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144 lines
4.3 KiB
144 lines
4.3 KiB
/* |
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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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* fixed-point AC-3 encoder. |
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*/ |
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#define AC3ENC_FLOAT 0 |
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#define FFT_FLOAT 0 |
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#include "internal.h" |
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#include "audiodsp.h" |
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#include "ac3enc.h" |
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#include "eac3enc.h" |
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#include "kbdwin.h" |
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static void sum_square_butterfly(AC3EncodeContext *s, int64_t sum[4], |
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const int32_t *coef0, const int32_t *coef1, |
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int len) |
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{ |
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s->ac3dsp.sum_square_butterfly_int32(sum, coef0, coef1, len); |
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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, int32_t *coef, |
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unsigned int len) |
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{ |
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adsp->vector_clip_int32(coef, coef, COEF_MIN, COEF_MAX, len); |
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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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if (energy_cpl <= COEF_MAX) { |
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return 1048576; |
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} else { |
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uint64_t coord = energy_ch / (energy_cpl >> 24); |
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uint32_t coord32 = FFMIN(coord, 1073741824); |
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coord32 = ff_sqrt(coord32) << 9; |
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return FFMIN(coord32, COEF_MAX); |
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} |
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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_fixed_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_fixed_mdct_init(AC3EncodeContext *s) |
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{ |
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float fwin[AC3_BLOCK_SIZE]; |
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int32_t *iwin = av_malloc_array(AC3_BLOCK_SIZE, sizeof(*iwin)); |
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if (!iwin) |
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return AVERROR(ENOMEM); |
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ff_kbd_window_init(fwin, 5.0, AC3_BLOCK_SIZE); |
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for (int i = 0; i < AC3_BLOCK_SIZE; i++) |
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iwin[i] = lrintf(fwin[i] * (1 << 22)); |
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s->mdct_window = iwin; |
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s->fdsp = avpriv_alloc_fixed_dsp(s->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_mdct_init(&s->mdct, 9, 0, -1.0); |
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} |
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static av_cold int ac3_fixed_encode_init(AVCodecContext *avctx) |
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{ |
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AC3EncodeContext *s = avctx->priv_data; |
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s->fixed_point = 1; |
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s->mdct_end = ac3_fixed_mdct_end; |
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s->mdct_init = ac3_fixed_mdct_init; |
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s->allocate_sample_buffers = allocate_sample_buffers; |
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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 AVCodec ff_ac3_fixed_encoder = { |
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.name = "ac3_fixed", |
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.long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"), |
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.type = AVMEDIA_TYPE_AUDIO, |
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.id = AV_CODEC_ID_AC3, |
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.capabilities = AV_CODEC_CAP_DR1, |
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.priv_data_size = sizeof(AC3EncodeContext), |
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.init = ac3_fixed_encode_init, |
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.encode2 = ff_ac3_fixed_encode_frame, |
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.close = ff_ac3_encode_close, |
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.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32P, |
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AV_SAMPLE_FMT_NONE }, |
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.priv_class = &ff_ac3enc_class, |
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.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP, |
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.supported_samplerates = ff_ac3_sample_rate_tab, |
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#if FF_API_OLD_CHANNEL_LAYOUT |
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.channel_layouts = ff_ac3_channel_layouts, |
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#endif |
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.ch_layouts = ff_ac3_ch_layouts, |
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.defaults = ff_ac3_enc_defaults, |
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}; |
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FF_ENABLE_DEPRECATION_WARNINGS
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