codec/bitrate question

[mjohn911]

I have been wanting to make a dvd-rip backup of some dvd's that I own.

What I want to do is take a dvd and put it into an AVI file.
So what I do, is I rip the dvd to my computer with SmartRipper. Then I use MPEG4 Direct maker > DVD converter to open the vts_01_0.ifo file. Then I can select the encoding options (xvid, divx, other) and can customize bitrate, resolution, audio, frame-rate, etc. etc.

This is my question. I have seen several dvd-rips available online where they take a 2.5 hour movie, and compress it into a xvid or dvix avi file that is 700 megabytes, and the quality is (in my opinion) VERY good.

This is my problem. I'm trying to convert the DVD into an avi file around 700 megabytes, just like the others I've mentioned. However, I've tried many different combinations of bitrate/resolution, and when the video size get down even to 1500 megabytes, the quality is horrible.

1. How in the world do people compress DVD movies into 700mb avi files with astounding quality?

2. Exactly what bitrates and advanced settings do these people use? (i.e. resolution, frame-rate, codec, bitrate, audio frequency, audio bitrate, motion pixel search, etc etc. )

3. What am I doing wrong? I've tried xvid, divx, and others to no avail.

4. How can I duplicate this effect?

Thanks - any advice is greatly appreciated.

[anonymez]

1. i don't know about "people", but you'll want a better program such as staxrip, gordian knot or meGUI

2. should give close to max quality in most cases http://forum.digital-digest.com/show...702#post343702

3. stick with xvid, or x264 if you're willing to try something new (and aren't after standalone playback)

4. see 1-->3

[mjohn911]

quote anonymez:
"enable qpel, enable gmc, set max bvops to 2, use mpeg quantization matrix for higher bitrates (say 1500+) and H.263 for anything lower. enable chroma optimizer and chroma motion, set motion search precision to max (ultra high) and VHQ mode to max as well (wide search). enable VHQ for bframes, set max i-frame interval value to framerate x 10. enable trellis.

this should go without saying-- do 2-pass encoding

also pick a decent resolution, depending on the bitrate. don't go any less than (IMO) 0.19 bits/pixelxframe. you could also decrease audio bitrate to allow higher video bitrate."


Thanks, so do you say that I need to have qpel and gmc on for it in order to be compatible or no?

Also, what kind of 2-pass option do I use? I have options for "2-pass - 1st pass", "2-pass - 2nd pass Ext.", and "2-pass - 2nd pass Int."

What are bvops, and H.263?


Thanks for the info.

[anonymez]

leave qpel and gmc disabled if you're planning to play these files on an mpeg4 capable standalone player.

2-pass encode means you do 2 passes. first "2pass - 1st pass" then "2pass - 2nd pass"

[mjohn911]

OK I was able to enable all of the options you mentioned. However, when I select 2-pass for my encoding method (I'm still not sure if I should select 2-pass/2nd Int. or 2nd ext.) the bitrate selector gets grayed out.

When I select two-pass encoding, will it choose the bitrate automatically? When I use the one-pass CBR, I can select a custom bitrate, but when I select two-pass, that option gets ghosted. What's going on?

[anonymez]

(I'm still not sure if I should select 2-pass/2nd Int. or 2nd ext.)

let xvid do br curve scaling-- use int.

When I select two-pass encoding, will it choose the bitrate automatically? When I use the one-pass CBR, I can select a custom bitrate, but when I select two-pass, that option gets ghosted. What's going on?

do the first pass, then the 2nd pass. the first pass doesn't need a bitrate value, you specify when setting up the 2nd pass (use the bitrate calculator)

[celtic_druid]

Looks like you are using an old devapi3 build. First thing I would do is update to a 1.2cvs build.

[mjohn911]

Thank you. Actually I did figure out the wrong build problem. I was able to update it. I've been able to do some two-pass encoding. However, I have some more questions. The dvd-title I'm trying to convert has 7 vobs. After I convert them to xvid, is there a program that will merge them into one avi? Or should I look for a program that should automatically convert it in to one big avi?

Also, with the 2-pass encoding, how do I know where the statsfile is stored after the first pass? After I do the first pass, I get avi files that have the audio but no video. Then when I do the second pass, the video comes in. Does xvid have some sort of memory where it remembers the last avi file encoded for the first pass, and automatically uses that info for the second pass, or how does that all work?

Also what should I be looking at for resolution? I'm trying to crunch the size somewhat, but the movie is 16x9. With avi files, if i use the regular 720x480, the avi is bigger, and the aspect ratio gets changed to 4x3, resulting in an anamorphic picture in the avi file. I'm looking at something smaller (with a width around 600 maybe, and a height that would preserve the 16x9 aspect ratio.) Any suggestions?

[celtic_druid]

You should definatly encode the lot at once. Otherwise the 2 pass rate control can't work properly.

Current cvs, the stats file goes in the output's folder. In older builds it was set to the root of the output drive. You can of course change it to whatever you like though.

720x480 is actually 3:2, not 4:3. You can set the PAR so that it displays at the correct DAR though whether that be 4:3, 16:9, 2.35:1 or whatever. If you aren't setting the DAR, then you should resize to 1:1.

You might want to try something like AutoGK, FairUse Wizard, StaxRip, AVI.NET, etc.

[mjohn911]

Thank you for your help. I probably wouldn't have figured out how to use xvid without your advice. If I have any more problems or questions, I will come back to this form.

[mjohn911]

OK. Now my xvid encoding (both the 1st pass & the 2nd pass) it taking the better part of 6-10 hours to encode. Is this normal or am I doing something wrong? (for comparision, I can encode an mpeg2/svcd file in under an hour.)

[anonymez]

you haven't stated your system's specs, but that sounds about right. there is a quality/speed tradeoff with most codecs

[mjohn911]

should be fine: 1.7ghz, 160gb hd, 448 ddr ram, etc etc.
So this long encoding time is normal?

[anonymez]

for a movie, yes

[mjohn911]

Now I have a new problem.

When the avi is done encoding, the audio/video is out of sync. The video lags behind the audio about 2 seconds. What causes this and how do I fix it?