VBV Buffer Size in TMPGEnc - prevent stutters?

[zizou108]

Hello,

Recently used TMPGEnc to make a 2-pass VBR SVCD with min, avg and max bitrate at 1300, 2300, 3300. During high-action scenes, my DVD player (Pioneer DV-333) stuttered a bit (got choppy). I know I am way over the SVCD standard of 2520 kbps, but I was wondering why my DVD player can play DVDs fine (at 6000 kbps or more) but chokes on an SVCD at 3300 kbps.

Then I began to wonder about the "VBV Buffer Size" setting in TMPGEnc. 112 is the standard setting for SVCD, but can I increase this? And if I do, can this help the player deal with high-bitrate scenes? Anybody tried this?

Thanks for your help,

zizou

[afreitas]

Hello,

Recently used TMPGEnc to make a 2-pass VBR SVCD with min, avg and max bitrate at 1300, 2300, 3300. During high-action scenes, my DVD player (Pioneer DV-333) stuttered a bit (got choppy). I know I am way over the SVCD standard of 2520 kbps, but I was wondering why my DVD player can play DVDs fine (at 6000 kbps or more) but chokes on an SVCD at 3300 kbps.

zizou

Maybe its because DVD medias are read faster than CDs, so the limit is the media.

Why dont you try to find out out is the max bitrate your player are able to reproduce without got choppy? Try to burn in CBR some videos above 2500kbps.

About the VBV Buffer size I cant help...

[HillJack]

For my DVD player to play SVCD's (standard <= 2,500kbps) I have to increase the VBV buffer to 224. If I use 112, the audio is really REALLY choppy. I've never needed to push the bitrate beyond 2,500 so have never tried > 224 personally.

But, now that you mention the idea of increasing beyond 224 for higher bitrates.... I didn't think of that when testing > 2,500... Maybe my DVD player can play XSVCD's

[bbb]

It stutter because you are exceeding SVCD bitrate! Who told you to use 3300 as the max video bitrate?!!!

For standard SVCD players, the max is 2600 for video. However, it is safer to go lower like 2500. 2450 works great on all Pioneer players. Also, lower your sound bitrate to 160 kbits/sec (192 might also work).

Changing VBV won't solve your problem because during high motion scenes, your Pioneer will be trying to use the illegally high bitrate 3300, but the drive mechanism cannot spin that fast and hence it will stutter. Solution: reencode with lower bitrates as stated above.

DVD are read using a smaller wavelength laser and the data (pits?) on DVDs are smaller than CDRs, so DVDs don't have to spin as fast to read high bitrates. In any case, stick to the SVCD standards.

[zizou108]

I tried the high max bitrate 'cause the Pioneer DV-333 handles non-standard SVCDs quite well. And I know that some folks make "XSVCDs" that work at bitrates higher than the SVCD standard.

bbb, you may be right that the limitation is the CD read speed - makes some sense. But HilJack seems to have gotten some mileage out of boosting the VBV Buffer Size - I'll experiment with that and see if it helps.

BTW, I am encoding audio at 128 kbps so that I can squeeze as much video quality onto 1 CD as possible, and I find 128 quite adequate (sounds at least TV-broadcast-quality to me).

Thanks everyone for your help,

zizou

[bbb]

Maximum bitrate is directly related to how fast the media can spin in the dvdplayer.

For Pioneers (I have 3 Pioneers and they max out at roughly 2500 video bitrate for cdrs). It doesn't matter if it's 720x480, 480x480, 352x480, 352x240, the max bitrate for cdr remains the same.

DVD players (i.e., inexpensive ones made from China, like Apex and Apex clones) that use computer DVDROM drives, have higher maximum bitrates for reading CDRs.

Pioneers don't use DVDROM drives but supposedly produce better video quality (blacker blacks and better color dithering).

Good luck trying higher VBVs. I think VBV will only help if you are encoding at the border of the maximum bitrate and are experiencing mild stutter.

[JBC2002]

I have two Pioneer DVD players - dv333 and dv440; both have difficulty reading audio encoded at 128 kb/s.
For example, I encoded Spiderman at lower than spec SVCD so I could fit the movie on two discs. The audio was encoded at 128 and both players stuttered horribly. After re-encoding at an audio bitrate of 160 kb/s , it played fine on both players.
Try encoding at no lower than 160 and you should be fine!
Hope this helps!
8)

[zizou108]

bbb, very interesting what you say about max bitrate of Pioneers vs. Apex, etc. Latest finding is that I still get stutter at 3000kbps - next try is at 2800 - I'll keep stepping down to the SVCD standard of 2520.

Re the audio rate, I have been encoding all my SVCDs at 128kbps for some time now and have had no problems. This stutter only happened when I pushed the video bitrate higher - I had been encoding at a max of 2300-2500kbps. So I think the stutter I am experiencing is related to the max CD read speed issue that bbb has explained. However, I may try doing audio at 160 - why not?

Good thread! There's always more to learn...

zizou