mgcp: Add RTP audio transcoding
This patch implements audio transcoding between the formats GSM, PCMA, L16, and optionally G.729. The feature needs to be enabled by using the autoconf option '--enable-mgcp-transcoding'. In this case mgcp_transcode.c will be compiled and linked to osmo-bsc_mgcp, and the transcoding functions provided will be registered as processing callbacks. If G.729 support is required, libcg729 needs to be installed and '--with-g729' must be passed to ./configure. Ticket: OW#1111 Sponsored-by: On-Waves ehf
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239a853f40
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@ -57,6 +57,21 @@ fi
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AM_CONDITIONAL(BUILD_SMPP, test "x$osmo_ac_build_smpp" = "xyes")
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AC_SUBST(osmo_ac_build_smpp)
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# Enable/disable transcoding within osmo-bsc_mgcp?
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AC_ARG_ENABLE([mgcp-transcoding], [AS_HELP_STRING([--enable-mgcp-transcoding], [Build the MGCP gateway with internal transcoding enabled.])],
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[osmo_ac_mgcp_transcoding="$enableval"],[osmo_ac_mgcp_transcoding="no"])
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AC_ARG_WITH([g729], [AS_HELP_STRING([--with-g729], [Enable G.729 encoding/decoding.])], [osmo_ac_with_g729="$withval"],[osmo_ac_with_g729="no"])
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if test "$osmo_ac_mgcp_transcoding" = "yes" ; then
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AC_SEARCH_LIBS(gsm_create, gsm)
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if test "$osmo_ac_with_g729" = "yes" ; then
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PKG_CHECK_MODULES(LIBBCG729, libbcg729 >= 0.1, [AC_DEFINE([HAVE_BCG729], [1], [Use bgc729 decoder/encoder])])
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fi
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AC_DEFINE(BUILD_MGCP_TRANSCODING, 1, [Define if we want to build the MGCP gateway with transcoding support])
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fi
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AM_CONDITIONAL(BUILD_MGCP_TRANSCODING, test "x$osmo_ac_mgcp_transcoding" = "xyes")
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AC_SUBST(osmo_ac_mgcp_transcoding)
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found_libgtp=yes
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PKG_CHECK_MODULES(LIBGTP, libgtp, , found_libgtp=no)
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@ -1,11 +1,17 @@
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AM_CPPFLAGS = $(all_includes) -I$(top_srcdir)/include -I$(top_builddir)
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AM_CFLAGS=-Wall $(LIBOSMOCORE_CFLAGS) $(LIBOSMOGSM_CFLAGS) \
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$(LIBOSMOVTY_CFLAGS) $(LIBOSMOABIS_CFLAGS) $(COVERAGE_CFLAGS)
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$(LIBOSMOVTY_CFLAGS) $(LIBOSMOABIS_CFLAGS) $(COVERAGE_CFLAGS) \
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$(LIBBCG729_CFLAGS)
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bin_PROGRAMS = osmo-bsc_mgcp
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osmo_bsc_mgcp_SOURCES = mgcp_main.c
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if BUILD_MGCP_TRANSCODING
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osmo_bsc_mgcp_SOURCES += mgcp_transcode.c
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endif
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osmo_bsc_mgcp_LDADD = $(top_builddir)/src/libcommon/libcommon.a \
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$(top_builddir)/src/libmgcp/libmgcp.a -lrt \
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$(LIBOSMOVTY_LIBS) $(LIBOSMOCORE_LIBS) \
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$(LIBOSMONETIF_LIBS)
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$(LIBOSMONETIF_LIBS) $(LIBBCG729_LIBS)
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noinst_HEADERS = g711common.h mgcp_transcode.h
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@ -0,0 +1,187 @@
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/*
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* PCM - A-Law conversion
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* Copyright (c) 2000 by Abramo Bagnara <abramo@alsa-project.org>
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*
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* Wrapper for linphone Codec class by Simon Morlat <simon.morlat@linphone.org>
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*
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
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*/
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static inline int val_seg(int val)
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{
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int r = 0;
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val >>= 7; /*7 = 4 + 3*/
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if (val & 0xf0) {
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val >>= 4;
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r += 4;
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}
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if (val & 0x0c) {
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val >>= 2;
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r += 2;
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}
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if (val & 0x02)
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r += 1;
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return r;
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}
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/*
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* s16_to_alaw() - Convert a 16-bit linear PCM value to 8-bit A-law
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*
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* s16_to_alaw() accepts an 16-bit integer and encodes it as A-law data.
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*
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* Linear Input Code Compressed Code
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* ------------------------ ---------------
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* 0000000wxyza 000wxyz
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* 0000001wxyza 001wxyz
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* 000001wxyzab 010wxyz
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* 00001wxyzabc 011wxyz
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* 0001wxyzabcd 100wxyz
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* 001wxyzabcde 101wxyz
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* 01wxyzabcdef 110wxyz
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* 1wxyzabcdefg 111wxyz
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*
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* For further information see John C. Bellamy's Digital Telephony, 1982,
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* John Wiley & Sons, pps 98-111 and 472-476.
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* G711 is designed for 13 bits input signal, this function add extra shifting to take this into account.
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*/
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static inline unsigned char s16_to_alaw(int pcm_val)
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{
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int mask;
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int seg;
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unsigned char aval;
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if (pcm_val >= 0) {
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mask = 0xD5;
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} else {
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mask = 0x55;
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pcm_val = -pcm_val;
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if (pcm_val > 0x7fff)
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pcm_val = 0x7fff;
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}
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if (pcm_val < 256) /*256 = 32 << 3*/
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aval = pcm_val >> 4; /*4 = 1 + 3*/
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else {
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/* Convert the scaled magnitude to segment number. */
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seg = val_seg(pcm_val);
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aval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0x0f);
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}
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return aval ^ mask;
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}
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/*
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* alaw_to_s16() - Convert an A-law value to 16-bit linear PCM
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*
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*/
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static inline int alaw_to_s16(unsigned char a_val)
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{
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int t;
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int seg;
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a_val ^= 0x55;
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t = a_val & 0x7f;
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if (t < 16)
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t = (t << 4) + 8;
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else {
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seg = (t >> 4) & 0x07;
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t = ((t & 0x0f) << 4) + 0x108;
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t <<= seg -1;
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}
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return ((a_val & 0x80) ? t : -t);
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}
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/*
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* s16_to_ulaw() - Convert a linear PCM value to u-law
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*
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* In order to simplify the encoding process, the original linear magnitude
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* is biased by adding 33 which shifts the encoding range from (0 - 8158) to
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* (33 - 8191). The result can be seen in the following encoding table:
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*
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* Biased Linear Input Code Compressed Code
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* ------------------------ ---------------
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* 00000001wxyza 000wxyz
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* 0000001wxyzab 001wxyz
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* 000001wxyzabc 010wxyz
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* 00001wxyzabcd 011wxyz
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* 0001wxyzabcde 100wxyz
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* 001wxyzabcdef 101wxyz
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* 01wxyzabcdefg 110wxyz
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* 1wxyzabcdefgh 111wxyz
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*
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* Each biased linear code has a leading 1 which identifies the segment
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* number. The value of the segment number is equal to 7 minus the number
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* of leading 0's. The quantization interval is directly available as the
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* four bits wxyz. * The trailing bits (a - h) are ignored.
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*
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* Ordinarily the complement of the resulting code word is used for
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* transmission, and so the code word is complemented before it is returned.
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*
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* For further information see John C. Bellamy's Digital Telephony, 1982,
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* John Wiley & Sons, pps 98-111 and 472-476.
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*/
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static inline unsigned char s16_to_ulaw(int pcm_val) /* 2's complement (16-bit range) */
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{
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int mask;
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int seg;
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unsigned char uval;
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if (pcm_val < 0) {
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pcm_val = 0x84 - pcm_val;
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mask = 0x7f;
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} else {
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pcm_val += 0x84;
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mask = 0xff;
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}
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if (pcm_val > 0x7fff)
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pcm_val = 0x7fff;
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/* Convert the scaled magnitude to segment number. */
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seg = val_seg(pcm_val);
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/*
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* Combine the sign, segment, quantization bits;
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* and complement the code word.
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*/
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uval = (seg << 4) | ((pcm_val >> (seg + 3)) & 0x0f);
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return uval ^ mask;
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}
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/*
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* ulaw_to_s16() - Convert a u-law value to 16-bit linear PCM
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*
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* First, a biased linear code is derived from the code word. An unbiased
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* output can then be obtained by subtracting 33 from the biased code.
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*
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* Note that this function expects to be passed the complement of the
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* original code word. This is in keeping with ISDN conventions.
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*/
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static inline int ulaw_to_s16(unsigned char u_val)
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{
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int t;
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/* Complement to obtain normal u-law value. */
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u_val = ~u_val;
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/*
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* Extract and bias the quantization bits. Then
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* shift up by the segment number and subtract out the bias.
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*/
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t = ((u_val & 0x0f) << 3) + 0x84;
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t <<= (u_val & 0x70) >> 4;
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return ((u_val & 0x80) ? (0x84 - t) : (t - 0x84));
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}
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@ -49,6 +49,10 @@
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#include "../../bscconfig.h"
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#ifdef BUILD_MGCP_TRANSCODING
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#include "mgcp_transcode.h"
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#endif
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/* this is here for the vty... it will never be called */
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void subscr_put() { abort(); }
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@ -207,6 +211,12 @@ int main(int argc, char **argv)
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if (!cfg)
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return -1;
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#ifdef BUILD_MGCP_TRANSCODING
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cfg->setup_rtp_processing_cb = &mgcp_transcoding_setup;
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cfg->rtp_processing_cb = &mgcp_transcoding_process_rtp;
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cfg->get_net_downlink_format_cb = &mgcp_transcoding_net_downlink_format;
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#endif
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vty_info.copyright = openbsc_copyright;
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vty_init(&vty_info);
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logging_vty_add_cmds(&log_info);
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@ -0,0 +1,452 @@
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/*
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* (C) 2014 by Sysmocom s.f.m.c. GmbH
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* (C) 2014 by On-Waves
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* All Rights Reserved
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU Affero General Public License as published by
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* the Free Software Foundation; either version 3 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Affero General Public License for more details.
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*
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* You should have received a copy of the GNU Affero General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*
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*/
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#include <stdlib.h>
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#include <string.h>
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#include <errno.h>
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#include "bscconfig.h"
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#include "g711common.h"
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#include <gsm.h>
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#ifdef HAVE_BCG729
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#include <bcg729/decoder.h>
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#include <bcg729/encoder.h>
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#endif
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#include <openbsc/debug.h>
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#include <openbsc/mgcp.h>
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#include <openbsc/mgcp_internal.h>
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#include <osmocom/core/talloc.h>
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enum audio_format {
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AF_INVALID,
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AF_S16,
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AF_L16,
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AF_GSM,
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AF_G729,
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AF_PCMA
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};
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struct mgcp_process_rtp_state {
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/* decoding */
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enum audio_format src_fmt;
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union {
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gsm gsm_handle;
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#ifdef HAVE_BCG729
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bcg729DecoderChannelContextStruct *g729_dec;
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#endif
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} src;
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size_t src_frame_size;
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size_t src_samples_per_frame;
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/* processing */
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/* encoding */
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enum audio_format dst_fmt;
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union {
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gsm gsm_handle;
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#ifdef HAVE_BCG729
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bcg729EncoderChannelContextStruct *g729_enc;
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#endif
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} dst;
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size_t dst_frame_size;
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size_t dst_samples_per_frame;
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};
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static enum audio_format get_audio_format(const struct mgcp_rtp_end *rtp_end)
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{
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if (rtp_end->subtype_name) {
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if (!strcmp("GSM", rtp_end->subtype_name))
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return AF_GSM;
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if (!strcmp("PCMA", rtp_end->subtype_name))
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return AF_PCMA;
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#ifdef HAVE_BCG729
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if (!strcmp("G729", rtp_end->subtype_name))
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return AF_G729;
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#endif
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if (!strcmp("L16", rtp_end->subtype_name))
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return AF_L16;
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}
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switch (rtp_end->payload_type) {
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case 3 /* GSM */:
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return AF_GSM;
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case 8 /* PCMA */:
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return AF_PCMA;
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#ifdef HAVE_BCG729
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case 18 /* G.729 */:
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return AF_G729;
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#endif
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case 11 /* L16 */:
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return AF_L16;
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default:
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return AF_INVALID;
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}
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}
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static void l16_encode(short *sample, unsigned char *buf, size_t n)
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{
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for (; n > 0; --n, ++sample, buf += 2) {
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buf[0] = sample[0] >> 8;
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buf[1] = sample[0] & 0xff;
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}
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}
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static void l16_decode(unsigned char *buf, short *sample, size_t n)
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{
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for (; n > 0; --n, ++sample, buf += 2)
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sample[0] = ((short)buf[0] << 8) | buf[1];
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}
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static void alaw_encode(short *sample, unsigned char *buf, size_t n)
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{
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for (; n > 0; --n)
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*(buf++) = s16_to_alaw(*(sample++));
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}
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static void alaw_decode(unsigned char *buf, short *sample, size_t n)
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{
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for (; n > 0; --n)
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*(sample++) = alaw_to_s16(*(buf++));
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}
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static int processing_state_destructor(struct mgcp_process_rtp_state *state)
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{
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switch (state->src_fmt) {
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case AF_GSM:
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if (state->dst.gsm_handle)
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gsm_destroy(state->src.gsm_handle);
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break;
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#ifdef HAVE_BCG729
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case AF_G729:
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if (state->src.g729_dec)
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closeBcg729DecoderChannel(state->src.g729_dec);
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break;
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#endif
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default:
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break;
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}
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switch (state->dst_fmt) {
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case AF_GSM:
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if (state->dst.gsm_handle)
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gsm_destroy(state->dst.gsm_handle);
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break;
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#ifdef HAVE_BCG729
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case AF_G729:
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if (state->dst.g729_enc)
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closeBcg729EncoderChannel(state->dst.g729_enc);
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break;
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#endif
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default:
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break;
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}
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return 0;
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}
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int mgcp_transcoding_setup(struct mgcp_endpoint *endp,
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struct mgcp_rtp_end *dst_end,
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struct mgcp_rtp_end *src_end)
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{
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struct mgcp_process_rtp_state *state;
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enum audio_format src_fmt, dst_fmt;
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/* cleanup first */
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if (dst_end->rtp_process_data) {
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talloc_free(dst_end->rtp_process_data);
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dst_end->rtp_process_data = NULL;
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}
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if (!src_end)
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return 0;
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src_fmt = get_audio_format(src_end);
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dst_fmt = get_audio_format(dst_end);
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LOGP(DMGCP, LOGL_ERROR,
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"Checking transcoding: %s (%d) -> %s (%d)\n",
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src_end->subtype_name, src_end->payload_type,
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dst_end->subtype_name, dst_end->payload_type);
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if (src_fmt == AF_INVALID || dst_fmt == AF_INVALID) {
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if (!src_end->subtype_name || !dst_end->subtype_name)
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/* Not enough info, do nothing */
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return 0;
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if (strcmp(src_end->subtype_name, dst_end->subtype_name) == 0)
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/* Nothing to do */
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return 0;
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LOGP(DMGCP, LOGL_ERROR,
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"Cannot transcode: %s codec not supported (%s -> %s).\n",
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src_fmt != AF_INVALID ? "destination" : "source",
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src_end->audio_name, dst_end->audio_name);
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return -EINVAL;
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||||
}
|
||||
|
||||
if (src_end->rate && dst_end->rate && src_end->rate != dst_end->rate) {
|
||||
LOGP(DMGCP, LOGL_ERROR,
|
||||
"Cannot transcode: rate conversion (%d -> %d) not supported.\n",
|
||||
src_end->rate, dst_end->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_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_PCMA:
|
||||
state->dst_frame_size = 80;
|
||||
state->dst_samples_per_frame = 80;
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
|
||||
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_end->payload_type, src_end->rate, src_end->fmtp_extra,
|
||||
dst_fmt, dst_end->payload_type, dst_end->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;
|
||||
if (!state || endp->net_end.payload_type < 0) {
|
||||
*payload_type = endp->bts_end.payload_type;
|
||||
*audio_name = endp->bts_end.audio_name;
|
||||
*fmtp_extra = endp->bts_end.fmtp_extra;
|
||||
return;
|
||||
}
|
||||
|
||||
*payload_type = endp->net_end.payload_type;
|
||||
*fmtp_extra = endp->net_end.fmtp_extra;
|
||||
*audio_name = endp->net_end.audio_name;
|
||||
}
|
||||
|
||||
|
||||
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 = dst_end->rtp_process_data;
|
||||
size_t rtp_hdr_size = 12;
|
||||
char *payload_data = data + rtp_hdr_size;
|
||||
int payload_len = *len - rtp_hdr_size;
|
||||
size_t sample_cnt = 0;
|
||||
size_t sample_idx;
|
||||
int16_t samples[10*160];
|
||||
uint8_t *src = (uint8_t *)payload_data;
|
||||
uint8_t *dst = (uint8_t *)payload_data;
|
||||
size_t nbytes = payload_len;
|
||||
size_t frame_remainder;
|
||||
|
||||
if (!state)
|
||||
return 0;
|
||||
|
||||
if (state->src_fmt == state->dst_fmt)
|
||||
return 0;
|
||||
|
||||
/* TODO: check payload type (-> G.711 comfort noise) */
|
||||
|
||||
/* Decode src into samples */
|
||||
while (nbytes >= state->src_frame_size) {
|
||||
if (sample_cnt + state->src_samples_per_frame > ARRAY_SIZE(samples)) {
|
||||
LOGP(DMGCP, LOGL_ERROR,
|
||||
"Sample buffer too small: %d > %d.\n",
|
||||
sample_cnt + state->src_samples_per_frame,
|
||||
ARRAY_SIZE(samples));
|
||||
return -ENOSPC;
|
||||
}
|
||||
switch (state->src_fmt) {
|
||||
case AF_GSM:
|
||||
if (gsm_decode(state->src.gsm_handle,
|
||||
(gsm_byte *)src, samples + 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, samples + sample_cnt);
|
||||
break;
|
||||
#endif
|
||||
case AF_PCMA:
|
||||
alaw_decode(src, samples + sample_cnt,
|
||||
state->src_samples_per_frame);
|
||||
break;
|
||||
case AF_S16:
|
||||
memmove(samples + sample_cnt, src,
|
||||
state->src_frame_size);
|
||||
break;
|
||||
case AF_L16:
|
||||
l16_decode(src, samples + sample_cnt,
|
||||
state->src_samples_per_frame);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
src += state->src_frame_size;
|
||||
nbytes -= state->src_frame_size;
|
||||
sample_cnt += state->src_samples_per_frame;
|
||||
}
|
||||
|
||||
/* Add silence if necessary */
|
||||
frame_remainder = sample_cnt % state->dst_samples_per_frame;
|
||||
if (frame_remainder) {
|
||||
size_t silence = state->dst_samples_per_frame - frame_remainder;
|
||||
if (sample_cnt + silence > ARRAY_SIZE(samples)) {
|
||||
LOGP(DMGCP, LOGL_ERROR,
|
||||
"Sample buffer too small for silence: %d > %d.\n",
|
||||
sample_cnt + silence,
|
||||
ARRAY_SIZE(samples));
|
||||
return -ENOSPC;
|
||||
}
|
||||
|
||||
while (silence > 0) {
|
||||
samples[sample_cnt] = 0;
|
||||
sample_cnt += 1;
|
||||
silence -= 1;
|
||||
}
|
||||
}
|
||||
|
||||
/* Encode samples into dst */
|
||||
sample_idx = 0;
|
||||
nbytes = 0;
|
||||
while (sample_idx + state->dst_samples_per_frame <= sample_cnt) {
|
||||
if (nbytes + state->dst_frame_size > buf_size) {
|
||||
LOGP(DMGCP, LOGL_ERROR,
|
||||
"Encoding (RTP) buffer too small: %d > %d.\n",
|
||||
nbytes + state->dst_frame_size, buf_size);
|
||||
return -ENOSPC;
|
||||
}
|
||||
switch (state->dst_fmt) {
|
||||
case AF_GSM:
|
||||
gsm_encode(state->dst.gsm_handle,
|
||||
samples + sample_idx, dst);
|
||||
break;
|
||||
#ifdef HAVE_BCG729
|
||||
case AF_G729:
|
||||
bcg729Encoder(state->dst.g729_enc,
|
||||
samples + sample_idx, dst);
|
||||
break;
|
||||
#endif
|
||||
case AF_PCMA:
|
||||
alaw_encode(samples + sample_idx, dst,
|
||||
state->src_samples_per_frame);
|
||||
break;
|
||||
case AF_S16:
|
||||
memmove(dst, samples + sample_idx, state->dst_frame_size);
|
||||
break;
|
||||
case AF_L16:
|
||||
l16_encode(samples + sample_idx, dst,
|
||||
state->src_samples_per_frame);
|
||||
break;
|
||||
default:
|
||||
break;
|
||||
}
|
||||
dst += state->dst_frame_size;
|
||||
nbytes += state->dst_frame_size;
|
||||
sample_idx += state->dst_samples_per_frame;
|
||||
}
|
||||
|
||||
*len = rtp_hdr_size + nbytes;
|
||||
/* Patch payload type */
|
||||
data[1] = (data[1] & 0x80) | (dst_end->payload_type & 0x7f);
|
||||
|
||||
return 0;
|
||||
}
|
|
@ -0,0 +1,34 @@
|
|||
/*
|
||||
* (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/>.
|
||||
*
|
||||
*/
|
||||
#ifndef OPENBSC_MGCP_TRANSCODE_H
|
||||
#define OPENBSC_MGCP_TRANSCODE_H
|
||||
|
||||
int mgcp_transcoding_setup(struct mgcp_endpoint *endp,
|
||||
struct mgcp_rtp_end *dst_end,
|
||||
struct mgcp_rtp_end *src_end);
|
||||
|
||||
void mgcp_transcoding_net_downlink_format(struct mgcp_endpoint *endp,
|
||||
int *payload_type,
|
||||
const char**audio_name,
|
||||
const char**fmtp_extra);
|
||||
|
||||
int mgcp_transcoding_process_rtp(struct mgcp_endpoint *endp,
|
||||
struct mgcp_rtp_end *dst_end,
|
||||
char *data, int *len, int buf_size);
|
||||
#endif /* OPENBSC_MGCP_TRANSCODE_H */
|
Loading…
Reference in New Issue