| /* -*- c++ -*- */ |
| /* |
| * @file |
| * @author (C) 2015 by Roman Khassraf <rkhassraf@gmail.com> |
| * (C) 2017 by Piotr Krysik <ptrkrysik@gmail.com> |
| * @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 <gnuradio/io_signature.h> |
| #include <grgsm/gsmtap.h> |
| #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, boost::placeholders::_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<int>(burst_bits[87]) == 1) || (ii >= 4 && static_cast<int>(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<tch_mode>(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 */ |
| |