From ceef936ea894781a14584efc9256856cca6d1c0f Mon Sep 17 00:00:00 2001 From: Holger Hans Peter Freyther Date: Wed, 19 Aug 2015 14:43:35 +0200 Subject: mgcp: Add transcoding from PCMU as well Use the existing ulaw encode/decode to support PCMU as well. The MERA VoIP switch has some severe issues with the GSM codec and it appears easier to enable transcoding for it. The mera switch doesn't appear to cope with codec change between a SIP 180 trying and the 200 ok connection result. Inserting the codec is touching too many places. Ideally we should have the transcoding function as pointer in the struct as well but the arguments differ.. so it is not a direct way forward. --- openbsc/include/openbsc/mgcp_transcode.h | 3 ++- openbsc/src/libmgcp/mgcp_sdp.c | 8 ++++++++ openbsc/src/libmgcp/mgcp_transcode.c | 26 ++++++++++++++++++++++++++ 3 files changed, 36 insertions(+), 1 deletion(-) diff --git a/openbsc/include/openbsc/mgcp_transcode.h b/openbsc/include/openbsc/mgcp_transcode.h index cb11cb217..147e48bba 100644 --- a/openbsc/include/openbsc/mgcp_transcode.h +++ b/openbsc/include/openbsc/mgcp_transcode.h @@ -33,7 +33,8 @@ enum audio_format { AF_L16, AF_GSM, AF_G729, - AF_PCMA + AF_PCMA, + AF_PCMU }; diff --git a/openbsc/src/libmgcp/mgcp_sdp.c b/openbsc/src/libmgcp/mgcp_sdp.c index aa4ef3054..b64894496 100644 --- a/openbsc/src/libmgcp/mgcp_sdp.c +++ b/openbsc/src/libmgcp/mgcp_sdp.c @@ -54,6 +54,7 @@ int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec, if (!audio_name) { switch (payload_type) { + case 0: audio_name = "PCMU/8000/1"; break; case 3: audio_name = "GSM/8000/1"; break; case 8: audio_name = "PCMA/8000/1"; break; case 18: audio_name = "G729/8000/1"; break; @@ -89,6 +90,8 @@ int mgcp_set_audio_info(void *ctx, struct mgcp_rtp_codec *codec, payload_type = 3; else if (!strcmp(audio_codec, "PCMA")) payload_type = 8; + else if (!strcmp(audio_codec, "PCMU")) + payload_type = 0; else if (!strcmp(audio_codec, "G729")) payload_type = 18; } @@ -109,6 +112,11 @@ void codecs_initialize(void *ctx, struct sdp_rtp_map *codecs, int used) for (i = 0; i < used; ++i) { switch (codecs[i].payload_type) { + case 0: + codecs[i].codec_name = "PCMU"; + codecs[i].rate = 8000; + codecs[i].channels = 1; + break; case 3: codecs[i].codec_name = "GSM"; codecs[i].rate = 8000; diff --git a/openbsc/src/libmgcp/mgcp_transcode.c b/openbsc/src/libmgcp/mgcp_transcode.c index 12cce2616..c994d3291 100644 --- a/openbsc/src/libmgcp/mgcp_transcode.c +++ b/openbsc/src/libmgcp/mgcp_transcode.c @@ -52,6 +52,8 @@ static enum audio_format get_audio_format(const struct mgcp_rtp_codec *codec) return AF_GSM; if (!strcasecmp("PCMA", codec->subtype_name)) return AF_PCMA; + if (!strcasecmp("PCMU", codec->subtype_name)) + return AF_PCMU; #ifdef HAVE_BCG729 if (!strcasecmp("G729", codec->subtype_name)) return AF_G729; @@ -61,6 +63,8 @@ static enum audio_format get_audio_format(const struct mgcp_rtp_codec *codec) } switch (codec->payload_type) { + case 0 /* PCMU */: + return AF_PCMU; case 3 /* GSM */: return AF_GSM; case 8 /* PCMA */: @@ -102,6 +106,18 @@ static void alaw_decode(unsigned char *buf, short *sample, size_t n) *(sample++) = alaw_to_s16(*(buf++)); } +static void ulaw_encode(short *sample, unsigned char *buf, size_t n) +{ + for (; n > 0; --n) + *(buf++) = s16_to_ulaw(*(sample++)); +} + +static void ulaw_decode(unsigned char *buf, short *sample, size_t n) +{ + for (; n > 0; --n) + *(sample++) = ulaw_to_s16(*(buf++)); +} + static int processing_state_destructor(struct mgcp_process_rtp_state *state) { switch (state->src_fmt) { @@ -226,6 +242,7 @@ int mgcp_transcoding_setup(struct mgcp_endpoint *endp, } break; #endif + case AF_PCMU: case AF_PCMA: state->src_frame_size = 80; state->src_samples_per_frame = 80; @@ -264,6 +281,7 @@ int mgcp_transcoding_setup(struct mgcp_endpoint *endp, } break; #endif + case AF_PCMU: case AF_PCMA: state->dst_frame_size = 80; state->dst_samples_per_frame = 80; @@ -331,6 +349,10 @@ static int decode_audio(struct mgcp_process_rtp_state *state, bcg729Decoder(state->src.g729_dec, *src, 0, state->samples + state->sample_cnt); break; #endif + case AF_PCMU: + ulaw_decode(*src, state->samples + state->sample_cnt, + state->src_samples_per_frame); + break; case AF_PCMA: alaw_decode(*src, state->samples + state->sample_cnt, state->src_samples_per_frame); @@ -381,6 +403,10 @@ static int encode_audio(struct mgcp_process_rtp_state *state, state->samples + state->sample_offs, dst); break; #endif + case AF_PCMU: + ulaw_encode(state->samples + state->sample_offs, dst, + state->src_samples_per_frame); + break; case AF_PCMA: alaw_encode(state->samples + state->sample_offs, dst, state->src_samples_per_frame); -- cgit v1.2.3