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

George Ou george_ou at lanarchitect.net
Tue Oct 3 20:42:07 PDT 2006


Sampling from 44.1 KHz to 33 KHz isn't the greatest conversion but it's
certainly possible.  I tried it and it sounds OK, but the strange thing is
that -w or -u yields a file roughly the same size for some stupid reason. 

-----Original Message-----
From: Tom Grandgent [mailto:tgrand at canvaslink.com] 
Sent: Tuesday, October 03, 2006 1:35 PM
To: George Ou; 'Bertie Coopersmith'
Cc: speex-dev at xiph.org
Subject: RE: [Speex-dev] How to get podcasters to adopt Speex?

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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