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-rw-r--r--openbsc/src/libmgcp/mgcp_transcode.c612
1 files changed, 0 insertions, 612 deletions
diff --git a/openbsc/src/libmgcp/mgcp_transcode.c b/openbsc/src/libmgcp/mgcp_transcode.c
deleted file mode 100644
index f31e7aefb..000000000
--- a/openbsc/src/libmgcp/mgcp_transcode.c
+++ /dev/null
@@ -1,612 +0,0 @@
-/*
- * (C) 2014 by On-Waves
- * All Rights Reserved
- *
- * This program is free software; you can redistribute it and/or modify
- * it under the terms of the GNU Affero General Public License as published by
- * the Free Software Foundation; either version 3 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 Affero General Public License for more details.
- *
- * You should have received a copy of the GNU Affero General Public License
- * along with this program. If not, see <http://www.gnu.org/licenses/>.
- *
- */
-
-#include <stdlib.h>
-#include <string.h>
-#include <errno.h>
-
-
-#include "g711common.h"
-
-#include <openbsc/debug.h>
-#include <openbsc/mgcp.h>
-#include <openbsc/mgcp_internal.h>
-#include <openbsc/mgcp_transcode.h>
-
-#include <osmocom/core/talloc.h>
-#include <osmocom/netif/rtp.h>
-
-int mgcp_transcoding_get_frame_size(void *state_, int nsamples, int dst)
-{
- struct mgcp_process_rtp_state *state = state_;
- if (dst)
- return (nsamples >= 0 ?
- nsamples / state->dst_samples_per_frame :
- 1) * state->dst_frame_size;
- else
- return (nsamples >= 0 ?
- nsamples / state->src_samples_per_frame :
- 1) * state->src_frame_size;
-}
-
-static enum audio_format get_audio_format(const struct mgcp_rtp_codec *codec)
-{
- if (codec->subtype_name) {
- if (!strcasecmp("GSM", codec->subtype_name))
- 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;
-#endif
- if (!strcasecmp("L16", codec->subtype_name))
- return AF_L16;
- }
-
- switch (codec->payload_type) {
- case 0 /* PCMU */:
- return AF_PCMU;
- case 3 /* GSM */:
- return AF_GSM;
- case 8 /* PCMA */:
- return AF_PCMA;
-#ifdef HAVE_BCG729
- case 18 /* G.729 */:
- return AF_G729;
-#endif
- case 11 /* L16 */:
- return AF_L16;
- default:
- return AF_INVALID;
- }
-}
-
-static void l16_encode(short *sample, unsigned char *buf, size_t n)
-{
- for (; n > 0; --n, ++sample, buf += 2) {
- buf[0] = sample[0] >> 8;
- buf[1] = sample[0] & 0xff;
- }
-}
-
-static void l16_decode(unsigned char *buf, short *sample, size_t n)
-{
- for (; n > 0; --n, ++sample, buf += 2)
- sample[0] = ((short)buf[0] << 8) | buf[1];
-}
-
-static void alaw_encode(short *sample, unsigned char *buf, size_t n)
-{
- for (; n > 0; --n)
- *(buf++) = s16_to_alaw(*(sample++));
-}
-
-static void alaw_decode(unsigned char *buf, short *sample, size_t n)
-{
- for (; n > 0; --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) {
- case AF_GSM:
- if (state->src.gsm_handle)
- gsm_destroy(state->src.gsm_handle);
- break;
-#ifdef HAVE_BCG729
- case AF_G729:
- if (state->src.g729_dec)
- closeBcg729DecoderChannel(state->src.g729_dec);
- break;
-#endif
- default:
- break;
- }
- switch (state->dst_fmt) {
- case AF_GSM:
- if (state->dst.gsm_handle)
- gsm_destroy(state->dst.gsm_handle);
- break;
-#ifdef HAVE_BCG729
- case AF_G729:
- if (state->dst.g729_enc)
- closeBcg729EncoderChannel(state->dst.g729_enc);
- break;
-#endif
- default:
- break;
- }
- return 0;
-}
-
-int mgcp_transcoding_setup(struct mgcp_endpoint *endp,
- struct mgcp_rtp_end *dst_end,
- struct mgcp_rtp_end *src_end)
-{
- struct mgcp_process_rtp_state *state;
- enum audio_format src_fmt, dst_fmt;
- const struct mgcp_rtp_codec *dst_codec = &dst_end->codec;
-
- /* cleanup first */
- if (dst_end->rtp_process_data) {
- talloc_free(dst_end->rtp_process_data);
- dst_end->rtp_process_data = NULL;
- }
-
- if (!src_end)
- return 0;
-
- const struct mgcp_rtp_codec *src_codec = &src_end->codec;
-
- if (endp->tcfg->no_audio_transcoding) {
- LOGP(DMGCP, LOGL_NOTICE,
- "Transcoding disabled on endpoint 0x%x\n",
- ENDPOINT_NUMBER(endp));
- return 0;
- }
-
- src_fmt = get_audio_format(src_codec);
- dst_fmt = get_audio_format(dst_codec);
-
- LOGP(DMGCP, LOGL_ERROR,
- "Checking transcoding: %s (%d) -> %s (%d)\n",
- src_codec->subtype_name, src_codec->payload_type,
- dst_codec->subtype_name, dst_codec->payload_type);
-
- if (src_fmt == AF_INVALID || dst_fmt == AF_INVALID) {
- if (!src_codec->subtype_name || !dst_codec->subtype_name)
- /* Not enough info, do nothing */
- return 0;
-
- if (strcasecmp(src_codec->subtype_name, dst_codec->subtype_name) == 0)
- /* Nothing to do */
- return 0;
-
- LOGP(DMGCP, LOGL_ERROR,
- "Cannot transcode: %s codec not supported (%s -> %s).\n",
- src_fmt != AF_INVALID ? "destination" : "source",
- src_codec->audio_name, dst_codec->audio_name);
- return -EINVAL;
- }
-
- if (src_codec->rate && dst_codec->rate && src_codec->rate != dst_codec->rate) {
- LOGP(DMGCP, LOGL_ERROR,
- "Cannot transcode: rate conversion (%d -> %d) not supported.\n",
- src_codec->rate, dst_codec->rate);
- return -EINVAL;
- }
-
- state = talloc_zero(endp->tcfg->cfg, struct mgcp_process_rtp_state);
- talloc_set_destructor(state, processing_state_destructor);
- dst_end->rtp_process_data = state;
-
- state->src_fmt = src_fmt;
-
- switch (state->src_fmt) {
- case AF_L16:
- case AF_S16:
- state->src_frame_size = 80 * sizeof(short);
- state->src_samples_per_frame = 80;
- break;
- case AF_GSM:
- state->src_frame_size = sizeof(gsm_frame);
- state->src_samples_per_frame = 160;
- state->src.gsm_handle = gsm_create();
- if (!state->src.gsm_handle) {
- LOGP(DMGCP, LOGL_ERROR,
- "Failed to initialize GSM decoder.\n");
- return -EINVAL;
- }
- break;
-#ifdef HAVE_BCG729
- case AF_G729:
- state->src_frame_size = 10;
- state->src_samples_per_frame = 80;
- state->src.g729_dec = initBcg729DecoderChannel();
- if (!state->src.g729_dec) {
- LOGP(DMGCP, LOGL_ERROR,
- "Failed to initialize G.729 decoder.\n");
- return -EINVAL;
- }
- break;
-#endif
- case AF_PCMU:
- case AF_PCMA:
- state->src_frame_size = 80;
- state->src_samples_per_frame = 80;
- break;
- default:
- break;
- }
-
- state->dst_fmt = dst_fmt;
-
- switch (state->dst_fmt) {
- case AF_L16:
- case AF_S16:
- state->dst_frame_size = 80*sizeof(short);
- state->dst_samples_per_frame = 80;
- break;
- case AF_GSM:
- state->dst_frame_size = sizeof(gsm_frame);
- state->dst_samples_per_frame = 160;
- state->dst.gsm_handle = gsm_create();
- if (!state->dst.gsm_handle) {
- LOGP(DMGCP, LOGL_ERROR,
- "Failed to initialize GSM encoder.\n");
- return -EINVAL;
- }
- break;
-#ifdef HAVE_BCG729
- case AF_G729:
- state->dst_frame_size = 10;
- state->dst_samples_per_frame = 80;
- state->dst.g729_enc = initBcg729EncoderChannel();
- if (!state->dst.g729_enc) {
- LOGP(DMGCP, LOGL_ERROR,
- "Failed to initialize G.729 decoder.\n");
- return -EINVAL;
- }
- break;
-#endif
- case AF_PCMU:
- case AF_PCMA:
- state->dst_frame_size = 80;
- state->dst_samples_per_frame = 80;
- break;
- default:
- break;
- }
-
- if (dst_end->force_output_ptime)
- state->dst_packet_duration = mgcp_rtp_packet_duration(endp, dst_end);
-
- LOGP(DMGCP, LOGL_INFO,
- "Initialized RTP processing on: 0x%x "
- "conv: %d (%d, %d, %s) -> %d (%d, %d, %s)\n",
- ENDPOINT_NUMBER(endp),
- src_fmt, src_codec->payload_type, src_codec->rate, src_end->fmtp_extra,
- dst_fmt, dst_codec->payload_type, dst_codec->rate, dst_end->fmtp_extra);
-
- return 0;
-}
-
-void mgcp_transcoding_net_downlink_format(struct mgcp_endpoint *endp,
- int *payload_type,
- const char**audio_name,
- const char**fmtp_extra)
-{
- struct mgcp_process_rtp_state *state = endp->net_end.rtp_process_data;
- struct mgcp_rtp_codec *net_codec = &endp->net_end.codec;
- struct mgcp_rtp_codec *bts_codec = &endp->bts_end.codec;
-
- if (!state || net_codec->payload_type < 0) {
- *payload_type = bts_codec->payload_type;
- *audio_name = bts_codec->audio_name;
- *fmtp_extra = endp->bts_end.fmtp_extra;
- return;
- }
-
- *payload_type = net_codec->payload_type;
- *audio_name = net_codec->audio_name;
- *fmtp_extra = endp->net_end.fmtp_extra;
-}
-
-static int decode_audio(struct mgcp_process_rtp_state *state,
- uint8_t **src, size_t *nbytes)
-{
- while (*nbytes >= state->src_frame_size) {
- if (state->sample_cnt + state->src_samples_per_frame > ARRAY_SIZE(state->samples)) {
- LOGP(DMGCP, LOGL_ERROR,
- "Sample buffer too small: %zu > %zu.\n",
- state->sample_cnt + state->src_samples_per_frame,
- ARRAY_SIZE(state->samples));
- return -ENOSPC;
- }
- switch (state->src_fmt) {
- case AF_GSM:
- if (gsm_decode(state->src.gsm_handle,
- (gsm_byte *)*src, state->samples + state->sample_cnt) < 0) {
- LOGP(DMGCP, LOGL_ERROR,
- "Failed to decode GSM.\n");
- return -EINVAL;
- }
- break;
-#ifdef HAVE_BCG729
- case AF_G729:
- 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);
- break;
- case AF_S16:
- memmove(state->samples + state->sample_cnt, *src,
- state->src_frame_size);
- break;
- case AF_L16:
- l16_decode(*src, state->samples + state->sample_cnt,
- state->src_samples_per_frame);
- break;
- default:
- break;
- }
- *src += state->src_frame_size;
- *nbytes -= state->src_frame_size;
- state->sample_cnt += state->src_samples_per_frame;
- }
- return 0;
-}
-
-static int encode_audio(struct mgcp_process_rtp_state *state,
- uint8_t *dst, size_t buf_size, size_t max_samples)
-{
- int nbytes = 0;
- size_t nsamples = 0;
- /* Encode samples into dst */
- while (nsamples + state->dst_samples_per_frame <= max_samples) {
- if (nbytes + state->dst_frame_size > buf_size) {
- if (nbytes > 0)
- break;
-
- /* Not even one frame fits into the buffer */
- LOGP(DMGCP, LOGL_INFO,
- "Encoding (RTP) buffer too small: %zu > %zu.\n",
- nbytes + state->dst_frame_size, buf_size);
- return -ENOSPC;
- }
- switch (state->dst_fmt) {
- case AF_GSM:
- gsm_encode(state->dst.gsm_handle,
- state->samples + state->sample_offs, dst);
- break;
-#ifdef HAVE_BCG729
- case AF_G729:
- bcg729Encoder(state->dst.g729_enc,
- 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);
- break;
- case AF_S16:
- memmove(dst, state->samples + state->sample_offs,
- state->dst_frame_size);
- break;
- case AF_L16:
- l16_encode(state->samples + state->sample_offs, dst,
- state->src_samples_per_frame);
- break;
- default:
- break;
- }
- dst += state->dst_frame_size;
- nbytes += state->dst_frame_size;
- state->sample_offs += state->dst_samples_per_frame;
- nsamples += state->dst_samples_per_frame;
- }
- state->sample_cnt -= nsamples;
- return nbytes;
-}
-
-static struct mgcp_rtp_end *source_for_dest(struct mgcp_endpoint *endp,
- struct mgcp_rtp_end *dst_end)
-{
- if (&endp->bts_end == dst_end)
- return &endp->net_end;
- else if (&endp->net_end == dst_end)
- return &endp->bts_end;
- OSMO_ASSERT(0);
-}
-
-/*
- * With some modems we get offered multiple codecs
- * and we have selected one of them. It might not
- * be the right one and we need to detect this with
- * the first audio packets. One difficulty is that
- * we patch the rtp payload type in place, so we
- * need to discuss this.
- */
-struct mgcp_process_rtp_state *check_transcode_state(
- struct mgcp_endpoint *endp,
- struct mgcp_rtp_end *dst_end,
- struct rtp_hdr *rtp_hdr)
-{
- struct mgcp_rtp_end *src_end;
-
- /* Only deal with messages from net to bts */
- if (&endp->bts_end != dst_end)
- goto done;
-
- src_end = source_for_dest(endp, dst_end);
-
- /* Already patched */
- if (rtp_hdr->payload_type == dst_end->codec.payload_type)
- goto done;
- /* The payload we expect */
- if (rtp_hdr->payload_type == src_end->codec.payload_type)
- goto done;
- /* The matching alternate payload type? Then switch */
- if (rtp_hdr->payload_type == src_end->alt_codec.payload_type) {
- struct mgcp_config *cfg = endp->cfg;
- struct mgcp_rtp_codec tmp_codec = src_end->alt_codec;
- src_end->alt_codec = src_end->codec;
- src_end->codec = tmp_codec;
- cfg->setup_rtp_processing_cb(endp, &endp->net_end, &endp->bts_end);
- cfg->setup_rtp_processing_cb(endp, &endp->bts_end, &endp->net_end);
- }
-
-done:
- return dst_end->rtp_process_data;
-}
-
-int mgcp_transcoding_process_rtp(struct mgcp_endpoint *endp,
- struct mgcp_rtp_end *dst_end,
- char *data, int *len, int buf_size)
-{
- struct mgcp_process_rtp_state *state;
- const size_t rtp_hdr_size = sizeof(struct rtp_hdr);
- struct rtp_hdr *rtp_hdr = (struct rtp_hdr *) data;
- char *payload_data = (char *) &rtp_hdr->data[0];
- int payload_len = *len - rtp_hdr_size;
- uint8_t *src = (uint8_t *)payload_data;
- uint8_t *dst = (uint8_t *)payload_data;
- size_t nbytes = payload_len;
- size_t nsamples;
- size_t max_samples;
- uint32_t ts_no;
- int rc;
-
- state = check_transcode_state(endp, dst_end, rtp_hdr);
- if (!state)
- return 0;
-
- if (state->src_fmt == state->dst_fmt) {
- if (!state->dst_packet_duration)
- return 0;
-
- /* TODO: repackage without transcoding */
- }
-
- /* If the remaining samples do not fit into a fixed ptime,
- * a) discard them, if the next packet is much later
- * b) add silence and * send it, if the current packet is not
- * yet too late
- * c) append the sample data, if the timestamp matches exactly
- */
-
- /* TODO: check payload type (-> G.711 comfort noise) */
-
- if (payload_len > 0) {
- ts_no = ntohl(rtp_hdr->timestamp);
- if (!state->is_running) {
- state->next_seq = ntohs(rtp_hdr->sequence);
- state->next_time = ts_no;
- state->is_running = 1;
- }
-
-
- if (state->sample_cnt > 0) {
- int32_t delta = ts_no - state->next_time;
- /* TODO: check sequence? reordering? packet loss? */
-
- if (delta > state->sample_cnt) {
- /* There is a time gap between the last packet
- * and the current one. Just discard the
- * partial data that is left in the buffer.
- * TODO: This can be improved by adding silence
- * instead if the delta is small enough.
- */
- LOGP(DMGCP, LOGL_NOTICE,
- "0x%x dropping sample buffer due delta=%d sample_cnt=%zu\n",
- ENDPOINT_NUMBER(endp), delta, state->sample_cnt);
- state->sample_cnt = 0;
- state->next_time = ts_no;
- } else if (delta < 0) {
- LOGP(DMGCP, LOGL_NOTICE,
- "RTP time jumps backwards, delta = %d, "
- "discarding buffered samples\n",
- delta);
- state->sample_cnt = 0;
- state->sample_offs = 0;
- return -EAGAIN;
- }
-
- /* Make sure the samples start without offset */
- if (state->sample_offs && state->sample_cnt)
- memmove(&state->samples[0],
- &state->samples[state->sample_offs],
- state->sample_cnt *
- sizeof(state->samples[0]));
- }
-
- state->sample_offs = 0;
-
- /* Append decoded audio to samples */
- decode_audio(state, &src, &nbytes);
-
- if (nbytes > 0)
- LOGP(DMGCP, LOGL_NOTICE,
- "Skipped audio frame in RTP packet: %zu octets\n",
- nbytes);
- } else
- ts_no = state->next_time;
-
- if (state->sample_cnt < state->dst_packet_duration)
- return -EAGAIN;
-
- max_samples =
- state->dst_packet_duration ?
- state->dst_packet_duration : state->sample_cnt;
-
- nsamples = state->sample_cnt;
-
- rc = encode_audio(state, dst, buf_size, max_samples);
- /*
- * There were no samples to encode?
- * TODO: how does this work for comfort noise?
- */
- if (rc == 0)
- return -ENOMSG;
- /* Any other error during the encoding */
- if (rc < 0)
- return rc;
-
- nsamples -= state->sample_cnt;
-
- *len = rtp_hdr_size + rc;
- rtp_hdr->sequence = htons(state->next_seq);
- rtp_hdr->timestamp = htonl(ts_no);
-
- state->next_seq += 1;
- state->next_time = ts_no + nsamples;
-
- /*
- * XXX: At this point we should always have consumed
- * samples. So doing OSMO_ASSERT(nsamples > 0) and returning
- * rtp_hdr_size should be fine.
- */
- return nsamples ? rtp_hdr_size : 0;
-}