CHANGE SETTINGS OF MPEG4 CODEC

[guy1]

hello , i use AVI_IO to capture now...more user friendly than virtual dub
i got best results when using MPEG4 V3 codec but to got a good capture i have to change the videocodec to a higher bitrate ( i change it from 3000 to 6000 ) but everytime when i stop recording , the setting goes back to normal...is there a way to permanentely change the codec setting and save it ?
thx for reply

[theDruid]

I'm not aware of a way to change the default setting of that codec.

However, it seems to me that you may not be using the best codec for the job.

(Best is a very subjective term, but anyway...)

You're using a slightly outdated MicroSoft codec to capture, and having to use it at very high bitrates to get "a good capture".

I would suggest that you try either:

1). A more up-to-date MPEG4 codec - such as DivX or Xvid.

OR

2). Try with a lower-compression codec such as HuffyUV or one of the MJPEG codecs.

These are what people generally recommend for capture.

DivX etc.. will probably give you better results at similar bitrates (or similar results at lower bitrates).

HuffyUV is a lossless video codec (using the same algorithms as zip files, AFAIK) which compresses the video stream to make it (a bit) smaller, but does not lose any video data. This is very good if you're going to subsequently edit/filter/encode your video (e.g. to put it on a DVD/(S)VCD etc..).

The lower compression codecs need a lot of disc space though (and you're better off with NTFS so that your system can handle very big files - for this you'll need to be running WinXP or Win2K).

The codecs I've mentioned above are all free (with the possible exception of the MJPEG codecs, which I've never used), and are available in the Tools section of this site.

I suggest you try some of them out - perhaps capturing small samples, and compare your results to those using the M$ MPEG-4 v3 codec.

Let us know how you get on.

cheers,
mcdruid.

[guy1]

hello McDruid
thx for the great reply
it's strange ..i used DVIX codec long before the MPEG4 codec but that gave me a bad image..( also a smaller file ofcourse )
HUFFY codec i tried ...very good image ofcourse but 127 MB / minute....way too big for me
i just use it to record from TV...so if you can tell me a good codec for let us say 700mb/hour , that's fine for me
thx!
guy1
belgium

[theDruid]

The size of the file totally depends upon the bitrate.

Using the same bitrates with different (avi) codecs will give broadly the same filesize (allowing for a little difference in overhead etc..)

I'd be surprised if M$ MPEG-4 v3 looks as good as DivX5 at the same bitrates.

Just use a bitrate calculator (several in the tools section) to work out what bitrate to use for the target filesize you want.

e.g.:



This tells you to use roughly 1500kbps for video, and 128kbps mp3 for audio if you want an hour to occupy roughly 700mb.

This will be the same for more-or-less any codec for avi - AFAIK.

According to that calculator, setting your bitrate to 6000kbps would produce a file roughly 2.5gb for one hour of video.

I would seriously try using DivX again - make sure that you're setting the codec up correctly in terms of bitrate etc..

I believe that the visual quality of DivX will be better than the codec you're using, at the same bitrates.

cheers,
mcdruid.

[guy1]

hello McDruid, i did some test witk XVID codec...
what is the difference between XVID and DVIX5.05 ? ( i used to use the old low motion dvix codec )
what do you recommend ?
thx again for reply
rgds
Guy1

[theDruid]

There's a newer version of DivX5 than 5.05, I think.

XVid, as far as I know, is very similar to DivX - but DivX is now a commercial product, whereas XVid is open source.

As far as the technical differences... no idea! I'm sorry.

Have a look at this article over at doom9 - it's a comparison of several popular codecs; including DivX5 and XVid.

They're discussed in relation to encoding from DVD source, rather than for capturing, but the information should be useful anyway.

One thing you should maybe bear in mind though, is that real-time capturing to one of these codecs is pretty CPU-intensive, and your system will need to be pretty fast to keep up and do a good job.

As a general guide (a way to read the doom9 article) - the longer each codec took the tester to encode his test samples, the more number crunching was needed. Therefore, the ones which encoded the fastest might be more suitable for capturing.

For capturing, you may want to have a look at lordsmurf's website - which is apparently full of good stuff!

cheers,
mcdruid.

[RabidDog]

huffyuv isnt lossless AFAIK but it is the least lossy. Also the least cpu intensive.

[theDruid]

@RabidDog

I don't know this for a fact, but have a look at the developer's page for HuffyUV:

http://neuron2.net/www.math.berkeley.edu/benrg/huffyuv.html

Huffyuv is a very fast, lossless Win32 video codec. "Lossless" means that the output from the decompressor is bit-for-bit identical with the original input to the compressor.

Apparently it does use the same algorithms as 'zip' files (Huffman) - and they have to be lossless I suppose.

That must be why you can't set bitrate or anything with HuffyUV - it compresses as much as it can without losing any data.

cheers,
mcdruid.