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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.
55 lines
1.5 KiB
C
55 lines
1.5 KiB
C
/*
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* E-AC-3 encoder
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* Copyright (c) 2011 Justin Ruggles <justin.ruggles@gmail.com>
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*
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* This file is part of Libav.
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*
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* Libav 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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* Libav 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 Libav; 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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/**
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* @file
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* E-AC-3 encoder
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*/
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#ifndef AVCODEC_EAC3ENC_H
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#define AVCODEC_EAC3ENC_H
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#include "ac3enc.h"
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/**
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* Initialize E-AC-3 exponent tables.
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*/
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void ff_eac3_exponent_init(void);
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/**
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* Determine frame exponent strategy use and indices.
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*/
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void ff_eac3_get_frame_exp_strategy(AC3EncodeContext *s);
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/**
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* Set coupling states.
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* This determines whether certain flags must be written to the bitstream or
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* whether they will be implicitly already known by the decoder.
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*/
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void ff_eac3_set_cpl_states(AC3EncodeContext *s);
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/**
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* Write the E-AC-3 frame header to the output bitstream.
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*/
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void ff_eac3_output_frame_header(AC3EncodeContext *s);
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#endif /* AVCODEC_EAC3ENC_H */
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