choppy video playback

[RobotFood]

I'm having problems converting AVI and WMV movie files with DivX and Xvid codecs into DVD format. during playback the video constantly freezes briefly, and it's most noticable when the camera pans sideways or up/downwards.

I have the following codec packs: K-Lite, CCCP and ACE Mega Pack; as well as the latest DivX and Xvid codecs.

Programs I have tried to create DVDs with are Nero 8 and ConvertXtoDVD. The movies play just fine on my computer with Media Player Classic. I had a lengthy e-mail exchange with Nero Support who suggested the problem lies with the movie files themself, but I doubt this to be the case as the source I got the movies from is very reliable.

I'm assuming the problem may lie in how the codecs/packs are set-up on my system and was wondering what changes I'd need to make to help rectify the problem or whether I need to install something else? Would greatly appreciate any help you guys could offer!

[Maikeru-sama]

Not familiar with ACE or K-lite.

If I were you, I would try an encoder like HCenc or Quenc in conjunction with AvisSynth, although ConvertX should be able to handle AVI files (note sure about WMV files).

Let me know if you need help using these encoders.

[Ai Haibara]

Just curious: why do you need so many codec packs? I'd think there would be a bit of overlap between them (for example, they probably each have some form of DivX and Xvid support).

Does the problem persist if you use a player that doesn't rely on the system codecs/filters, like VLC or mplayer?

[guns1inger]

Multiple codec packs is just asking for conflicts. That said, jerky pans and zooms are often a sign of poor quality format conversion. Try using FAVC instead of crap like Nero. ConvertXtoDVD should be able to do a reasonable job, depending on the source. Note : there is no nice method using software that will convert 29.970 fps NTSC video to PAL.

[mpack]

during playback the video constantly freezes briefly, and it's most noticable when the camera pans sideways or up/downwards.

Bit rate too high?

[guns1inger]

during playback the video constantly freezes briefly, and it's most noticable when the camera pans sideways or up/downwards.

Bit rate too high?

For PC playback it would have to be very high. That said, I just looked at the OP's specs, and it is a pretty old machine with a small HDD. Makes me wonder how much space it has on it, and when it was last defragged.

[mpack]

For PC playback it would have to be very high.

Not necessarily - compliant software DVD players on PCs may apply the rules for data rate and buffer size even when the source medium in use at the time (ie. hard disk) is capable of going faster, and of course the PC has the memory for larger buffers. I know for example that the version of PowerDVD I use works this way - and it's a handy feature, because it's telling me not to bother burning this project to disk.

DVD has a minimum bitrate too (though I don't remember offhand what it is), but that would give the opposite problem, ie. jerky video at times of little or no motion in the scene. This is what I usually get wrong, ie. forget to enable the "pad if data falls below minimum bitrate" option in the MPEG2 encoder.

[guns1inger]

DVD doesn't have a minimum bitrate specified. It is, however, virtually impossible to get very low bitrates with any decent encoder.

My money is on an inadequate PC that has been soundly rooted by the installation of not just one, but multiple codec packs.

[mpack]

DVD doesn't have a minimum bitrate specified.

Really? Are you sure??

I freely admit that I have no access to the official DVD specs, but I always thought that DVD did have a required minimum bitrate, though I don't remember ever knowing what it actually was (since I relied on "DVD" presets in the encoder to get most parameters right). And this morning in fact I had a problem with a newly encoded video being jerky in low motion scenes (but fine in high motion!) - it seemed clear to me that this was a min bitrate problem.

The MPEG2 encoder I use btw is the TMPGEnc Plus v2.5, by all accounts a good quality codec. Yet, on video frames where there is no motion and the video has been temporally filtered, it is possible to get very low bitrates on B frames (maybe P frames too). TMPGEnc has the zero-padding option I mentioned before.

[RobotFood]

sorry for the delay in replying. I initially didn't have any codec packs when the problems first materialised, and so I installed k-lite. when that didn't help, I googled around a bit and saw other suggestions for CCCP and ACE so I installed those, which again made little difference.

the movie formats are usually in either 23 or 25 fps (I rarely get the 29fps). the choppy playback persists even when I don't attempt to convert from NTSC to PAL or vice versa.

I'll try again using the programs you guys referred to and see if that works, and also play 'em on FLC. will update again in the next day or two.