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* Shared functions between AMR codecs
* Copyright (c) 2010 Marcelo Galvao Povoa
* This file is part of FFmpeg.
* FFmpeg is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
* FFmpeg is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* Lesser General Public License for more details.
* You should have received a copy of the GNU Lesser General Public
* License along with FFmpeg; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
#include <string.h>
#include "avcodec.h"
typedef uint16_t R_TABLE_TYPE;
typedef uint8_t R_TABLE_TYPE;
* Fill the frame structure variables from bitstream by parsing the
* given reordering table that uses the following format:
* Each field (16 bits) in the AMR Frame is stored as:
* - one byte for the number of bits in the field
* - one byte for the field index
* - then, one byte for each bit of the field (from most-significant to least)
* of the position of that bit in the AMR frame.
* @param out pointer to the frame struct
* @param size the size in bytes of the frame struct
* @param data input bitstream after the frame header
* @param ord_table the reordering table as above
static inline void ff_amr_bit_reorder(uint16_t *out, int size,
const uint8_t *data,
const R_TABLE_TYPE *ord_table)
int field_size;
memset(out, 0, size);
while ((field_size = *ord_table++)) {
int field = 0;
int field_offset = *ord_table++;
while (field_size--) {
int bit = *ord_table++;
field <<= 1;
field |= data[bit >> 3] >> (bit & 7) & 1;
out[field_offset >> 1] = field;
#endif /* AVCODEC_AMR_H */