Juan Zapatero
2006-Jan-04 04:12 UTC
[Speex-dev] Writting a line in encoder with speex compression.
Hello, first of all, I am going to sum up what I am trying to do, so that best advice can be given. The final objective is to write a simple application to establish a VoIP communication over a GPRS link. So it would be to get a full duplex (capture/playback) sound application that captured from microphone, compresses speech with Speex, and sends it trough the socket API over the GPRS link. By now, I am trying to get the audio part to work. I wrote a simplest capture-playback program, based on the ALSA api, optimized to capture speech (mono, 8000Hz, 16bits little-endian). Once wrote, I tested capturing into a raw file, and then compressing the file with speexenc. So far everything was a succeed. Then, I tried introducing the compression into the audio program following the indications given in Speex Codec Manual (both into de API section and mostly in the sampleenc code: - The resulting program works, but the quality is much poorer than using speexenc over a raw file (much noisier). - The ALSA PCM api, uses a capture buffer of 340bytes, but speex encoder expects a 160bytes buffer, I think here could be the problem, as I am trying to force speex_encoder to use a 340bytes buffer. Any help would be grateful. Juan Zapatero. ______________________ Este mensaje, y en su caso, cualquier fichero anexo al mismo, puede contener informacion clasificada por su emisor como confidencial en el marco de su Sistema de Gestion de Seguridad de la Informacion siendo para uso exclusivo del destinatario, quedando prohibida su divulgacion copia o distribucion a terceros sin la autorizacion expresa del remitente. Si Vd. ha recibido este mensaje erroneamente, se ruega lo notifique al remitente y proceda a su borrado. Gracias por su colaboracion. ______________________ This message including any attachments may contain confidential information, according to our Information Security Management System, and intended solely for a specific individual to whom they are addressed. Any unauthorised copy, disclosure or distribution of this message is strictly forbidden. If you have received this transmission in error, please notify the sender immediately and delete it. ______________________