[Speex-dev] [SPAM] [BombData][alltestmode] Re: [SPAM] [BombData][alltestmode] Using Speex Echo Canceller

[Christopher Adoremos]

Hi Anton

Thanks again for the tips... its worth a try... =)

I know now how to proceed...

1. From playback thread I need to save the clean buffer/frame via *
speex_echo_playback()*
2. In the audio recorder thread, I'll read a new buffer/frame(which might
include far-end+echo fragments)
3. Then I'll use the *speex_echo_capture()* to cancel out the echo fragment
coming from the playback buffer
4. The resulting *"out"* buffer contains the cleaned frame which in turn
I'll use to encode to my target codec, ex. G77, GSM, etc..

I hope I'm on the right track.. I'll let you know if I succeed on this AEC
development..

Many thanks
Chris Adoremos

On Thu, Sep 30, 2010 at 3:00 PM, Anton A. Shpakovsky <saa at tomsksoft.com>wrote:

> Hi
>
>
>
> So in your case if you don’t want to use *speex_echo_cancellation** *than
> you should do next way:
>
>
>
> Save the playback frames (clean echo) within separate playback thread with
> *speex_echo_playback** *func.
>
> Then use speex_echo_capture - it will remove the clean echo frame (saved
> with *speex_echo_playback** *func) from
>
> const spx_int16_t *rec buffer (saved with *speex_echo_**capture)** *and
> you will get clean frame in "out" buffer.
>
>
>
> The sync is very important - because *speex_echo_**capture *won't be able
> to remove clean echo frame that you didn't provide with *
> speex_echo_playback**.*
>
> * *
>
> I hope I didn't messed up anything :)
>
>
>
> Best Regards,
>
> Anton A. Shpakovsky
>
>
>
>
>
> *From:* Christopher Adoremos [mailto:chrisadoremos at gmail.com]
> *Sent:* Thursday, September 30, 2010 11:52 AM
> *To:* Anton A. Shpakovsky
> *Cc:* speex-dev at xiph.org
> *Subject:* [SPAM] [BombData][alltestmode] Re: [SPAM]
> [BombData][alltestmode] [Speex-dev] Using Speex Echo Canceller
>
>
>
> Hi Anton
>
> Thanks for the info...
>
> What if I use this function do I still need to sync the playback and
> capture?
> Assuming that the captured voice (*rec) already contains the echo which I
> need to cancel out...
> --------------------------------
> void speex_echo_capture (SpeexEchoState *st, const spx_int16_t *rec,
> spx_int16_t *out)
>
> Parameters:
>         st     Echo canceller state
>         rec     signal from the microphone (near end + far end echo)
>         out     Returns near-end signal with echo removed
> ----------------------------------
>
> thanks & regards,
> Chris Adoremos
>
> On Wed, Sep 29, 2010 at 5:46 PM, Anton A. Shpakovsky <saa at tomsksoft.com>
> wrote:
>
> Hi
>
>
>
> Yes, it's absolutely unnecessary to use speex codec. You can encode the
> echo cancelled auido data with any codec you want.
>
> The Echo Canncelation API is here -
> http://www.speex.org/docs/api/speex-api-reference/group__SpeexEchoState.html
>
> I would advice you to look at *speex_echo_cancellation *function but you
> will have to sync playback and capture streams by yourself.
>
>
>
> I've used GSM, iLBC and Speex codecs with Speex AEC and it works fine.
>
>
>
> Best Regards,
>
> Anton A. Shpakovsky
>
>
>
>
>
> *From:* speex-dev-bounces at xiph.org [mailto:speex-dev-bounces at xiph.org] *On
> Behalf Of *Christopher Adoremos
> *Sent:* Wednesday, September 29, 2010 4:39 PM
> *To:* speex-dev at xiph.org
> *Cc:* jean-marc.valin at usherbrooke.ca
> *Subject:* [SPAM] [BombData][alltestmode] [Speex-dev] Using Speex Echo
> Canceller
>
>
>
> Hi
>
>
>
> Is it possible to use only the speex echo cancellation module w/o using the
> speex codec?
>
>
>
> Here's the scenario:
>
> 1. I have my voice recorded in PCM audio file format
>
> 2. I want to cleanup the recorded voice by removing any echo included in
> the audio file/buffer
>
> 3. can I just use the ff APIs?
>
>    - SpeexEchoState* speex_echo_state_init()
>
>    - int speex_echo_ctl()
>
>    - void speex_echo_capture()
>
> 4. then, will it be possible to encode the output buffer from
> speex_echo_capture() to any codec?
>
>     Like G711? GSM? etc....
>
>
>
> I'm quite new to audio format concepts/development, so if you have any
> ideas your advice is highly appreciated..
>
>
>
> Thanks in advance
>
> Chris A
>
>
>
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