mp4 file

[Myouh]

Now I have a mp4 video.
I want to modify the brightness/contrast of this video, without changing anything else.

what are the different ways to achieve that?

(it's of course impossible to open it with Vdub, and even if it were possible, I would have to recompress it (uncompressed or lossless codec), and I said I don't want to change anything except the brightness and contrast.)

[Zarxrax]

Changes like that should be made before you encode the video, as reencoding introduces crappiness.

FFDshow will let you adjust settings like that on playback.

[NeoQuixotic]

If you're playing any H.264 content using Quicktime, it always looks lighter than it should. It is a known issue with Quicktime that Apple has know for years and done nothing about. Avoid playing things in Quicktime because of this, and it's stupidly inefficient decoding among other things.

Anyways, most players will have adjustments of sorts. Check the options or the help file to see what it can control.

[Myouh]

here's what I did:
In VirtualDubmod, I clicked "file", then "open video file via AviSynth", that as you must know is enough to create a AviSynth script file with the instruction:
AVISource("C:\...........................")

now would you explain to me Zarxrax, or anyone else, why doesn't Zarx264gui accept that script as "input video"?
it's a AVI file, not MPEG here, so what's the matter?

[The Origonal Head Hunter]

From what I've heard, that option in VDM is glitchy and doesn't really work. It's probably best to create the avs file manually.

[Myouh]

ok, can you, or someone, tell me how to create a very simple AviSynth script, with just an instruction to open the AVI file of course, and instructions to modify the brightness and contrast, I will try then to use this one in Zarx264gui.

(I thought to create a AviSynth script one had to write the instuctions on any text editor and save the file with the extension .avs)

[Myouh]

I've solved one problem.
I had to write:
AVISource("C:\...................avi").ConvertToYV12()

.ConvertToYV12() missing was the reason why Zarx264gui didn't accept my scripts.

now I need the instructions to modify the brightness and contrast.
can someone help me with those, and tell me if they should be written before or after the first instruction.

[Myouh]

I succeeded.
I always post a problem and end up sovling 80% of it myself.
Thanks everyone, anyway.

[ArashiKurobara]

Ah, I didn't realize that Zarx364gui needed YV12 input. I'd actually been having that exact same input issue (and I'd been typing my AVISynth scripts by hand. =P).