware, I had everything set in terms of render settings, but never knew there was another area I had to focus on called 'Project settings'. Duh! I've archived all the lossless AVI captures so hopefully I can render them all again with the right settings.

I am not really familiar with the program Davinci Resolve but the first thing i notice on the MAC settings is NTSC/24p 720x486???
Also from the equipment you listed i understand you are capturing from the HDMI output of your DVD recorder (pass-through?).
You need to check/verify how your VHS tapes were originally recorded and how they are captured.
Were they full screen 4:3, or may be letter-boxed 16:9 recorded?
Also i see some Widescreen signaling in some of your screenshots.
Possible from a set-top box?
The DVD recorder settings also change the way how the HDMI signal is outputted.
This can be the cause off the extra black letter/pillar boxes in your video's.

In general there are 3 areas where you have to pay attention to the settings for all editors, not just resolve:

1) The file interpretation settings - what flags or signalling doe the file have and does the editor read it correctly? If not you have to override or "interpret" the file. In resolve , right click a clip => clip attributes . For example, aspect ratio signalling might be wrong , or field order etc...

2) The project / timeline settings

3) The export settings


If you're capturing 625i50 PAL from VHS, why are you using 24p ? What is the original content - is it a drama/film, some documentary, home video ?

Normally for interlaced VHS content, 50Hz "PAL" areas, you would use 25i , and progressive exports would use 50p

24p is likely problematic and you will have dropped frames ; unless the original, original content was from NTSC area, or shot on 24p film. But then you would need other programs to handle it correctly , because if you're capturing at 50 fields/s interlaced, it's going to have duplicates or blends or potentially a dozen other problems

What are the viewing target/audience / how is it going to be played back ?

Originally Posted by The_Doman

I am not really familiar with the program Davinci Resolve but the first thing i notice on the MAC settings is NTSC/24p 720x486???
Also from the equipment you listed i understand you are capturing from the HDMI output of your DVD recorder (pass-through?).
You need to check/verify how your VHS tapes were originally recorded and how they are captured.
Were they full screen 4:3, or may be letter-boxed 16:9 recorded?
Also i see some Widescreen signaling in some of your screenshots.
Possible from a set-top box?
The DVD recorder settings also change the way how the HDMI signal is outputted.
This can be the cause off the extra black letter/pillar boxes in your video's.

Appreciating your feedback a lot, thanks for this.

I'm capturing from the DVD Recorder as S-Video into the Black Magic Shuttle as a pass through. I'm capturing Betamax and VHS, it's mostly Betamax I'm concerned with regards to accuracey. But the VHS recordings, they do vary a lot as they are recordings from DV or betamax, & there's a few commercial VHS tapes too which I'm uncertain of regards to aspect ratio. Most will be before the 90s though, I'd imagine most of those to be 4:3.

A great thing to point out. It might mean I have to re-do most of them, but if I can do it without having to copy them over to the macbook, it will be fine. I'm in no rush really, they can be capturing and rendering whilst I do other things. I just got excited and assumed I had my settings right, since I've had about 15 years of trial and error to get this far. The Windows Laptop was the only device I found capable of retaining audio sync, so I've been over the moon that I'm almost there within the last few months.

My knowledge in widescreen signalling is very minimal (thanks for the link though, I'll take that in for further reading). The example I screenshotted, if I remember right, was recorded in the 90s from channel 4 in the UK vai a standard coaxial input from the ariel. Although (I'll have to cast my mind back), it could have been recorded when we eventually got sky TV, which would have been going through a set-top box before it reached my VCR for recording to VHS.
The other example in the screenshots which says 'Earache' (earplugged - the videos) was captured from a commercial VHS tape from 1994. I couldn't see reference to the format, but looking it up on discogs now, it's PAL.

Originally Posted by Neil-Betamax

I'm capturing from the DVD Recorder as S-Video into the Black Magic Shuttle as a pass through.

I am still not sure what capture box you are using, there are various products with the name black magic shuttle.
I am also using the Panasonic DVD-Recorder pass-through method for my VHS captures using my DV/Camcorder and recently also with a Dazzle DVC100.

Originally Posted by Neil-Betamax

I'm capturing Betamax and VHS, it's mostly Betamax I'm concerned with regards to accuracey. But the VHS recordings, they do vary a lot as they are recordings from DV or betamax, & there's a few commercial VHS tapes too which I'm uncertain of regards to aspect ratio. Most will be before the 90s though, I'd imagine most of those to be 4:3.

Yes normally you should always capture the full 4:3 image , with letterboxing or not.
VCR recordings in real 16:9 anamorph from set-top boxes is not really that common i think.
If so you can always adjust for that later in your process editing/conversion process.

[QUOTE=The_Doman;2733215]

Originally Posted by Neil-Betamax

Yes normally you should always capture the full 4:3 image , with letterboxing or not.
VCR recordings in real 16:9 anamorph from set-top boxes is not really that common i think.
If so you can always adjust for that later in your process editing/conversion process.

It's a black magic intensity shuttle. I'm thinking if I export ecerything as 4:3 I'll be in safe grounds for the home recordings and non commercial footage, perhaps I could experiment in 16:9 as & when I notice for commercial videos.

It's amazing how much we need to understand in order to use these devices correctly, it's taken me 15 years to get this far with trial & error.

It's good to see I'm hopefully looking in the right direction now though. Once I've set up a good combo in project settings on the windows laptop, I can crack on with the process & have them all complete (easier said than done I know). It's a shame I hadn't thought to check there to begin with, so my next step is to see how I can manage to export the files as 4:3 on windows, whilst keeping the file size to a minimum.

Originally Posted by hello_hello

Neil-Betamax,
It might pay to upload a small section from 1 or 2 of your original AVIs so someone can look at them to see how they're supposed to display.
I'm not familiar with davinci resolve, but neither of the screenshots from the first image in post #6 look correct to me. They both appear to be stretched horizontally. The different display size might be because the program is adding borders for some reason, and it might be adding to existing borders. There's no way to know without seeing the original.

This is very rough as I just cropped the picture from your screenshot, but the picture itself looks like it should be 4:3 to me. Running fullscreen, ideally what you should be seeing on playback is something like the pic below (at least it appears that way to me). The pillarbox borders are necessary on a 16:9 display unless you want to stretch the picture.


[Attachment 78660 - Click to enlarge]

If you really want to reduce the size of the borders you can crop away some of the picture top and bottom, which would mean you'd effectively be zooming in without distorting the image. It's probably better to keep the whole picture though, otherwise you can risk cropping away part of the picture you shouldn't at times, such as the top of people's heads, but even if all you need to do is crop any existing borders to end up with something like the screenshot above, I don't know how to do it with davinci resolve, although I'm sure someone else here would.

Samples from 1 or 2 of your original AVIs would probably be helpful though. I could be wrong....


[Attachment 78661 - Click to enlarge]

Thanks for taking the time to analyse this, & crop them for comparison.
To be honest, I think as I've been a bit overwhelmed with possibilities, I shouldn't really have gone into the area of questioning how it displays from my Desktop PC, which those screenshots are both from. I'm not sure what it is, but when I play a file back from the Desktop PC I get varying results.

I think in order to get where I'm aiming, I'm going to only test using the output from my Windows Laptop (Thinkpad) as this appears to be more accurate. I've screenshotted some comparisons so we can see what the difference is on playback.

It appears that if I'm exporting on the Windows Laptop (Thinkpad), I'm getting the best results I'm aware of when I export as 16:9 Anamorphic.
This is because the picture is big enough on playback and the ratio/dimensions seem accurate.
I would have thought that exporting as 4:3 SD would give a better result, but that appears to only be true when I export on the mac - whatever settings I have in project settings, would probably explain this. But now, I'm hoping to get project settings all set up on the windows machine so I can export everything from there, so it seems to make sense to stop comparing results between mac and pc exports.

Yes, ideally I don't want to crop anything. I know how to in davinci as I were cropping the distorted lines at the bottom, although I prefer to leave them in now.

I've spent some time on Photoshop today so I can hopefully make it all a bit clearer.
I've put together an image with all my DVD Recorder settings, hardware set up description and project & render settings screenshots in Davinci Resolve.

I've put results next to each other to show the difference on playback when I use a desktop PC vs results from the Windows Laptop, shows how the image looks stretched when played back from the desktop PC. I generally think the ratio is fine, its probably due to playback on the desktop PC as to why it appears to be stretched. So from now on I'm only going to test, playing back on the Windows PC with HDMI out.

If there's something anyone can notice which I have set incorrect, it'd be a great help. When 16:9 Anamorphic is set in render settings I get the best result so far, but I'm unsure if there's anything in project settings which could provide a better result. It'd also be good to see if I can export as lower file size, since 3 hours ends up about 20GB. I know you can change this by editing the KPS under Quality > Restrict to - but I wonder if there's something more fundamental I could change, so I don't risk sacrificing quality too much for a smaller file size. I'm open to that being done in Vidcoder or MpegStream EG, but maybe there's something about how I have it set on the mac which could assist in this way?

(Ps, apologies if thats loads of info at once, I'm just trying to make what I'm asking as concise as I can. I'm also a little unused to how this forum works in terms of posting images, hopefully its working well enough..)

https://forum.videohelp.com/attachment.php?attachmentid=78698&stc=1&d=1714393320

https://forum.videohelp.com/attachment.php?attachmentid=78699&stc=1&d=1714393345