shift video to audio synch with another source

[buddha9]

PHP Code:

path="..."
pathDGD="..."
filename1="...mkv"
filename2="...mkv"

##################################################

LoadPlugin(pathDGD+"dgdecode.dll")

clip1 = FFmpegSource2(path+filename1)
clip2 = FFmpegSource2(path+filename2)

StackHorizontal(clip1, clip2) 


Hi, how can I add a frame offset (Ex.: 5245 from frame 0) to the clip2 ?
Thanks!

[tebasuna51]

Originally Posted by buddha9

LoadPlugin(pathDGD+"dgdecode.dll") # Not used, you need ffms2.dll

clip1 = FFmpegSource2(path+filename1)
clip2 = FFmpegSource2(path+filename2).Trim(5245,0)

StackHorizontal(clip1, clip2)

Maybe a trim()?

[buddha9]

Originally Posted by tebasuna51

Maybe a trim()?

Thanks for quick reply
I need add a +5245 (positive shift) offset frames/milliseconds to the clipv2

And what about need to -3520 (negative shift) offset frames/milliseconds? Does trim support negative values?

How can I do? Has Trim function this parameter?

[VoodooFX]

Be aware that you desync with audio by "shifting" video frames:

PHP Code:

clip1 = FFmpegSource2(path+filename1)
clip2 = FFmpegSource2(path+filename2)

blank = BlankClip(clip2, length=5245)
clip2_shifted = blank + clip2

StackHorizontal(clip1, clip2_shifted) 


[buddha9]

Originally Posted by VoodooFX

Be aware that you desync with audio by "shifting" video frames:

PHP Code:

clip1 = FFmpegSource2(path+filename1)
clip2 = FFmpegSource2(path+filename2)

blank = BlankClip(clip2, length=5245)
clip2_shifted = blank + clip2

StackHorizontal(clip1, clip2_shifted) 


on MKVToolNix GUI there is this option



You can insert positive/negative millisecond values for a video/audio track.

I need something like that on AVS+

Is there any addons?

Thanks

Trim and BlankClip aren't not good for my needs

[VoodooFX]

Originally Posted by buddha9

Trim and BlankClip aren't not good for my needs

It does what you described.
Why it's not good?

[buddha9]

Originally Posted by VoodooFX

It does what you described.
Why it's not good?

I need possibility to shift forward/backward (specifying frames or milliseconds) video (w/o audio desynch)

It wolud be nice to have something like this

clip1 = FFmpegSource2(path+filename1)
clip2 = FFmpegSource2(path+filename2)

StackHorizontal(clip1, clip2.offset(type="frames", n="5344")) # or other possibility --> .offset(type="ms", n="-2345")

[poisondeathray]

Originally Posted by buddha9

I need possibility to shift forward/backward (specifying frames or milliseconds) video (w/o audio desynch)

It wolud be nice to have something like this

eg.

StackHorizontal(clip1, clip2.offset(5344) )

function Offset(clip c, int "frames")
{
frames   = Default(frames, 0)
c1=BlankClip(c,length=frames)+c
return c1
}

[buddha9]

Originally Posted by poisondeathray

eg.
StackHorizontal(clip1, clip2.offset(5344) )

function Offset(clip c, int "frames")
{
frames   = Default(frames, 0)
c1=BlankClip(c,length=frames)+c
return c1
}

Thanks poisondeathray!
does it work with a negative need?

[VoodooFX]

Originally Posted by buddha9

I need possibility to shift forward/backward (specifying frames or milliseconds) video (w/o audio desynch)

Sorry but that doesn't make sense.
And of course MKVToolNix doesn't do such nonsense.

[buddha9]

Originally Posted by VoodooFX

Sorry but that doesn't make sense.

Example:

You have a movie (OPEN MATTE version). [vid1]
You have also the same movie but "standard" version. [vid2]

These 2 are from different sources. Vid1 from HDTV, vid2 from DVD.

Same FPS but the "real" movie (on vid2) starts after some milliseconds comparing with first version [vid1]

You can play with Audacity. But my solution (with AVS+) is more "visual"

PHP Code:

path1="I:\_WIP\path1"
filename1="file1.mkv"
path2="I:\_WIP\path2"
filename2="file2.avi"

clipv1 = FFmpegSource2(path1+filename1)
clipa1 = FFAudioSource(path1+filename1)

clipv2 = FFmpegSource2(path2+filename2)
clipa2 = FFAudioSource(path2+filename2)

clipt1= AudioDub(clipv1,clipa1)
clipt2= AudioDub(clipv2,clipa2)

StackHorizontal(Waveform(clipt1, window=5, height=0.333, zoom=5.0, under=false, smooth=true, aa=true), \
Waveform(clipt2.BilinearResize(968,720), window=5, height=0.333, zoom=5.0, under=false, smooth=true, aa=true)) 


[poisondeathray]

Originally Posted by buddha9

Thanks poisondeathray!
does it work with a negative need?

It appears to work ok, but it's pretty easy for you to test it

[buddha9]

Originally Posted by poisondeathray

It appears to work ok, but it's pretty easy for you to test it

PHP Code:

...

StackHorizontal(Waveform(clipt1, window=4, height=0.333, zoom=5.0, under=false, smooth=true, aa=true), Waveform(clipt2.BilinearResize(968,720).Offset(-5200), window=4, height=0.333, zoom=5.0, under=false, smooth=true, aa=true))


function Offset(clip c, int "frames")
{
frames   = Default(frames, 0)
c1=BlankClip(c,length=frames)+c
return c1
}

... 


It does work with positive and negative frames.
Thanks so much!

Ps
maybe do you have also a version with milliseconds?

[VoodooFX]

Originally Posted by buddha9

Same FPS but the "real" movie (on vid2) starts after some milliseconds comparing with first version [vid1]

Then we back again, why Trim and BlankClip is not good for you?

[poisondeathray]

Originally Posted by buddha9

Ps
maybe do you have also a version with milliseconds?

Not really possible for ms accuracy because video "frames" have a quantized ms duration. eg. a "23.976p" film source would have about 41.708 ms duration per frame. You cannot have something like a quarter frame

[buddha9]

Originally Posted by poisondeathray

Not really possible for ms accuracy because video "frames" have a quantized ms duration. eg. a "23.976p" film source would have about 41.708 ms duration per frame. You cannot have something like a quarter frame

Ok no problem.
I calculate ms (difference btw 2 points on timeline) with help of AVS+ status bar
Thans so much for support!

PHP Code:

# film 1
path1="I:\_WIP\path1\"
filename1="file1.mkv"
clipv1 = FFmpegSource2(path1+filename1)
clipa1 = FFAudioSource(path1+filename1)
src1w=Width(clipv1)
src1h=Height(clipv1)
clipt1= AudioDub(clipv1,clipa1)

# film 2
path2="I:\_WIP\path2\"
filename2="file2.avi"
clipv2 = FFmpegSource2(path2+filename2)
clipa2 = FFAudioSource(path2+filename2)
clipt2= AudioDub(clipv2,clipa2)

# HorizontalStack
StackHorizontal(Waveform(clipt1.DelayAudio(-1.6), window=4, height=0.333, zoom=5.0, under=false, smooth=true, aa=true), Waveform(clipt2.BilinearResize(src1w,src1h).AssumeFPS(23.976,sync_audio=true).Offset(25).DelayAudio(0.18), window=4, height=0.333, zoom=5.0, under=false, smooth=true, aa=true))

# Thanks to poisondeathray
function Offset(clip c, int "frames")
{
frames   = Default(frames, 0)
c1=BlankClip(c,length=frames)+c
return c1
} 


[VoodooFX]

So, in the end BlankClip IS good.

[StainlessS]

Nifty Offset() function PDR.
Possibility of 0 or -ve Length not mentioned on Wiki.

Some time ago, Pinterf [EDIT: qyot27] was gonna throw error (I think) on BlankClip(Length=0), because it caused some problem if not used correctly.
I was a bit miffed about it (I used Length=0 in some scripts), but accepted decision to make it illegal, but then
I think he changed his mind and accepted as legal again.

Looks like he also allowed for -ve length [as your Offset() func works], maybe could do with a mention of it on wiki.
[Dont know if Length=-ve also accepted in v2.60 Std or v2.58.]

EDIT: I think the problem with allowing 0 length clip was the possibility of trying to display a zero length clip in VDub/Player
which caused some kind of exception/illegal instruction. [but only if used incorrectly, ie trying to show a 0 len clip]

BlankClip on Wiki:- http://avisynth.nl/index.php/BlankClip

[poisondeathray]

Originally Posted by StainlessS

Nifty Offset() function PDR.
Possibility of 0 or -ve Length not mentioned on Wiki.

Honestly I had no idea (-) would work. I just wrapped VoodooFX's suggestion into a helper function. ( "Wrapped" because some people like presents to be wrapped this time of year )

Some time ago, Pinterf was gonna throw error (I think) on BlankClip(Length=0), because it caused some problem if not used correctly.
I was a bit miffed about it (I used Length=0 in some scripts), but accepted decision to make it illegal, but then
I think he changed his mind and accepted as legal again.

Probably this
https://github.com/AviSynth/AviSynth...aa2621d4b333a8

EDIT: I think the problem with allowing 0 length clip was the possibility of trying to display a zero length clip in VDub/Player
which caused some kind of exception/illegal instruction. [but only if used incorrectly, ie trying to show a 0 len clip]

BlankClip on Wiki:- http://avisynth.nl/index.php/BlankClip

I think zero total frames still throws an error in some programs - but when total number of frames is not zero - programs don't seem complain.

a=colorbars().trim(0,9).showframenumber() #10 total frames

#a.offset(-9) #works; 1 total frame

#a.offset(-10) #zero frames
# error message in avspmod about display_pitch, but still usable , can edit script, open other videos
# vdub2 doesn't crash , still usable, can open other scripts/videos
# mpchc doesn't crash, still usable, can open other vids/scripts

Or can you suggest a better way of handling it ? It seems ok to me

[StainlessS]

by ssS

Some time ago, Pinterf was gonna throw error

Actually qyot27.

by PDR

Probably this

Yep, and this is the point where Length=0 was initially (temporarily) made illegal
https://github.com/AviSynth/AviSynth...eee829223d1d54

Avisynth Developement thread, post about illegal Length=0,
https://forum.doom9.org/showthread.p...58#post1986258

And a thread from about same time as above changes about Length=0, actually using Length=0 example.
https://forum.doom9.org/showthread.p...D0#post1986352

Post in avs/devs where qyot27 got a bit spooked by the Length=0 whotsit

Originally Posted by qyot27

This. FFmpeg reads video and audio packets separately, and if either reaches EOF, it attempts to read the other one before exiting, because it is easily possible - and not a bug - that either video or audio might be longer than the other, and it shouldn't be truncated.

The error is that length=0 is treated by BlankClip as somehow valid when it isn't, and ends up creating an audio stream of infinite length, which FFmpeg then attempts to read/output. Forcing an output length via the -t parameter would probably demonstrate that it is indeed attempting to write an ever-increasing number of audio samples, until the process is killed.

Post in avs/devs where qyot27 reverted from the illegal Length=0 thingy.

Originally Posted by qyot27

There happened to be some stuff concerning general timestamps/duration/framecount in FFmpeg during April (and coincidentally after the no zero-length clips commit on our side), and if I had to guess, those commits addressed this from FFmpeg's side without ever touching the AviSynth demuxer, since a reverted version of AviSynth+ no longer seems to trip anything with a script consisting of just BlankClip(length=0) (ffplay doesn't reject it as empty, but that's probably just ffplay being ffplay; it doesn't close regular videos when they finish).

So tentatively, it's been reverted. If it re-emerges, though, it will have to be addressed. Memory overflows are not something I'm willing to roll the dice with just because there's useful edge cases.

by PDR

Or can you suggest a better way of handling it ? It seems ok to me

Seems ok to me tooooo.