Easy tool to change audio fps

[davidbowie]

Hello, I'm new here and I want some suggestions from you guys here how to change an audio file (DTS, AC3 or AAC) to 23.976 fps.

I've lot of 29 and mostly 25 fps mkv files. I'm using txmuxer and Mkvmerger/extract to rip the audio stream and want to merge them to a 1080p mkv file, most of them are 23.976 fps. Ofcourse, if I have found a high quality mkv file which is 25 fps, I need to change the 23.976 audio to 25 fps.

After googling I have read the besweet and eac3to are the most popular tools which I can change the audio framerate. I've tried both while ago, eac3to doesnt work at some way and the commandline method is 'too difficult' for me.

If was looking for a eac3to gui, but I've found several of them, but don't know which one is good and do they offer the change framerate option.

As for besweet I also don't know what problem I've got. Just cant have that correctly installed.

And if both audio streams are the same length with different fps (is it possible??). Is there anything I need to do to synchronise when merging?

Any suggestion is welcome.

I'm using Win7 X64 Ultimate.

[manono]

And if both audio streams are the same length with different fps (is it possible??)

Not only possible but quite common. If they're the same length, then nothing has to be done as far as stretching the audio.

But I use BeSweet for changing 25fps to 23.976fps. I don't know why you can't get it to work. Once you define the path to the BeSweet.exe file, it's pretty easy. Maybe try the BeLight GUI for it instead.

eac3to can do it easily also. Why would one GUI be better than another if they both use the same underlying eac3to. Just pick one and try it out. I think they can all do the audio stretching.

Oh, and audio doesn't really have an FPS. It may be attached to a video with an FPS, but it works on length. Before changing an audio's length, make sure it really needs changing.

[davidbowie]

And if both audio streams are the same length with different fps (is it possible??)

Not only possible but quite common. If they're the same length, then nothing has to be done as far as stretching the audio.

Hm... I've tried to merge an audio stream to a mkv with diferent fps and adjust the delay in playing the audio stream. Result is that most of the attempt the audiostream is running smoothly in the beginning, but later in the movie it runs out of synch. So that's why I thought that the audiofile and videofile does have different length.

I will try belight in stead of besweet.

[blud7]

You can also do this easily in MeGUI.
From the Config button for audio, you can change the sample rate if you like.

[somespirit]

people, people i have suggestion, get starting speaking each other from 29.900 to 23.976 fps ..... hm ......am i clear

[blud7]

people, people i have suggestion, get starting speaking each other from 29.900 to 23.976 fps ..... hm ......am i clear

No, I don't know what you are asking. Do you have the same problem as the OP?

If you want to completely change the frame rate of audio+video and you don't want complicated options, try Handbrake for windows. See the video tab there? Select Constant Framerate and use the drop down box to select whatever framerate you want. Then tweak the video settings to what you want.



If you are like the OP and want to change the sample rate of the audio stream only, I was suggesting that you can use MeGUI.
1. Select the audio file
2. Select the audio codec (MPA, MP3 etc)
3. Click the config button.



Then the config Screen comes up:



Use the preset to change the audio sample rate.

[somespirit]

when you change audio from 29.97 to 23.97 then your audio will have pattern like - "boooooo moooooooo .................", you will hear playing your audio at slow motion speed

changing audio motion speed (or audio fps) is useless except you want to achieve some weird effect

[jagabo]

Changing video from 29.97 fps interlaced (telecined) to 23.976 fps progressive (ie, inverse telecine) doesn't require any change in the audio. It's pointless to talk about converting audio in this context.

[blud7]

Changing video from 29.97 fps interlaced (telecined) to 23.976 fps progressive (ie, inverse telecine) doesn't require any change in the audio. It's pointless to talk about converting audio in this context.

True, but he did ask.

[AlanHK]

Audio "frame rate" is nothing to do with the 24/25/29.97 video frame rate.
If you convert the video frame rate, you have to compress or stretch the audio proportionately. But maybe not even then if the video was changed by adding or deleting frames, keeping the time constant.

[turk690]

Audio "frame rate" is nothing to do with the 24/25/29.97 video frame rate.
If you convert the video frame rate, you have to compress or stretch the audio proportionately. But maybe not even then if the video was changed by adding or deleting frames, keeping the time constant.

Audio does have a frame rate, if you can say a sector is a frame as in the case of the original Red Book CDDA, then that is 75fps. But it's true, audio is never referred to with that, but instead by the form hh:mm: ss.msc when it's a file standing alone by itself or demuxed from whatever container that held it along with some video. Everyone here and their pet dragons will know that sample rate, bit depth, and number of channels suffice instead to describe any uncompressed audio file.
But when audio is linked or interleaved in a container with video (like a *.avi) then changing the framerate of that file will necessarily also change the length of the audio along with it if audio and video remained linked or together in that container.

I've lot of 29 and mostly 25 fps mkv files. I'm using txmuxer and Mkvmerger/extract to rip the audio stream and want to merge them to a 1080p mkv file, most of them are 23.976 fps. Ofcourse, if I have found a high quality mkv file which is 25 fps, I need to change the 23.976 audio to 25 fps.

A

1st, stop referring to audio with framerates or ascribing video framerates to them. If you want to mux an extracted audio stream or file (which basically doesn't know or care that it came from a 25fps or 30fps container) to some video just mux and see if it's in sync. But there's a minefield here, though. You need a full-fledged NLE to put the intended audio and video on a timeline to inspect, for one. In a majority of cases, the audio is correct; it just has a delay or a long or short lead-in. Trimming off ends and dragging the audio clip back and forth the timeline before exporting does the trick. If for some reason the audio is indeed longer or shorter then you'll have to stretch or compress it to match the video: never an easy thing to do, and can introduce artifacts. I use Audition CS2 for this; seems to introduce the least distortion among others when stretching or compressing the audio clip length must absolutely be done.

[jagabo]

But when audio is linked or interleaved in a container with video (like a *.avi) then changing the framerate of that file will necessarily also change the length of the audio along with it if audio and video remained linked or together in that container.

That's not true. Use AviFrate to change the frame rate of an AVI. The Audio will remain the original length and the two will become de-sync'd after a while. The audio will only stay sync'd if you use an editor that automatically adjust the audio length to match the new video length.

[davexnet]

I recently changed an AVI 24 fps video to 23.976. Although the 24 fps version, at first glance, plays
fine on my standalone player, none of the skip, fast forward/back play or time search functions work
at all. Similarly, a non-standard sample rate to get it to fit, may not be acceptable to all external
devices.

I usually use Sony Sound Forge (for two-channel), or Audacity (ac3 5/1, etc) to stretch the file rather
than mess with the sample rate.

In the file I mentioned above (24>23.96), I ended up making it about 3 seconds longer to make it fit.

[somespirit]

if you change audio in this way:




and if this is audio from movie, the actors in movie will start speaking slowly .......

Slow-down (25-23.976) - means changing the speed of talking

[ranosb]

The way I do this is demux the video & audio with Tsmuxer.
Then import the audio into Audacity and select effects/change tempo without changing pitch.
for changing PAL(25fps) to NTSC(23.976), enter -4.096% to adjust the audio.

Save and then convert the saved audio to your desired format ie (AC3/DTS/FLAC/DTS-MA).

Open Mkvtoolnix and import the audio and video and select the video & "Format specific options" tab and select FPS, 24000/1001, which is 23.976.

Then start muxing!

[somespirit]

adjust your mind please, audio has nothing common with speed of video frames .......

[S1m0n]

Hi all.

I use this instruction to: extract audio (avidemux _to ac3) - modify audio (BeSweet _25 fps to 23.976) - and put together (MKVtoolnix _FPS 23.976).

But still not synchronized audio and video.
Audio is slightly ahead and still growing i think.

I have: _Beowulf 2007 Directors Cut 1080p H264 AAC 5 1 2D-3D (HSBS) Bluray.mp4
And audio from: _Beowulf-cz-dubbing.avi

I check other threads too but there are similar instructions.

Any ideas what i am doing wrong ?

[manono]

Any ideas what i am doing wrong ?

1. You're trying to discuss copyrighted and illegally downloaded movies.
2. You're expecting audio from one source to magically line up with the video from a different source. Do they both have exactly the same frame count? No, I didn't think so.

[AlanHK]

I have: _Beowulf 2007 Directors Cut 1080p H264 AAC 5 1 2D-3D (HSBS) Bluray.mp4
And audio from: _Beowulf-cz-dubbing.avi

That's your problem.
Wherever the CZ version came from, its unlikely to be the director's cut.

So you can spend a few days with a video/audio editor to sync the dub scene by scene.
Some scenes my not be present at all in the dub.
I think it'd be better just to get CZ subtitles myself.

[S1m0n]

Thank you for answers.

AlanHK
That's your problem.
Wherever the CZ version came from, its unlikely to be the director's cut.

So you can spend a few days with a video/audio editor to sync the dub scene by scene.
Some scenes my not be present at all in the dub.
I think it'd be better just to get CZ subtitles myself.

AlanHK You are totally right !
I was blind.
I have different versions of video source we can say and different dubbing also.
I have to find cz dubbing for director cut and then should be ok.

manono
1. You're trying to discuss copyrighted and illegally downloaded movies.
2. You're expecting audio from one source to magically line up with the video from a different source. Do they both have exactly the same frame count? No, I didn't think so.

manono : 1.i have original blueray disc at home ordered from amazon and cz version i bought from local store. Copy is only for my own purpose. At my country it is not prohibited.


2.Now i understand that you wrote same thing like AlanHK after you. Am i right ? (:

[manono]

manono : 1.i have original blueray disc at home ordered from amazon and cz version i bought from local store. Copy is only for my own purpose. At my country it is not prohibited.

Really? It's very different where I am and in most of the world.

2.Now i understand that you wrote same thing like AlanHK after you. Am i right ? (:

Yes, this slowing the audio to film speed works only if source and destination are exactly the same, except for the framerate. Sometimes the only difference might be logos, in which case you slow the audio and adjust the delay. In many cases (including this one) you're using 2 different cuts of the film. It can still be done but, as AlanHK mentioned, not without many hours of work. I don't believe in using dub tracks either, except maybe for young children. Like AlanHK, I'd go with subtitles if you can find them in your language.