Question for computer gurus?

[Deuce 007 MD]

I've been recording lectures w/a digital recorder and they come out in WAV format how can I compress them to really small and still keep good sound quality. I've tried turning them into MP3 and the smallest I can get them to is about 8MB for each hour of lecture. Is there any way I can get the lectures any smaller and still maintain quality, cuz I wanna be able to email them to fellow classmates, save more of them w/less space, and post them on our class message board. Thanks for the help.

 

[Kalel]

Have you tried programs like winzip to compress these files?

 

[Daedalus]

: deleted :

 

[Andrew_Doan]

I wanna be able to email them to fellow classmates, save more of them w/less space, and post them on our class message board. Thanks for the help.

This is an awesome idea!

 

[snapdad]

Depending on your mp3 encoding software, you could try playing around with the various settings and seeing how the quality turns out. Usually you can get away with a smaller bitrate and sample rate for spoken word stuff, but you might want to experiment. For the smallest file size, try using a variable bit rate, a 22,050 Hz sample rate (this is the sample rate used by FM radio), and if the original file is in stereo, try changing it to mono before encoding it as an mp3.

 

[TRUE]

Did you try expermenting with the mp3 bitrates? You can go pretty low with speech and still have good quality. For a reference, 128 is common for mp3's, but you could likely go much lower (not sure of the exact #'s). Just fool around with it. I agree, though, that 8 MB an hour is solid. One mp3 song is generally 3-5 MB's and that lasts about 4-5 minutes.

 

[BubbleBobble]

Did you try expermenting with the mp3 bitrates? You can go pretty low with speech and still have good quality. For a reference, 128 is common for mp3's, but you could likely go much lower (not sure of the exact #'s). Just fool around with it. I agree, though, that 8 MB an hour is solid. One mp3 song is generally 3-5 MB's and that lasts about 4-5 minutes.

This is an excellent suggestion. You could also try converting them into .WMA format, which takes up a little bit less space.

 

[Xega]

Another option may be the IMBE format. I don't have time to look it up, but the link is http://www.ind.rwth-aachen.de/research/speech_coding.html it is a codec specifically for speech coding and is quite impressive down ot 5k

 

[Gleevec]

I've been recording lectures w/a digital recorder and they come out in WAV format how can I compress them to really small and still keep good sound quality. I've tried turning them into MP3 and the smallest I can get them to is about 8MB for each hour of lecture. Is there any way I can get the lectures any smaller and still maintain quality, cuz I wanna be able to email them to fellow classmates, save more of them w/less space, and post them on our class message board. Thanks for the help.

Did you record in mono? You dont really need stereo for lectures, and Im pretty sure recording in mono can result in some huge space savings.

Also, definitely take the bitrate down. You can probably get away with 56kbps mono encoding.

 

[Blade28]

What settings are you using? Bitrate? Mono/stereo?

 

[SunnyS81]

Is there a reason you are set on transferring them as MP3's? Maybe you should use your computer as a server, and stream the audio at 50kbps or something......just an idea, otherwise, 10mb/hour is pretty small.

 

[uclabruin725]

If, after trying everything stated above, you receive a file that is still a bit large to transfer, you can always use an archival program such as winrar or winzip to split it up into smaller parts (say 1-2 megs each) that can be transferred easily. Note that since MP3 is a compression format in itself, you should not expect much, if any, further compression by winrar or winzip. You will however, be able to split the file up into parts that you can email.

 

[Deuce 007 MD]

Thanks for the suggestions, yah tried mono, and got the bitrate down and the HZ down too.

 

[CalBeE]

Thanks for the suggestions, yah tried mono, and got the bitrate down and the HZ down too.

WHile you're doing this yourself...maybe you can suggest to the UCLA administration to record the lecture for students in the future?? Save people the hazzle.