Downsizing the resolution to 50%, but not the color quality

[silencer]

Edit: Seems a playback configuration issue of any converted videos on my pc only.

Hi folks,

I have tried many converters and compared each of the results of the converted videos.
For me the mp4 with h.264 seems ok for now.

The original resolution is 1280x720 (mp4, 25fps), and i would like shrink it to 640x360. The size of the file is not important for now, only the quality. As I am going to cut and edit them in the near future to the latter size.

So, whenever I do the conversion, whatever tools or settings I use, even higher bitrates, I find out that in the end I never achieve the quality the same as the following:

When I watch the original video file and just resize the window of the player to 50%, I realize still how clear, sharp and vivid colourful it is.

Like that I would like convert the video to a similar result. I think if that is possible to see such a quality while watching, then it should be also somehow possible to have it converted and resulted the same way, shouldnt it? Or what do I do wrong or do I forget somethings in the settings? any suggestions? Or is that not possible?

I hope somone can help me out of this. im really bit frustrated.
Any help or advice is appreciated

Cheers
silencer

[DB83]

You do not say what you have used or what settings.

But IMHO you would make a big mistake to permanently downsize. Play the smaller video on a display that wants 1280*720 full-screen and your video will look much softer.

And, do it properly, the filesize will be exactly the same.

[El Heggunte]

The original resolution is 1280x720 (mp4, 25fps), and i would like shrink it to 640x360. The size of the file is not important for me, only the quality.

......

When I watch the original video file and just resize the window of the player to 50%, I realize still how clear, sharp and vivid colourful it is.

......

Like that I would like convert the video to a similar result.

That's possible, BUT you'll have to use uncompressed video OR a lossless video codec.

You say you don't care about the final file size,
however you might change your mind,
depending on how HUGE the reencoded video will be.

Otherwise, that is, by using a lossy codec, you'll have to determine which are the "best" settings for resizing and reencoding your video file(s).

[jagabo]

When I watch the original video file and just resize the window of the player to 50%, I realize still how clear, sharp and vivid colourful it is.

Players usually use a "point", aka, "nearest neighbor", resize filter for downscaling. That may look sharp but it leads to lots of aliasing and moire artifacts. That's why few programs offer it as an option.

[manono]

The original resolution is 1280x720 (mp4, 25fps), and i would like shrink it to 640x360.

That's 25% the resolution, not 50%.

any suggestions?

There's no mention anywhere of what program(s) you've tried or the settings. How can anyone help? Of course, there will always be at least some quality loss, but if you know what you're doing, not much. You should be able to view it in decent quality at 640x360, but once you full-screen it there's no way it will look as good as the 1280x720 one. And like DB83, I also think this is a dumb idea.

[smrpix]

The size of the file is not important for me, only the quality.

If this is true -- leave it alone.

[jagabo]

Watch this video full screen. The first half uses a bicubic resize to downscale (from DVD), the second a point resize. Which would you rather watch?

[DB83]

The original resolution is 1280x720 (mp4, 25fps), and i would like shrink it to 640x360.

That's 25% the resolution, not 50%.

You can not blame the OP for that one. That is exactly how the reduction is described in the players ie it just takes either the horizontal or vertical resolution rather than combining them.

[manono]

That is exactly how the reduction is described in the players ie it just takes either the horizontal or vertical resolution rather than combining them.

After checking my player and VDub, I see you're right about that. The fact remains, though, that 640x360 has 25% the resolution of 1280x720. It's worth pointing out, I think, as he might not realize that and it might impact his decision whether or not to shrink the resolution and by how much.

[jagabo]

[QUOTE=manono;2251077]

The fact remains, though, that 640x360 has 25% the resolution of 1280x720.

No. Resolution is a linear measurement. 640x360 has half the resolution of 1280x720. It has one quarter the number of pixels.

[manono]

You're saying pixel count doesn't equate to resolution? You're saying being able to fit four 640x360 videos inside of a single 1280x720 one doesn't mean it has a quarter the resolution? I wouldn't think it to be a linear measurement but a two-dimensional one. After all, it takes both width and height to define resolution. In this case both the width and the height are half the original one.

What about 640x720, or 1280x360? 3/4 the resolution of 1280x720? Or half?

[Noahtuck]

The title alone is ridiculous!!

Downsizing the resolution to 50%, but not the quality

The size of the file is not important for me, only the quality.

If this is true -- leave it alone.

What more can be said.....

[deadrats]

the very definition of resolution is the number of pixels wide times the number of pixels tall, thus resolution = # of pixels and 640x360 is 1/4 or 25% of 1280x720.

by jagabo's reasoning 1280x1080, 1440x1080, 1920x1080 and 2048x1080 all have the same resolution, something no one here would even think of saying.

[yoda313]

I do see a reason for possibly doing this - playing back on an underpowered or picky tablet.

I've had to do some crazy things with video to get it to work on an older tablet before I got my current tablet. And as it is I still have better luck with lower res video on my current tablet than higher res videos. THough I suspect its mostly due to the number of reference frames and how high of a level it was encoded at. ( edit - though my current tablet is LIGHTYEARS ahead in terms of playback compatibility than my first tablet that I had)

But there are instances that reencoding will be a necessary evil - though as has been mentioned previously:

There will be SOME quality loss in a reencoding job - that is unavoidable. How much depends on what you do with it in your reencoding and how sensitive you are to video artifacts.

And of course if you have a large harddrive or large sd memory card or are streaming the video than size isn't always a factor in the end file.

[El Heggunte]

^ Well-spotted, yoda313

However IMHO going from 1280x720 to 640x360 is an excessive loss of quality Resizing to 960x540, or even 720x576 (DAR=16:9), would give a better result than 640x360.

Anyway, it looks like the OP will look at this thread again sometime between this summer and next winter

[silencer]

Hello and thank you El Heggunte, jagabo and yoda313,

I had actually no fun anymore to discuss further since I saw the posts about my "dumb idea" and the resolution which should be 25%, not 50%, the frame area, or yes, the resolution, at least according to Freemake Video Converter it means 50%, for VLC Video Player it means 50%. But I really dont need to discuss about this.

the reason why i would like it smaller is that i am going to cut and edit the converted video files in the near future anyway. I have many files and it is much easier and faster for my computer when i prepare, process and edit them in the end with Sony Vegas 9, which obviously doesn't fight with the size of the file but with the larger resolutions and formats. it takes the uncompressed files much better for easier editing and smoother processings. Or while using Vegas, its alot easier jumping between frames without big lags or hanging etc.

Thats why for my first conversions I need the higher or the highest possible quality. There is nothing wrong in preparing the files.

For the conversion I ve tried Free Video Converter, Freemake Video Converter, Format Factory and few more. Just changed the resolution and remained for example all other settings Original.

@ jagabo

thank you for the fox intro video. The first half of the video seems better. maybe the colours in the 2nd part might see a bit better but not the pixels.


@ El Heggunte

However IMHO going from 1280x720 to 640x360 is an excessive loss of quality Resizing to 960x540, or even 720x576 (DAR=16:9), would give a better result than 640x360.

I would like 16:9 without bars and without stretching. First I wanted use 720x405 which is 16:9 and would be comfortable, but believe or not, whenever I try this and set it, the height goes depending on programs, either to 404 or 406 or 408 after processing, either with black bar or stretched and I dont like it. Try any converter and you will see. That is a riddle for me. 960x540 is still too high. Thats why I dont want give much time for it anymore and simply go with 640x360 which will be also used for Vegas then.

what would you suggest me to do and what tools for uncompressing?

Thanks

[jagabo]

First I wanted use 720x405 which is 16:9 and would be comfortable, but believe or not, whenever I try this and set it, the height goes depending on programs, either to 404 or 406 or 408

YV12 video (the colorspace used by most encoders) requires even (as in even/odd) frame sizes. Some encoders have further restrictions like integer multiples of 4, 8, or even 16.

[El Heggunte]

For the conversion I ve tried Free Video Converter, Freemake Video Converter, Format Factory and few more. Just changed the resolution and remained for example all other settings Original.
what would you suggest me to do and what tools for uncompressing?

One big problem in many/most of the "generic video converters" is, they don't teach the user how to fine-tune the codecs, sometimes they even don't let the user access all the "possibilities" of a given codec or encoder. Xvid for example, has an option called "Variance Adaptive Quantization", which may improve the quality of the encodes in some cases, at least. Also, choosing the quantization type "MPEG-2" instead of "H.263" usually translates as a sharper image. If you don't use B-frames, which generally are compressed harder than P-frames, the overall quality will improve even more, if you're not bitrate-starved (even if your eyes cannot notice the difference in the beginning).

Regarding resolutions, I forgot to mention 720x480 A pixel aspect ratio = 71:60 will resize the video to 852x480 during playback; 53:45 will give you 848x480, and 427:360 will return 854x480

[poisondeathray]

The other option if you have slower hardware - is to use "proxy editing" in vegas (edit at a low quality, low resolution just for ease of editing - then swap in the full quality, full resolution assets for final render) . There should be guides and tutorials if you search

Other option is to use a "near lossless" but easy editing intermediate like cineform (there is a free version now, "cineform go pro studio" )

Or upgrade your hardware

[_Al_]

The other option if you have slower hardware - is to use "proxy editing" in vegas (edit at a low quality, low resolution just for ease of editing - then swap in the full quality, full resolution assets for final render) . There should be guides and tutorials if you search

Most brutal approach works.
You edit low resolution files and then he just uses "Replace" clip function at the end to replaces that clip with original. Set project to properties of that high resolution clip though because if some graphics are generated during editing we want those in HD.

[silencer]

YV12 video (the colorspace used by most encoders) requires even (as in even/odd) frame sizes. Some encoders have further restrictions like integer multiples of 4, 8, or even 16.

hey jagabo, wow good to know! I decided to use then 704x396 and this really works fine, thanks!

@ El Heggunte

Thanks also. I tried four more converters today, one mentioned below and the others: SnowFox Total Video Converter, Any Video Converter and DVDVideoSoft Free Studio. I would tried maybe more converters if u could suggest me one. the last one was good, but all achieve with mpeg, avi, mp4, either with Original settings or different, not a powerful result same as when you resize the original video while watching.

@ poisondeathray

I just gave a try to Cineform GoPro Studio. There is unfortunately no much choices, output just AVI and MOV, and only four frame sizes to choose. But still I gave a try, with 480p (848x480) avi and the result looks not different than the other converters, while its file was ten times larger.
and exporting to MP4 gives a similar quality result to the converted one but just with reduced file size.


Meanwhile, I don't mind it so carefully anymore, also the file format, as long as it can come to such a powerful result like the original. But it would be interesting to know, anyone can try it:

1. Choose any HQ HD video
2. Convert it with the best converter you think to 50% resolution (half width, half height).
3. Watch it and do somewhere a pause. Watch the original HQ in a different window, just resize the window 50%, pause it and compare the difference at the same place/frame to the converted one.

You will see the original video is still better (color, sharpness). If it's a player related issue, then it is done for me.

Still, any suggestions are welcome, any info or about the possibility or the reason why or which programs to use or uncompress in order to use the same quality in any format like resizing the original player window.

Maybe it is possible to record the window while watching the original in resized window, but thats not an elegant option, and I better give up. Even now I am tired already.

[manono]

Thats why for my first conversions I need the higher or the highest possible quality.

I think you've made my point and the point of many others here. For highest possible quality use your 'source' video. Why use a video a quarter the dimensions (happy now?) of the source? Just because your editor is slow to respond? Welcome to the wonderful world of working with Hi-Def video files. Apparently, as both pdr and _Al_ have mentioned, you can edit in a lower quality/lower resolution version and then use the original for the final (and very slow) rendering. But if the final output is to be 1280x720 (have you even said?), lowering the resolution followed by raising it again is a very poor way to do it. If you care about quality.

If you insist on making a lower resolution version for your editor, and using it all the way through (no substituting out at the end), at least use a lossless codec (Lagarith or the like).

[silencer]

@ manono,

you dont need to give me an answer like your first paragraph just if its because to correct your high mathematical, super intelligent dimensions or resolutions issue.
also i thank to pdr and _Al_ that they gave me their hint, you dont need to repeat their wonderful information.
and no, my final output will not be 1280x720.

[DB83]

Well I am game to try the resize test. But to ensure we are on the same wave-length 'any' HD video will not do. We should all be working on one of your videos. All you need to do is upload a short, say 10 second sample of your 1280*720 original video. And the reason for that is to ensure that we have the correct video codecs to work with.

[silencer]

Good idea thanks. Please find attached one original file and the other one resized example output. I am happy if you can manage converting the original file, so I can follow you.

[DB83]

Here is a very quick attempt at a resize retaining as much quality as the original. Your own resize did not come close.

[_Al_]

I enclosed some samples too.

I quite do not understand what are you trying to achieve, you cannot compare original video resized by player to the smaller resolution and encoded video resized before encoding to the smaller resolution, it was already mentioned that, that first case is uncompressed result, not re-encoded and was created knowing HD so it downsamples to better overall result, just like you compare the same BD movie in smaller window with the DVD, BD will be sharper.


You have here two examples crf18 and cq18 which gave me using High@L4.1 bitrates 3700kbps and 6600kbps. If you try to go lower you will get under microscope always some problems. You will find it much worse anyway either case on full screen because it was re-encoded and resized. You go with higher quantizers for that CRF and it is going to be only worse, but smaller bitrates. Choosing profile Base and lower levels you will get smoother playback on weak machines but bitrate will go higher also.

Notice that purple scarf that lady in red sitting on scooter is wearing (9s in the video). You just see purple peace of cloth but still you can see quite an original structure playing original even resized.

[silencer]

Hello DB83 and _Al_

thanks for your samples. I attach a picture for the comparision of them all. The first pic is the original resized in the player. The colors are better than the other samples. So does it now mean it is not possible to achieve the same thing for converted videos?

I simply want to preserve also the colors. You see the dilemma? if those pixels remain in good quality when resizing the player, does it now mean we can not convert it like that at all?

Your conversions dont differ with the ones I did, it got a bit sharper but still the color quality is lost. So, this is really normal? We cannot preserve the colors?

[DB83]

Well with a little work on the brightness and contrast that should be quite easy. Like I said, mine was 'quick'.

With respect, the conversions are different. Your resize has a much lower bitrate. Of course you can go low with a smaller frame but the real quality is lower.

[poisondeathray]

There is no difference in color or levels with DB83's example (I didn't look at _Al_'s , but it's probably OK too in terms of color or levels)

You have a screenshot taking problem , or playback problem

You probably have more than 1 player application open at one time (only one can use the graphics overlay, so the other instances will use another renderer , and look different)