add codec_mapping.h,c
Converting between different codec representations is confusing. This
codec mapping provides a consolidated overview of all our codec
representations, and how they match up.
In particular, it adds the SDP codec representation repertoire,
preparing the use of full SDP on the MNCC interface.
Related: SYS#5066
Change-Id: Iaa307be6a8487aa8d4ba7cd59d5c5ef04818a744
diff --git a/include/osmocom/msc/codec_mapping.h b/include/osmocom/msc/codec_mapping.h
new file mode 100644
index 0000000..1232d2d
--- /dev/null
+++ b/include/osmocom/msc/codec_mapping.h
@@ -0,0 +1,64 @@
+/* Routines for translation between codec representations: SDP, CC/BSSMAP variants, MGCP, MNCC */
+#pragma once
+
+#include <osmocom/gsm/protocol/gsm_04_08.h>
+#include <osmocom/gsm/protocol/gsm_08_08.h>
+#include <osmocom/mgcp_client/mgcp_client.h>
+#include <osmocom/msc/sdp_msg.h>
+#include <osmocom/gsm/mncc.h>
+
+#define NO_MGCP_CODEC 0xffffffff
+
+extern const struct gsm_mncc_bearer_cap bearer_cap_empty;
+
+enum codec_frhr {
+ CODEC_FRHR_NONE = 0,
+ CODEC_FRHR_FR,
+ CODEC_FRHR_HR,
+};
+
+struct codec_mapping {
+ /* The sdp.payload_type number in a mapping is not necessarily imperative, but may just reflect the usual
+ * payload type number for a given codec. */
+ struct sdp_audio_codec sdp;
+ /* The id that mgcp_client.h uses for this codec. Must be set in each mapping, because 0 means PCMU. */
+ enum mgcp_codecs mgcp;
+ /* Nr of used entries in speech_ver[] below. */
+ unsigned int speech_ver_count;
+ /* Entries to add to Speech Version lists when this codec is present, if any. */
+ enum gsm48_bcap_speech_ver speech_ver[8];
+ /* If applicable, one of GSM_TCHF_FRAME, GSM_TCHF_FRAME_EFR, GSM_TCHH_FRAME, GSM_TCH_FRAME_AMR; or zero. */
+ uint32_t mncc_payload_msg_type;
+ /* Set to true if gsm0808_speech_codec below reflects a meaningful value. */
+ bool has_gsm0808_speech_codec;
+ struct gsm0808_speech_codec gsm0808_speech_codec;
+ /* If applicable, entries to add to Permitted Speech lists when this codec is present; or zero. */
+ enum gsm0808_permitted_speech perm_speech;
+ /* If applicable, indicator whether this codec can work on a GERAN half-rate lchan, or whether full-rate is
+ * required. Leave zero when this codec does not apply to GERAN. */
+ enum codec_frhr frhr;
+};
+
+const struct codec_mapping *codec_mapping_by_speech_ver(enum gsm48_bcap_speech_ver speech_ver);
+const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec_type(enum gsm0808_speech_codec_type sct);
+const struct codec_mapping *codec_mapping_by_gsm0808_speech_codec(const struct gsm0808_speech_codec *sc);
+const struct codec_mapping *codec_mapping_by_perm_speech(enum gsm0808_permitted_speech perm_speech);
+const struct codec_mapping *codec_mapping_by_subtype_name(const char *subtype_name);
+const struct codec_mapping *codec_mapping_by_mgcp_codec(enum mgcp_codecs mgcp);
+
+int bearer_cap_add_speech_ver(struct gsm_mncc_bearer_cap *bearer_cap, enum gsm48_bcap_speech_ver speech_ver);
+int sdp_audio_codec_add_to_bearer_cap(struct gsm_mncc_bearer_cap *bearer_cap, const struct sdp_audio_codec *codec);
+int sdp_audio_codecs_to_bearer_cap(struct gsm_mncc_bearer_cap *bearer_cap, const struct sdp_audio_codecs *ac);
+int bearer_cap_set_radio(struct gsm_mncc_bearer_cap *bearer_cap);
+
+struct sdp_audio_codec *sdp_audio_codecs_add_speech_ver(struct sdp_audio_codecs *ac,
+ enum gsm48_bcap_speech_ver speech_ver);
+struct sdp_audio_codec *sdp_audio_codecs_add_mgcp_codec(struct sdp_audio_codecs *ac, enum mgcp_codecs mgcp_codec);
+void sdp_audio_codecs_from_bearer_cap(struct sdp_audio_codecs *ac, const struct gsm_mncc_bearer_cap *bc);
+
+void sdp_audio_codecs_to_speech_codec_list(struct gsm0808_speech_codec_list *cl, const struct sdp_audio_codecs *ac);
+void sdp_audio_codecs_from_speech_codec_list(struct sdp_audio_codecs *ac, const struct gsm0808_speech_codec_list *cl);
+
+int sdp_audio_codecs_to_gsm0808_channel_type(struct gsm0808_channel_type *ct, const struct sdp_audio_codecs *ac);
+
+enum mgcp_codecs sdp_audio_codec_to_mgcp_codec(const struct sdp_audio_codec *codec);