Jerky Project Playback

[WestbrookNH]

OK, this is strange.

I have two projects. One is 1:20 long, the other is only 0:32 long.

The longer project runs playback very smoothly, while the shorter project runs playback very jerky. There appears to be a lot of disk thrashing during the jerky playback of the shorter project, while disk operation is much smoother during the playback of the longer project. Also, the shorter project with the jerky playback takes a while to respond to the STOP button, or any other button for that matter, while the longer project responds virtually instantly to any and all buttons.

My system is a built around an ASUS A7N8X Deluxe V2.0 with AMD 3200+, 1 GB PC 3200 SDRAM @ 400 MHz, and a 60 GB 7200 RPM Ultra ATA Maxtor disk with 30 GB free. DMA is enabled for all drives. I also have a 200 GB external USB 2.0 Seagate with 160 GB free.

That should be plenty of resource for what I'm doing, and as corroboration of that, one project runs playback smoothly, while the other one is jerky.

Here are the properties of the project that runs a jerky playback.

• NTSC drop frame (29.97 fps)
  MPEG files
  24 Bits, 720 x 480, 29.97 fps
  Field Order B
  (MPEG-2)
  Video data rate: Variable (Max. 6000 kbps)
  Audio data rate: 192 kbps
  MPEG audio layer 2, 48 KHz, Stereo

Here are the properties of the project that runs a smooth playback.

• NTSC drop frame (29.97 fps)
  MPEG files
  24 Bits, 720 x 480, 29.97 fps
  Field Order B
  (DVD-NTSC), 4:3
  Video data rate: Variable (Max. 6000 kbps)
  Audio data rate: 160 kbps
  MPEG audio layer 2, 48 KHz, Stereo

What am I missing?

[jchunter_2]

So, the question is: What are the properties of the captured video? My SWAG is that they match the properties of the smooth playback project.

Also, you are running version 7. The 7.01 update may or may not fix the memory leak problem (I don't know). Have you installed this update?

[WestbrookNH]

So, the question is: What are the properties of the captured video? My SWAG is that they match the properties of the smooth playback project.

Also, you are running version 7. The 7.01 update may or may not fix the memory leak problem (I don't know). Have you installed this update?

Properties of the MPEG file that has the jerky project playback:

• File
  --------------------------------
  File size: 1,450,788 KB
  File duration: 00:18:59.07
  
  Video
  --------------------------------
  Format: 24 Bits, [720 x 480]
  Compression: MPEG-2, Field B, Variable bit rate
  Comp Ratio: 0%
  Frame rate: 29.970 Frames/sec
  Total Frames: 34143 Frames
  
  Audio
  --------------------------------
  Format: MPEG Audio Layer 2 Files
  Attributes: 48000 Hz, 16 Bit, Stereo

Properties of the MPEG file that has the smooth project playback:

• File
  ---------------------------------
  File Size: 3,885,154 KB
  FIle duration: 1:24:54.03
  
  Video
  ---------------------------------
  Format: 24 Bits, [720 x 480]
  Compression: NTSC DVD, Field B, 6000 kbps
  Comp. ratio: 0%
  Frame rate: 29.970 Frames/sec
  Total frames: 152671 Frames
  
  Audio
  ----------------------------------
  Format: MPEG Audio Layer 2 Files
  Attributes: 48000 Hz, 16 Bit, Stereo

Hmmmm.....

The only difference is that the file having the jerky playback has:

. Compression: MPEG-2, Field B, Variable bit rate

while the file having the smooth playback has:

. Compression: NTSC DVD, Field B, 6000 kbps

But I don't see a project properties field that seems to care about this difference.

I'm sure I'm missing something.

[jchunter_2]

There are some missing properties. Select New Project, set menu: File/Preferences check "Show Message When Inserting First Video..." then drop one of your video clips in the timeline. Let Video Studio set Project Properties to match. Then copy the lower window in File/Project Properties into your reply. Do the same to get the properties of the other clip.

[WestbrookNH]

There are some missing properties. Select New Project, set menu: File/Preferences check "Show Message When Inserting First Video..." then drop one of your video clips in the timeline. Let Video Studio set Project Properties to match. Then copy the lower window in File/Project Properties into your reply. Do the same to get the properties of the other clip.

OK. Using your procedure, this is what I've got.

Here are the properties of the project that exhibits jerky playback.

• NTSC drop frame (29.97 fps)
  MPEG files
  24 Bits, 720 x 480, 29.97 fps
  Field Order B
  (MPEG-2)
  Video data rate: Variable (Max. 12000 kbps)
  Audio data rate: 192 kbps
  MPEG audio layer 2, 48 KHz, Stereo

Here are the propeties of the project that exhibits the smooth playback.

• NTSC drop frame (29.97 fps)
  MPEG files
  24 Bits, 720 x 480, 29.97 fps
  Field Order B
  (DVD-NTSC), 4:3
  Video data rate: 6000 kbps
  Audio data rate: 128 kbps
  MPEG audio layer 2, 48 KHz, Stereo

Wow, now there's a difference.

The file that exhibits jerky playback is 12000 Kbps VBR,
but the file that exhibits smooth playback is 6000 Kbps CBR.

So, how do I fix this?

[THoff]

You really have no choice but to re-render the problematic video file to be compliant with the DVD spec. The total allowed bitrate for both audio and video is 10080 kbps for NTSC DVDs, and in order to avoid playback problems on older standalone DVD players, you should never exceed 8000 kbps.

[WestbrookNH]

You really have no choice but to re-render the problematic video file to be compliant with the DVD spec. The total allowed bitrate for both audio and video is 10080 kbps for NTSC DVDs, and in order to avoid playback problems on older standalone DVD players, you should never exceed 8000 kbps.

The reason for the high bit-rate was that I was using a lot of slow motion. I was capturing from an analog device (VCR) and I thought the highest bitrate would give me the smoothest slow motion.

If I want to render this into 8000 Kbps, can I do that from within VideoStudio, or do I have to re-capture the video?

[THoff]

Yes, you can re-render the file from within UVS. Go to Share, Create Video File, and choose Custom. You can now specify the output file format and any options specific to that format.

[WestbrookNH]

Yes, you can re-render the file from within UVS. Go to Share, Create Video File, and choose Custom. You can now specify the output file format and any options specific to that format.

Still jumpy.

Here are the MPEG file properties:

• NTSC drop frame (29.97 fps)
  MPEG files
  24 Bits, 720 x 480, 29.97 fps
  Field Order B
  (MPEG-2)
  Video data rate: Variable (Max. 6000 kbps)
  Audio data rate: 128 kbps
  MPEG audio layer 2, 44.1 KHz, Stereo

And here are the Project properties:

• NTSC drop frame (29.97 fps)
  MPEG files
  24 Bits, 720 x 480, 29.97 fps
  Field Order B
  (MPEG-2)
  Video data rate: Variable (Max. 6000 kbps)
  Audio data rate: 128 kbps
  MPEG audio layer 2, 44.1 KHz, Stereo

They're identical now, but playback is still jumpy.

Is it the slow motion?

[WestbrookNH]

By the way, it is only jumpy in Project Playback.

Clip Playback is smooth.

[jchunter_2]

When you re-rendered, you also changed the audio frequency from 48kHz to 44.1kHz. There is no logical reason why this should affect playback but I have experienced problems with clips with this audio frequency in the past.

Try re-rendering with the fewest changes possible. Just drop the maximum video bitrate to 8000 kbps and leave all the other properties alone.

[WestbrookNH]

When you re-rendered, you also changed the audio frequency from 48kHz to 44.1kHz. There is no logical reason why this should affect playback but I have experienced problems with clips with this audio frequency in the past.

Try re-rendering with the fewest changes possible. Just drop the maximum video bitrate to 8000 kbps and leave all the other properties alone.

Nope. That does not help.

I just don't know what to do.

Maybe I'll try rebuilding the project from scratch.

[WestbrookNH]

I found it!!!

I know what's causing the jerky Project Playback.

The Transition effects between scenes!!!!

Remove the Transition effects, and voila', smooth playback.

Put the Transition effects back in between the scenes, and voila', jerky playback.

It doesn't matter whether the project and the MPEG file agree on compression settings.

Oy!!!

[WestbrookNH]

OK, it's a little more complicated than that.

Almost anything that changes the timing can cause the Playback to become jerky.

For example, if I change the slow motion coefficient from 50% to 51%, I get the jerky playback.

If I add a photo between scenes, or superimpose a photo on a scene, I get the jerky playback again.

I think it's because I have a lot of slow-motion.

[GeorgeW]

Hi,

If the project preview is where you see the "jumpy" playback, then I would go ahead and burn the disc anyway. I think the project previews don't give you the actual results as when you burn the project.

George