1) when calling the function PJ_DEF(pj_status_t) pjmedia_codec_evrc_init( pjmedia_endpt *endpt ) { evrc_codec_factory.pool =pjmedia_endpt_create_pool(endpt, "evrc", 4000, 4000); } What could the values for initial data and increment ? Which here i hv written 4000 and 4000.Because these are values for GSM ' initial data and increment. 2) What are the variables like avg_bps and max_bps ? attr->info.avg_bps = 8000;//check here attr->info.max_bps = 8000;//check here Since,The Enhanced Variable Rate Codec (EVRC) [1] compresses each 20 milliseconds of 8000 Hz, 16-bit sampled speech input into output frames in one of the three different sizes: Rate 1 (171 bits), Rate 1/2 (80 bits), or Rate 1/8 (16 bits). For typical speech patterns, this results in an average output of 4.2 kilobits/second for normal mode and a lower average output for reduced rate modes. Shall I take max_bps and avg_bps 4.2 kbps? Please help me out! -- Thanks & Regards. Sameer Prajapati | Software Engineer