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This is possible, because every given FFCodec has to implement exactly one of these. Doing so decreases sizeof(FFCodec) and therefore decreases the size of the binary. Notice that in case of position-independent code the decrease is in .data.rel.ro, so that this translates to decreased memory consumption. Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
149 lines
4.4 KiB
C
149 lines
4.4 KiB
C
/*
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* The simplest AC-3 encoder
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* Copyright (c) 2000 Fabrice Bellard
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* Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
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* Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
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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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/**
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* @file
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* floating-point AC-3 encoder.
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*/
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#define AC3ENC_FLOAT 1
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#include "audiodsp.h"
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#include "ac3enc.h"
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#include "codec_internal.h"
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#include "eac3enc.h"
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#include "kbdwin.h"
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/*
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* Scale MDCT coefficients from float to 24-bit fixed-point.
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*/
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static void scale_coefficients(AC3EncodeContext *s)
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{
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int chan_size = AC3_MAX_COEFS * s->num_blocks;
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int cpl = s->cpl_on;
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s->ac3dsp.float_to_fixed24(s->fixed_coef_buffer + (chan_size * !cpl),
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s->mdct_coef_buffer + (chan_size * !cpl),
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chan_size * (s->channels + cpl));
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}
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/*
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* Clip MDCT coefficients to allowable range.
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*/
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static void clip_coefficients(AudioDSPContext *adsp, float *coef,
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unsigned int len)
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{
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adsp->vector_clipf(coef, coef, len, COEF_MIN, COEF_MAX);
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}
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/*
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* Calculate a single coupling coordinate.
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*/
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static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl)
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{
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float coord = 0.125;
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if (energy_cpl > 0)
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coord *= sqrtf(energy_ch / energy_cpl);
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return FFMIN(coord, COEF_MAX);
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}
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static void sum_square_butterfly(AC3EncodeContext *s, float sum[4],
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const float *coef0, const float *coef1,
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int len)
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{
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s->ac3dsp.sum_square_butterfly_float(sum, coef0, coef1, len);
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}
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#include "ac3enc_template.c"
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/**
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* Finalize MDCT and free allocated memory.
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*
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* @param s AC-3 encoder private context
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*/
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static av_cold void ac3_float_mdct_end(AC3EncodeContext *s)
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{
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ff_mdct_end(&s->mdct);
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}
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/**
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* Initialize MDCT tables.
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*
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* @param s AC-3 encoder private context
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* @return 0 on success, negative error code on failure
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*/
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static av_cold int ac3_float_mdct_init(AC3EncodeContext *s)
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{
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float *window = av_malloc_array(AC3_BLOCK_SIZE, sizeof(*window));
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if (!window) {
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av_log(s->avctx, AV_LOG_ERROR, "Cannot allocate memory.\n");
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return AVERROR(ENOMEM);
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}
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ff_kbd_window_init(window, 5.0, AC3_BLOCK_SIZE);
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s->mdct_window = window;
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return ff_mdct_init(&s->mdct, 9, 0, -2.0 / AC3_WINDOW_SIZE);
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}
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av_cold int ff_ac3_float_encode_init(AVCodecContext *avctx)
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{
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AC3EncodeContext *s = avctx->priv_data;
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s->mdct_end = ac3_float_mdct_end;
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s->mdct_init = ac3_float_mdct_init;
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s->allocate_sample_buffers = allocate_sample_buffers;
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s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
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if (!s->fdsp)
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return AVERROR(ENOMEM);
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return ff_ac3_encode_init(avctx);
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}
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FF_DISABLE_DEPRECATION_WARNINGS
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const FFCodec ff_ac3_encoder = {
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.p.name = "ac3",
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.p.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
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.p.type = AVMEDIA_TYPE_AUDIO,
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.p.id = AV_CODEC_ID_AC3,
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.p.capabilities = AV_CODEC_CAP_DR1,
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.priv_data_size = sizeof(AC3EncodeContext),
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.init = ff_ac3_float_encode_init,
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FF_CODEC_ENCODE_CB(ff_ac3_float_encode_frame),
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.close = ff_ac3_encode_close,
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.p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP,
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AV_SAMPLE_FMT_NONE },
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.p.priv_class = &ff_ac3enc_class,
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.p.supported_samplerates = ff_ac3_sample_rate_tab,
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#if FF_API_OLD_CHANNEL_LAYOUT
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.p.channel_layouts = ff_ac3_channel_layouts,
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#endif
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.p.ch_layouts = ff_ac3_ch_layouts,
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.defaults = ff_ac3_enc_defaults,
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.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
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};
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FF_ENABLE_DEPRECATION_WARNINGS
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