VS9 Long video starts well, then video/audio skips

macks64 · Post by **macks64** » Fri Apr 14, 2006 11:28 pm

Dear Experts,

I hope someone has some wisdom on this.

I have a 1 hour 30 minute DV tape which I am turning into PAL DVD format (via MPEG rather than via AVI). The first section (~16minutes) works perfectly. However, for the remainder, the video/audio starts skipping as if I were pressing the fast forward button on the DVD player. This is evident as soon as the mpg file has been created on the hard disk.

The capture process seems to work fine:
I asked VS9 to acquire 1hr:30min:20sec of tape (2 secs less than the full tape).
The tape faithfully runs through to this time then stops at that point (I watched it all).
Then there is a message indicating (something like) frame buffers are being transcoded - about 11,000 of them, which takes a while.

HOWEVER, when I look at the created .mpg file, the clip is only 1hr:6min long - with the time shortening seeming to come from all the latter section of the video/audio which has this fast forwarded style about it (crisp/clear, but bits being skipped). No dropped frames are indicated during the capture process.

When it happened the first time, I thought it might have been due to the internet being in use through the computer (our other computer shares its ADSL connection), so I repeated the entire process, having re-started the computer, disconnected the internet and de-activated the virus scanning program, just to make sure the computer's resources were fully focused. I had audio preview switched off during the capture.

The computer is listed in my profile, but for ease of reference, here it all is anyway:

Dell Dimension 8300
Intel P4 2.8GHz (Hyperthreading OFF)
2GB RAM
120GB SATA 7200 rpm disk, with 80GB free.
128MB ATI Radeon 9800 (set to 1024x768, 32 bit, 60Hz refresh)
Swap file set permanently to 4GB.
Sound Blaster 5.1 Digital Sound Card
Swann Firewire card
Win XP Prof.

Sony TRV355E Digital 8 PAL Camcorder (set to "16 bit" audio) connected via the firewire.

I have thoroughly read through the "Recommended Procedure" (and read numerous other posts) and follow the PAL procedure almost exactly (I use variable bit rate of 8264 everywhere - trying to squeeze that extra ounce of quality). [Although I would like to know why the initial capture phase suggests "95%" quality, then later uses "100%"]. In my case, I am going directly from the Capture phase to the burn phase (no editing required), but this does not seem relevant because the .mpg has the problem as soon as it is created. I believe the computer should have the grunt to acquire directly to mpg, however I will try going via AVI, despite it seeming more complicated (thus more prone to error) and more time consuming. The only other thing that might be relevant, is that the screen saver (blank screen, no cpu power required) cuts in about 80% through the frame transcoding bit - and when I move the mouse it takes the screen almost a minute to refresh because the computer is still working on the transcoding.

If anyone out there has some suggestions as to what is wrong, that would be so much appreciated - I want the absolute best quality replication I can get of my 1.5 hr tapes onto a single PAL DVD. I have to say "thanks" to jc_hunter for the summary procedure, as VS9 is very unclear about whether its multitude of settings in multitudes of menus are supposed to match input devices/files or represent the properties of the created output. So for example, if my Camcorder is set to "12 bit audio" compared to "16 bit audio", I have no idea whether a change of setting is compulsory within VS9.

acejake · Post by **acejake** » Sat Apr 15, 2006 12:50 am

I am not an expert, but I notice you only have one Disk Drive. Everything I have read and experienced says it is best practice to have two drives, one for the operation and one to render to. Anyway this is my bet, will be interesting to see what the guru says.

THoff · Post by **THoff** » Sat Apr 15, 2006 1:06 am

What do you mean by "via MPEG rather than via AVI" -- are you capturing directly to MPEG2 format on-the-fly? Have you turned on the "Show drop frame information" option in File -> Preferences -> Capture to see if the material goes missing during the capture stage?

macks64 · Post by **macks64** » Sat Apr 15, 2006 1:36 am

Dear THoff,

Thanks for taking the time to reply.

"via MPEG rather than AVI" means that I am using the section in the Recommended Procedure which starts: "If you elect to capture digital video direct to NTSC [PAL in my case] MPEG2".......

I am very sure that "Show Drop Frame Information" was checked.... when I go back into to VS9 now, it is one of those VS9 items which must be stored in an .ini file (rather than a .VSP file), because it was already checked, despite not being checked by default when I started using VS9.

I am new to VS9, so it's possible that the computer cannot cope with direct capture to MPEG..... however its spec should be enough, and I believe I have disabled extraneous junk - and I am moderately confident I had one success with a "Sonic Direct to DVD" with this same computer 18 months ago, which I thought had converted direct to MPEG - but not so sure about the Sonic process now.

sjj1805 · Post by **sjj1805** » Sat Apr 15, 2006 8:45 am

As luck would have it I just saw reply from skier hughes to another user with a similar issue.
Please view this link mentioned by skier hughes.
http://www.myvideoproblems.com/Tutorial ... rVideo.htm

THoff · Post by **THoff** » Sat Apr 15, 2006 4:12 pm

Macks64, you mentioned that the "Flushing transcode buffer" message appears -- that indicates that the computer is not able to keep up with the DV-to-MPEG2 transcoding in realtime and is forced to buffer the incoming DV stream in memory. Eventually, that buffer fills up, the capture is stopped temporarily, and the backlog of data gets converted and the buffer emptied. Capturing then resumes.

At least that's the theory. If the device control commands that Videostudio sends to stop the camcorder for some reason are ignored or never sent, the camcorder will keep playing, and significant portions of the video will be missing from what gets captured.

I would try recapturing using the DV AVI format, just to see if the problem with the missing video disappears. I'm also sure you'll be much happier with the quality you get from non-realtime transcoding.

jchunter · Post by **jchunter** » Sat Apr 15, 2006 7:23 pm

In your system spec, you mention that you have turned off hyperthreading. This will slow up your computer. Turn it on and also be sure that DMA is enabled on your hard drives.

I am able to capture with a 3.0GHz 8300 to mpeg2 @ 8000kbps as long as I don't push the Quality slider in the Compression Tab past the default setting. If I max out quality setting, I can only capture about 5 minutes before pausing to let the transcode buffer empty.

There are preference settings that may help you past the transcode flush "Stop DV Tape when Capturing Stops" and "Allow access to capture device settings". As Torsten says, Video Studio is supposed to pause the capture process when the buffer fills up. Checking these preferences may work.

DVDDoug · Post by **DVDDoug** » Mon Apr 17, 2006 11:16 pm

You can avoid lots of problems if you "capture" to AVI/DV. This is just a data-transfer from the tape to hard-drive without much (if any) CPU processing / calculating.

Once the AVI/DV file is on your hard drive, the CPU can take its time to perform the MPEG encoding. (You can even use high-quality two-pass encoding.) Once you are working with data on your hard drive, you don't have to worry about CPU speed or multitasking. The data won't get corrupted by a slow system, or because the CPU is off doing something else... it just might take a little longer. (Of course, this whole procedure will take longer and chew-up more disk space.)

macks64 · Post by **macks64** » Sun Apr 23, 2006 12:31 pm

Dear All,

Thanks for all the helpful info. I have decided (and successfully used) the DV/AVI format which, although slower, does guarantee me maximum quality - which is my current priority. In fact, I just bought a dual layer DVD writer (AUD $73!! - bargain) so I can get my 90 minute tapes onto one DVD without having to skimp on quality. I'm just off to check the posts to see if there are any tricks using VS with Dual Layer.

As an aside (and hopefully to help future users), the transcode buffer message did not appear until the absolute end of the capture (I sat watching the whole thing), but presumably the problem must have been occuring in the background during the capture - and probably would be solved using the suggestions to change preferences to ensure the tape is stopped when VS is working on the buffer. And based on your (John) advice and other posts, I will switch Hyperthreading back on (it was off for non-VS reasons). DMA is already on. The fact that you have a gruntier version of my computer re-confirms the need for me to capture to DV/AVI whilst I am obsessing over maximum quality - rather than risk the tape succesfully starting and stopping every few minutes.