Good Quality Settings for PSP? What is Overkill?

[blinkstar]

Hello everyone. Forgive me if my question is stupid but I'm wondering what I should set my video and audio bitrates to for the best possible quality when converting .vob and .avi files for my PSP (using Xvid4psp).

In other words, I'm currently using a video bitrate of 5000 and an audio bitrate of 320 ... Am I maxing out with those settings? Should I go lower? Or is it possible to see an improvement if I go even higher?

Again, sorry if these are dumb questions, but I've done several Google searches trying to find what the max video and audio bitrates are for the PSP and I can't find a definitive answer ... Lots of threads dealing with settings for a mix of quality and file size, but I don't care about file size, I just want good quality for the PSP ...

[Dark Shikari]

5000 is already ridiculous, you can get away with much less for no visual quality loss.

The PSP has basically no limit on bitrate at all, so a "limit" on quality isn't an issue, only the space you need to get the quality you want.

[blinkstar]

5000 is already ridiculous, you can get away with much less for no visual quality loss.

The PSP has basically no limit on bitrate at all, so a "limit" on quality isn't an issue, only the space you need to get the quality you want.

Thanks for responding so quickly! If 5000 is ridiculous, what would you say is more reasonable? 3000? What is the limit, beyond which I will see no improvements in picture quality?

And what do you think is the limit for audio? Is 320 too high as well?

Thanks again for responding!

[Yoshiyuki Blade]

Thanks for responding so quickly! If 5000 is ridiculous, what would you say is more reasonable? 3000? What is the limit, beyond which I will see no improvements in picture quality?

And what do you think is the limit for audio? Is 320 too high as well?

Thanks again for responding!

Its highly subjective to determine these things. You have to trust your eyes (and ears) on that. Try various CRF values and see if a given CRF looks good to you at a reasonable bitrate.

Also, I'd suggest editing your thread title (you aren't allowed to ask about what's "best").

[Dark Shikari]

Thanks for responding so quickly! If 5000 is ridiculous, what would you say is more reasonable? 3000? What is the limit, beyond which I will see no improvements in picture quality?If you don't care about a specific bitrate, just use CRF mode. CRF 18 is generally transparent.

[Atak_Snajpera]

In other words, I'm currently using a video bitrate of 5000 and an audio bitrate of 320
512kbps and 128 AAC audio is enough for 480x272 screen !!!!!!!

[Sagekilla]

For reference I regularly do 800 - 1000 kbps on my DVD (848x480) encodes. I don't encode using bitrate, only crf 18. PSP requirements will be MUCH lower.

[Dark Eiri]

Try the PSP x264 Ultra profile with CRF 22. Most of the times you will get awesome quality.
Normally I try using 500 kbps + 64 kbps HE-AAC audio for movies \ tv series and around 800 kbps + 128 kbps AAC for music videos with lots of effects and high motion.
For animes and cartoons, set deblocking to 1:1 and use 350 kbps.

[Sagekilla]

From the looks of what Dark Eiri does, it sounds like yes you are using extremely overkill bitrate :) I don't think any "normal" source could possibly use 1 mbps unless it's horribly blocked up and has tons of artifacts present.

[blinkstar]

Thank you all for responding!


Its highly subjective to determine these things. You have to trust your eyes (and ears) on that. Try various CRF values and see if a given CRF looks good to you at a reasonable bitrate.

You'll have to forgive me. I'm totally new to this. What are CRF values and can I set them through Xvid4psp? I don't see the option offhand.


Also, I'd suggest editing your thread title (you aren't allowed to ask about what's "best").

Why is it wrong to ask what is best? I thought that bitrate would work the same way say native screen resolution would. In other words, the best resolution for the psp would be 480x272, because that is it's native resolution. Is there no native bitrate or max bitrate for the psp?

[fleon]

This is really usefull for me because like the user that made this thread I always wonder wich bitrate to use, I know it depends in the video, an action movie with explosions needs more bitrate than a comedy movie, but sometimes still is hard to figured out a good bitrate, and I am gonna try the suggestions that all the people gave here

Since I have an intel q6600 i dont care about the options that make x264 slower since the q6600 is pretty fast:eek:

So I have modified the lastest sharktooth's psp profile(v81) and I have added -no-fast-pskip --trellis 2 --subme 9 what do you guys think? also there are more options that improve quality but make the encoding slower? so i can put them?(that the psp can support)

Also what about the resizers? all the bitrates that the people gave are for wich resizer? like Dark Eiri said he uses 500 kbps for movies, but wich resizer do you use?, and you seem to know a lot, could you explain when to use wich resizer? or anyone else could explain it?

[Blue_MiSfit]

trellis 2 and subme 9 are both great ideas to kill encoding speed - maybe also switch the ME algorithm to UMH (--me umh).

I don't know if the PSP would be compatible with CRF mode - probably if you use VBV, but 1 pass VBV is sketchy :)

I would stick with 2pass, anywhere from 500-1500kbps for most titles.

It's always hard to chose a bitrate :)

Also, the choice of resizer isn't that important. General purpose all-around good is spline36, lanczos is sharper but can introduce halos, bicubic is the old standard but can be soft. You're not doing much resizing so I wouldn't worry about it. It's only really important when you do HD -> SD, or even 4k -> HD ;)

~MiSfit

[Yoshiyuki Blade]

You'll have to forgive me. I'm totally new to this. What are CRF values and can I set them through Xvid4psp? I don't see the option offhand.

I've never used xvid4psp, but if the name indicates something, it uses XviD. CRF is a popular mode used in x264 (after all, we are in the AVC forums :)). Getting into H.264 encoding is an entire subject on its own.

Instead of encoding video at an explicit user-defined bitrate (such as single pass bitrate, 2 pass, etc.), CRF encodes at a constant quality. The higher the CRF value you choose, the lower the quality. Likewise, specifying a low CRF value will usually indicate very good quality. The exact value you want is ultimately up to you, but many people choose in a range between 18 and 22. Some people will say that the quality of CRF is as good as 2-pass encoding, only you dont specify the bitrate. You specify the quality.


Why is it wrong to ask what is best? I thought that bitrate would work the same way say native screen resolution would. In other words, the best resolution for the psp would be 480x272, because that is it's native resolution. Is there no native bitrate or max bitrate for the psp?

As explained in the rules, such a question can't be answered objectively. There's really no way of telling people what's best for anything, simply because it relies on individual preferences.

Using your hypothetical situation as an example, I'd argue that it would be "best" to keep the full resolution of the source, and encode at a high bitrate. So whenever you pull the files out of the memory stick, you can also enjoy it in high quality on a computer.

On the flipside, if you plan on using it exclusively on a PSP and you're concerned about filesizes, then I would recommend downscaling it to the PSP's native resolution, and do a 2-pass encode for accurate file sizes.

If you plan on using it only on the PSP, and youre not concerned about filesizes, you can downscale and use CRF.

See how many possible "best" situations I can come up with? It depends on what *you* intend to do with the files. If you state your preferences, we may be able to recommend settings according to the situation. You'll have to be extremely specific though.

[nm]

I don't know if the PSP would be compatible with CRF mode - probably if you use VBV, but 1 pass VBV is sketchy :)
As Dark Shikari already said, PSP can handle very high bitrates (about 20 Mbps IIRC) so it is compliant with any sane CRF setting at SD resolutions, even without VBV limits.

[Atak_Snajpera]

As Dark Shikari already said, PSP can handle very high bitrates (about 20 Mbps IIRC) so it is compliant with any sane CRF setting at SD resolutions, even without VBV limits.
I made a test 720x480@25mbps and PSP had absolutely no problems with decoding :)

[Sagekilla]

I don't think I can imagine a case where SD video @ 720x480 (which is the resolution limit I believe?) could possibly use that much bitrate to give a "Good" image. Point remains though, PSP = hardcore bitstream decoder.

[fleon]

what about --b-rdo and --bime those options seem to be good why I can't find them in the part where I can configure the psp profile?

[J_Darnley]

Because they don't exist since r996.

[fleon]

Because they don't exist since r996.

oh ok I was reading this http://forum.digital-digest.com/showthread.php?t=67180 but this doesnt seem very updated also all the options arent there

so is there a much updated "x264 options explained"?

[deets]

I made a test 720x480@25mbps and PSP had absolutely no problems with decoding :)

aww what a powerful little beast he is! im impressed :)

for the op. do some small tests to find out.

750 is normally loads for movies and TV, but if your doing something like sports, it might show up things a little more.

ripbot is also good to play with

[blinkstar]

I've never used xvid4psp, but if the name indicates something, it uses XviD. CRF is a popular mode used in x264 (after all, we are in the AVC forums :)). Getting into H.264 encoding is an entire subject on its own.

Thanks for responding, Yoshiyuki!

xvid4psp does use x264--at least it lets me select that as an encoding method. Ybder x264, instead of CRF it lists something called Q, which I think is the same thing--the values seem to be the same. And I am using xvid4psp to make Mp4 AVC files.


See how many possible "best" situations I can come up with? It depends on what *you* intend to do with the files. If you state your preferences, we may be able to recommend settings according to the situation. You'll have to be extremely specific though.

I see what you mean. Looks like there is no simple answer. I think the most specific way I can put is that I want the best picture and audio quality that the PSP can provide, regardless of filesize ...

I ran a few visual tests and as far as I can tell there is no visible difference between a bitrate of 1000 and a bitrate of 5000 on the psp. I'm going to try CRF 18 next.

[Yoshiyuki Blade]

xvid4psp does use x264--at least it lets me select that as an encoding method. Ybder x264, instead of CRF it lists something called Q, which I think is the same thing--the values seem to be the same. And I am using xvid4psp to make Mp4 AVC files.

Ah i see. xvid4psp might not have that much flexibility if CRF isn't an option in it.

There's another option called "constant quantizer" or "QP" which is much different than "contstant quality" or "CRF." Keep that in mind so you dont get the two confused.

To be honest, I can't think of an everyday situation to use QP mode.

I think QP mode strictly encodes most of the video around 1 quantizer. By the way, a quantizer is kind of a way of measuring quality. The lower the value, the better the quality. For example, a quantizer of 0 means a frame will look exactly the same as the source (aka lossless, but it takes a *lot* space... often times more than the source itself), while a quantizer of 51 would look absolutely horrible.

What QP mode does is that it'll encode all the frames at a fixed quantizer (or at least most of the frames, it depends on other factors). This is generally a bad idea. For example, complex and high motion scenes need lower quantizers to maintain good quality, whereas simpler scenes could look fine at higher quantizers. A fixed quantizer won't be able to adjust according to the situation.

CRF is the one to do the job. The quantizers are chosen according to the complexity to each frame, while maintaining an average quality level (set by the user).


I see what you mean. Looks like there is no simple answer. I think the most specific way I can put is that I want the best picture and audio quality that the PSP can provide, regardless of filesize ...

I ran a few visual tests and as far as I can tell there is no visible difference between a bitrate of 1000 and a bitrate of 5000 on the psp. I'm going to try CRF 18 next.

Yeah, 5000 kbps is quite a lot of bitrate, even for full DVD resolution video. If you've resized your videos to PSP resolutions, go ahead and use CRF 18-22 to get a decent ballpark on the quality/filesize tradeoff. Just doublecheck to make sure you're using CRF mode, and not QP :).

[Sagekilla]

Yeah, QP encodes at a constant quantizer. What CRF does differently (crf 22 vs qp 22) is that it varies the bit distribution according to complexity, so certain frames will get a higher quantizer than other frames. In the end, the file sizes end up being more or less the same, but CRF is higher quality.

[Dark Shikari]

Yeah, QP encodes at a constant quantizer. What CRF does differently (crf 22 vs qp 22) is that it varies the bit distribution according to complexity, so certain frames will get a higher quantizer than other frames. In the end, the file sizes end up being more or less the same, but CRF is higher quality.More importantly, given its name, Constant Quantizer encoding disables AQ ;)

[Sagekilla]

Does QP also affect psy-rd in any manner or is it independent of rc method?

[Dark Shikari]

Does QP also affect psy-rdno it doesn't

[blinkstar]

Ah i see. xvid4psp might not have that much flexibility if CRF isn't an option in it.

There's another option called "constant quantizer" or "QP" which is much different than "contstant quality" or "CRF." Keep that in mind so you dont get the two confused.

Well, how's this for confusing.

With xvid4psp, under "Video encoding settings," if you select "Constant Quality," you then have to choose a number for "Quantizer." So Quantizer is a subsetting of "Constant Quality." But I'm guessing that Quantizer in this instance does NOT mean "constant quantizer," because there is a separate selection for "Constant Quantizer" at the start. In other words, you can choose either "Constant Quality," or "Constant Quantizer." If you choose Constant Quality, you then enter a number for Quantizer, but if you choose Constant Quantizer, you then enter a number for bitrate ... I'm guessing "Constant Quality" equals CRF (at least I hope it does).

[Ranguvar]

In my experience, it does mean CRF. Ring Winnydows :)

You could always do an encode and then take a loot at it with MediaInfo or similar, or a hex editor.

[Yoshiyuki Blade]

Well, how's this for confusing.

With xvid4psp, under "Video encoding settings," if you select "Constant Quality," you then have to choose a number for "Quantizer." So Quantizer is a subsetting of "Constant Quality." But I'm guessing that Quantizer in this instance does NOT mean "constant quantizer," because there is a separate selection for "Constant Quantizer" at the start. In other words, you can choose either "Constant Quality," or "Constant Quantizer." If you choose Constant Quality, you then enter a number for Quantizer, but if you choose Constant Quantizer, you then enter a number for bitrate ... I'm guessing "Constant Quality" equals CRF (at least I hope it does).

Yeah, whether you choose "constant quality" mode or "constant quantizer," you have to specify the quantizer you want (instead of bitrate).

It's pretty safe to assume that "Constant Quality" in xvid4psp is CRF. If you really wanna be certain, you can open your clip with avinaptic (http://fsinapsi.altervista.org/) and take a look at the user data.

[blinkstar]

Thanks Yoshiyuki and Ranguvar for helping me clear that up!

What are the advantages and disadvantages of using CRF versus setting a bitrate?

[Atak_Snajpera]

What are the advantages and disadvantages of using CRF versus setting a bitrate?
Jesus! Use search! It was explained million times.

[Yoshiyuki Blade]

Thanks Yoshiyuki and Ranguvar for helping me clear that up!

What are the advantages and disadvantages of using CRF versus setting a bitrate?

CRF only needs a single pass, and supposedly has the equivalent quality of 2-pass bitrate encoding. And from what I gathered, single-pass bitrate is bad for various reasons.

Anyhow, for example, let's say you encode a video clip at CRF 20 and the output video has a bitrate of 2532kbps. Then you encode the same clip with the same settings, but choose 2-pass encoding at 2532kbps. The resultant video should have similar average quantizers as the CRF encode did, but took longer because it's 2-pass.

CRF is great for single-pass high quality encoding, but you can't really predict how big the file size is gonna be except through trial-and-error. 2-pass bitrate encoding can allow you to easily predict how big you want a file to be, but it it requires a 2nd pass (and thus, more time to complete).

Jesus! Use search! It was explained million times.

Hehe, I know how you feel. But it's sometimes difficult to get all your thoughts together on this subject after going through several threads. Some misinformation or outdated information is present as well.

[blinkstar]

Hehe, I know how you feel. But it's sometimes difficult to get all your thoughts together on this subject after going through several threads. Some misinformation or outdated information is present as well.

Yes, sorry If I was being annoying there. And thanks for answering my question anyway, Yoshiyuki! Very much appreciated.

[Yoshiyuki Blade]

Yes, sorry If I was being annoying there. And thanks for answering my question anyway, Yoshiyuki! Very much appreciated.

You're welcome. It was really no problem for me. I wouldn't have bothered making posts that just tell people to use search or whatever, otherwise I'd rather just refrain from posting anything at all. Plus it's nice to get other relevant questions answered consecutively in the same thread. That'll leave newbies with less searching to do.

[Rumbah]

The great thing about CRF is that you can do some test encodes with different CRF values and choose the one that has the quality you like. Then you can use that chosen CRF value in any other encoding you do and get a similar quality. That way you do not have to worry about bitrate to gain your desired quality. If you use 2-pass encoding you can get very different results at the same bitrate for different clips (calm clips vs. action clips).
The obvious disadvantage is that you cannot predict the final file size but if your memory card is big enough you sould not have a problem with that (especially for resized movies to PSP resolution) :p .

[blinkstar]

The great thing about CRF is that you can do some test encodes with different CRF values and choose the one that has the quality you like. Then you can use that chosen CRF value in any other encoding you do and get a similar quality. That way you do not have to worry about bitrate to gain your desired quality. If you use 2-pass encoding you can get very different results at the same bitrate for different clips (calm clips vs. action clips).
The obvious disadvantage is that you cannot predict the final file size but if your memory card is big enough you sould not have a problem with that (especially for resized movies to PSP resolution) :p .

Thanks for the advice, Rumbah! I have an 8 gig mem card and so far the biggest movie file I have encoded has been a little bit over 3 gigs. I would much rather deal with a really large file if it means better picture quality. (If they ever come down in price I'd love to grab a 16 gig card for this very same reason.)

Looks like CRF is definitely the way to go for me.

[Sagekilla]

I should expect if you use CRF at PSP res (480x272) you should be getting very small (< 1 GB) and high quality videos. I tend to get 2 GB rips myself @ DVD resolution.

[Dark Eiri]

Yeah, with CRF22 you'll probably get less than 700 MB for a movie.

[chainring]

Yeah, with CRF22 you'll probably get less than 700 MB for a movie.Just did this yesterday with RipBot264 and I Robot. CRF22 and all options maxed out, with 96kbps stereo, it came in just a touch over 400 MB. It could have been lower, but I messed up with cropping so it left the black bars.

BTW, here's the settings I used to max out and have a playable file on my PSP (4.05 fw).

Note: This test was performed in Handbrake (latest SVN version), and on a Mac.

Reference Frames: 3 (That's it, no more!)
Mixed References: yes
B-Frames: 16
Direct Prediction: Auto
Weighted B-Frames: yes
B-RDO: yes
Bidirectional Refinement: yes
Motion Estimation: ME-UMH
ME Range: 32
Subpixel Refinement: 7
Analysis: All
8x8 DCT: No!
Deblocking: -0:-0
Trellis: 2
No Fast-P-Skip: yes
No DCT-Decimate: yes

I'm testing a newly created CRF profile in MeGUI right now and will report the findings.

[Dark Eiri]

PSP can play 16 B-Frames? That's news to me. Good news.

[Sagekilla]

If you were using the latest x264 from git, you could also have subme 9 (Subpixel refinement 9). Why no 8x8 dct? PSP doesn't support this?

[Atak_Snajpera]

Why no 8x8 dct? PSP doesn't support this?
8x8dct belongs to HiGH Profile. PSP needs Main Profile

[chainring]

PSP can play 16 B-Frames? That's news to me. Good news.I pumped it all the way to 16 B-Frames and it had absolutely zero problems. Now, my understanding of B-Frames is, even though you tell the encoder to use that many it will only use what is necessary. Someone correct me if that's incorrect.

Take Reference Frames to anything over 3 and it will not play.

[Dark Shikari]

I pumped it all the way to 16 B-Frames and it had absolutely zero problems. Now, my understanding of B-Frames is, even though you tell the encoder to use that many it will only use what is necessary. Someone correct me if that's incorrect.

Take Reference Frames to anything over 3 and it will not play.
This is correct.

Of course, this also means the encoder might never have used 16 b-frames, or even maybe not over three, and so the PSP never encountered a problem ;)

Try --no-b-adapt --scenecut=-1 --bframes 16 and see if the PSP plays it.

[chainring]

If you were using the latest x264 from git, you could also have subme 9 (Subpixel refinement 9). Why no 8x8 dct? PSP doesn't support this?
For the test I posted, those settings were from the latest SVN version of Handbrake for the Mac. Later, I did a full encode of "I Robot" just out of curiosity sake to see the final size at CRF 22, and it came in just over 400 MB.

I'm now doing tests with r999 in MeGUI and all settings maxed. I'll report the findings in a bit.

[Dark Eiri]

This is correct.

Of course, this also means the encoder might never have used 16 b-frames, or even maybe not over three, and so the PSP never encountered a problem ;)

Try --no-b-adapt --scenecut=-1 --bframes 16 and see if the PSP plays it.

If it doesn't works, well, we can always use b-adapt 2 and 3 bframes. It's similar to or even better than --b-adapt 1 --bframes 16, anyways, isn't it?

It would be really nice to see the PSP allowing higher specs, though.

[fleon]

Thanks for all the findings that everyone have aported to this, I do not want to discredit the psp profile of sharktooth, I mean he is a coder of megui he knows a lot!, but I always thought that the psp was limited as here we are finding that! thanks again I have learned a lot!

Also can anyone explain me what the switches --b-adapt and psy rdo do? the megui wiki is a little outdated

As implied in my post I also have a psp so feel free to request my help for some testing options

[kemuri-_9]

there's already plenty of threads that go into detail on --b-adapt and psy-rdo

the major original ones being
b-adapt: http://forum.doom9.org/showthread.php?t=139827
psy-rdo: http://forum.doom9.org/showthread.php?t=138293

[fleon]

This is correct.

Of course, this also means the encoder might never have used 16 b-frames, or even maybe not over three, and so the PSP never encountered a problem ;)

Try --no-b-adapt --scenecut=-1 --bframes 16 and see if the PSP plays it.

I can confirm this does work! this is the complete settings that I used

program --crf 19.0 --level 3 --ref 3 --mixed-refs --no-fast-pskip --bframes 16 --b-adapt 0 --weightb --direct auto --subme 9 --trellis 2 --partitions p8x8,b8x8,i4x4 --vbv-bufsize 10000 --vbv-maxrate 10000 --scenecut 1 --me umh --threads auto --thread-input --progress --no-psnr --no-ssim --output "output" "input"

if you want I can upload the video

[Dark Shikari]

--scenecut -1
not 1