Narrowband (dialup) will work for streaming but only at low bitrates (32
Kbps and lower). Even today, most 56k modems connect at best at 50Kbps and
can sustain a maximum streaming datarate of 34Kbps if all is perfect. A more
realistic figure is 24-28Kbps which will still give decent audio
performance. The issue for streaming vs. download is how much data can you
squeeze down that pipe? Higher datarates than the connection will handle
when streaming will overwhelm the connection resulting in continuous
rebuffering and user frustration.
Another issue beyond filesize and datarate that's VERY important is which
codec you use for audio encoding. MP3 is not the most efficient codec and
you can get equivalent performance out of less bandwidth by using a
different one. You may wish to consider transcoding the file to WMA 9,
RealAudio G2 or another codec. Another advantage therein is the ability to
apply DRM should you wish to control the content (I personally abhor DRM but
there's a time and a place...).
From: Association for Recorded Sound Discussion List
[mailto:[log in to unmask]] On Behalf Of Steven C. Barr
Sent: Friday, November 19, 2004 9:09 PM
To: [log in to unmask]
Subject: Re: [ARSCLIST] .mp3 and streaming
----- Original Message -----
From: "andy kolovos" <[log in to unmask]>
To: <[log in to unmask]>
> I realize that the size of an .mp3 file will have an influence on the time
> it takes to download and play the file. What effect does file size have
> streaming--in particular streaming using a .m3u file?
> My reason for asking is that we're about to put up some interview excerpt
> audio on our website and I'm trying to weigh encoding rates v.s. file size
> to come up with a good balance. My instinct at this point is to err on
> side of file size to make it easier for all those folks in our communities
> who don't have broadband access, and I'm thinking in terms of encoding
> .mp3s at 24kbs/24kHz. Although at this rate there is a noticeable
> difference in sound quality between the .mp3 and the .wav, it isn't too
> and the file size difference is enormous.
> However, if file size isn't quite the concern it is with streaming as it
> with download, I'd rather boost the quality of the streamed file a bit.
> Any thoughts or experiences more than welcome.
File size only affects streaming in terms of the time it takes to recieve
the file, since streaming is more or less equivalent to downloading except
that the bytes are placed in a buffer. Streaming depends on the receiving
party being able to receive bytes as fast as they are played, so the
computer doesn't "run out of material" before to finishes playing what
it already has received. I don't know (somebody may) if a 56K dial-up
connection will allow effective streaming.
Steven C. Barr