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FFmpeg/libavcodec/eac3enc.h
Justin Ruggles 08a747afb9 eac3enc: use frame exponent strategy when applicable.
This checks if the set of selected exponent strategies for all blocks in a
channel are in the frame exponent strategy table, and if so, writes the
table index instead of each strategy. This saves up to 7 bits per channel per
frame, so the overall effect on quality is small.
2011-07-19 14:15:00 -04:00

55 lines
1.5 KiB
C

/*
* E-AC-3 encoder
* Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com>
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* E-AC-3 encoder
*/
#ifndef AVCODEC_EAC3ENC_H
#define AVCODEC_EAC3ENC_H
#include "ac3enc.h"
/**
* Initialize E-AC-3 exponent tables.
*/
void ff_eac3_exponent_init(void);
/**
* Determine frame exponent strategy use and indices.
*/
void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s);
/**
* Set coupling states.
* This determines whether certain flags must be written to the bitstream or
* whether they will be implicitly already known by the decoder.
*/
void ff_eac3_set_cpl_states(AC3EncodeContext *s);
/**
* Write the E-AC-3 frame header to the output bitstream.
*/
void ff_eac3_output_frame_header(AC3EncodeContext *s);
#endif /* AVCODEC_EAC3ENC_H */