Best method for time lapse video

[jairovital]

In the version of AviSynth I have TimeStreth's tempo parameter is percent. Ie, tempo=10 makes the tempo 1/10 of the original (very slow). If you want it twice as fast you specify tempo=200. 10 times as fast, tempo=1000.

Yes, jagabo. I saw it.

@Gavino.
I had considered this whole thread solved before test your example. But now, putting it on the desk, your example has no sound at all.
What is wrong here?

v1=DirectShowSource("D:\work\test1.mp4")

#v=ffmpegsource2("D:\work\test1.mp4", atrack=-1)

#v = FFVideoSource("D:\work\test1.mp4", atrack=-1)
#selectevery(last, 2)

#selectrangeevery(v, 5, 1, audio=true)

v=SelectEvery(v1, 10).AssumeFPS(v1)
a=TimeStretch(v1, tempo=500)

#a = FFAudioSource("D:\work\test1.mp4")

#AssumeFPS(30000,1001)

AudioDub(v,a)

P.S.: And, with some situations, AvsPmod crashed miserably...

[jairovital]

your example has no sound at all.

Shame on me...


My kid had turned off my speaker...

Sorry, guys. It's all fine.

[Gavino]

In the version of AviSynth I have TimeStreth's tempo parameter is percent. Ie, tempo=10 makes the tempo 1/10 of the original (very slow). If you want it twice as fast you specify tempo=200. 10 times as fast, tempo=1000.

Yes, my mistake - I meant 1000.

I had considered this whole thread solved before test your example. But now, putting it on the desk, your example has no sound at all.

P.S.: And, with some situations, AvsPmod crashed miserably...

I tried your example code and it worked OK (used AvsP to launch MPC as a player).

What are you using to play the script?
You could try adding ConvertAudioTo16Bit() at the end.
TimeStretch delivers float audio, which some players might not like, but the Avisynth VfW interface converts this to 16 bit anyway, so it shouldn't make a difference unless the player is using the Avisynth API directly.

EDIT: Ah, I see it was a false alarm. I'll leave the info there as it might be useful in future searches about TimeStretch().

[jairovital]

Yes, my friends, this long walk didn't reach its end...
I keep creating challenges, trying to make different scripts to better understand that infinite thing called avisynth.
For the most of you, of course, the end is nearby, but for me... journey just began.
Maybe I'm asking basic lessons, but it's because I already searched and tried too much and could not find an answer.

So, how to make a script to get some normal pieces of the same video and put inside it a speedup one? Let's say:
1 - normal speed
2 - normal speed
3 - fast
4 - normal speed
And keep the corresponding audios?

I'm trying something like this:

v1=DirectShowSource("D:\work\test1.mp4")

v2=trim(v1, 120, 180)
v3=trim(v1, 1860, 2160)
v4=trim(v1, 3000, 4049)
v5=trim(v1, 4050, 8460)

a2=AudioTrim(v1, 120, 180)
a3=AudioTrim(v1, 1860, 2160)

v6=SelectEvery(v5, 5).AssumeFPS(v5)
a=TimeStretch(v5, tempo=500)

v=v2+v3+v4+v5+v6
a=a2+a3+a4+a5+a6

AudioDub(v,a)
ConvertAudioTo16bit()

AudioTrim is documented, but it always say "no function named AudioTrim". My Avisynth was alpha2, but I updated to alpha3 (september, 2011). The lack of the function remains.

At page of Trim, it states:
Prior to v2.60, to trim an audio-only clip, you may not just set a fake frame rate with AssumeFPS. Instead, you must make a BlankClip, use AudioDub, trim that, and then KillVideo. Otherwise, AviSynth makes an error message "cannot trim if there is no video".

I'm not sure how to use Audiodub, if it can be used twice...
And about concatenate audio like a1+a2...
Confused...
Scratching the head...

Any help?

[Gavino]

There is no need to separate out the video and audio.
Just do this:

v1=DirectShowSource("D:\work\test1.mp4")

v2=trim(v1, 120, 180)
v3=trim(v1, 1860, 2160)
v4=trim(v1, 3000, 4049)
v5=trim(v1, 4050, 8460)

v6=SelectEvery(v5, 5).AssumeFPS(v5)
v6=TimeStretch(v6, tempo=500).ConvertAudioTo16bit()

return v2+v3+v4+v5+v6

AudioTrim is not yet available in the released version, although it has been documented in the wiki.

[jairovital]

There is no need to separate out the video and audio.
Just do this:

No. There are some problems when reaches the fast segment. It plays at normal speed and the audio is also weird, may be slower than it would be. Make a test for yourself.

[jagabo]

Gavino's script works fine here (on a random AVI file). DirectShowSource() may be your problem. Was it your intent to repeat section 5? Once at normal speed, once at 5x?

[jairovital]

Holy jagabo! Yes! My mistake again!
Section 5 must stay out of v1+v2...

return v2+v3+v4+v6

Not v5!

I confess I try, but programming is not my talent...

[jairovital]

Hey, folks, it's show time!
A little bonus for those who had patience to go so far, a sample of our hard work.

Some crazy dude will explain to us how it can be done.

Some parts speedup, others not.

Enjoy.