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Unofficial VirtualDub Support Forums > VirtualDub Filters and Filter Development > Use Filters Without Compression ?

Posted by: Legolas Apr 2 2003, 02:25 AM

Is it possible to use the filters without compress the video by a codec ??

Thank you

Legolas

Posted by: phaeron Apr 2 2003, 03:50 AM

Nope.

Posted by: Morsa Apr 2 2003, 06:21 AM

You can use Image sequences or uncompressed video.I do it all the time.

Posted by: Legolas Apr 2 2003, 11:23 PM

Do you know if this feature will be available in the next releases of VirtualDub ?

Thank you

Legolas

Posted by: David.Bucci Apr 3 2003, 03:52 AM

Ah, Legolas, how the elves have fallen ... several thousand years ago there wouldn't have been an elf that didn't know the answer to this

The very nature of filters is that they alter the videostream in some fashion, e.g., blurring more, adjusting hue or colors, changing size of frames, etc.

The video encoding formats in use today don't permit you to alter such features in the video without re-encoding them ...

You have two options ... us an uncompressed file (no codec involved), or a lossless codec (e.g., HuffyUV) like Morsa suggested ... or achieve the results you want on playback via a decoder that provides post-processing (e.g., ffdshow). Likely neither of those is what you're seeking.

Posted by: Legolas Apr 4 2003, 04:20 AM

I don't want use the uncompressed feature because this make an huge file.
I want just use the "resize" filter.

May the wisdom be with you.

Legolas

Posted by: Legolas Apr 4 2003, 04:22 AM

Sorry

, it's not the "resize" filter but the "rotate" filter.

Legolas

Posted by: Morsa Apr 4 2003, 06:37 AM

Try being a little bit more clear, please.

Posted by: Legolas Apr 4 2003, 08:45 PM

First, thank you to take care of this question.
Indeed I have a source AVI containing DivX5.0.2 and WAV in 320x240.
I want keep the DivX compression, but rotate the screen in order to obtain a 240 x 320 resolution to read this AVI file on a PPC, without code the video. I don't want code the video stream a 2nd time (!!)
(In the same time I code the WAV in MP3, this is not a problem).

Peace

Legolas.

Posted by: Arctonyx Apr 4 2003, 11:04 PM

Now that you have given more details it is easy to answer "no",
not unless you are willing to accept a degraded picture.

Your current file is compressed via a lossy codec. In order
to do your manipulation it would have to be decoded,
manipulated, and recoded. This would double up the
compression artefacts and generally give you a poorer
image.

If the image degradation is acceptable to you then that
is a different matter.

Posted by: David.Bucci Apr 5 2003, 05:42 PM

QUOTE (Arctonyx @ Apr 4 2003, 06:04 PM)

Now that you have given more details it is easy to answer "no",
not unless you are willing to accept a degraded picture.

But just for context ... the image degradation could be kept to a minimum by e.g. two-pass encoding with careful control of the bitrate. It wouldn't be as good as the original, but it might be perfectly acceptable, depending on the quality of the original, etc.

I just don't want you to get discouraged from trying it ... i've used Rotate before with very acceptable results, even though it meant re-encoding.

Posted by: valja Apr 5 2003, 07:11 PM

Hi admins.

Would you mind to close this thread. May be I'm overreacting, but there was a clear answer - NO WAY TO USE FLTERS WITHOUT RECOMPRESSION. That should be "selbstverstandig == obvious" for people who have any experience with video.

For members with IQ <10: try again, it might work! All guys here who tells opposite, are just joking!

For members with IQ > 10 erm... we have to thik about... it may work maybe???

Just to be clear: Yes, if you have some particular codec and want to do some particular changes, it might be possible (in some case), but... that's another thread and needs IQ > 20

Posted by: Legolas Apr 5 2003, 07:12 PM

Yes indeed, I have ever a 200 Kbits/s divx bitrate and I enforce the same bitrate when I use the "Rotate" filter, so I don't have a loss of quality in the video stream (??!). But what is annoy me it is to loss 2 hours time in the 2nd code of this stream.
In the same time, a code of the WAV in MP3 take how much time ?

Thks

Legolas

Posted by: Kippesoep Apr 6 2003, 10:54 AM

QUOTE (Legolas @ Apr 5 2003, 08:12 PM)

Yes indeed, I have ever a 200 Kbits/s divx bitrate and I enforce the same bitrate when I use the "Rotate" filter, so I don't have a loss of quality in the video stream (??!).

You will have a loss in quality. Quite a significant one, too, as the bitrate is so low.