Subject:Changing bit-rate when saving MP3s in SF 10.0b

Posted by: Walt_43

Date:11/3/2010 1:22:01 PM

I noticed in SF 10.0b recently that if I open a 128 kbps MP3, edit it and press Save (not Save As), it saves it as a 256 kbps MP3. I never noticed this before. There was a similar problem with SF 5.0 where it used to save MP3s as 64 kbps if you just hit Save.

I didn't think this was a problem in SF 10. Has it changed since version b?

Thanks,
Walt

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Chienworks

Date:11/3/2010 2:33:04 PM

I have never expected Sound Forge to save at some particular bitrate. Since Sound Forge uncompresses the file when it opens it and recompresses when saving, there really isn't any relationship between the original and destination bitrates. I always choose the template i want when i save.

For that matter, i rarely open MP3 files for editing/resaving.

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Walt_43

Date:11/3/2010 5:45:39 PM

Thanks, Chienworks. Interesting - I didn't know the mechanics of what went on in the background when opening an MP3 file. However, I'm sure this worked in previous versions of SF and SF 10 in particular.

I produce a lot of VO audio and music for eLearning where MP3s are essential for clients narrow bandwidths, so I'd often find myself tweaking MP3 files and it really is a pain when you find it's saved your 128 kbps file as a 256 kbps.

From what you're saying, though, it can't be fixed?

Thanks,
Walt

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Geoff_Wood

Date:11/3/2010 7:37:19 PM

Mine does this too. Even if Save As-ed before at 128kbps. At least Save As remembers the last-used template !

geoff

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: musicvid10

Date:11/3/2010 7:50:24 PM

I would do my editing and save as WAV in Sound Forge, then do my conversion in a frontend that supports Lame. No better way to go afaic.

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: rraud

Date:11/4/2010 8:02:40 AM

Same here, arbitrarily saves a 256mps MP3. As I recall earlier versions of SF, opened the 'Save as' prompt window when initiating 'Save' for an MP3.
Like my other forum buddies, I rarely edit or re-render an MP3.

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Walt_43

Date:11/4/2010 8:06:37 AM

Thanks for the suggestions, Geoff and musicvid, but I would expect a professional program like Sound Forge Pro 10 to be able to re-save a file in its existing format when you press Save.

99% of the VO audio I edit is saved as a 44kHz, 16 bit, WAV, but sometimes clients send me a processed MP3 version and want me to make a simple change to it. So if I click Save As, the format that comes up is WAV (the one I usually use). I'd then have to change this to MP3 and set up the parameters or select a preset, every time I'm requested to do this. Clicking Save is a lot more convenient and, if technically possible, I don't think it's asking a lot that the program be able to do this.

Can any Admins shed light on whether or not this is a bug or something that can't be avoided?

Thanks,
Walt

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: musicvid10

Date:11/4/2010 9:39:13 AM

With respect for the fact that you are using MP3 in a professional setting, I think the inclusion of support for MP3 (and a few others) in Sound Forge was more of a consumer aftermarket feature, rather than something most producers would anticipate using in their everyday workflow. For instance, I still don't think Sound Forge has an M4A encoder.

Regarding the "Save" behavior, there are some audio editors that operate directly on the mp3 file (this is called "destructive" MP3 editing), but as Chienworks mentioned, Sound Forge is not one of them. Since conversion must take place anyway, there is nothing wrong with upsampling to 256K, and one could easily set up a custom template for other bitrates.

Again, a good Lame frontend remains my first choice for MP3 encoding.
CDEx is a ripper / converter that exposes all Lame params.

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Walt_43

Date:11/4/2010 1:55:23 PM

I understand, musicvid, but most of the work I do is not for broadcast. It's for eLearning. As you probably know, this is online training, usually delivered on a Flash platform. Most of the online courses are developed for corporate staff so you could have an audience of thousands at one time. For this reason, bandwidth is always an issue and therefore compression is used on audio to leave more bandwidth for (sometimes) intensive vector graphics. This is why I often end up working with MP3s. Also, many eLearning clients' media people will specify what bitrate they want and sometimes I'm required to deliver files at just 48kbps. I know this not exactly pristine audio, but it suits the purpose. So it's not for me to deliver a 256 kbps file when 128 kbps is specified in the job spec. Therefore, it would be much handier if I could just hit Save. But I do understand what you're saying about destructive editing. It seems that the fact SF 10 changes the bitrate is just a 'feature' then. I only mentioned it as I could have sworn I had edited 128 kbps files before and they remained as such when I hit Save.

Anyway, thanks for explaining what way this works as I wasn't aware of the technical limitations of working with the MP3 format. Much appreciated.

Cheers,
Walt

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Geoff_Wood

Date:11/4/2010 2:15:20 PM

Editing a 128kbps (or any) MP3 then resaving will (further) compromise the sound quality. Maybe the default of 256kbps is to try and minimise that additional damage ? You will need to Save As, it seems.

An already data-reduced file such as an mp3 is a bad source. Always better to start with the original (non-mp3) file anyway, if possible. Of course it's not always possible...

geoff

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: Walt_43

Date:11/4/2010 2:25:21 PM

I hear ya, Geoff. I archive all the original WAVs, so most of the time, I can return to the original file if required. But there are some times when I can't. Files wouldn't be resaved more than twice, if at all, so I wouldn't be overly worried about progressive degradation (if that's not an oxymoron). eLearning companies usually set Flash to further compress the audio anyway so most of the anomolies are introduced at this stage.

When we're at a stage when 100 MB broadband is standard, the whole online training industry can move on from MP3s altogether. But until then... :-/

Thanks,
Walt

Subject:RE: Changing bit-rate when saving MP3s in SF 10.0b

Reply by: roblesinge

Date:11/5/2010 6:24:49 AM

Yeah, the telecommunications industry is very similar. Except we save bandwidth by taking everything to low-quality wav files, instead of mp3. We try to only work from originals, or attempt to convince clients to re-record if there are no originals available.

It's always a balancing act. You've been taught to make things sound as good as possible, and now you've traded that in for making it as small as possible.

Rob.