/* -*- c++ -*- */ /* * @file * @author (C) 2015 by Roman Khassraf * (C) 2017 by Piotr Krysik * @section LICENSE * * Gr-gsm 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 3, or (at your option) * any later version. * * Gr-gsm 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. * * You should have received a copy of the GNU General Public License * along with gr-gsm; see the file COPYING. If not, write to * the Free Software Foundation, Inc., 51 Franklin Street, * Boston, MA 02110-1301, USA. */ #ifdef HAVE_CONFIG_H #include "config.h" #endif #include #include #include "stdio.h" #include "tch_f_decoder_impl.h" extern "C" { #include "osmocom/coding/gsm0503_coding.h" } #define DATA_BYTES 23 namespace gr { namespace gsm { static int ubits2sbits(ubit_t *ubits, sbit_t *sbits, int count) { int i; for (i = 0; i < count; i++) { if (*ubits == 0x23) { ubits++; sbits++; continue; } if ((*ubits++) & 1) *sbits++ = -127; else *sbits++ = 127; } return count; } tch_f_decoder::sptr tch_f_decoder::make(tch_mode mode, bool boundary_check) { return gnuradio::get_initial_sptr (new tch_f_decoder_impl(mode, boundary_check)); } /* * Constructor */ tch_f_decoder_impl::tch_f_decoder_impl(tch_mode mode, bool boundary_check) : gr::block("tch_f_decoder", gr::io_signature::make(0, 0, 0), gr::io_signature::make(0, 0, 0)), d_tch_mode(mode), d_collected_bursts_num(0), d_boundary_check(boundary_check), d_boundary_decode(!boundary_check), d_header_sent(false), mBlockCoder(0x10004820009ULL, 40, 224), mU(228), mP(mU.segment(184,40)), mD(mU.head(184)), mDP(mU.head(224)), mC(CONV_SIZE), mClass1_c(mC.head(378)), mClass2_c(mC.segment(378, 78)), mTCHU(189), mTCHD(260), mClass1A_d(mTCHD.head(50)), mTCHParity(0x0b, 3, 50) { //setup input/output ports message_port_register_in(pmt::mp("bursts")); set_msg_handler(pmt::mp("bursts"), boost::bind(&tch_f_decoder_impl::decode, this, _1)); message_port_register_out(pmt::mp("msgs")); message_port_register_out(pmt::mp("voice")); int j, k, B; for (k = 0; k < CONV_SIZE; k++) { B = k % 8; j = 2 * ((49 * k) % 57) + ((k % 8) / 4); interleave_trans[k] = B * 114 + j; } setCodingMode(mode); } tch_f_decoder_impl::~tch_f_decoder_impl() { } void tch_f_decoder_impl::decode(pmt::pmt_t msg) { if(!d_header_sent) { if (d_tch_mode != TCH_FS) { const unsigned char amr_nb_magic[7] = "#!AMR\n"; message_port_pub(pmt::mp("voice"), pmt::cons(pmt::PMT_NIL, pmt::make_blob(amr_nb_magic,6))); } d_header_sent = true; } d_bursts[d_collected_bursts_num] = msg; d_collected_bursts_num++; bool stolen = false; if (d_collected_bursts_num == 8) { ubit_t bursts_u[116 * 8]; d_collected_bursts_num = 0; // reorganize data for (int ii = 0; ii < 8; ii++) { pmt::pmt_t header_plus_burst = pmt::cdr(d_bursts[ii]); int8_t * burst_bits = (int8_t *)(pmt::blob_data(header_plus_burst))+sizeof(gsmtap_hdr); memcpy(&bursts_u[ii*116], &burst_bits[3],58); memcpy(&bursts_u[ii*116+58], &burst_bits[3+57+1+26],58); for (int jj = 0; jj < 57; jj++) { iBLOCK[ii*114+jj] = burst_bits[jj + 3]; iBLOCK[ii*114+jj+57] = burst_bits[jj + 88]; //88 = 3+57+1+26+1 } if ((ii <= 3 && static_cast(burst_bits[87]) == 1) || (ii >= 4 && static_cast(burst_bits[60]) == 1)) { stolen = true; } } // deinterleave for (int k = 0; k < CONV_SIZE; k++) { mC[k] = iBLOCK[interleave_trans[k]]; } // Decode stolen frames as FACCH/F if (stolen) { mVR204Coder.decode(mC, mU); mP.invert(); unsigned syndrome = mBlockCoder.syndrome(mDP); if (syndrome == 0) { unsigned char outmsg[28]; unsigned char sbuf_len=224; int i, j, c, pos=0; for(i = 0; i < sbuf_len; i += 8) { for(j = 0, c = 0; (j < 8) && (i + j < sbuf_len); j++){ c |= (!!mU.bit(i + j)) << j; } outmsg[pos++] = c & 0xff; } pmt::pmt_t first_header_plus_burst = pmt::cdr(d_bursts[0]); gsmtap_hdr * header = (gsmtap_hdr *)pmt::blob_data(first_header_plus_burst); int8_t header_plus_data[sizeof(gsmtap_hdr)+DATA_BYTES]; memcpy(header_plus_data, header, sizeof(gsmtap_hdr)); memcpy(header_plus_data+sizeof(gsmtap_hdr), outmsg, DATA_BYTES); ((gsmtap_hdr*)header_plus_data)->type = GSMTAP_TYPE_UM; pmt::pmt_t msg_binary_blob = pmt::make_blob(header_plus_data,DATA_BYTES+sizeof(gsmtap_hdr)); pmt::pmt_t msg_out = pmt::cons(pmt::PMT_NIL, msg_binary_blob); message_port_pub(pmt::mp("msgs"), msg_out); // if d_boundary_check is enabled, we set d_boundary_decode to true, when a // "Connect" or "Connect Acknowledge" message is received, and // we set d_boundary_decode back to false, when "Release" message is received if (d_boundary_check) { // check if this is a call control message if ((outmsg[3] & 0x0f) == 0x03) { // Connect specified in GSM 04.08, 9.3.5 if ((outmsg[4] & 0x3f) == 0x07) { d_boundary_decode = true; } // Connect Acknowledge specified in GSM 04.08, 9.3.6 else if ((outmsg[4] & 0x3f) == 0x0f) { d_boundary_decode = true; } // Release specified in GSM 04.08, 9.3.18 else if ((outmsg[4] & 0x3f) == 0x2d) { d_boundary_decode = false; } } } // if we are in an AMR-mode and we receive a channel mode modify message, // we set the mode according to the multirate configuration from the message // see GSM 04.18, section 9.1.5 and 10.5.2.21aa if (d_tch_mode != TCH_FS && d_tch_mode != TCH_EFR) { if (outmsg[3] == 0x06 && outmsg[4] == 0x10) { // Verify that multirate version 1 is set if ((outmsg[11] >> 5) == 1) { // the set of active codecs, max 4 modes // active_codec_set[0] corresponds to CODEC_MODE_1 with lowest bit rate // active_codec_set[3] corresponds to CODEC_MODE_4 with highest bit rate tch_mode active_codec_set[4]; uint8_t mode_count = 0; for (i = 0; i<8; i++) { if (((outmsg[12] >> i) & 0x1) == 1 && mode_count < 4) { active_codec_set[mode_count++] = static_cast(7-i); } } // check Initial Codec Mode Indicator ICMI // if ICMI == 1, then use the one defined in start mode field // else use implicit rule defined in GSM 05.09, section 3.4.3 if (((outmsg[11] >> 3) & 0x1) == 1) { // from start field setCodingMode(active_codec_set[ (outmsg[11] & 0x3) ]); } else { // implicit mode // if the set contains only 1 codec, we use that one // else if there are 2 or 3 codecs in the set, we use the one with lowest bitrate if (mode_count >= 1 && mode_count <= 3) { setCodingMode(active_codec_set[0]); } // if there are 4 codecs in the set, we use the second lowest bitrate else if (mode_count == 4) { setCodingMode(active_codec_set[1]); } } } } } } } // if voice boundary_check is enabled and d_boundary_decode is false, we are done if (d_boundary_check && !d_boundary_decode) { return; } // Decode voice frames and send to the output if (d_tch_mode == TCH_FS || d_tch_mode == TCH_EFR) { mVR204Coder.decode(mClass1_c, mTCHU); mClass2_c.sliced().copyToSegment(mTCHD, 182); // 3.1.2.1 // copy class 1 bits u[] to d[] for (unsigned k = 0; k <= 90; k++) { mTCHD[2*k] = mTCHU[k]; mTCHD[2*k+1] = mTCHU[184-k]; } // 3.1.2.1 // check parity of class 1A unsigned sentParity = (~mTCHU.peekField(91, 3)) & 0x07; unsigned calcParity = mClass1A_d.parity(mTCHParity) & 0x07; unsigned tail = mTCHU.peekField(185, 4); bool good = (sentParity == calcParity) && (tail == 0); if (good) { uint8_t frameBuffer[33]; sbit_t bursts_s[116 * 8]; int n_errors, n_bits_total; unsigned int mTCHFrameLength; ubits2sbits(bursts_u, bursts_s, 116 * 8); if (d_tch_mode == TCH_FS) // GSM-FR { mTCHFrameLength = 33; gsm0503_tch_fr_decode(frameBuffer, bursts_s, 1, 0, &n_errors, &n_bits_total); //std::cout << "Errors: " << n_errors << std::endl; } else if (d_tch_mode == TCH_EFR) // GSM-EFR { unsigned char mFrameHeader = 0x3c; // AMR Frame, consisting of a 8 bit frame header, plus the payload from decoding BitVector amrFrame(244 + 8); // Same output length as AMR 12.2 BitVector payload = amrFrame.tail(8); BitVector TCHW(260), EFRBits(244); // write frame header amrFrame.fillField(0, mFrameHeader, 8); // Undo Um's EFR bit ordering. mTCHD.unmap(GSM::g660BitOrder, 260, TCHW); // Remove repeating bits and CRC to get raw EFR frame (244 bits) for (unsigned k=0; k<71; k++) EFRBits[k] = TCHW[k] & 1; for (unsigned k=73; k<123; k++) EFRBits[k-2] = TCHW[k] & 1; for (unsigned k=125; k<178; k++) EFRBits[k-4] = TCHW[k] & 1; for (unsigned k=180; k<230; k++) EFRBits[k-6] = TCHW[k] & 1; for (unsigned k=232; k<252; k++) EFRBits[k-8] = TCHW[k] & 1; // Map bits as AMR 12.2k EFRBits.map(GSM::gAMRBitOrderTCH_AFS12_2, 244, payload); // Put the whole frame (hdr + payload) mTCHFrameLength = 32; amrFrame.pack(frameBuffer); //when itegrating with libosmocore lines above can be removed and line below uncommented, efr decoding with libosmocore need to be tested however //gsm0503_tch_fr_decode(frameBuffer, bursts_s, 1, 1, &n_errors, &n_bits_total); } message_port_pub(pmt::mp("voice"), pmt::cons(pmt::PMT_NIL, pmt::make_blob(frameBuffer,mTCHFrameLength))); } } else { // Handle inband bits, see 3.9.4.1 // OpenBTS source takes last 8 bits as inband bits for some reason. This may be either a // divergence between their implementation and GSM specification, which works because // both their encoder and decoder do it same way, or they handle the issue at some other place // SoftVector cMinus8 = mC.segment(0, mC.size() - 8); SoftVector cMinus8 = mC.segment(8, mC.size()); cMinus8.copyUnPunctured(mTCHUC, mPuncture, mPunctureLth); // 3.9.4.4 // decode from uc[] to u[] mViterbi->decode(mTCHUC, mTCHU); // 3.9.4.3 -- class 1a bits in u[] to d[] for (unsigned k=0; k < mClass1ALth; k++) { mTCHD[k] = mTCHU[k]; } // 3.9.4.3 -- class 1b bits in u[] to d[] for (unsigned k=0; k < mClass1BLth; k++) { mTCHD[k+mClass1ALth] = mTCHU[k+mClass1ALth+6]; } // Check parity unsigned sentParity = (~mTCHU.peekField(mClass1ALth,6)) & 0x3f; BitVector class1A = mTCHU.segment(0, mClass1ALth); unsigned calcParity = class1A.parity(mTCHParity) & 0x3f; bool good = (sentParity == calcParity); if (good) { unsigned char * frameBuffer = new unsigned char [mAMRFrameLth]; // AMR Frame, consisting of a 8 bit frame header, plus the payload from decoding BitVector amrFrame(mKd + 8); BitVector payload = amrFrame.tail(8); // write frame header amrFrame.fillField(0, mAMRFrameHeader, 8); // We don't unmap here, but copy the decoded bits directly // Decoder already delivers correct bit order // mTCHD.unmap(mAMRBitOrder, payload.size(), payload); mTCHD.copyTo(payload); amrFrame.pack(frameBuffer); message_port_pub(pmt::mp("voice"), pmt::cons(pmt::PMT_NIL, pmt::make_blob(frameBuffer,mAMRFrameLth))); delete[] frameBuffer; } } } } void tch_f_decoder_impl::setCodingMode(tch_mode mode) { if (mode != TCH_FS && d_tch_mode != TCH_EFR) { d_tch_mode = mode; mKd = GSM::gAMRKd[d_tch_mode]; mTCHD.resize(mKd); mTCHU.resize(mKd+6); mTCHParity = Parity(0x06f,6, GSM::gAMRClass1ALth[d_tch_mode]); mAMRBitOrder = GSM::gAMRBitOrder[d_tch_mode]; mClass1ALth = GSM::gAMRClass1ALth[d_tch_mode]; mClass1BLth = GSM::gAMRKd[d_tch_mode] - GSM::gAMRClass1ALth[d_tch_mode]; mTCHUC.resize(GSM::gAMRTCHUCLth[d_tch_mode]); mPuncture = GSM::gAMRPuncture[d_tch_mode]; mPunctureLth = GSM::gAMRPunctureLth[d_tch_mode]; mClass1A_d.dup(mTCHD.head(mClass1ALth)); switch (d_tch_mode) { case TCH_AFS12_2: mViterbi = new ViterbiTCH_AFS12_2(); mAMRFrameLth = 32; mAMRFrameHeader = 0x3c; break; case TCH_AFS10_2: mViterbi = new ViterbiTCH_AFS10_2(); mAMRFrameLth = 27; mAMRFrameHeader = 0x3c; break; case TCH_AFS7_95: mViterbi = new ViterbiTCH_AFS7_95(); mAMRFrameLth = 21; mAMRFrameHeader = 0x3c; break; case TCH_AFS7_4: mViterbi = new ViterbiTCH_AFS7_4(); mAMRFrameLth = 20; mAMRFrameHeader = 0x3c; break; case TCH_AFS6_7: mViterbi = new ViterbiTCH_AFS6_7(); mAMRFrameLth = 18; mAMRFrameHeader = 0x3c; break; case TCH_AFS5_9: mViterbi = new ViterbiTCH_AFS5_9(); mAMRFrameLth = 16; mAMRFrameHeader = 0x14; break; case TCH_AFS5_15: mViterbi = new ViterbiTCH_AFS5_15(); mAMRFrameLth = 14; mAMRFrameHeader = 0x3c; break; case TCH_AFS4_75: mViterbi = new ViterbiTCH_AFS4_75(); mAMRFrameLth = 13; mAMRFrameHeader = 0x3c; break; default: mViterbi = new ViterbiTCH_AFS12_2(); mAMRFrameLth = 32; mAMRFrameHeader = 0x3c; break; } } } } /* namespace gsm */ } /* namespace gr */