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| outlyer |
| Posted: Dec 11 2002, 07:02 PM |
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| QUOTE (S_O @ Dec 11 2002, 06:31 PM) | | I record sometimes from TV, too, but in PAL 25fps, is there any way to reconstruct the original 24fps here? Iīve read they use speed-up, the film plays faster than normal, but anyway there is interlacing, how does the interlacing come into the film in PAL? Is it reversibly? |
In PAL there's no such thing like telecine, interlacing is simply done, AFAIK, splitting every frame in two fields (with alternative lines, you know).
As you mentioned they speed up films to convert 24fps to 25fps (audio included, so original audio has a bit of a lower pitch), so there's no frame repetition or any weird thing used in telecine, (really straight: 24 frames per second => speed up => 25 frames per second => 50 fields per second).
I've done some reconstructions from DVDs, simply slowing down and changing the audio pitch to match the duration, and I've got good results. |
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| Morsa |
| Posted: Dec 11 2002, 07:06 PM |
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Moderator of the Vdub support board
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Sometimes the audio speed up is performed without changing the pitch.
Also sometimes they really add an extra frame to maintain the same duration.
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| jcsston |
| Posted: Dec 11 2002, 07:09 PM |
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Matroska Dev
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Is telecine possible with 240 height video? The telecine setting under framerate options causes my video to have interlacing artifacts 
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Use the Matroska file format |
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| outlyer |
| Posted: Dec 11 2002, 07:20 PM |
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| QUOTE (Morsa @ Dec 11 2002, 08:06 PM) | Sometimes the audio speed up is performed without changing the pitch.
Also sometimes they really add an extra frame to maintain the same duration. |
@Morsa
ok, so, usually "what I said" 
anyway... how can audio been speed up without changing the pitch?
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| fccHandler |
| Posted: Dec 11 2002, 07:26 PM |
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| QUOTE (jcsston @ Dec 11 2002, 03:09 PM) | | Is telecine possible with 240 height video? The telecine setting under framerate options causes my video to have interlacing artifacts |
You need to capture at height = 480 to get both fields.
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May the FOURCC be with you... |
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| S_O |
| Posted: Dec 11 2002, 07:50 PM |
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Vdubmod Alpha Testing Team
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| QUOTE | | In PAL there's no such thing like telecine, interlacing is simply done, AFAIK, splitting every frame in two fields (with alternative lines, you know). |
Do I understand that correctly:
frame A is splitted into field A1 (line 1, 3, 5,...) and A2 (line 2, 4, 6,..), same for frame B. But if I capture both fields again into one frame it would be without interlacing, so the fieild order must be something like that:
| CODE | A2 - B2 - C2 A1 - B1 - C1 - D1
B1 - C1 - D1 or B2 - C2 - D2 - E2 |
The two fields one above the other means one frame. That could be easily converted back, why doesnīt that filter excists?
| QUOTE | As you mentioned they speed up films to convert 24fps to 25fps (audio included, so original audio has a bit of a lower pitch), so there's no frame repetition or any weird thing used in telecine, (really straight: 24 frames per second => speed up => 25 frames per second => 50 fields per second).
I've done some reconstructions from DVDs, simply slowing down and changing the audio pitch to match the duration, and I've got good results. |
You converted interlaced PAL-DVDs back to film?
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| fccHandler |
| Posted: Dec 11 2002, 08:21 PM |
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| QUOTE (S_O @ Dec 11 2002, 03:50 PM) | But if I capture both fields again into one frame it would be without interlacing, so the fieild order must be something like that:
| CODE | A2 - B2 - C2 A1 - B1 - C1 - D1
B1 - C1 - D1 or B2 - C2 - D2 - E2 |
The two fields one above the other means one frame. That could be easily converted back, why doesnīt that filter excists?
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If that's the case, it's easily fixed with Avisynth:
| CODE | SeparateFields
Trim(1,0)
Weave |
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May the FOURCC be with you... |
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| Morsa |
| Posted: Dec 12 2002, 07:17 AM |
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I use Cooledit, and it changes duration without changing the pitch.
All professional Audio editors performs this task too.
Believe me, I had worked with audio for cinema many times.
In the digital domain almost everything is possible!!! |
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| outlyer |
| Posted: Dec 12 2002, 01:00 PM |
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| QUOTE (Morsa @ Dec 12 2002, 08:17 AM) | I use Cooledit, and it changes duration without changing the pitch.
(...)
Believe me, I had worked with audio for cinema many times.
In the digital domain almost everything is possible!!! |
I believe you, it's only that I don't see how can audio been speed up without changing the pitch. It isn't such an important thing for me as it's hardly noticeable al least to me (by the way, I also use Cooledit to do this  ).
| QUOTE (S_O @ Dec 11 2002, 08:50 PM) | | You converted interlaced PAL-DVDs back to film? |
I can't remember but I guess that they were non interlaced, as I was doing it like an experiment probably I choosed the easier films to do this...
I haven't the knowledge to answer your questions about field ordering, I just knew how the fields are obtained; maybe in www.100fps.com there are some answers, I don't remember 
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| muf |
| Posted: Dec 12 2002, 02:02 PM |
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| QUOTE (S_O @ Dec 11 2002, 11:31 AM) | [QUOTE]
I record sometimes from TV, too, but in PAL 25fps, is there any way to reconstruct the original 24fps here? Iīve read they use speed-up, the film plays faster than normal, but anyway there is interlacing, how does the interlacing come into the film in PAL? Is it reversibly? |
Three options here .
1) Your capture card screws up fields in some way so the original progressive frames don't align with the combined-field progressive output.
2) Film is converted to NTSC and the NTSC is converted to PAL with generic NTSC conversion (no IVTC or anything)-- your video is screwed up: you may kick your broadcaster in the ass.
3) Star Trek ISN'T shot at 24fps .
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| outlyer |
| Posted: Dec 12 2002, 08:52 PM |
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Spanish Section Mod
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| QUOTE (muf @ Dec 12 2002, 03:02 PM) | 2) Film is converted to NTSC and the NTSC is converted to PAL with generic NTSC conversion (no IVTC or anything)-- your video is screwed up: you may kick your broadcaster in the ass.
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Oh! S**t I forgot to mention this , really there are some PAL films, series, etc which follow what muf said and if this is the case it will sure be a pain in the ass |
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| Spire |
| Posted: Dec 13 2002, 08:47 AM |
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Unregistered
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| QUOTE (outlyer @ Dec 12 2002, 05:00 AM) | | I believe you, it's only that I don't see how can audio been speed up without changing the pitch. |
It's done by resampling/interpolating the audio waveform. The same technique is also used to change the pitch without changing the speed. |
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| sh0dan |
| Posted: Dec 23 2002, 11:54 AM |
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Avisynth Developer
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| QUOTE (Spire @ Dec 13 2002, 09:47 AM) | | It's done by resampling/interpolating the audio waveform. The same technique is also used to change the pitch without changing the speed. |
Time-stretching is a very destructive way of changing the length of a sample, and I'd recommend against it.
There are several ways of doing it (zero-cross / spectral split, etc.) but ALL of them are quite destructive. You loose "attack" and clearness of your sound, because there are small portions of the sound taken out, or repeated.
Change the samplerate instead, and make it play at a different pitch - it'll give you a much better result. |
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| S_O |
| Posted: Dec 23 2002, 01:45 PM |
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Vdubmod Alpha Testing Team
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| QUOTE | 1) Your capture card screws up fields in some way so the original progressive frames don't align with the combined-field progressive output.
2) Film is converted to NTSC and the NTSC is converted to PAL with generic NTSC conversion (no IVTC or anything)-- your video is screwed up: you may kick your broadcaster in the ass.
3) Star Trek ISN'T shot at 24fps . |
1.) ?
2.) I know they did it that way for the older series (star trek TOS & TNG), but for the new series (DS9 & VOY) I donīt thing they have done it in a that crappy way.
3.) Star Trek is 100% shot on film, so most likely on 24fps, or does someone shot on 29,97fps film?
| QUOTE | Time-stretching is a very destructive way of changing the length of a sample, and I'd recommend against it.
There are several ways of doing it (zero-cross / spectral split, etc.) but ALL of them are quite destructive. You loose "attack" and clearness of your sound, because there are small portions of the sound taken out, or repeated.
Change the samplerate instead, and make it play at a different pitch - it'll give you a much better result. |
Download this: http://www.sunpoint.net/~oparviai/soundtouch/
Itīs a open-source sound-processing-lib, which can in/de-crease playback-rate/tempo/pitch. There is also a winamp-plug-in (use the new beta, the quality is better) and itīs quite high-quality. Sometimes when you hear exactly at a old movie you can hear the crappy methodes, it sounds sometimes like xing-mp3, unsharp. |
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| jcsston |
| Posted: Jan 13 2003, 06:29 AM |
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Matroska Dev
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| QUOTE (S_O @ Dec 23 2002, 07:45 AM) |
3.) Star Trek is 100% shot on film, so most likely on 24fps, or does someone shot on 29,97fps film? |
It's a mixture  in the episode 'Caretaker Part 1' at the beginning with the text scrolling up it is fine no interlacing artifacts at all. But then two ships come on and start firing at each other with interlacing artifacts, every field is different.
Once they switch to interior view of a ship 24fps or duplicate fields for the rest of the show 
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Use the Matroska file format |
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