What kind of encoding speed should I expect x264?

[markrb]

I have searched and searched, but I have not found an answer to this one.

I am concerned that there might be something wrong in my attempts to encode.

I have been trying MeGui with x264 on a DVD source.
I am using the Insane profile with a target filesize of 2.2GB(roughly).
I have an AMD 64 X2 3800+ with 2gb of ram.

On my first pass I am getting roughly 43-44fps according to Megui, but it goes way down to about 5-7fps on the second pass.

Is this normal? Could a bad setting cause the second pass to crawl like that?

BTW if I missed any kind of explanation on what is happening if you could link it that would be great.

Thanks,
Mark

[ChronoCross]

yes it's normal. the 1st pass is probably using turbo which explains the speed. once you add all the advanced features it takes it down greatly.

[markrb]

Wow I feel like I am back in the P3 500 days with CCE again.
Not quit though. I don't think it will take 18hrs to encode.

Thanks,
Mark

[shon3i]

Wow I feel like I am back in the P3 500 days with CCE again.
Not quit though. I don't think it will take 18hrs to encode.

Thanks,
Mark
If that for you slow (it is slow on my machine is avg 2.2fps) why simply use XviD instead x264 with that bitrate resulting movie must be good.

[Doom9]

insane imho is a bad setting ;)

[videomixer9]

2.2 GB ... dunno what kind of movie it is but indeed sounds blown up. Why not just copy the vobs ...

[markrb]

I am new to x264 and just trying to learn.
This is my first ever encode with it.
I have no point of reference.

I am looking to archive my DVD's with greater compression, but as little loss in quality as possible. I am just guessing here at how good x264 is compared to mpeg-2.

What would be a good rough target percentage of the original if I wanted to keep as much quality as possible? I though 50% would be a good testing point for me. My original is roughly 4.4GBs. So I set the target size to 2.2Gb's, but if I can maintain quality and try to hit 1.5gb's I would try that.

Can you suggest some settings to try as a starting point that would be more realistic, including a profile to test?

Thanks,
Mark

[foxyshadis]

For excellent quality try using Slowest (Insane can actually be counterproductive on noisy unfiltered sources, and even Slowest shows it a bit), with 1-pass quality based (crf) of 14 or 16. If that ends up huger than xbox, try 18, but 16 shouldn't be much more than 1.5 gb for 2 hours.

However, at higher bitrates avc does lose a lot of quality advantages over xvid and gets progressively more cpu demanding. (Much like jpeg2000.)

[MeteorRain]

@markrb: if possible, try an encode on CQ18 and see if it reaches the target size and/or quality. IMHO, a 2hrs movie won't cost so much space

btw, would you mind telling me what resolution are you encoding at?

[markrb]

I am trying not to alter the video.
So I am encoding at DVD resolution 720 x 480.

Mark

[Kayaker]

However, at higher bitrates avc does lose a lot of quality advantages over xvid and gets progressively more cpu demanding. (Much like jpeg2000.)

foxyshadis, so If i don't understand wrong, the great advantage of H.264 over Xvid is in low bitrates.
From medium to high btrates de advantages won't be so great ?

Could you please give me some numbers to get an idea to start with ?

I also was told that for cartoons or anime x.264 is a lot better than Xvid. This last statement applies regardless bitrate ?
this is strange because x.264 doesn't have a "cartoon mode" like Xvid, and I don't understand how can it be tuned to both real life and cartoons.

[*.mp4 guy]

It always does better on cartoons/anime Becuase of the built in deblocker and a few other things that take better advantage of redundancy in cartoons/anime. At bitrates similar to Mpeg quantisization @Q2 in Xvid X264 loses most of its advantades over mpeg4 asp besides doing better in metrics, Imo this is becuase X264 hasn't matured enough yet.

[foxyshadis]

Yes, x264 has improved dramatically each of the last two years, and it still has many interesting places it could go.

I do not - yet - think it makes sense for transparent or near-lossless encoding. In order to reach the same quality of the golden grail of xvid - 1/3 to 1/2 dvd w/ 6of9 matrix - you need almost as much bitrate, longer encoding times, and you mostly won't be using inloop filtering anyway (it disables itself at high bitrates; you can't have it if you want the sharpest picture possible). It does quite well where most people use it, the "1-2 cd" range, and really shines when fitting a whole tv season on one cd or flash card. =p It's like AAC compared to MP3.

For anime, at dvd res, try starting at 500 kbps (or crf 24). You shouldn't need to go above 800-900 (crf 20-21?) with a clean source to get an excellent looking picture.

[Kayaker]

Very clear foxyshadis. thanks.