mp3 44khz vs. 48khz -> what about size?

[flooo]

hi everybody.

never tried 44khz at all. 2 much work :(

has any1 converted ac3 to mp3 with 44khz and with 48khz? what about the differences in size? assuming i.e. 90min audio.

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other question: by searching the forum i noticed someone saying lame has problems with 48khz encoding. is it still actual in lame v3.91 or was this a hoax @ all? any1 knows that?

thanx,
flooo

[DJ Bobo]

Changing Sample Rate hasn't effect on size if you're encoding to a target bitrate!

128kbps is 128kbps and will bring exactly the same size in all situations!

I recommend downsampling to 44,1KHz for 160kbps and lower bitrates to get less compression artifacts.
You can keep 48KHz for higher bitrates.

Downsampling has no effect on synch!
And Downsampling doesn't take that much time as you expect!
Lame seems to be optimized for 44,1KHz

[ChristianHJW]

Thanks to Naoki Shibata creating SSRC and DSPguru who gave ssrc.dll with 32 Bit FP input to the world :D the whole process of downsampling doesnt cost you more than ticking a box and some 10% - 15% more encoding time ( on SMP machines 0% with HeadAC3he ) .... at least if you are using BeSweet or HeadAC3he for transcoding AC3 to Lame MP3/Vorbis ...

[MaTTeR]

Originally posted by flooo
other question: by searching the forum i noticed someone saying lame has problems with 48khz encoding. is it still actual in lame v3.91 or was this a hoax @ all? any1 knows that?


This has come up from time to time over the past year or so. By all accounts it seems to be more of a myth than anything though. Back in the days when I used MP3s, I never downsampled and not once heard an artifact at 48kHz. Maybe my ears aren't what they used to be but at 29, I hope I can hear a major flaw at 48kHz.

Thanks to Dark Avenger and DSPguru we also have some fine Vorbis transcoders. I'd recommend looking into Vorbis if your trying to save space on your CD's. Much smaller file sizes can be achieved with superb quality. The developers of Vorbis sees donasmapling to 44kHz a waste in general though;)

[Prosper]

Made a comparo about a gazillion years ago, but there is about a 4% increase in filesize when encoding 48k material in VBR mode. In CBR mode, of course, there is no difference.