similar to: Acoustic echo cancellation

Simply to say, in a quiet room, you can play a impulse signal and then find it's impulse response signal from the microphone. For example, if the delay between the impulse signal and its response signal range from 500 to 3000 cycles, you can buffer the far-end signal to 0-300 cycles and set the filter length to 4000. It is also called to align far-end signal and near-end signal. BTW: Speex

2011/4/20 Li Maoquan <limaoquan2000 at 126.com> > Simply to say, in a quiet room, you can play a impulse signal and then find > it's impulse response signal from the > microphone. For example, if the delay between the impulse signal and its > response signal range from 500 to > 3000 cycles, you can buffer the far-end signal to 0-300 cycles and set the > filter length

As for me - speex_echo_cancellation is a better choise. Try using it in capture thread instead of those speex_echo_capture and speex_echo_playback functions. And please, describe your problem in details. Cause the fact that you "didn get echo cancellation" doesn't mean you are doing smth wrong. Regards, Anton A. Shpakovsky -----Original Message----- From: speex-dev-bounces at

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

Hi Jean Marc, We are running the speex echo canceller code on a Windows Mobile smartphone using a TI OMAP 201MHz 850. We are making voip calls and audio is working without echo canceller code. Simply adding the following 2 functions whether the echo cancellation is wired in (ie we use the output frame ) or not performance becomes terrible. Note 2 separate threads are used to handle audio.

> Hi, > > I have a scenario in a mobile VoIP app that requires echo cancellation but > is somewhat different from what's described in the docs. > > Audio is received from and sent to the network at 8000Hz. Each packet > contains 160 samples worth a playback of 20ms. > > But the hardware requires aggregation for both playback and capture. So for >

>>* Hi, *>>* *>>* I have a scenario in a mobile VoIP app that requires echo cancellation but *>>* is somewhat different from what's described in the docs. *>>* *>>* Audio is received from and sent to the network at 8000Hz. Each packet *>>* contains 160 samples worth a playback of 20ms. *>>* *>>* But the hardware requires aggregation for

Hello, i'm adding echo cancellation to my voip application, but when i call speex_echo_capture() or speex_echo_playback() causes an assertion failed, it seens that there is a delete in any where. i've encapsulated echo canceller in a class that storage the state and simply call the functions: void EchoCanceller::Playback(short *echo_frame) { speex_echo_playback(echo_state,

Hi, I have a scenario in a mobile VoIP app that requires echo cancellation but is somewhat different from what's described in the docs. Audio is received from and sent to the network at 8000Hz. Each packet contains 160 samples worth a playback of 20ms. But the hardware requires aggregation for both playback and capture. So for playback, I coalesce 4 packets in a buffer and queue them as a

hello jean-marc and everybody, I keep getting no results when trying to use speex_echo_capture, speex_echo_playback and speex_echo_cancel in a multi-threaded application, as suggested in the manual. Though, the cancellation works properly when i use a file with human voice for far-end input and the same file with echo added in SoundForge for mic input. When i try to insert and remove silence

Hi Jean-Marc and all others! I am having some troubles with the echo cancellation feature of speex in a voip project. I have two threads, one for sound input and one for sound output. In the output thread, I call speex_echo_playback(). or every frame sent to the sound card. In the input thread, I call speex_echo_capture() for every frame captured from the sound card. Also, I do

>> Simply to say, in a quiet room, you can play a impulse signal and then find >> it's impulse response signal from the >> microphone. For example, if the delay between the impulse signal and its >> response signal range from 500 to >> 3000 cycles, you can buffer the far-end signal to 0-300 cycles and set the >> filter length to 4000. It is also called

Hello all. A few questions on using speex's echo cancellation, for clarifying: 1) I assume that the echo_frame in this method: speex_echo_playback(echo_state, echo_frame) is just raw "pcm_s16le" type bits/data? I'm a bit new to all this... 2) I assume from this thread: http://lists.xiph.org/pipermail/speex-dev/2009-March/007151.html that speex_echo_playback and

Hi, when I use preprocessor with AEC, VC++ alerts me about heap corruption. I have protected speex_echo_playback, speex_echo_capture and speex_preprocess_run with mutexes, to avoid echo_state being used at the same time, but it still happens. Any help about this ussue? Thank you.

_____ From: Mohammed Sulaiman [mailto:mhh.sulaiman@talk21.com] Sent: Monday, February 11, 2008 12:53 AM To: Dennis Liu Subject: RE: [Speex-dev] Echo Canceller on Windows Mobile Hi, thanks. One question did you use these 2 functions speex_echo_playback speex_echo_capture No, I didn't use them. I use my own code to buffer microphone and speaker data. or do you have your audio in

2006/11/2, Jean-Marc Valin <jean-marc.valin@usherbrooke.ca>: > > Today I tried speex echo cancellation on my VoIP application running > > on a windows mobile based PDA (OMAP1510 168MHz). The result is > > disappointing: it takes 150-250 ms to do echo cancellation (by calling > > speex_echo_capture() ) for a 20 ms frame! > > Are you by any chance using an insane

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

Hi Folks, I am having trouble using speex_echo_cancel. As a starting point, I am using the testecho.c source code. I compiled the 1.2beta1 version. I have not tried any other versions of speex. The document says that the order of arguments to Speex_echo_cancel is (echo_state, input_frame, echo_frame, output_frame, residue) where "input_frame" is as captured from mic and

Hello all, Today I tried speex echo cancellation on my VoIP application running on a windows mobile based PDA (OMAP1510 168MHz). The result is disappointing: it takes 150-250 ms to do echo cancellation (by calling speex_echo_capture() ) for a 20 ms frame! I've defined the FIXED_POINT macro. Is there anyway to do some optimization? Nick

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()