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| Maurizio |
 Posted: Oct 31 2002, 01:53 PM |
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I'm trying to compress Dune,
using VDub, last version, aViSynth vers 2.06, with the filters to read directly from the Vobs, XVid , last stable version, compressing in two passes.
I'm not sure about it, but it seems that during the compression
I lose some frame from the file.
I've not here the figures, because I'm at work, but if I remember
correctly the film is 2/3 seconds shorter then it should be.
I made a first conversion months ago, and a new one last week,
to try the vdub temporal smoother (very effective).
Now opening both films with VDub I see that the last made is shorter
(=less frames) then the previous. The audio is also progressively desynchronyzed.
Seeems that I lose a frame every now and then.
I don't use telecine since the original is already 24 fps.
I don't know if it's a VDdub , a filter or an XVid problem, but i suppose it could be the filter (it's the first time I use it and I have never had such
problem before).
Any suggestion ?
Maurizio
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| fccHandler |
| Posted: Oct 31 2002, 03:30 PM |
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Change the video frame rate to 23.976.
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May the FOURCC be with you... |
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| Maurizio |
| Posted: Oct 31 2002, 04:20 PM |
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Is it a magic number ?  |
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| fccHandler |
| Posted: Nov 1 2002, 06:45 AM |
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Administrator n00b
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| QUOTE (Maurizio @ Oct 31 2002, 12:20 PM) | | Is it a magic number ? |
Yes.
Film rate is 24 fps, but NTSC television is 29.97 fps. When films are broadcast on TV, every fourth film frame is split across two NTSC frames; this is "telecine" or "3:2 pulldown" (look it up on the Web). NTSC DVDs do this too since they are meant to be viewed on TV.
The "magic" number derives from: (29.97 * 4) / 5.
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May the FOURCC be with you... |
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| Maurizio |
| Posted: Nov 1 2002, 08:41 AM |
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Thanks, I'll try it in the weekend.
Maurizio
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| Maurizio |
| Posted: Nov 11 2002, 05:11 PM |
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It is not a frame number error
the number is correct.
seems that the audio and video are incorrectly mixed (or played).
Since the audio was 1 second before the video,
I used CoolEdit to add 1 second of silence to the beginning and trimmed
the end so that both audio and video are the same length. (2h,10m,45.200 sec)
Then I've controlled with VDub and CoolEdit the synchronization of the film and the audio, taking two points, at film start and end,
before mixing them.
They corresponds perfectly.
after the mix, however, during playing, the audio is progressively delayed
in respect to the video.
I've tried in several ways : to compress separately the audio in MP3
using Cdex and lame encoder, with differents bitrates, or making the compression during the mix (also with different bitrates).
The results are the same.
I tried also to alter the video frame rate, but when playing I see that
every 5/6 seconds there is an accelerated sequence, very disturbing.
This is he only film I experience this problem in more than 50
succesfully encodings.
Where is the problem ?
regards
Maurizio.
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| Morsa |
| Posted: Nov 11 2002, 05:26 PM |
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The problem may be that your system is not fast enough to process the image.
What resolution are you using?
Try encoding in something around 640xXXX or 576xXXX or 512xXXX |
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| Maurizio |
| Posted: Nov 12 2002, 10:51 AM |
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I don't remember 'cause I'm at work,
but it should be 576*244 or similar.
I'm using a laptop pIII 800 Mhz, 256 mb ram, winXp.
I've never had such a problem before.
Could it be this particular film ?
How can I know if audio and video are not properly sinchronyzed
or if it's a problem during playing ?
Maurizio
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| Morsa |
| Posted: Nov 12 2002, 02:44 PM |
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Let me see if I understud, youīre saying that Image is going faster than audio? |
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| Maurizio |
| Posted: Nov 12 2002, 04:18 PM |
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Yes, I first see someone opening its mouth, and then I hear the sound.
this is progressively getting worse as the film advances.
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| Morsa |
| Posted: Nov 12 2002, 04:52 PM |
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Donīt know fellow.
If your audio sequence is at Constant bitrate and you interleaved it I canīt imagine what happens, cause most of the times Image goes slower than sound not the opposite!
Did you try using Ffdshow as the decoder?
May be this helps, but I donīt really know.
Are you sure you have the correct frame rate?
Sorry for asking too much.
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| Maurizio |
| Posted: Nov 13 2002, 08:37 AM |
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Well, yesterday evening I had no time to check it
perhaps this evening I'll check it more closely.
Thanks for the help
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