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]

Originally Posted by 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.

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]

Originally Posted by blinkstar

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]

Originally Posted by blinkstar

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!

Originally Posted by Yoshiyuki Blade

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.

Originally Posted by Yoshiyuki Blade

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

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]

Originally Posted by blinkstar

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.

Originally Posted by blinkstar

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]

Originally Posted by Blue_MiSfit

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]

Originally Posted by J_Darnley

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]

Originally Posted by Atak_Snajpera

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