/* Copyright (C) 2014 Matthias P. Braendli (http://www.opendigitalradio.org) This program 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 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 General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see . dabplussnoop.cpp Parse DAB+ frames from a ETI file Authors: Matthias P. Braendli */ /* From the spec: subchannel_index = MSC sub-channel size (kbps) / 8 audio_super_frame_size (bytes) = subchannel_index * 110 // Derived from // au_start[n] = au_start[n - 1] + au_size[n - 1] + 2; // 2 bytes for CRC au_size[n] = au_start[n+1] - au_start[n] - 2; he_aac_super_frame(subchannel_index) { he_aac_super_frame_header() { header_firecode 16 rfa 1 dac_rate 1 sbr_flag 1 aac_channel_mode 1 ps_flag 1 mpeg_surround_config 3 // end of audio parameters if ((dac_rate == 0) && (sbr_flag == 1)) num_aus = 2; // AAC core sampling rate 16 kHz if ((dac_rate == 1) && (sbr_flag == 1)) num_aus = 3; // AAC core sampling rate 24 kHz if ((dac_rate == 0) && (sbr_flag == 0)) num_aus = 4; // AAC core sampling rate 32 kHz if ((dac_rate == 1) && (sbr_flag == 0)) num_aus = 6; // AAC core sampling rate 48 kHz for (n = 1; n < num_aus; n++) { au_start[n]; 12 } if !((dac_rate == 1) && (sbr_flag == 1)) alignment 4 } for (n = 0; n < num_aus; n++) { au[n] 8 * au_size[n] au_crc[n] 16 } } */ #include #include #include #include #include #include #include #include "faad_decoder.h" #ifndef __DABPLUSSNOOP_H_ #define __DABPLUSSNOOP_H_ class DabPlusSnoop { public: DabPlusSnoop() : m_index(0), m_subchannel_index(0), m_data(0) {} void set_subchannel_index(unsigned subchannel_index) { m_subchannel_index = subchannel_index; } void set_index(int index) { m_index = index; } void push(uint8_t* streamdata, size_t streamsize); void close(void); private: /* Data needed for FAAD */ FaadDecoder m_faad_decoder; int m_index; bool m_ps_flag; bool m_aac_channel_mode; bool m_dac_rate; bool m_sbr_flag; int m_mpeg_surround_config; /* Functions */ bool seek_valid_firecode(void); bool decode(void); bool extract_au(std::vector au_start); bool analyse_au(std::vector >& aus); unsigned m_subchannel_index; std::vector m_data; }; #endif