I've spent the last couple hours Googling this and I'm no closer to a solution than when I started.
I have some videos encoded at 25FPS. The sound is slightly too high pitched. I want to slow the videos down to 23.976FPS. I want to do this entirely via the command line so that I can write a script to automate process.
I know that I can change the framerate on the videos without re-encoding. I know that I need to re-encode the audio to match the new length of the video. However I don't want to simply change the audio length while preserving the pitch. I WANT the pitch to be slightly lower.
That last part is what I can't figure out.
I saw a few people suggesting the program BeSweet. So I downloaded BeSweet 1.5b31. When I run it, it prints a partial command summary, pops up a box telling me that it's a command line program and telling me to go to DSPguru.doom9.org to download a GUI for it, then it opens that adress in my browser when I click the OK button.
I was hoping that maybe that only came up if you typed BeSweet by itself, but nope, it comes up EVERY SINGLE TIME. It tells me that I should look in the help directory for more information, but that seems to be kind of a mess with no section geared toward just showing you the basic usage of BeSweet from a beginner's perspective.
I tried (based on something I saw);
BeSweet -r 25000 23976 -input INPUT.AC3 -output OUTPUT.AC3
Of course that didn't do anything at all (other than print the help message, open the message box and open Doom9 in my browser).
So what am I doing wrong?
What is the magic command line that will convert INPUT.AC3 to OUTPUT.AC3, and changing it from an original 25FPS to 23.976FPS with the appropriate change in pitch?
NOTE: Before anyone feels the need to correct me on the technical details, yes I know that audio doesn't actually have a framerate. Saying that, I've read messages indicating the BeSweet has options that will convert audio and do the equivalent of changing the framerate such that the length will be correct for the longer/slower video while also adjusting the pitch to be slightly lower.
Also note that I am completely clueless when it comes to bitrates, framerates, calculating them, choosing sample rates, etc. I normally just Google until I find a command line that I can use. I just know that if you slow down audio, the pitch goes down, so converting the videos from 25FPS to 23.976FPS seems like the way to fix them. Now I just need to know how to convert the audio to match the slower framerate of the video. Failing that, is there an easy way I can process the audio from the command line and lower the pitch without affecting the length?
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Something like this:
Code:BeSweet -core( -input in.AC3 -output out.AC3 ) -ota( -r 25000 23976 )
Last edited by davexnet; 9th Oct 2021 at 16:01.
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Code:
BeSweet -core( -input in.AC3 -output out.AC3 ) -ota( -r 25000 23976 )
It REQUIRES spaces after the parenthesis in order to function. In virtually every other program, spaces after parenthesis are optional.
Now I just need to figure out how to get it to create AC3 files.
Your command line produces an MP3 file with the AC3 extension. So does;
Code:BeSweet -core ( -input INPUT.AC3 -output OUTPUT.AC3 ) -ota ( -r 25000 23976 ) -bsn ( -exe aften.exe )
What am I doing wrong?
On the bright side, it seems to perfectly correct the length and pitch.
EDIT: After much experimentation and much fruitless Googling, I have come to the conclusion that the entire section of the guide claiming that you can have BeSweet encode to AC3 using Aften.exe is complete BS. I see lots of mentions of using Aften with BeSweet, but not one single actual example of how to do it. Nothing I've tried has worked. I had hoped the GUI would use it and I could just copy the command line, but nope, it uses the built-in AC3 encoder, which everyone says not to use.
So then I downloaded BeLight, which says it requires both BeSweet and Aften. The command line includes the exact same parameters as I've been trying to use. Do they work here? Nope! In fact, it won't even run as-is due to it not putting a space betwee -bsn and the (. Even after fixing that, it just creates an MP3 file. I think BeSweet, at least the latest beta version is bugged. And unfortunately the developers site is gone and nobody has any older versions for me to try.Last edited by Rekrul; 9th Oct 2021 at 22:09.
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The original command provided is correct but omits the aften section so it defaults to mp3 encoding. The command you show has incorrect spacing which causes -bsn switch to be ignored and again defaults to mp3 encoding (I tested this).
This should work if all necessary files are available (besweet.exe, bsn.dll, aften.exe):
Code:BeSweet -core( -input INPUT.AC3 -output OUTPUT.AC3 ) -ota( -r 25000 23976 ) -bsn( -exe aften.exe )
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All necessary files are in the same directory, but when I issue that command, I get this;
Code:G:\>BeSweet -core( -input input.AC3 -output OUTPUT.AC3 ) -ota( -r 25000 23976 ) -bsn( -exe aften.exe ) BeSweet v1.5b31 by DSPguru. -------------------------- Using azid.dll v1.9 (b922) by Midas (midas@egon.gyaloglo.hu). Using Shibatch.dll v0.25 by Naoki Shibata & DSPguru (shibatch.sourceforge.net). Using bsn.dll v0.24 by DPeshev,Richard,E-Male,DSPguru (DSPguru.Doom9.org). [00:00:00:000] +------- BeSweet ----- [00:00:00:000] | Input : input.ac3 [00:00:00:000] | Output: OUTPUT.AC3 [00:00:00:000] | Floating-Point Process: No Error 84: error configuring bsn!. Quiting...
BTW, Aften comes with multiple directories in the archive, including several libaftendll ones. All have Aften.exe in them, all of which seem to execute just fine from the command line. I have tried putting the contents of all the various Aften directories in with BeSweet, but none of them worked.