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Diffstat (limited to 'src/dabplussnoop.hpp')
-rw-r--r-- | src/dabplussnoop.hpp | 133 |
1 files changed, 133 insertions, 0 deletions
diff --git a/src/dabplussnoop.hpp b/src/dabplussnoop.hpp new file mode 100644 index 0000000..865a35e --- /dev/null +++ b/src/dabplussnoop.hpp @@ -0,0 +1,133 @@ +/* + 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 <http://www.gnu.org/licenses/>. + + dabplussnoop.cpp + Parse DAB+ frames from a ETI file + + Authors: + Matthias P. Braendli <matthias@mpb.li> +*/ + +/* 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 <stdio.h> +#include <stdint.h> +#include <stdlib.h> +#include <string.h> +#include <string> +#include <sstream> +#include <vector> +#include "faad_decoder.hpp" + +#ifndef __DABPLUSSNOOP_H_ +#define __DABPLUSSNOOP_H_ + + +class DabPlusSnoop +{ + public: + DabPlusSnoop() : + m_index(0), + m_subchannel_index(0), + m_data(0), + m_raw_data_stream_fd(NULL) {} + + 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<int> au_start); + bool analyse_au(std::vector<std::vector<uint8_t> >& aus); + + unsigned m_subchannel_index; + std::vector<uint8_t> m_data; + + FILE* m_raw_data_stream_fd; +}; + +#endif + |