a question about video's resolution

[lever1119]

Hi, I have a question about video's resolution. Please help.

I got a laptop with 1366*768 resolution. If I want to make a video of 1000K bitrates with MEGUI, should I set up a 1280* or 1024* or 848* or 720* video's resolution? Which one is the best for fullscreen watching?

I always confuse. Is video's resolution decided by monitor's resolution ? Is it connected with bitrates?

Thanks a lot.

[LoRd_MuldeR]

It generally is recommended to keep the resolution of your input video as-is and let the individual playback device do the required scaling.

If, however, you are encoding for one particular playback device and want to do the scaling beforehand, then I would scale to the device's exact resolution in order to avoid another scaling on playback time!

In your case this would mean scaling to a resolution of 960x768 (assuming that 1280x1024 is the proper aspect ratio with a PAR of 1:1).

[lever1119]

It generally is recommended to keep the resolution of your input video as-is and let the individual playback device do the required scaling.

If, however, you are encoding for one particular playback device and want to so the scaling beforehand, then I would scale to the device's exact resolution in order to avoid another scaling on playback time!

In your case this would mean scaling to a resolution of 960x768 (assuming that 1280x1024 is the proper aspect ratio with a PAR of 1:1).

Thanks a lot for applying.

The source video is a 1080P with 1920*1080 resolution. So I should scale to a resolution of 1366*768, not 960*768, right?

If I give 500K bitrates , 2000K bitrates, or any other bitrates to the video, should I set up the same resolution(1366*768) in order to get the best quality for fullscreen watching in my laptop?

[lever1119]

And one more question, please.
If I scale to a resolution of 720*404, not 1366*768, what's the difference between them on fullscreen watching? Is it worse a lot?

[LoRd_MuldeR]

The source video is a 1080P with 1920*1080 resolution. So I should scale to a resolution of 1366*768, not 960*768, right?

Correct.

If I scale to a resolution of 720*404, not 1366*768, what's the difference between them on fullscreen watching? Is it worse a lot?

Well, downscaling from 1920x1080 to 720x404 or 1366x768 will destroy detail in both cases. But obviously 1366x768 will be able to preserve more much more detail than 720x404. Also, even if you keep the video at 1920x1080, it would be downscaled to 1366x768 at playback time anyway (when watching on your laptop 1366x768 screen). So in this particular case you don't loose anything when downscaling from 1920x1080 to 1366x786. On the other hand, if you downscale to 720x404, you not only destroy more detail, you also would be upscaling from 720x404 back to 1366x786 at playback time...

(Going from 1920x1080 straight to 1366x768 seems the preferable solution, compared to going from 1920x1080 to 720x404 and then from 720x404 to 1366x768)

[lever1119]

I understand what you mean. But I still confuse that why 720*404 destroys more detail than 1366*768. You know that the bits/(pixel*frame) of 720*404 is higher than 1366*768 because they both get the same bitrates(1000K). It means that the quality of 720*404 is much better than 1366*768 on original resolution. When I scale 720*404 to fullscreen, I don't know what the difference between it and 1366*768. It seems similar or not?

Also, can you answer this question, please?
If I give 500K bitrates , 2000K bitrates, or any other bitrates to the video, should I set up the same resolution(1366*768) in order to get the best quality for fullscreen watching in my laptop? (what I mean is that video's resolution setup is decided by the laptop's resolution, not bitrates's business?)

Thanks.

[LoRd_MuldeR]

Lower resolution -> less detail.

It's a simple as that! At least if we assume that your source really was a "native" 1080p source, not something that was upscaled from a low resolution master.

Also "bits per pixel" is complete useless as a quality measure, as it completely leaves out the "complexity" of the video. This has been discussed more than enough in this forum (use search!).

Moreover, downscaling a video to a lower resolution doesn't necessarily make it easier to compress:
http://forum.doom9.org/showpost.php?p=1311212&postcount=14

[lever1119]

Ok, I see. Really appreciate it.

[lever1119]

Sorry, I have one last question.

Should I set up 1920*1080 resolution with 1000K bitrates or whatever for my video in order to watch fullscreen on bigger resolution (1600* or 1920*) of the computer in the future?

[7ekno]

If you don't care about the final filesize, use CRF encoding instead of bitrate, it's single pass and will determine the required bitrate based on how complex the video is ...

1000kbps will trash a 1080p video pretty well (depending on complexity of course) ...

7ek

[lever1119]

If you don't care about the final filesize, use CRF encoding instead of bitrate, it's single pass and will determine the required bitrate based on how complex the video is ...

1000kbps will trash a 1080p video pretty well (depending on complexity of course) ...

7ek

Thanks. I prefer 2PASS.

[Blue_MiSfit]

It's not all about resolution. Though it's basically impossible to know which resolution is optimal for a given average bitrate, you probably shouldn't encode 1080p at 1mbps.

Here's what I consider good "rules of thumb" for "acceptable bitrates" for "typical" footage - i.e live action, 24p, average detail and motion, using standard settings with x264 etc...

1920x1080 - 3-10 mbps
1280x720 - 2-4 mbps
720x480 - 1-3 mbps

In other words, for most 1080p footage, you usually need at least 3mbps, and will be reasonably transparent (or damned close) at 10mbps. For 720p, at least 2mbps and looking good at 4mbps. For 480p, at least 1mbps and looking good at 3mbps.

These are by no means scientific, and are by no means applicable to all cases.

Regardless, I think we can all agree that attempting to encode average 1080p content at 1mbps is madness.

Also, @lever1119, why do you prefer 2pass? the only reason to use it is if you must hit a specific bitrate. This is generally only important if you're encoding to fit a specific specification, or are going to store your encodes on physical media like CD or DVD (which I'd submit is a dreadful idea). CRF is very much a great idea for most purposes.

Derek

[lever1119]

It's not all about resolution. Though it's basically impossible to know which resolution is optimal for a given average bitrate, you probably shouldn't encode 1080p at 1mbps.

1920x1080 - 3-10 mbps
1280x720 - 2-4 mbps
720x480 - 1-3 mbps

In other words, for most 1080p footage, you usually need at least 3mbps, and will be reasonably transparent (or damned close) at 10mbps. For 720p, at least 2mbps and looking good at 4mbps. For 480p, at least 1mbps and looking good at 3mbps.

These are by no means scientific, and are by no means applicable to all cases.

Regardless, I think we can all agree that attempting to encode average 1080p content at 1mbps is madness.

Also, @lever1119, why do you prefer 2pass? the only reason to use it is if you must hit a specific bitrate. This is generally only important if you're encoding to fit a specific specification, or are going to store your encodes on physical media like CD or DVD (which I'd submit is a dreadful idea). CRF is very much a great idea for most purposes.

Derek

Hi, Derek. Thanks for applying.

What you said is just like what I confused. But it's different from what LoRd MuldeR's said before. You are both professional. Maybe my question is not very clear.

I often encode movies by MEGUI. So I wanna make a rule for them. The rule is that all the movies got same resolution(like 720*), similar bitrate(like 1000K-1200K). I wanna control the size in a range(700M-1.5G,depend on length of the movies). So I use 2pass, not CRF. I think it's the reason that why 2pass is more popular than CRF on the net.

But I'm not sure about the movie's average resolution. So I wrote this thread. I always watch movies on fullscreen.

I have introduced all the things. Is your answer still like before, please? Which resolution should I set up for all the movies when watching on fullscreen? 720*? 1366*?

[LoRd_MuldeR]

What you said is just like what I confused. But it's different from what LoRd MuldeR's said before.

Well, the more you downsize from your original source, the more details you destroy, already before the re-encoding (again assuming that the original source was "native" footage, not something that had been upsized from a lower resolution). Now the bitrate controls the additional quality loss during the re-encoding stage. And, if you already downsized the video, you usually will be able to get away with a lower bitrate for "transparent" quality - compared to encoding the source at its original resolution. However you can not assume that reducing the total number of pixels by x percent will reduce the required bitrate by x percent too. If, for example, we assume a maximum of 10 Mbps for 1920x1080, this would give us a maximum of ~1,66 Mbps for 720x480, according to the (useless) "bits per pixel" rule. In reality you probably won't be able to get away with such low bitrate, which perfectly agrees with Derek's numbers (max. 3 Mbps for 720x480). Also keep in mind that once you have downsized the video, you will not be able to retain the same level of quality/detail as the source, no matter how much bitrate you throw at it! Therefore downsizing the source only makes sense if you have a "hard" bitrate limitation for whatever reason...

I often encode movies by MEGUI. So I wanna make a rule for them. The rule is that all the movies got same resolution(like 720*), similar bitrate(like 1000K-1200K). I wanna control the size in a range(700M-1.5G,depend on length of the movies). So I use 2pass, not CRF. I think it's the reason that why 2pass is more popular than CRF on the net.

2-Pass mode is the mode of choice if you have a predefined bitrate (file size) limit that you need to hit as exactly as possible. For anything else CRF mode is highly recommended!

[lever1119]

Also keep in mind that once you have downsized the video, you will not be able to retain the same level of quality/detail as the source, no matter how much bitrate you throw at it! Therefore downsizing the source only makes sense if you have a "hard" bitrate limitation for whatever reason...

Thanks for so patient explain. Now I totally understand what you mean. I never want to get the same quality with the source video.

You are agreed with what Derek's said, right? So just like my question, the original source was "native" footage, and I give 1000K bitrate for encoding. I should set up 720* average resolution for all my videos because of the rule that Derek said, right? If I set up 1280* or 1366* resolution for my videos, the quality is worse than 720* when I watch on fullscreen, right? Please make sure for me.

[Target Practice]

have you run tests OP? here's one I did:
Avisynth Scripts:
FFVideoSource("E:\x264\input\Universal.mkv").AssumeFPS(24000,1001).Spline36Resize(720,400)
FFVideoSource("E:\x264\input\Universal.mkv").AssumeFPS(24000,1001).Spline36Resize(848,480)
FFVideoSource("E:\x264\input\Universal.mkv").AssumeFPS(24000,1001).Spline36Resize(1024,576)
FFVideoSource("E:\x264\input\Universal.mkv").AssumeFPS(24000,1001).Spline36Resize(1280,720)
FFVideoSource("E:\x264\input\Universal.mkv").AssumeFPS(24000,1001)Then I ran:cd /d E:/x264/avs2pipe
avs2pipe26_gcc video "../input/Universal0720.avs" > "../intermediate/Universal0720.y4m"
avs2pipe26_gcc video "../input/Universal0848.avs" > "../intermediate/Universal0848.y4m"
avs2pipe26_gcc video "../input/Universal1024.avs" > "../intermediate/Universal1024.y4m"
avs2pipe26_gcc video "../input/Universal1280.avs" > "../intermediate/Universal1280.y4m"
avs2pipe26_gcc video "../input/Universal1920.avs" > "../intermediate/Universal1920.y4m"
pauseFollowed By:cd /d E:/x264/r2074
x264 --preset veryslow --tune film --pass 1 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "0720.stats" -o "../output/0720.mkv" "../intermediate/Universal0720.y4m" --sar 80:81
x264 --preset veryslow --tune film --pass 2 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "0720.stats" -o "../output/0720.mkv" "../intermediate/Universal0720.y4m" --sar 80:81
x264 --preset veryslow --tune film --pass 1 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "0848.stats" -o "../output/0848.mkv" "../intermediate/Universal0848.y4m" --sar 160:159
x264 --preset veryslow --tune film --pass 2 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "0848.stats" -o "../output/0848.mkv" "../intermediate/Universal0848.y4m" --sar 160:159
x264 --preset veryslow --tune film --pass 1 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "1024.stats" -o "../output/1024.mkv" "../intermediate/Universal1024.y4m"
x264 --preset veryslow --tune film --pass 2 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "1024.stats" -o "../output/1024.mkv" "../intermediate/Universal1024.y4m"
x264 --preset veryslow --tune film --pass 1 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "1280.stats" -o "../output/1280.mkv" "../intermediate/Universal1280.y4m"
x264 --preset veryslow --tune film --pass 2 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "1280.stats" -o "../output/1280.mkv" "../intermediate/Universal1280.y4m"
x264 --preset veryslow --tune film --pass 1 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "1920.stats" -o "../output/1920.mkv" "../intermediate/Universal1920.y4m"
x264 --preset veryslow --tune film --pass 2 --bitrate 1000 --vbv-bufsize 62500 --vbv-maxrate 62500 --stats "1920.stats" -o "../output/1920.mkv" "../intermediate/Universal1920.y4m"
pauseResults: 720 (http://www.mediafire.com/?5i1ckzsk90zn7b6), 848 (http://www.mediafire.com/?z11x8i74nib203i), 1024 (http://www.mediafire.com/?3ga2de5wrlvvt93), 1280 (http://www.mediafire.com/?h25bg2a42bhpdp6), 1920 (http://www.mediafire.com/?i7z28r27o09noar)
I don't think it got horrible 'till 1280

[7ekno]

I think it's the reason that why 2pass is more popular than CRF on the net.

Hardly, 2-pass was great back in XviD days, but with x264 it's CRF all the way ... plenty of "professionals" using CRF too :P

You want 700MB -1.5GB files, that's easily achieved with CRF encoding ...

For 700MB to 1500MB files, 720p (1280x720) is about all the resolution you can expect without completely butchering the quality ...

Resize to 720p and do test encodes with CRF 32-38 (maybe one at 32, one at 34, one at 36 and one at 38) to see which CRF fits "between 700MB and 1.5GB" ...

Not using CRF in your particular case is a little crazy and much slower :P

7ek

[Blue_MiSfit]

Why are you so concerned with hitting a given file size? Hard drives are cheap :)

Hitting a given file size / bitrate is the only reason to use 2 pass mode over CRF.

Derek

[lever1119]

Why are you so concerned with hitting a given file size? Hard drives are cheap :)

Hitting a given file size / bitrate is the only reason to use 2 pass mode over CRF.

Derek

Well, Using a same CRF value could cause the big difference of sizes among the movies that have same running time. For example, one is 700M, the other is over 2G.
And also, most of video's types on the net, like 480P, 720P, 1080P, use 2pass. What I want is controling the size of my videos by bitrates.

Let's go back to my question. Please make sure for me.

"The original source was "native" footage, and I give 1000K bitrate for encoding. I should set up 720* average resolution for all my videos because of the rule that Derek said, right? If I set up 1280* or 1366* resolution for my videos, the quality is worse than 720* when I watch on fullscreen, right? "

[ramicio]

Why are you so concerned with hitting a given file size? Hard drives are cheap :)

Hitting a given file size / bitrate is the only reason to use 2 pass mode over CRF.

Derek

It's not the only reason. CRF produces WILDLY variable sizes between content. I encode all my videos with a bit rate rule. I don't care about size, but I care about the consistency of it.

[Sharc]

It's not the only reason. CRF produces WILDLY variable sizes between content. I encode all my videos with a bit rate rule. I don't care about size, but I care about the consistency of it.
Here is your rule then:
Fixed bitrate produces WILDLY variable quality between content. You don't care about consistent quality, but you care about bitrate (same filesize for same movie duration).

[ramicio]

CRF cares more about film grain than what how our brains actually perceive the image. Quality can't be represented in a number.

[LoRd_MuldeR]

Quality can't be represented in a number.

You are correct that an objective quality metric, which perfectly predicts the perceived quality, does not exist yet.

Anyway, the CRF mode of x264 certainly is the closest to a "constant quality" mode (given that no other influential encoding parameters are changed) that is available to us these days.

At the same time encoding everything with a fixed target bitrate is far away from "constant quality", because quality will vary greatly between content of different complexity.

Well, unless you crank up your target bitrate so much that even the most complex sources will still look decent, of course.

(But then you waste a lot of bitrate with less complex sources)

CRF cares more about film grain than what how our brains actually perceive the image.

You may want to apply a subtle denoising filter before the encoding then.

It's always preferable to filter out noise on purpose rather than having it destroyed by the encoder...

[ramicio]

You only waste bit rate if you do 1 pass, but 2 passes will lower bit rates in less complex scenes, and raise is in more complex scenes. Add motion. My bit rates range from ~15 to ~17 mbps depending on dimensions.

http://timramich.com/crap/vidform.png

Oops, I see you said you waste bit rate between sources. Oh well. My point is, CRF, to me, has not been reliable to what my eyes may see.

[LoRd_MuldeR]

I know how 2-Pass mode works. Still, a less complex source will need a lower average bitrate (using 2-Pass mode!) than a more complex source - for the same level of quality.

The problem is that you can't know the "proper" average bitrate for a specific source beforehand, as complexity differs between different sources.

So if you are using 2-Pass mode with a pre-defined average bitrate, then the quality will vary depending on the complexity of the individual source that you are encoding.

As said before, you can choose your bitrate high enough, so that even high complexity sources will look decent, but then you obviously will waste bitrate for lower complexity sources.

Or, if you choose your bitrate in a way that gives a good quality/filesize trade-off for lower complexity sources, you will get bad quality for more complex sources.

With CRF mode you can define the desired level of quality (again assuming no other influential parameters are changed) and the encoder will use as much bitrate as needed...

(BTW: Choosing the bitrate based on the resolution of the video is nothing else but assuming that quality can be measured by "bits per pixel" - which is a bad assumption)

[ramicio]

I don't believe it's wasteful of bit rate. Even cartoons with lines and colors are given the same bit rates as live action on released media. CRF is a complete waste to me, because between two similar-length live action movies, one will be 10 GB and the other will be 20 GB.

[hello_hello]

You only waste bit rate if you do 1 pass, but 2 passes will lower bit rates in less complex scenes, and raise is in more complex scenes.

Doesn't CRF mode do that anyway? Or are you saying it raises and lowers bit rates differently to running 2 passes?

Oops, I see you said you waste bit rate between sources. Oh well. My point is, CRF, to me, has not been reliable to what my eyes may see.

Dark Shikari: (http://forum.doom9.org/showpost.php?p=1373437&postcount=2396)
"Given the same amount of encoding time, CRF is superior to 2-pass at the same bitrate. Given the same settings rather than the same time, they're effectively identical within margin of error. My recent tests show that CRF generally has a very slight edge, albeit the difference is so small that you'd have to have OCD to care."

Sometimes I think our eyes see what we want them to see.

[LoRd_MuldeR]

Please be nice to each other!

This time I removed the rule #4 posts. Next time I will have to file a strike...

[hello_hello]

Please be nice to each other!

This time I removed the rule #4 posts. Next time I will have to file a strike...

I'm copping nothing but attitude while trying to rationally discuss the subject.

[ramicio]

1. I never said it was inferior in quality.
2. I don't care about file sizes in the scheme of space doesn't matter to me. I care about their consistency, though. I think it's gay-looking to have some movies that are roughly the same length, same dimensions, similar content/motion, be so wildly varying in size.

It's not rational to you, but what authority are you (or any other human being) to call others rational or not? YOU still think computers are able to humanly say what quality is.

[hello_hello]

Okay.....
ramicio's not claiming for the same file size, a CRF encode will produce lower quality than two passes. How does that not negate his entire argument?
I'd like it explained to me how the computer distributes the bits differently when comparing a 2 pass encode and a CRF encode of the same file size and whether it effects the quality in a noticeable way.
I assume the computer doesn't suddenly stop being a calculator because you run two passes?

Earlier ramicio said a 2 pass encode looks better to him, but was that comparing a 2 pass encode with an CRF encode of the same bitrate? Maybe he just needed to lower the CRF value?

He's still not offered any real explanation as to why CRF encoding is inferior to 2 pass encoding in quality. His only argument for 2 pass encoding seems to be file sized based and he's already stated he doesn't care about the file size anyway.

Wild file sizes based on what a computer thinks is quality isn't a rational argument in itself. At least not to me. 2 pass encoding is still based on what a computer thinks is quality. The main difference between the two, is by picking the file size in advance you're either restricting the quality, or wasting bits. But the file sizes, which you don't care about, will be the same. Terrific.

[ramicio]

Where did I say a 2-pass encode looked better than a CRF encode? If you took my comment at the end of #24, then you took it totally wrong. The meaning of what I said is, why, if I have 2 different films, but close to length, content, and grain, would I want 1 file be [as an example] 10 GB and the other be 20 GB, on things I'm not going to perceive?

Levels of grain throw file sizes all over the place with CFR, and I haven't found that a 2-pass method has given me poor quality with grainy stuff, while having super-awesome-reference quality with stuff with little-to-no grain.

Again, you're trying to force your rationale on others. Stop it. You tell others they are blinkered (the term makes no sense), while you are probably just as much, or more so, as anyone else.

[hello_hello]

1. I never said it was inferior in quality.

"My point is, CRF, to me, has not been reliable to what my eyes may see."

You certainly seemed to.

2. I don't care about file sizes in the scheme of space doesn't matter to me. I care about their consistency, though.

So do I. Consistency in quality.

I think it's gay-looking to have some movies that are roughly the same length, same dimensions, similar content/motion, be so wildly varying in size.

Gay-looking? LOL! I store all my video in folders so I don't have to worry about the file sizes looking gay next to each other.
You've reminded me of the Xvid days when I transferred a bunch of episodes I'd encoded to my ex's PC. The first thing she said was "but they're not all the same size". It gave me a laugh. Then I opened up some of her "same sized" copies and showed her why.

It's not rational to you, but what authority are you (or any other human being) to call others rational or not? YOU still think computers are able to humanly say what quality is.

I'm my own authority. But I don't think it'd be too far of a stretch to say when the opinion of an x264 developer is offered and you dismiss it without giving a logical reason, most people would see that as irrational. So far you've only offered some gay-file size logic for not using CRF encoding, which I think is fairly gay in itself. ;)

[ramicio]

Quality is in the eye of the beholder. To say it's in the eye of a computer is asinine. Now go troll somewhere else.

[Guest]

Gents, please drop the "gay" references, or strikes can follow. It's inflammatory and conveys no useful information.

[ramicio]

It's only inflammatory to those who thinks the word only has one meaning, anymore.

[hello_hello]

Levels of grain throw file sizes all over the place with CFR, and I haven't found that a 2-pass method has given me poor quality with grainy stuff, while having super-awesome-reference quality with stuff with little-to-no grain.

If you're removing the grain simply by limiting the bitrate, how can you not be limiting detail in the rest of the video?
I get super-awesome-reference quality with stuff with little to-no grain sources using CRF mode too.

Again, you're trying to force your rationale on others. Stop it. You tell others they are blinkered (the term makes no sense), while you are probably just as much, or more so, as anyone else.

I'm not blinkered. (You don't understand the reference?). I'm not trying to force my opinion on anyone. Just discuss a topic. When I did, you decided to ignore it and call me names instead. That's being blinkered.

[ramicio]

I don't remove grain, I preserve it. I find no difference in discernible quality between stuff with high grain and stuff with no grain. Aren't you one of these mongoloids who thinks you should only assign so much resources to something, and beyond that is placebo?

[hello_hello]

Quality is in the eye of the beholder. To say it's in the eye of a computer is asinine.

I'm not saying it's in the eye of the computer, but you're continually ignoring my point. When you run two passes, it's not you who decides how to distribute the quality, it's the computer.

By picking the file size you're setting the overall quality, but the computer still decides how to distribute it. The main difference between that method and CRF encoding, is one lets you select the desired overall quality, while the other has you picking it in advance without knowing what that quality will be. You either restrict the quality, or you waste bits, but for that you get nice consistent file sizes, even though you don't care about the actual file size anyway.

[ramicio]

Well why didn't you say something as simple as that in the first place?

[hello_hello]

I don't remove grain, I preserve it. I find no difference in discernible quality between stuff with high grain and stuff with no grain.

Well if you encoded two copies of the same movie, the only difference between them being one is grainy while the other isn't, I don't think you'd find anyone who'd claim the grainy version won't require a higher bit rate than the non-grainy version to achieve the same quality.

That's why using a CRF value produces a larger file size when encoding the grainy version. Logically, if you use the same file size for both, you're either wasting bits when encoding one, or reducing the quality when encoding the other. But at least the file sizes will be the same.

To a certain extent, yes when you assign more resources than is required to something, any perceived extra benefit may well be placebo (ie the non-grainy encoding example) just as it might be placebo when you don't see the quality reduction from not assigning enough resources (ie the grainy encoding example).

[Blue_MiSfit]

This thread has been effectively hijacked. Please take angry discussion to PM.

@lever1119: There are no rules regarding resolutions and bitrates. When I think about encoding for personal purposes, I don't care how big something is, just that the quality is fairly consistent and it's smaller than the source. Usually, CRF values between 18 and 22 accomplish this goal for me very nicely.

If you're concerned with having all your content have identical file sizes, then by all means, use 2 pass VBR. My suggested bitrates are probably appropriate for most content.

[ramicio]

Then there's a whole lot of wasted bit-rate on all these Blu-rays.

[hello_hello]

Well why didn't you say something as simple as that in the first place?

I did. I asked about it in post #31 and in one which was removed.

[hello_hello]

Then there's a whole lot of wasted bit-rate on all these Blu-rays.

Probably. Also more than one encoding method (codec) used.

[ramicio]

Well darn them.

[hello_hello]

If you took my comment at the end of #24, then you took it totally wrong. The meaning of what I said is, why, if I have 2 different films, but close to length, content, and grain, would I want 1 file be [as an example] 10 GB and the other be 20 GB, on things I'm not going to perceive?

Aren't you one of these xxxxxxx who thinks you should only assign so much resources to something, and beyond that is placebo?

Your arguments contradict each other.

[ramicio]

I want excessive use of resources no matter if perceived (for the masses) quality increases or not. This is the red-blooded American way.

[hello_hello]

We're not discussing perceived quality for the masses. You specifically said "on things I'm not going to perceive".

You pick the file size in advance without knowing whether resource usage will be enough or excessive, I guess because the red-blooded American way only applies to quality, not file sizes. ;)

And yes, in my opinion your last post doesn't constitute a rational discussion of the topic.

[ramicio]

You act like I arbitrarily came up with my choices for bit rate without testing...

[hello_hello]

Likewise I didn't arbitrarily come up my CRF choices without testing. Admittedly I've got to deal with "happy" file sizes, but if by your own admission a CRF encode and a 2 pass encode of the same file size will be of the same quality, then by not picking the same set file size each time, CRF encoding saves me bits on one video I can spend on another, whether the difference is perceivable or placebo (depending on which argument you're using there at any given time), and encoding is much faster.

If I wanted to, the time I saved encoding using the CRF method instead of 2 passes could be spent using better quality settings instead. I don't mind "happy" file sizes.

[lever1119]

@lever1119: There are no rules regarding resolutions and bitrates. When I think about encoding for personal purposes, I don't care how big something is, just that the quality is fairly consistent and it's smaller than the source. Usually, CRF values between 18 and 22 accomplish this goal for me very nicely.

If you're concerned with having all your content have identical file sizes, then by all means, use 2 pass VBR. My suggested bitrates are probably appropriate for most content.

Thanks a lot. I know what you mean.
Just wanna be sure. 1000K bitrates, fullscreen watching, is it good that I set up 720* resolution for all my videoes?

[Blue_MiSfit]

lever1119: I'd say it's a terrible waste to downscale all the way to 720x480, especially if you're coming from a nice 1080p source. I'd maybe do 1280x720 at ~4mbps. This will be very close to transparent for most sources.

If you're hard set on 720x480, then I'd go with at least 1.5mbps.

Derek

[nurbs]

I do 720p with CRF 21 and it looks pretty good even on 1080p screens. With my settings I get 1.5 to 3 Mbps on most sources, so if you use 4 you should practically always get a transparent result.

[hello_hello]

I use CRF 20 for 720p encodes. The files are larger then the OP wants (they vary between around 3 and 5gig) but the quality is great. Still looks really good on my 50" TV.

Is there any way to run a quality test before running two passes these days (compression test, that sort of thing)?

When it comes to x264 encoding I generally decide on a resolution and CRF value and let the file size be whatever it needs to be, but as the OP wants to keep the file sizes down.....

Back in the Xvid days using AutoGK I'd try to aim for a certain quality and adjust the resolution down if necessary to keep the file sizes under control. To me dropping the resolution to achieve a file size seems preferable to dropping the quality.

Unfortunately most GUIs don't report the quality that way, but if I was trying to achieve the same file sizes as the OP I'd probably be tempted to still use a CRF value I was happy with and take a guess at the required resolution. Once the encoding has been running for 5 or 10 minutes you generally have a pretty good idea if the file size will fall into an acceptable range. If it looks like it'll be too large I'd stop the encoding, reduce the resolution and start again. It might take a few goes but it'd still probably be quicker than running two full passes, and because you're using CRF encoding you'll know what sort of quality to expect.

What are people's thoughts on tackling it that way?

[lever1119]

lever1119: I'd say it's a terrible waste to downscale all the way to 720x480, especially if you're coming from a nice 1080p source. I'd maybe do 1280x720 at ~4mbps. This will be very close to transparent for most sources.

If you're hard set on 720x480, then I'd go with at least 1.5mbps.

Derek

Could you make sure for me at last that 720* with 1000k bps is better than 1280* with 1000k bps for most videos on fullscreen watching, please?

(Any technical reasons? Just experiences?)

[Target Practice]

Could you make sure for me at last that 720* with 1000k bps is better than 1280* with 1000k bps for most videos on fullscreen watching, please?

(Any technical reasons? Just experiences?)OP, run some tests yourself. see my earlier post if you'd like to see how I ran one.

[nm]

Could you make sure for me at last that 720* with 1000k bps is better than 1280* with 1000k bps for most videos on fullscreen watching, please?

If you must have a bitrate of 1 Mbps, then 480p or something in between might be a better choice than 720p for most videos. I'd go for 960x540.

But as Derek said, 480p is quite a low resolution, so you'll lose a lot of detail from the 1080p sources. Whether that matters to you or not, depends on the screen size and viewing distance.


+1 to using CRF for your encoding task.

[lever1119]

OP, run some tests yourself. see my earlier post if you'd like to see how I ran one.

If I do tests by myself, I should run a lot, maybe hundreds of footages, 'cause movies got different types and details. For example, this footage fits 720*, but that one fits 1024*. I need an average resolution for all the movies. So it's unlikely to get the result on this way.

[lever1119]

If you must have a bitrate of 1 Mbps, then 480p or something in between might be a better choice than 720p for most videos. I'd go for 960x540.

But as Derek said, 480p is quite a low resolution, so you'll lose a lot of detail from the 1080p sources. Whether that matters to you or not, depends on the screen size and viewing distance.


+1 to using CRF for your encoding task.

Did you see the rule that Derek said?

[nm]

If I do tests by myself, I should run a lot, maybe hundreds of footages, 'cause movies got different types and details. For example, this footage fits 720*, but that one fits 1024*. I need an average resolution for all the movies. So it's unlikely to get the result on this way.

But it's a good way to get a result that pleases you instead of whoever is giving the advice.

Did you see the rule that Derek said?

Yes, and what about that? I prefer to keep a slightly higher resolution even if there aren't that many bits to spend. Just denoise the grain out if you decide to go for 960x540 @ 1 Mbps.

However, I'm starting to wonder if you have missed some of the more valuable advice given in this thread. Did you see this later comment:


@lever1119: There are no rules regarding resolutions and bitrates.

[hello_hello]

If I do tests by myself, I should run a lot, maybe hundreds of footages, 'cause movies got different types and details. For example, this footage fits 720*, but that one fits 1024*. I need an average resolution for all the movies. So it's unlikely to get the result on this way.

Hundreds of footages is probably somewhat of an exaggeration, but I think you'll find that's how most of the regulars here decided on the settings/resolution/bitrates they use.... through having run their own tests.

I'd still be starting with the minimum resolution you'll be happy with and running CRF encoding. By the time MeGUI's been running for five or ten minutes you'll have a pretty good idea what the file size will be. If it's too low, increase the resolution or decrease the CRF value and start again. Even if it takes a few tries till you're happy it'll still be quicker than running two full passes and at least you'll know what the final quality will be.

There's not really any "one size fits all" resolution or bitrate. That's why most of us use CRF single pass encoding.
The 700MB to 1.5GB encodes on the net which you referred to all vary dramatically in quality.

[Target Practice]

If I do tests by myself, I should run a lot, maybe hundreds of footages, 'cause movies got different types and details. For example, this footage fits 720*, but that one fits 1024*. I need an average resolution for all the movies. So it's unlikely to get the result on this way.that's another reason to test yourself, as I (and everyone else that posted) probably doesn't have every title in your collection.

if I did, and I found the resolution that got best results to my eye, it would be only my eye's opinion. its yours that counts.

[lever1119]

If you have to try everything by yourself, you guys don't need to come here for help.
You guys have no idea about it. I need professional advice.

[lever1119]

I think there should be a rule for resolutions and bitrates. Or next time I give 2M, 3M....bitrates for videoes, what should I do? Test again and again?

[nurbs]

Wouldn't it be great if it was so simple? Unfortunatly there isn't just on variable, the resolution, there are many. The video quality at a given bitrate depends on the video compression standard, the encoder, the settings you use as well as the framerate, resolution and properties (complexity) of your source video. Then there is the fact that the relation between the quality and bitrate for framerate and resolution isn't linear, e.g. twice the pixels require less than twice the bitrate for similar quality.

I didn't see you mention why you need the files to be between 700 MB and 1.5 GB, because that limitation makes things much harder for you.

If that's not a hard limit but just a range you want the majority of your encodes to fall in you can still use CRF encoding and not worry about bitrates too much. You just need to do some test encodes on parts of a source at different resolutions (say 960*x and 720*x or whatever) and with different CRF values and then find the smallest encode that still looks acceptable to you. Then confirm that by testing some other sources and you are set. You don't even need to encode the whole movies, just parts with SelectRangeEvery(). You can do that in a couple of hours.

[lever1119]

Wouldn't it be great if it was so simple? Unfortunatly there isn't just on variable, the resolution, there are many. The video quality at a given bitrate depends on the video compression standard, the encoder, the settings you use as well as the framerate, resolution and properties (complexity) of your source video. Then there is the fact that the relation between the quality and bitrate for framerate and resolution isn't linear, e.g. twice the pixels require less than twice the bitrate for similar quality.


Actually I know CRF very much. Even if I use CRF, I have to choose a resolution for all my videos. Resolutions on CRF value is just like resolutions on bitrates. You understand?

[hello_hello]

Actually I know CRF very much. Even if I use CRF, I have to choose a resolution for all my videos. Resolutions on CRF value is just like resolutions on bitrates. You understand?

Yes. You want the "magic" answer. There isn't one.
The suggested bitrates in post #12 are probably about as close as you'll get.