DV Video Will Not Play Smoothly

[Tyler2000]

I have a 44gb (3.5 hours long) dv avi. I'm trying to get it to play smoothly on my pc screen so I can output to a VHS tape. But I keep seeing occasional small jumps/choppy playback. I tried looking at the video frame by frame, but the frames are all there. I tried defragmenting my harddrive but it keeps telling me that the avi file can not be defragmented. The only thing I can think of is trying a different dv codec, but I'm not sure what codec to try. I'm trying to play the video in windows media player. I also tried to use pinnacle studio 9 plus, but whenever I try to 'make tape' the screen goes completely black on the output to the vcr. I tried turning down video acceleration to fix to this problem, but then the video looked all grainy.

Any ideas? By the way, I created this avi file in pinnacle studio 9 plus, but I can't recreate it now because I don't have the original videos.


My system:
3.2GHZ dual core
2gb RAM
Nvidia geforce 7900 gs
windows xp pro

[JohnnyMalaria]

Can't you send the DV file back to a DV camcorder via Firewire and hook up the VHS deck to the analog outputs of the camcorder? That would be the most reliable way to record the video.

From your description, it sounds like you are playing the video full-screen on the secondary monitor of your nVidia and, presumably, taking the S-video or composite signal from the nVidia? Is that right?

If so, you need to ensure that your video acceleration is set to the max and that absolutely nothing else is running! Also make the resolution of the secondary display as low as possible (but not less than the video) - check the nVidia settings - choose 720 x 480. Does the sound suffer the choppiness, too? If not, this is a clear sign that the system is struggling to: 1) decode the DV video, 2) display it full screen and 3) decode/play the audio. By default, the Windows multimedia "subsystem" will drop video frames to ensure audio continuity.

Are you doing anything else while trying to play the video? For example, if you are doing anything that involves minimizing/restoring/maximizing other windows, the video will stop momentarily unless you turn off the "Animate Windows When..." settings.

[edDV]

Explain the origin of this 44GB 3.5 hour DV format file. Normally DV format is encoded in camcorder hardware at a fixed 25 Mb/s + audio rate.

An output of camcorder DV to a DV-AVI file normally averages 13.5 GB/hr or 47.25 GB for 3.5 hours. Could the lost 3.25 GB be due to dropped frames from realtime software encoding?

Try playing with VLC with deinterlace set to "disable" (aka field weave) mode". If that doesn't play, try "discard" (single field) mode. If that won't play, you probably have dropped frames in the file.

[JohnnyMalaria]

Explain the origin of this 44GB 3.5 hour DV format file. Normally DV format is encoded in camcorder hardware at a fixed 25 Mb/s + audio rate.

44GB isn't far off the mark.

For exactly 3.5 hours:

3.5 x 3600 x 29.97 x 120000 bytes (NTSC) = 42.20 GB
3.5 x 3600 x 25 x 144000 bytes (PAL) = 42.24 GB

(120000 and 144000 are the compressed frame sizes for NTSC and PAL, respectively).

Add on some overhead for AVI file stuff such as indexing....

This assumes Type-1 DV AVI.

For Type-2, add on 3.5 hours of stereo PCM audio (2.25 GB for 16-bit stereo @ 48.0kHz).

[SingSing]

If the frames are all there, then the likely issue is the player itself. Change players or get it back in a cam and play it or just go ahead and convert and burn it on a DVD-R/W disc and check it on your stand alone player.

[edDV]

I ran a quick test playing DV clips through various software players with interesting results.

Using the same clip, I found significant differences in CPU loading. First I shut down all other applications.

CPU = 2.4GHz P4, 1GB RAM
ATI AIW-8500DV display card.

CPU
Load......Player

~49%...VirtualDubMod v1.5.10.2 (Panasonic DV codec)
~38%...Windows Media Player 10 (MS DV codec)
~25%...ATI Media Player
~25%...Nero Showtime
~20%...PowerDVD (Deineterlace set to Auto)
~15%...VLC (Deinterlace set to Bob)
~07%...VLC (Deinterlace set to Disable or Discard)

Also, WinDV in "Capture" mode with decode for monitoring (MS DV codec)
~14%

Quite a difference. If you are running other CPU applications, some players may skip while others stay solid.

[JohnnyMalaria]

~38%...Windows Media Player 10 (MS DV codec)

Also, WinDV in "Capture" mode with decode for monitoring (MS DV codec)
~14%

At first glance this seems odd but the MS DV decoder can operate in a number of resolution modes. For a small window (like monitoring), you can use the quarter resolution mode. Our DV processor has input and output monitoring windows - both requiring DV decoding. Running two instances of the MS DV decoder at quarter resolution is very frugal in CPU terms.

[edDV]

~38%...Windows Media Player 10 (MS DV codec)

Also, WinDV in "Capture" mode with decode for monitoring (MS DV codec)
~14%

At first glance this seems odd but the MS DV decoder can operate in a number of resolution modes. For a small window (like monitoring), you can use the quarter resolution mode. Our DV processor has input and output monitoring windows - both requiring DV decoding. Running two instances of the MS DV decoder at quarter resolution is very frugal in CPU terms.

I'm curious what others are seeing on slower machines. My Core2Duo machine goes too fast to see much spread. They all run well under 10% CPU.

I'm also not sure if these players use the display card hardware to play DV format.

[jagabo]

I have a very old Matorx 2x AGP card on my C2D E6300 machine (becuase of the excellent SD TV out). Most players (MPC, WMP 6.4, WMP 10, WinAmp) are around 13 percent with occasional bumps up and down. Curiously, VLC runs at 0 to 1!

On my Athlon 64 X2 3800+ with an ATI X300 PCIe card CPU usage runs around 5 percent. I don't have VLC installed on that machine.

On a P4 2.8 GHz HT with an ATI X800 AGP CPU usage runs 15 to 20 percent. No VLC there either.

[Tyler2000]

I tried VLC media player. When I open the file, it says 'avi is broken, do you want to try to repair it?" I click yes and a couple hours later it crashes.

The origin of this 44GB file. It is exactly 3 hours, 27 minutes & 51 seconds long. It was created using Pinnacle Studio 9 Plus (& virtualdub was used for some parts of it.) I split this file into two parts and burned to two DVDs(one dual layer and one single layer). Those DVDs play and do not have this choppiness problem.

For the VHS copies of the same video(which is what I'm trying to do) I rendered a new file in studio, but added titles to the beginning of each section to make up for not having a menu system with VHS. So that is the file I have now. I can look at the video frame by frame in virtualdub, but they are all there. I tried 'scanning video stream for errors' in virtualdub, but it didn't find any. However, it does seem like the 'jumps' occur at the same spots everytime.

I looked to see how much cpu power windows media player used to play the file as I was writing this. About 15%. I don't think that is the problem.

I haven't tried playing the video back to my camcorder. I'm not sure that is even possible(Canon ZR65MC) even if it is, it still has to play back at the same rate to the camcorder as it does with the a vcr so I don't understand what the difference would be.

I don't see the option to display the secondary monitor to 720x480. I had it set to 800x600. I don't think the problem has anything to do with the secondary monitor settings. I'm still seeing the problem on my primary monitor with all other secondary monitor settings turned off.

Since VLC media player said my avi file is 'broken', are there any good programs that may fix it?

[edDV]

DV format video at 3.5hr would be around 45-47GB.

We need to separate issues here. DV transfer some video from your camcorder to the computer using your Studio 9 or WinDV. Does the DV-AVI file play smoothly? If so your system is ok.

As for the file you processed in Studio 9 + VirtualDub, only you know what you did.

[Scorpion King]

Did you transfer the video through firewire or did you use a capture card?

You could try a direct stream copy in VirtualDub as sometimes that can fix problem videos. If the problem is dropped frames then that won't help.

You could always full process using a different avi codec like Huffyuv. That should play smoothly unless there is dropped frames in the original file.

Good luck.

[JohnnyMalaria]

I haven't tried playing the video back to my camcorder. I'm not sure that is even possible(Canon ZR65MC) even if it is, it still has to play back at the same rate to the camcorder as it does with the a vcr so I don't understand what the difference would be.

There's a world of difference. Firstly, according to this, you should be able to send the DV AVI file back to your camcorder via Firewire. (Then it's a simple matter of hooking up the analog output of the camcorder to the analog inputs of your VHS recorder).

Sending the video as a DV stream to the camcorder doesn't put much load on the computer. In fact, Firewire uses DMA transfer which means the CPU doesn't have to do very much at all!

Playing the DV AVI file to the computer's display requires decoding the DV, creating a full-screen size image and displaying it. Plus, there's the audio, too. All told, it puts a considerable load on the system.

As I stated in my earlier post, if the audio plays okay but the video jumps/misses frames, this is a sure sign that your system is struggling to render the audio and the video. By default, Windows, will drop video frames rather than create choppy audio.

Please try the Firewire option and let us know how you get on.

[Tyler2000]

I finally got it to play smoothly by doing a direct stream copy with virtualdub.

Thanks.

[Scorpion King]