| /* Filter/overlay codec selections for a voice call, across MS, RAN and CN limitations */ |
| /* |
| * (C) 2019-2022 by sysmocom - s.f.m.c. GmbH <info@sysmocom.de> |
| * All Rights Reserved |
| * |
| * Author: Neels Hofmeyr |
| * |
| * SPDX-License-Identifier: GPL-2.0+ |
| * |
| * This program is free software; you can redistribute it and/or modify |
| * it under the terms of the GNU General Public License as published by |
| * the Free Software Foundation; either version 2 of the License, or |
| * (at your option) any later version. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| * GNU General Public License for more details. |
| */ |
| #pragma once |
| |
| #include <osmocom/gsm/gsm_utils.h> |
| #include <osmocom/gsm/mncc.h> |
| #include <osmocom/mgcp_client/mgcp_client.h> |
| |
| #include <osmocom/msc/sdp_msg.h> |
| |
| struct gsm0808_speech_codec_list; |
| |
| /* Combine various codec selections to obtain a resulting set of codecs allowed by all of them. |
| * Members reflect the different entities/stages that select codecs in a voice call. |
| * Call codec_filter_run() and obtain the resulting set of codecs in codec_filter.result. */ |
| struct codec_filter { |
| /* The fixed set of codecs available on the RAN type, per definition. */ |
| struct sdp_audio_codecs ran; |
| /* The codecs advertised by the MS Bearer Capabilities */ |
| struct sdp_audio_codecs ms; |
| /* If known, the set of codecs the current RAN cell allows / has available. |
| * This may not be available if the BSC does not issue this information early enough. |
| * Should be ignored if empty. */ |
| struct sdp_audio_codecs bss; |
| |
| /* SDP as last received from the remote call leg. */ |
| struct sdp_msg remote; |
| |
| /* After a channel was assigned, this reflects the chosen codec. */ |
| struct sdp_audio_codec assignment; |
| |
| /* Resulting choice of supported codecs, usually the intersection of the above, |
| * and the local RTP address to be sent to the remote call leg. |
| * The RTP address:port in result.rtp is not modified by codec_filter_run() -- set it once. */ |
| struct sdp_msg result; |
| }; |
| |
| void codec_filter_init(struct codec_filter *codec_filter); |
| void codec_filter_set_ran(struct codec_filter *codec_filter, enum osmo_rat_type ran_type); |
| void codec_filter_set_bss(struct codec_filter *codec_filter, |
| const struct gsm0808_speech_codec_list *codec_list_bss_supported); |
| int codec_filter_set_remote(struct codec_filter *codec_filter, const char *remote_sdp); |
| void codec_filter_set_local_rtp(struct codec_filter *codec_filter, const struct osmo_sockaddr_str *rtp); |
| int codec_filter_run(struct codec_filter *codec_filter); |
| |
| int codec_filter_to_str_buf(char *buf, size_t buflen, const struct codec_filter *codec_filter); |
| char *codec_filter_to_str_c(void *ctx, const struct codec_filter *codec_filter); |
| const char *codec_filter_to_str(const struct codec_filter *codec_filter); |