[Speex-dev] How to get podcasters to adopt Speex?

Tom Grandgent tgrand at canvaslink.com
Tue Oct 3 13:35:27 PDT 2006


This is a really good point, and definitely a recurring theme on this 
mailing list. :)  I wonder, what are some better options for handling 
this issue, other than to keep saying "just use 8/16/32kHz"?

- Extend Speex to support other sample rates (seems unlikely..?)

- Integrate a resampling algorithm into libspeex

- Maintain a list of recommended resampling libraries that work well 
with Speex ... maybe even have sample code?

Any others?

Anecdote - I've noticed one somewhat legitimate case in which it is 
impossible to record at 8/16/32kHz.  On Windows, if the hardware is 
already being used to record at a certain sample rate by another 
application, attempting to record at a different sample rate will 
usually not yield an error but produce incorrect results.  But if 
the sample rates match, then multiple applications can record at the 
same time.  This comes into play when someone is running multiple 
VoIP programs (typical of some hardcore gamers) and could also be a 
problem if Google's creepy 24/7 audio monitoring advertisement 
targeting system ever catches on.  (I would hope not.)

Tom

"George Ou" <george_ou at lanarchitect.net> wrote:
> 
> Only thing that bugs me about Speex for podcasting is that it's geared for
> 8, 16, or 32 KHz.  Most podcasters are set up for 44.1 KHz recording.
> 
> -----Original Message-----
> From: Tom Grandgent [mailto:tgrand at canvaslink.com] 
> Sent: Tuesday, October 03, 2006 11:42 AM
> To: Bertie Coopersmith; George Ou
> Cc: speex-dev at xiph.org
> Subject: Re: [Speex-dev] How to get podcasters to adopt Speex?
> 
> Please consider using 16-bit 16kHz (wideband) instead.  It's a huge increase
> in audio quality and the bitrate is still very low, especially if you take
> advantage of Speex features such as VBR.
> 
> 8kHz seems totally inappropriate to me for desktop streaming audio, let
> alone 8-bit samples.  Or perhaps your recording equipment is an original
> Sound Blaster from 1989?  (Even that could record at 12kHz.)
> 
> People often tell me how amazed they are with the audio quality of my VoIP
> software based on Speex, compared to other VoIP software they've used.  What
> amazes me is how low most people's standards are when it comes to sampling
> rates.  I don't think 16kHz is that much to ask.  And yes, I'm talking about
> SPEECH and not audio in general.
> 
> Of course, sometimes there are legitimate reasons to use 8kHz.  I'm just
> saying, try to make sure the sacrifice in quality is not in vain.
> 
> Tom
> 
> Bertie Coopersmith <bertie at coopersmith.demon.co.uk> wrote:
> > 
> > If its just speech that you're after, why not narrowband (8kHZ) speex. 
> > I have found that to be perfectly adequate at about a seven'th of the 
> > file size of a typical (music quality) MP3.
> > 
> > The other good thing is that neither server nor client needs to bother 
> > with streaming software or streaming protocol - http will do. I need 
> > this because my web host does not allow user-supplied server software on
> its free web pages.
> > I just upload my .spx files (mono,8-bit samples, 8000 samples/sec, 
> > 8KHz). which may have originated from various sources: Live recording,
> radio, TV, or Web.
> > 
> > My listening audience consists of family and friends, small in number 
> > but spread over 4 continents. At the crudest level they can do a 
> > binary download and convert to .wav with speexdec (speexdec.exe in the 
> > case of Windows). However, they can also play direct to a unix/linux 
> > client by means of curl url | speexdec - where the url string is 
> > http...spx . In the case of Windows XP this becomes curl.exe url | 
> > speexdec.exe -
> > 
> > I've elaborated this into a .cmd script which obviates the need to 
> > enter a long url plus filename and also, it displays a companion .txt 
> > file while playing the .spx:-
> > 
> > @echo off
> > rem   Play a speex (.spx) file on 
> > rem   Bertie's website. If there is a companion .txt
> > rem   file, display it while playing the .spx.
> > 
> > cd c:\...\wbin
> > rem  In this directory you keep, amongst other things,  
> > rem   the win32 executables known as Unix utilities.
> > rem   In particular this script depends on curl.exe,
> > rem   speexdec.exe, sed.exe, fgrep.exe, cat.exe,
> > rem   echo.exe, tr.exe and nl.exe.
> > 
> > rem  delete scratch files left over from a previous run:- del /q spxt* 
> > sndt*  txtt*
> > 
> > set url=http://www.coopersmith.demon.co.uk
> > echo Speex audio files on %url%:
> > echo -----------------------------
> > 
> > rem remove the html tags
> > curl -s %url% | sed -e "s+</A>++" -e "s/^.*>//" > spxt2
> > 
> > fgrep -c .spx spxt2 > nul || goto nospx echo ---------- Speex files 
> > ------------------- fgrep .spx spxt2 | nl echo 
> > ------------------------------------------
> > set /p num=Enter the number of the one to play and press SEND:
> > echo.
> > fgrep .spx spxt2 | sed -n %num%p > spxt3 echo.exe  -n "curl -f %url%/" 
> > > sndtout1 cat sndtout1 spxt3 >sndtout.cmd sed  -e s/-f/-fs/ -e 
> > s/\.spx/.txt/  sndtout.cmd > txttout.cmd
> > 
> > txttout | more
> > pause
> > sndtout | speexdec -
> > exit
> > :nospx
> > echo No .spx files found on %url%
> > pause
> > 
> > This works well on both dial-up and broadband. 
> > 
> > However, its not gui. I have found that with Foobar2000 on Windows XP 
> > one can open a url to one of the .spx files on my website and play it. 
> > One can even pause and play from a different position in the file. 
> > This cannot be done with the curl command file.
> > I tried doing the same with illiminable's Ogg DirectShow filter
> > but without success.   
> > 
> > Bertie Coopersmith
> > _______________________________________________
> > Speex-dev mailing list
> > Speex-dev at xiph.org
> > http://lists.xiph.org/mailman/listinfo/speex-dev
> > 
> > 
> 
> 



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