Simple question about CBR or 2Pass VBR

[Sosua]

I would like to know if i want to convert an AVI file witch is the best quality settings? Should i use in the Rate Control Mode CBR or it is better quality 2pass VBR? And what is the difference?

[Conquest10]

vbr is better. cbr is just a waste of bitrate.

[Sosua]

Thanks for your answer, i will convert with VBR. But can you tell me the difference?

[videocheez]

CBR (constant bitrate) will allocate the same bitrate for all frames even low motion frames that don't require a high bit rate. That is why the last guy said it s a waste. On the other hand CBR may not allocate enough bits for high motion scenes and this will result in poor quality. VBR (variable bit rate) usually involves more than one encoding pass. During the first pass the encoding program wil analyze the movie to determine how many bits per frame are needed to achieve maximum quality. During the second or subsequent passes the encoding program will use information obtained during the previous pass to assign the number of bits required per frame. I'm still fairly new so some of the more experience folk here can elaborate more on avg. bit rates and maximum bitrates while using VBR encoding. They may even correct me. I have found that for low motion movies, CBR works fine but for the high motion movies you will want to save some bits to make the action scenes not look to blurred.

Good luck,

VC

[Sosua]

Videocheez, BIG THANKS for your answer. Now it is more clear. Maybe that is the reason i had this jerkyness all the time when there was lot's of movement in my movies.

Thanks

[ZippyP.]

It really depends on your settings which gives better quality. VBR can give better quality with the same filesize as CBR by allocating bits more "smartly." That is, it allocates more bits for high motion scenes and conserves bits during low motion scenes. VBR can give better quality while conserving disk space but it can also take twice as long to process.

However, if you crank up the bitrate in CBR to the maximum setting used in VBR, then CBR might give better quality. The filesize would be bigger, meaning more disks possibly. Bits might be "wasted" in some scenes but some scenes might improve.

If you're trying to conserve diskspace and don't care about time then use VBR.

If you want it fast and filesize is not an issue then use CBR.

[hamman]

Is 2-pass VBR useful on VCD to? Or does is just take time?

[Sosua]

I have noticed that file size is smaler using 2PASS, does it take quality out of the file?

Also, even if i set the bitrate higher on VCD by unloking the template it only gave me 1150 kbps. Any way to get the bitrate higher or when you use 2Pass it is the maximum you can go??

[ZippyP.]

Is 2-pass VBR useful on VCD to? Or does is just take time?

I use 2-pass to put all-in-one movies on VCD. It's much better than CBR but it isn't a VCD standard. You'll have to see if it works on your machine.

[ZippyP.]

I have noticed that file size is smaler using 2PASS, does it take quality out of the file?

Also, even if i set the bitrate higher on VCD by unloking the template it only gave me 1150 kbps. Any way to get the bitrate higher or when you use 2Pass it is the maximum you can go??

The file size depends only on the length of the video and the average bitrate. Quality depends on your settings.

You need to select under the System tab, Mpeg1 Video-CD (non-standard). You are creating an XVCD, an out of specification VCD. Also, TMPGEnc version 2.59 had a bug which always kept the bitrate at 1150 for VCD's. You should be able to excedd 1150 but you should do a test with it. My machine won't play them.

[Sosua]

I am using 2.511 and can not up the bitrate more then 1150. I am not using 2.59.

Just finished converting my first movie with this method and it is the first time that i dont have Jerkyness. Using the CBR method allways gave me a bit of jerkyness no mather what the Bitrate was. Quality is very good and plays very smooth. I did convert with 2pass vbr then used VCDEASY to create the Bin and Cue file, VCD then burn image with Nero and everything is perfect. Seems that my player accept VBR.

I did not burn it Non Compliant cd unless VCDEASY did the cue sheet that way.

[hamman]

What bitrates should I use?

[Conquest10]

What bitrates should I use?

kind of out there with that question. for what? 0-9000 kb/s is what i would say.

[hamman]

Sorry, I mean for vcd, to fit about 60 mins on one cd

[Conquest10]

a vcd can only be 1015 kb/s. you can make an xvcd with a bitrate of 1578 kb/s. or vbr with an average of 1578 kb/s and a max of 2500 kb/s.

[-=Neo=-]

What bitrates should I use?

Use TMPGEnc's wizard to find out what bitrate you can use for your movie. I would make it an SVCD, not a VCD, and VBR 2-Pass encoding is much better than CBR.