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			126 lines
		
	
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			126 lines
		
	
	
	
		
			4.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/*
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 * Copyright (c) 2012 Andrew D'Addesio
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 * Copyright (c) 2013-2014 Mozilla Corporation
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 * Copyright (c) 2017 Rostislav Pehlivanov <atomnuker@gmail.com>
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 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
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 * modify it under the terms of the GNU Lesser General Public
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 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
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 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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 * Lesser General Public License for more details.
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 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 */
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#ifndef AVCODEC_OPUS_RC_H
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#define AVCODEC_OPUS_RC_H
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#include <stdint.h>
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#include "get_bits.h"
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#define OPUS_MAX_PACKET_SIZE 1275
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#define opus_ilog(i) (av_log2(i) + !!(i))
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typedef struct RawBitsContext {
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    const uint8_t *position;
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    uint32_t bytes;
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    uint32_t cachelen;
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    uint32_t cacheval;
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} RawBitsContext;
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typedef struct OpusRangeCoder {
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    GetBitContext gb;
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    RawBitsContext rb;
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    uint32_t range;
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    uint32_t value;
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    uint32_t total_bits;
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    /* Encoder */
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    uint8_t buf[OPUS_MAX_PACKET_SIZE + 12]; /* memcpy vs (memmove + overreading) */
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    uint8_t *rng_cur;                      /* Current range coded byte */
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    int ext;                               /* Awaiting propagation */
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    int rem;                               /* Carryout flag */
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    /* Encoding stats */
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    int waste;
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} OpusRangeCoder;
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/**
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 * CELT: estimate bits of entropy that have thus far been consumed for the
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 *       current CELT frame, to integer and fractional (1/8th bit) precision
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 */
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static av_always_inline uint32_t opus_rc_tell(const OpusRangeCoder *rc)
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{
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    return rc->total_bits - av_log2(rc->range) - 1;
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}
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static av_always_inline uint32_t opus_rc_tell_frac(const OpusRangeCoder *rc)
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{
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    uint32_t i, total_bits, rcbuffer, range;
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    total_bits = rc->total_bits << 3;
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    rcbuffer   = av_log2(rc->range) + 1;
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    range      = rc->range >> (rcbuffer-16);
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    for (i = 0; i < 3; i++) {
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        int bit;
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        range = range * range >> 15;
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        bit = range >> 16;
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        rcbuffer = rcbuffer << 1 | bit;
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        range >>= bit;
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    }
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    return total_bits - rcbuffer;
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}
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uint32_t ff_opus_rc_dec_cdf(OpusRangeCoder *rc, const uint16_t *cdf);
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void     ff_opus_rc_enc_cdf(OpusRangeCoder *rc, int val, const uint16_t *cdf);
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uint32_t ff_opus_rc_dec_log(OpusRangeCoder *rc, uint32_t bits);
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void     ff_opus_rc_enc_log(OpusRangeCoder *rc, int val, uint32_t bits);
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uint32_t ff_opus_rc_dec_uint_step(OpusRangeCoder *rc, int k0);
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void     ff_opus_rc_enc_uint_step(OpusRangeCoder *rc, uint32_t val, int k0);
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uint32_t ff_opus_rc_dec_uint_tri(OpusRangeCoder *rc, int qn);
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void     ff_opus_rc_enc_uint_tri(OpusRangeCoder *rc, uint32_t k, int qn);
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uint32_t ff_opus_rc_dec_uint(OpusRangeCoder *rc, uint32_t size);
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void     ff_opus_rc_enc_uint(OpusRangeCoder *rc, uint32_t val, uint32_t size);
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uint32_t ff_opus_rc_get_raw(OpusRangeCoder *rc, uint32_t count);
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void     ff_opus_rc_put_raw(OpusRangeCoder *rc, uint32_t val, uint32_t count);
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int      ff_opus_rc_dec_laplace(OpusRangeCoder *rc, uint32_t symbol, int decay);
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void     ff_opus_rc_enc_laplace(OpusRangeCoder *rc, int *value, uint32_t symbol, int decay);
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int      ff_opus_rc_dec_init(OpusRangeCoder *rc, const uint8_t *data, int size);
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void     ff_opus_rc_dec_raw_init(OpusRangeCoder *rc, const uint8_t *rightend, uint32_t bytes);
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void     ff_opus_rc_enc_end(OpusRangeCoder *rc, uint8_t *dst, int size);
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void     ff_opus_rc_enc_init(OpusRangeCoder *rc);
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#define OPUS_RC_CHECKPOINT_UPDATE(rc) \
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    rc_rollback_bits = opus_rc_tell_frac(rc); \
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    rc_rollback_ctx  = *rc
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#define OPUS_RC_CHECKPOINT_SPAWN(rc) \
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    uint32_t rc_rollback_bits = opus_rc_tell_frac(rc); \
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    OpusRangeCoder rc_rollback_ctx = *rc \
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#define OPUS_RC_CHECKPOINT_BITS(rc) \
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    (opus_rc_tell_frac(rc) - rc_rollback_bits)
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#define OPUS_RC_CHECKPOINT_ROLLBACK(rc) \
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    memcpy(rc, &rc_rollback_ctx, sizeof(OpusRangeCoder)); \
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#endif /* AVCODEC_OPUS_RC_H */
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