"carlsson" wrote:
> Codecs are algorithms how data is encoded to save space. You might
> have heard of DivX, which is one of the most common (and efficient)
> video codecs. MPEG is another one (or is DivX part of MPEG?). I don't
> know which type of codecs a standard DVD player can read, but many
> players are advertised as being able to read DivX. In order to be able
> to code (and read) AVIs with that codec, you need to download it from
>
www.DivX.com
Yes, I had a look into this & found quite a few. This site seems to explain
a few of them:
http://www.movavi.com/codec which is where I got this
program from to write AVIs.
I downloaded a couple & I think I've found the one for which my camera used. I tried to fine tune this thing in order to reproduce one of the movie files & did with my camera - so basically AVI in & AVI out. On the output I've used this stuff:
Video codec: PICVideo M-JPEG 3 VfW Codec
I've got many settings for this thing which include:
Enable Codec
Advanced Deblocking
Assume Normalized YUV
Swap Fields
Force YUV Output
Brightness Values Between -100 to 100
Contrast Values Between -100 to 100
M-JPEG Compressor Settings
Encode Normalized YUV
<< Compression Quality >> = 8 (or ?)
Luminance Quality: 60
Chrominance Quality: 65
2 Fields If More Than 240
Swap Fields
Make Primary M-JPEG Codec (haven't been able to disable this - simply Greyed out - same as Swap Fields, however this can be selected when 2 Fields If More 240 is enabled).
Subsamping Options
1 : 1 : 1
4 : 2 : 2
4 : 1 : 1
I've found having 4 : 1 : 1 produces a file with a Data Rate option (like the files my camera produces) but for some reason I can't get it quite the same the closest is when the M-JPEG Compressor Settings is on 8 & the Luminance Quality & Chrominance Quality seem slightly adjust in values - I thought these maybe some fine tuners which can adjust the Data Rate to what it is perhaps - but I can't be definite about anything.
When this Codec is enabled - my movie files made by my camera seem to light up telling me this is the video codec used. But I even with the codec - my camera won't play the reproduced file (which kinda left me to suggest there's an element of fine tuning involved to reproduce the same file).
The other trouble I've got is the sound. The file my camera produces is a PCM sound band - 8bit which is all fine, but the bit rate is entirely different at 128kbps. I can get the frequence inbetween at 88kbps & 176kpbs, but not 128kpbs! Then I read somewhere along the lines of there being Sound codecs as well. Do you know anything about these?
I mean the program I uses calls it MPCM, so perhaps I need simply a PCM codec (if that is what they call it).
> Some of the other codecs are close to useless, while others may be
> useful in a case where you play a movie on a computer or player that
> doesn't support DivX.
The close to useless ones perhaps are specifically setout to do a specific task on a specific video set up. And like you said there's the more common ones like DivX. The MPG maybe a component of it - not too sure.
> Probably your camera produced uncompressed AVIs?
Fraid it's not that. The smallest of my files is a 15 second AVI which is 16.7Mb in size. It sounds quite large, but an uncompressed AVIs of that size I produced was well over 100Mb. I think I've got the correct Codec - the simular files I've produced in question are 15.5Mb (that sample doesn't have any sound though - think it's around 17Mb with the sound). The Data rate also increases when Sound in added too. So perhaps that's where I'm falling down (theorically I mean). There is just so much trial & error with this stuff. I've already had to defragment my working HD space as a result (wasn't too bad though) since I working at producing large files & deleting the useless ones. Having a D drive definitely helps though. Simply there for the workspace.
> I don't quite know how to identify which codec a movie was
> saved as, but there should be some way to find out. You can set a lot of
> parameters about frame rate, compression rate, audio rate etc to
> customize the movie to your needs. I also don't know about why the
> resolution would be distorted, jerky and the sound out of sync.
Yeah, I think the SVCD I produced might of had some faults with the burning process. I have known there to be issues when it comes to burning stuff. In the NTI burner I have I know it's possible to test before burning - perhaps I should have done this prior to just burning a CD.
> Earlier this year I helped by boss converting some football games (!)
> he had recorded with a video camera to AVIs to be downloaded or
> burned to a CD. Although the movie did not cover a full 90 minutes, the
> files easily were in the size of 10 GB each before compressing with a
> good codec, and thus the target was < 700 MB per movie.
Sounds pretty good for a 90 minute feature.
In addition I had some horrible thought that my Fuji camera perhaps leaves some kinda code in the files it's producing - hence a new file wouldn't have it & it wouldn't work on the camera. I mean come-on it would have to be real nasty to have figured the whole system out, only to be stopped by some minor glitch which stops the executing the file back on it - even if everything was the same. Would that be possible that is what Fuji have done? In that case I'd need a disassembler to look at the files. Know of any good Freeware disassemblers?
I mean there must be a way of duplicating a file structure?
CP/M User.
