/* * FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application * Copyright (C) 2005/2006, Anthony Minessale II * * Version: MPL 1.1 * * The contents of this file are subject to the Mozilla Public License Version * 1.1 (the "License"); you may not use this file except in compliance with * the License. You may obtain a copy of the License at * http://www.mozilla.org/MPL/ * * Software distributed under the License is distributed on an "AS IS" basis, * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License * for the specific language governing rights and limitations under the * License. * * The Original Code is FreeSWITCH Modular Media Switching Software Library / Soft-Switch Application * * The Initial Developer of the Original Code is * Anthony Minessale II * Portions created by the Initial Developer are Copyright (C) * the Initial Developer. All Rights Reserved. * * Contributor(s): * * Anthony Minessale II * Brian K. West * * The amr codec itself is not distributed with this module. * * mod_amr.c -- GSM-AMR Codec Module * */ #include "switch.h" #include "amr/interf_enc.h" #include "amr/interf_dec.h" /* * Check section 8.1 of rfc3267 for possible sdp options. * * SDP Example * * a=fmtp:97 mode-set=0,2,5,7; mode-change-period=2; mode-change-neighbor=1 * * Class A total speech * Index Mode bits bits * ---------------------------------------- * 0 AMR 4.75 42 95 * 1 AMR 5.15 49 103 * 2 AMR 5.9 55 118 * 3 AMR 6.7 58 134 * 4 AMR 7.4 61 148 * 5 AMR 7.95 75 159 * 6 AMR 10.2 65 204 * 7 AMR 12.2 81 244 * 8 AMR SID 39 39 * * Table 1. The number of class A bits for the AMR codec. * */ static const char modname[] = "mod_amr"; struct amr_context { void *encoder_state; void *decoder_state; int enc_mode; }; enum { GENERIC_PARAMETER_AMR_MAXAL_SDUFRAMES = 0, GENERIC_PARAMETER_AMR_BITRATE, GENERIC_PARAMETER_AMR_GSMAMRCOMFORTNOISE, GENERIC_PARAMETER_AMR_GSMEFRCOMFORTNOISE, GENERIC_PARAMETER_AMR_IS_641COMFORTNOISE, GENERIC_PARAMETER_AMR_PDCEFRCOMFORTNOISE }; enum { AMR_BITRATE_475 = 0, AMR_BITRATE_515, AMR_BITRATE_590, AMR_BITRATE_670, AMR_BITRATE_740, AMR_BITRATE_795, AMR_BITRATE_1020, AMR_BITRATE_1220 }; #define AMR_Mode 7 static switch_status_t switch_amr_init(switch_codec_t *codec, switch_codec_flag_t flags, const switch_codec_settings_t *codec_settings) { struct amr_context *context = NULL; int encoding, decoding; int x, argc; char *argv[10]; encoding = (flags & SWITCH_CODEC_FLAG_ENCODE); decoding = (flags & SWITCH_CODEC_FLAG_DECODE); if (!(encoding || decoding) || (!(context = switch_core_alloc(codec->memory_pool, sizeof(struct amr_context))))) { return SWITCH_STATUS_FALSE; } else { if (codec->fmtp_in) { argc = switch_separate_string(codec->fmtp_in, ';', argv, (sizeof(argv) / sizeof(argv[0]))); for(x = 0; x < argc; x++) { char *data = argv[x]; char *arg; while(*data && *data == ' ') { data++; } if ((arg = strchr(data, '='))) { *arg++ = '\0'; //printf("Codec arg %d [%s]=[%s]\n", x, data, arg); } } } codec->fmtp_out = "octet-align=0; mode-set=7"; context->enc_mode = AMR_Mode; /* start in mode 7 */ context->encoder_state = NULL; context->decoder_state = NULL; if (encoding) { context->encoder_state = Encoder_Interface_init(1); } if (decoding) { context->decoder_state = Decoder_Interface_init(); } codec->private_info = context; return SWITCH_STATUS_SUCCESS; } } static switch_status_t switch_amr_destroy(switch_codec_t *codec) { struct amr_context *context = codec->private_info; if (context->encoder_state) { Encoder_Interface_exit(context->encoder_state); } if (context->decoder_state) { Decoder_Interface_exit(context->decoder_state); } codec->private_info = NULL; return SWITCH_STATUS_SUCCESS; } static switch_status_t switch_amr_encode(switch_codec_t *codec, switch_codec_t *other_codec, void *decoded_data, uint32_t decoded_data_len, uint32_t decoded_rate, void *encoded_data, uint32_t *encoded_data_len, uint32_t *encoded_rate, unsigned int *flag) { struct amr_context *context = codec->private_info; if (!context) { return SWITCH_STATUS_FALSE; } *encoded_data_len = Encoder_Interface_Encode( context->encoder_state, context->enc_mode, (int16_t *)decoded_data, (uint8_t *) encoded_data, 0); return SWITCH_STATUS_SUCCESS; } static switch_status_t switch_amr_decode(switch_codec_t *codec, switch_codec_t *other_codec, void *encoded_data, uint32_t encoded_data_len, uint32_t encoded_rate, void *decoded_data, uint32_t *decoded_data_len, uint32_t *decoded_rate, unsigned int *flag) { struct amr_context *context = codec->private_info; if (!context) { return SWITCH_STATUS_FALSE; } Decoder_Interface_Decode( context->decoder_state, (void *)encoded_data, (void *)decoded_data, 0 ); *decoded_data_len = codec->implementation->bytes_per_frame; //printf("D %d/%d\n", encoded_data_len, *decoded_data_len); return SWITCH_STATUS_SUCCESS; } /* Registration */ static const switch_codec_implementation_t amr_implementation = { /*.codec_type */ SWITCH_CODEC_TYPE_AUDIO, /*.ianacode */ 96, /*.iananame */ "AMR", /*.fmtp */ "octet-align=0", /*.samples_per_second */ 8000, /*.bits_per_second */ 0, /*.microseconds_per_frame */ 20000, /*.samples_per_frame */ 160, /*.bytes_per_frame */ 320, /*.encoded_bytes_per_frame */ 0, /*.number_of_channels */ 1, /*.pref_frames_per_packet */ 1, /*.max_frames_per_packet */ 1, /*.init */ switch_amr_init, /*.encode */ switch_amr_encode, /*.decode */ switch_amr_decode, /*.destroy */ switch_amr_destroy, }; static const switch_codec_interface_t amr_codec_interface = { /*.interface_name */ "GSM-AMR", /*.implementations */ &amr_implementation, }; static switch_loadable_module_interface_t amr_module_interface = { /*.module_name */ modname, /*.endpoint_interface */ NULL, /*.timer_interface */ NULL, /*.dialplan_interface */ NULL, /*.codec_interface */ &amr_codec_interface, /*.application_interface */ NULL }; SWITCH_MOD_DECLARE(switch_status_t) switch_module_load(const switch_loadable_module_interface_t **module_interface, char *filename) { /* connect my internal structure to the blank pointer passed to me */ *module_interface = &amr_module_interface; /* indicate that the module should continue to be loaded */ return SWITCH_STATUS_SUCCESS; }