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/* -*- c++ -*- */
/*
* 2017 by Moritz Luca Schmid, Communications Engineering Lab (CEL) / Karlsruhe Institute of Technology (KIT).
* A major part of this code is adapted from the kjmp2 library, slightly modified and written into a GNURadio block.
* Note that this is an altered version of kjmp2 and not the original library.
*/
/******************************************************************************
** kjmp2 -- a minimal MPEG-1/2 Audio Layer II decoder library **
** version 1.1 **
*******************************************************************************
** Copyright (C) 2006-2013 Martin J. Fiedler <martin.fiedler@gmx.net> **
** **
** This software is provided 'as-is', without any express or implied **
** warranty. In no event will the authors be held liable for any damages **
** arising from the use of this software. **
** **
** Permission is granted to anyone to use this software for any purpose, **
** including commercial applications, and to alter it and redistribute it **
** freely, subject to the following restrictions: **
** 1. The origin of this software must not be misrepresented; you must not **
** claim that you wrote the original software. If you use this software **
** in a product, an acknowledgment in the product documentation would **
** be appreciated but is not required. **
** 2. Altered source versions must be plainly marked as such, and must not **
** be misrepresented as being the original software. **
** 3. This notice may not be removed or altered from any source **
** distribution. **
******************************************************************************/
#ifndef INCLUDED_DAB_MP2_DECODE_BS_IMPL_H
#define INCLUDED_DAB_MP2_DECODE_BS_IMPL_H
#include <grdab/mp2_decode_bs.h>
#include <stdio.h>
#include <stdint.h>
#include <math.h>
//#include "pad-handler.h"
namespace gr {
namespace dab {
/*! \brief block that decodes DAB audio frames (= MPEG2 audio frames) to PCM frames
*
* DAB standard conform audio decoding after ETSI TS 103 466 V1.1.1
* The block always produces a stereo output. The sampling rate is 48kHz.
*
* @param bit_rate_n data rate in multiples of 8kbit/s
*/
#define KJMP2_MAX_FRAME_SIZE 1440 // the maximum size of a frame
#define KJMP2_SAMPLES_PER_FRAME 1152 // the number of samples per frame
// quantizer specification structure
struct quantizer_spec {
int32_t nlevels;
uint8_t grouping;
uint8_t cw_bits;
};
class mp2_decode_bs_impl : public mp2_decode_bs {
private:
int d_bit_rate_n;
int d_bit_rate;
int d_nproduced;
uint16_t *d_out;
int32_t d_sample_rate;
int16_t d_V_offs;
int32_t d_baud_rate;
int16_t d_mp2_framesize;
int16_t d_output_size;
int16_t d_mp2_header_OK;
int16_t d_mp2_header_count;
int16_t d_mp2_bit_count;
int16_t d_number_of_frames;
int16_t d_error_frames;
int32_t bit_window;
int32_t bits_in_window;
uint8_t *d_frame_pos;
uint8_t *d_mp2_frame;
int16_t d_V[2][1024];
int16_t d_N[64][32];
int32_t d_scfsi[2][32];
int32_t d_scalefactor[2][32][3];
int32_t d_sample[2][32][3];
int32_t d_U[512];
bool d_first;
void set_samplerate(int32_t);
int32_t mp2_samplerate(uint8_t *);
struct quantizer_spec *read_allocation(int, int);
struct quantizer_spec *d_allocation[2][32];
void read_samples(struct quantizer_spec *, int, int *);
int32_t get_bits(int32_t);
int32_t mp2_decode_frame(uint8_t *, int16_t *);
void add_bit_to_mp2(uint8_t *, uint8_t, int16_t);
public:
mp2_decode_bs_impl(int bit_rate_n);
~mp2_decode_bs_impl();
virtual int32_t get_sample_rate()
{return d_sample_rate;}
// Where all the action really happens
void forecast(int noutput_items, gr_vector_int &ninput_items_required);
int general_work(int noutput_items,
gr_vector_int &ninput_items,
gr_vector_const_void_star &input_items,
gr_vector_void_star &output_items);
};
} // namespace dab
} // namespace gr
#endif /* INCLUDED_DAB_MP2_DECODE_BS_IMPL_H */
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