25fps-source Ac3 to 23.976fps

[Lastman369]

Hi guys!

My problem is the following:

I have the same movie in 2 different versions: a 23.976fps H.264 one with English audio, and a 25fps Xvid one with Hungarian audio. What I'd like to do is adding the Hungarian audio stream to the 23.976fps .mkv file.

Until I had Windows reinstalled on my PC, I could do it more or less using BeHappy and MeGUI: I loaded the Hungarian Ac3 file into Behappy, set the stretch ratio (app. 95,904% (equals 23.976/25) -like HERE), then saved the Avisynth script. I loaded the avs script into Megui, chose Aften encoding settings and it worked for me almost* perfectly. However, now that I try to do it after having Windows reinstalled, something goes wrong. For instance the input file is 6355s long, but output file is 6626s instead of 6710s. What can be the problem?

*The method I mentioned above worked for me, but the 6CH Ac3 was downmixed to 2CH, which I did not want.


So, my real question is: How can I slow down my 25fps Ac3 audio to 23.976fps without downmixing from surround to stereo?


(It might have already been asked several times, but after reading a few similar topics I still don't know how to do it.)

[jagabo]

Mux the two tracks you want with MkvMerge GUI. Before saving, highlight the video track, go to Format Specific Options and set the FPS. That may be enough to sync your audio and video.

[Lastman369]

Thanks man, but that's not what I want:
1) If I change video framerate, then the English audio (which I want to keep aswell) will be out of synch.
2) I want to reencode the 25fps audio, so that I don't have to stretch it in MKVMerge GUI. I mean, if I stretch it by 25000/23976 in MKVMerge GUi, it might play OK, but when I demux it, it won't have the same lenght as the video stream.

[poisondeathray]

eac3to

eac3to input.ac3 output.ac3 -slowdown

[jagabo]

You can sync the audio by adjusting the video or the audio. Doing what I said in MkvMerge will not require any reencoding.

[Lastman369]

You can sync the audio by adjusting the video or the audio. Doing what I said in MkvMerge will not require any reencoding.

Yeah, but I'd prefer reencoding instead of that. I want real 23.976fps AC3 audio, not the original 25fps stretched to 23.976 only in the MKV container.

[Lastman369]

eac3to

eac3to input.ac3 output.ac3 -slowdown

I've already seen this in other topics, but couldn't figure out how to use it. Could you give me a longer explanation? I don't even know where to write it. I'm not familiar with command line mode at all, tbh..

[poisondeathray]

You're using the wrong ratio. It's not 23.976 - that's only an approximation. The precise value is 24000/1001. That's likely why your audio length is incorrect

Use eac3to if you want to re-encode. It's just a command line. Type start menu => run => "cmd" . Once the command box is open, type cd.. and enter a few times until you reach the root directory "C:"

Put all the items in the root directory C: to make it easier, then type the command posted earlier (change filenames to match)

There is a GUI for eac3to, but you have to setup the filepaths, and it's pretty convoluted. If you can't figure it out after a while, I'll try to help. Honestly command line is much easier (and I don't like using command line apps...)

Another option is besweet, some people use it for these types of conversions

EDIT: here is an old post illustrating the GUI usage for a different conversion. Follow the instructions for the setup, but for step 6 use AC3 instead of "wavs", and for step 6.5, choose the "slowdown" option from the "Resample/PAL Speed" dropdown menu (not numbered in the screenshot)

https://forum.videohelp.com/topic363308.html

[Lastman369]

Thanks a lot. It's still working on it:


I'll try that other way if the output is still wrong.

(I guess I should have set some lower bitrate, it's incredibly slow )

[fits79]

Hi i have the same problem and i can't speedown the 25fps to 23.976fps ac3 sound.
Here is the problem that eac3to bring me and doesn't do anything.


I try with tsmuxer, mkvtoolnix, clown vd 0.7.5 and NONE of these prgs does the speedown fps from 25 to 23.976

I try even manually with eac3to to change it and the results it is to sound like a broken tape very slow

And another thing is happened after the change of fps the source file it is 236mb and the target final file is 862mb
The time of the source file is 1.26.00 as you see in the above picture and the final target file is 4:29:00
Why is that happened guys?

PLEASE HELP ME.

[poisondeathray]

The filesize is determined by bitrate

Filesize = bitrate x running time

So instead of 448kbps, use 192kbps

If it's not working for you, try besweet

[fits79]

why i change the filesize - bitrate? i don't want to change the resolution of the audio only to make it from 25 to 23.976 fps

[B2K24]

Here is how you fix the problem


you can use delay cut to get pal audio in sync with ntsc video

play the video file with VLC player and by default the J and K keys on keyboard apply a positive or negative delay in MS by 50 to audio.

adjust until you get perfect sync then note the difference. For example lets say -2000 MS

Next you need a program called Delaycut open the audio file with Delaycut and put -2000 into delay column start box
leave crc errors to silence and hit process.

Remux fixed ac3 to MKV

[AlanHK]

Here is how you fix the problem


you can use delay cut to get pal audio in sync with ntsc video

What?
I don't think so -- Delaycut does not change the speed of the audio, it just cuts it. You use it to correct delays, not frame rate changes

What you actually need is AudioScale, which can stretch or compress AC3 to a specified duration.

I attach that here, as it's hard to find: audioscale.zip

[fits79]

B2K24 this is a different way i want to automized or manual slowdown or speedup the audio that is 25fps to 23.976 or i want to speedup the 23.976 video to 25 so all the sounds and videos are sycronized perfectly without neet to listen and mark the correct spot e.t.c.


Is there any program that make an ac3 or dts file from 25fps to 23.976fps with success or not?
Is there any program that i can see dvd structure and which files is the main movie and which the extra's?

A LOT OF THANKS.

[johns0]

Load the file into eac3togui through the add source tab.Then switch to the Eac3toaudio tab.
1.Click on the pulldown tab and select the file you just added.
2.Give the file a name.
3.Select the type of audio file you want.(ac3)
4.Choose the bitrate you want,if you dont select anything it will output 640 by default.
5.Select the slowdown 25->24/1.001 for pal to ntsc conversion.
6.Click on Run Command Line tab to start the conversion.

[fits79]

I already do that and when i "Run Command Line tab to start the conversion"
it doesn't do anything at all maybe because the eac3to and all others program makes fault look the pictures above.

And tell me please one program that tell us information that about what is every file in a blu-ray and dvd movies.
A lot of thanks.

[johns0]

Theres something wrong in your setup or audio file,have you tried another audio file to see if it will convert?Also check to see if all the program paths are there such as the eac3to in the path/source tab.

[B2K24]

Here is how you fix the problem


you can use delay cut to get pal audio in sync with ntsc video

What?
I don't think so -- Delaycut does not change the speed of the audio, it just cuts it. You use it to correct delays, not frame rate changes

What you actually need is AudioScale, which can stretch or compress AC3 to a specified duration.

My solution will indeed solve the problem without re-encoding the audio, shrinking, stretching, etc.
I have done it myself with PAL Star wars HDTV broadcasts with 2.0 AC3 audio.
I ripped the 5.1 channel AC3 from my NTSC DVD boxsets merged it to a MKV then played it with VLC player.
Using J or K keys on keyboard you can get everything in 100% sync then note the amount of MS VLC displays.

You have the option of trying what i say before you disregard it, or keep downloading programs that screw the audio over re-encoding it for no reason at all for such a minor time delay in MS.

[manono]

My solution will indeed solve the problem without re-encoding the audio, shrinking, stretching, etc.
I have done it myself with PAL Star wars HDTV broadcasts with 2.0 AC3 audio.

Nice try but your PAL TV broadcasts were, except for the delay involved, converted from film by field blending, keeping the length the same. The OP has sources one of which has PAL speed up and is roughly 4% shorter than the NTSC version and your method plainly won't work.

You have the option of trying what i say before you disregard it, or keep downloading programs that screw the audio over re-encoding it for no reason at all for such a minor time delay in MS.

Minor time delay? Is a roughly 4 minute difference in a 100 minute movie 'minor'? You're talking about something completely different. Be careful who you insult when you don't know what you're talking about. The audio has to be reencoded.

Me, I use BeSweet to get the WAV files with the time difference corrected, followed by reencoding to AC3 audio.

[fits79]

Here is how you fix the problem


you can use delay cut to get pal audio in sync with ntsc video

What?
I don't think so -- Delaycut does not change the speed of the audio, it just cuts it. You use it to correct delays, not frame rate changes

What you actually need is AudioScale, which can stretch or compress AC3 to a specified duration.

My solution will indeed solve the problem without re-encoding the audio, shrinking, stretching, etc.
I have done it myself with PAL Star wars HDTV broadcasts with 2.0 AC3 audio.
I ripped the 5.1 channel AC3 from my NTSC DVD boxsets merged it to a MKV then played it with VLC player.
Using J or K keys on keyboard you can get everything in 100% sync then note the amount of MS VLC displays.

You have the option of trying what i say before you disregard it, or keep downloading programs that screw the audio over re-encoding it for no reason at all for such a minor time delay in MS.

But never i say that your way doesn't work i just say that is more difficult - trouble because you must see the movie and you do the limits of begin and end of the dialogs e.t.c.

[AlanHK]

Here is how you fix the problem


you can use delay cut to get pal audio in sync with ntsc video

What?
I don't think so -- Delaycut does not change the speed of the audio, it just cuts it. You use it to correct delays, not frame rate changes

What you actually need is AudioScale, which can stretch or compress AC3 to a specified duration.

My solution will indeed solve the problem

No it won't.
You're solving the wrong problem.
It's not a DELAY, it's a different RATE.

[AlanHK]

i want to automized or manual slowdown or speedup the audio that is 25fps to 23.976

Apparently I wasted my time posting a utility that does exactly that.

You have the option of trying what i say before you disregard it

But never i say that your way doesn't work

You should, because it won't.

[fits79]

Do exactly that but with much trouble because you must see all the movies and add the limits of each movie by yourself.

A lot of thanks for the prg you add but i can't - don't want to use a program like that.

[AlanHK]

Do exactly that but with much trouble because you must see all the movies and add the limits of each movie by yourself.

A lot of thanks for the prg you add but i can't - don't want to use a program like that.

All you have to do is open an AC3, put in the new length in seconds and it will be stretched/compressed to fit.

If that's too hard, I give up.

[fits79]

I want to downconvert an ac3 file

From 25fps to 23.976 so i add it to one mkvfile with 23.976fps audio and video.
Can you tell me how exactly i do it?
I try eac3to but the result ac3 file isn't syncronized with my 23.976 mkv file.

A lot of thanks.

[manono]

I try eac3to but the result ac3 file isn't syncronized with my 23.976 mkv file.

Does it get worse as the movie goes along or is it off by the same amount all the way through?

It's very possible that the 2 audios you have are from 2 different cuts/edits of the film, in which case you're screwed. If it's off by the same amount all the way through, though, the fix could be as simple as setting a delay to bring them back into synch.

[fits79]

Yeah.
But is there a light program(Not like kmplayer) that i can play the movie and sound of one mkv file in different times so i find out how many milliseconds i must speed up or slow down the sound?
And is there any other program exept eac3to that i can slowdown one ac3 file with 25fps to 23.976fps?

A LOT OF THANKS.

[manono]

But is there a light program(Not like kmplayer) that i can play the movie and sound of one mkv file in different times so i find out how many milliseconds i must speed up or slow down the sound?.

I use Media Player Classic Home Cinema. Use the +/- keys on the keyboard to adjust the delay on the fly. Once you've figured out the delay (if that's really the problem), use DelayCut to remove the delay.

And is there any other program exept eac3to that i can slowdown one ac3 file with 25fps to 23.976fps?

As I mentioned earlier, I think, I use BeSweet to slow it and get a WAV file. Then you need an AC3 encoder like Aften (free) or Soft Encode (not free). There's nothing wrong with eac3to and its GUI, though.

[fits79]

I alrady have the media player classic home cinema 1.3.1264.0 but with +/- it doesn't adjust the audio on the fly.
Do i do something wrong?

And the delaycut what exactly do?
If i put like input the audio i want to add to the mkv file and as target the ac3 or dts that the mkv already has inside it tell me which is the exactly ms that it must adjust to the new audio i want to add in the mkv file?

A lot of thanks.