Change yuv individual pixel colour

[coolgit]

Is there a function/plugin that can change pixel with luma 17 to 16.

I got the hex numbers and loaded up an mp4 file with a hex software then replace 17 with 16.

When i checked with ColorYUV(analyze=true), both original and new file, it didn't work. Apparently it changed another colour but i don't know which.

tara

[Reel.Deel]

This mt_lut("x 17 == 16 x ?", u=2, v=2) or Expr("x 17 == 16 x ?", "") will change luma pixels with a value of 17 to 16. Chroma is copied.

[wonkey_monkey]

I got the hex numbers and loaded up an mp4 file with a hex software then replace 17 with 16.

The data in an .mp4 is compressed and won't bear any direct relation to pixel values. Changing bytes directly like that is likely to corrupt the file.

[coolgit]

Originally Posted by Reel.Deel

This mt_lut("x 17 == 16 x ?", u=2, v=2) or Expr("x 17 == 16 x ?", "") will change luma pixels with a value of 17 to 16. Chroma is copied.

Wow for that. I will try both to see which is faster.

[coolgit]

Originally Posted by wonkey_monkey

The data in an .mp4 is compressed and won't bear any direct relation to pixel values. Changing bytes directly like that is likely to corrupt the file.

Well i luckily didn't get a corrupt file but one pixel colour did change to another but no idea which. It's a pity as Hex editor was super super fast.

[Reel.Deel]

Originally Posted by coolgit

Wow for that. I will try both to see which is faster.

From my experience, on 8-bit, mt_lut is almost always faster than expr.

[coolgit]

Originally Posted by Reel.Deel

From my experience, on 8-bit, mt_lut is almost always faster than expr.

40 minutes video... expr 7 seconds faster. Not enough difference to fuss about really.

[Reel.Deel]

Originally Posted by coolgit

40 minutes video... expr 7 seconds faster. Not enough difference to fuss about really.

Interesting. With ColorBarsHD() as the source, I get 850fps with Expr and 1200 with mt_lut. I don't have an AVX2 capable processor. But yes, it does not make a difference once the encoder gets involved

[wonkey_monkey]

I find mt_lut to be 30% quicker single-threaded, but expr is 30% quicker using prefetch.

[Reel.Deel]

Using Prefetch(4) I get 2840fps with mt_lut and 2680 with Expr. With Prefetch(6), Expr is slightly faster (3480 vs 3450) and both about 50% cpu usage.

[StainlessS]

RD,
hows bout with

ColorBarsHD()
Loop()           # play the clip (almost) endlessly.
Prefetch(4)      # or not

(not sure if that speeds it up or not)
I aint got Avisynth installed at the moment.

[Reel.Deel]

Originally Posted by StainlessS

RD,
hows bout with

ColorBarsHD()
Loop()           # play the clip (almost) endlessly.
Prefetch(4)      # or not

(not sure if that speeds it up or not)
I aint got Avisynth installed at the moment.

I get 381839fps with that script. In AviSynth+ the ColorBar filters have a "staticframes" parameter, true by default so it only generates one frame and the rest are copied.

[StainlessS]

OOps, I forgot to insert the the mt_lut() and Expr() bits.

[Reel.Deel]

Originally Posted by StainlessS

OOps, I forgot to insert the the mt_lut() and Expr() bits.

I used Loop when testing with Prefetch in post #10, only because without it, it finishes too fast.

[StainlessS]

Makes sense.
I'm off to bed, 19:45 and I did not get to bed last night ZZZZzzzzz.....

[kedautinh12]

Yeah, you need sleep to charge, Staindroid

[StainlessS]

Sleep is for wimps.

(I somtimes have to wimp out - or pass out)

[kolak]

Originally Posted by coolgit

Is there a function/plugin that can change pixel with luma 17 to 16.

I got the hex numbers and loaded up an mp4 file with a hex software then replace 17 with 16.

When i checked with ColorYUV(analyze=true), both original and new file, it didn't work. Apparently it changed another colour but i don't know which.

tara

Are you trying to make file legal ?