INTERACT FORUM

More => Old Versions => Media Center 11 (Development Ended) => Topic started by: happy5 on February 04, 2007, 06:34:03 pm

Title: Changing sample rate of MP3 files
Post by: happy5 on February 04, 2007, 06:34:03 pm
Hi all,

Can I change the sample rate of MP3 files with Media Center? It is great that I can convert between file formats and increase the bitrate, but at the moment need to change the sample rate of some files from 22.1Khz to 44.1Khz or above.

If not possible, can you recommend an extension for MC or external program (freeware preferred) that can do so? Thanks.
Title: Re: Changing sample rate of MP3 files
Post by: KingSparta on February 04, 2007, 06:53:28 pm
Quote
Can I change the sample rate of MP3 files with Media Center?

Yes

I normaly Do This With The MP3 Encoder using a custom command line

lame.exe -V8 --vbr-new --lowpass 9.2 --resample 22 -m m

The Above forces a mono sample at 22050 because i normaly deal with old radio broadcasts, and 22050 works good when using in a podcast with a flash player.

I wish JRiver would add a easy way for users to build a custom command line using a GUI for the lame and gogo encoder and not force users to go back in time to the 1980's. with hand created command lines.
Title: Re: Changing sample rate of MP3 files
Post by: happy5 on February 04, 2007, 07:07:39 pm
Ok, I would go to Library Tools>Convert Format... and then what? Convert under MP3 or MP3 VBR?

A very quick tutorial would be most appreciated.
Title: Re: Changing sample rate of MP3 files
Post by: KingSparta on February 04, 2007, 07:50:56 pm
select file(s) to convert

tools > Advanced Tools > Convert Format

you can change the encoding and other options from there (like send orginal to recycle bin) from there also, and start the convert.
Title: Re: Changing sample rate of MP3 files
Post by: happy5 on February 04, 2007, 08:42:38 pm
I'm using Media Center 10.0.173 - will this work as well?

Also, it is taking forever... is this normal? It just says "converting..." with no change at all.

Perhaps a small tutorial could be added as a sticky around here...  :D
Title: Re: Changing sample rate of MP3 files
Post by: KingSparta on February 04, 2007, 09:03:03 pm
depends on your computer after that
Title: Re: Changing sample rate of MP3 files
Post by: happy5 on February 04, 2007, 09:31:17 pm
I mean it does not show a progress bar or anything... my computer is pretty powerful, so something else might be wrong. The computer, or Media Center, is not crashing up or anything, but it's been almost 30 minutes and nothing happens!

Should this be the exact command line, without the quotes?

"lame.exe -V8 --vbr-new --lowpass 9.2 --resample 22 -m m"

Also, I did as you wrote, but under the only way I can select the command line is by selecting "custom" under the "quality" menu.

Any thoughts?
Title: Re: Changing sample rate of MP3 files
Post by: happy5 on February 04, 2007, 11:12:51 pm
Finally got it working!

I really appreciate the command line you provided, and even though it may work for you, here is one that worked for me fast - very fast! Around 2 minutes per file.

Here is the command line I tried:

"-b 128 -- resample 44.1"

Just type that without the quotation marks on the command line and that is it!

Title: Re: Changing sample rate of MP3 files
Post by: Alex B on February 05, 2007, 01:55:32 am
happy5,

Just to make sure, are you aware that re-encoding of the already low quality files in MP3 format always reduces the audio quality a bit more? That may be a necessary sacrifice with hardware devices that do not support 22.05 kHz, but on PC playback with MC you can simply use the 44.1 kHz output option in MC's DSP Studio. (This can be used if the sound card driver does not support low sample rates like 22.05 kHz. I have found that at least some ASIO drivers don't like 22.05 kHz).
Title: Re: Changing sample rate of MP3 files
Post by: happy5 on February 05, 2007, 06:47:20 am
Hi,

I am fully aware that the audio quality might get reduced, but in this case it does not matter to me because it is just a classroom lecture - sound quality is not that important. The only thing I wanted was the ability to speed up the playback of the files, as my MP3 cannot speed up files with 22 KHz (or as I understand it, it was a mono sound file as well).



Title: Re: Changing sample rate of MP3 files
Post by: goatherder on February 05, 2007, 08:48:32 am
Is this just for playback only? How about using the format changer already built into MC?
Title: Re: Changing sample rate of MP3 files
Post by: KingSparta on February 05, 2007, 10:15:06 am
Quote
The only thing I wanted was the ability to speed up the playback of the files, as my MP3 cannot speed up files with 22 KHz (or as I understand it, it was a mono sound file as well).

that should not speed up the file, or slow it down.

when you re-sample from 44100 to 22050 it should play back the same, it may be missing 1\2 the quality (that you should not notice on voice only files).

when you go from 22050 to 44100 you do nothing for the file expect it makes it 100% larger (it duplicates the data it already has to make up the other 22050 samples), And you lose a bit of quality because you re-encoded a non-loss-less file to a non-loss-less file.

speeding up the play of a file is a bit different, and i think they added something for that in the EQ Suite for MC 12, i can be mistaken.
Title: Re: Changing sample rate of MP3 files
Post by: goatherder on February 06, 2007, 07:52:47 am
Just wanted to clarify my previous post - if you just want to play back from MC at a predetermined sample rate, you can do that in the Playback -> DSP & output format. Just set the bitdepth and sample rate to the desired format.

(http://img226.imageshack.us/img226/3891/dsppagexy8.th.jpg) (http://img226.imageshack.us/my.php?image=dsppagexy8.jpg)