[speex-dev] Removing silence at the start and end of sample encoded

[Jean-Marc Valin]

Actually, there are probably some batch programs that could do the job.
It's definitely not a job for speexenc, which I'd like to keep simple.

        Jean-Marc

Le ven 09/01/2004 à 17:37, Asger Kunuk Alstrup a écrit :
> Hi,
> 
> Speex is great!
> 
> We are using it to compress hundreds of megabytes of speech for use in our
> application that trains people in resuscitation. The previous version of our
> product used Ogg Vorbis, but after switching to Speex, we achieve fantastic
> compression, while retaining super quality. That allows us to cram more
> translated versions of the software onto each CD-ROM, making everything better.
> 
> However, we have a small feature requests for speexenc that would make things
> perfect for us: Support for trimming the start and end of the sound away, during
> the encoding process.
> 
> This feature request consists of two things:
> 
> 1) support for automatic detection and trimming of silence at the start and end
> of the sound out.
> 
> 2) support for intentionally skipping the very first and very last parts of the
> input WAV, even if it is not silence.
> 
> This is because we record a lot of small sentences using a recording tool on the
> PC - we are talking hundreds of sentences. Every time the actor records a sound,
> he has to press space first on the keyboard, wait a bit, read the text, and then
> click space again to stop recording when he is done reading it. Now, we can
> often hear the release of the space key at the start of the sample, and the
> pressing of space bar at the end of the sample.
> 
> So, our samples all look like this:
> 
>   "Noise---Silence---Noise-speech-with-wrong-gain---Silence---Noise"
> 
> We would like to automatically get this after feeding the WAVE file to speexenc:
> 
>   "Speech-without-noise-and-correct-gain"
> 
> with the leading noise and silence trimmed out. Speexenc already supports
> automatic gain control and noise reduction, so all we need is the trimming of
> the start and end, of both the noise and silence. Of course, the silence part
> varies in length from sample to sample, but we can cap the noise to X
> milliseconds.
> 
> As it is today, we have to manually edit these samples to remove the noise, and
> then Cooledit can batch-process the silence out for us. After that, we use
> speexenc to get the final sample, but it should be possible to do this in one
> operation, making everything simpler.
> 
> If you can not implement this for us, maybe you could give a few hints to where
> we should look to implement this feature? We are using the CVS version of Speex.
> 
> Thanks in advance,
> 
> Asger Ottar Alstrup
> 
> --- >8 ----
> List archives:  http://www.xiph.org/archives/
> Ogg project homepage: http://www.xiph.org/ogg/
> To unsubscribe from this list, send a message to 'speex-dev-request at xiph.org'
> containing only the word 'unsubscribe' in the body.  No subject is needed.
> Unsubscribe messages sent to the list will be ignored/filtered.

-- 
Jean-Marc Valin, M.Sc.A., ing. jr.
LABORIUS (http://www.gel.usherb.ca/laborius)
Université de Sherbrooke, Québec, Canada


-------------- next part --------------
A non-text attachment was scrubbed...
Name: signature.asc
Type: application/pgp-signature
Size: 190 bytes
Desc: Ceci est une partie de message numériquement signée.
Url : http://lists.xiph.org/pipermail/speex-dev/attachments/20040110/2244d57e/signature.pgp