ffmpeg / libavcodec / nellymoserenc.c @ 7d485f16
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/*


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* Nellymoser encoder

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* This code is developed as part of Google Summer of Code 2008 Program.

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*

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* Copyright (c) 2008 Bartlomiej Wolowiec

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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 021101301 USA

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*/

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/**

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* @file libavcodec/nellymoserenc.c

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* Nellymoser encoder

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* by Bartlomiej Wolowiec

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*

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* Generic codec information: libavcodec/nellymoserdec.c

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*

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* Some information also from: http://samples.mplayerhq.hu/Acodecs/Nelly_Moser/ASAO/ASAO.zip

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* (Copyright Joseph Artsimovich and UAB "DKD")

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*

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* for more information about nellymoser format, visit:

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* http://wiki.multimedia.cx/index.php?title=Nellymoser

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*/

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#include "nellymoser.h" 
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#include "avcodec.h" 
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#include "dsputil.h" 
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#define BITSTREAM_WRITER_LE

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#include "put_bits.h" 
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#define POW_TABLE_SIZE (1<<11) 
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#define POW_TABLE_OFFSET 3 
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#define OPT_SIZE ((1<<15) + 3000) 
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typedef struct NellyMoserEncodeContext { 
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AVCodecContext *avctx; 
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int last_frame;

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int bufsel;

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int have_saved;

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DSPContext dsp; 
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MDCTContext mdct_ctx; 
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DECLARE_ALIGNED_16(float, mdct_out[NELLY_SAMPLES]);

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DECLARE_ALIGNED_16(float, buf[2][3 * NELLY_BUF_LEN]); ///< sample buffer 
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float (*opt )[NELLY_BANDS];

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uint8_t (*path)[NELLY_BANDS]; 
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} NellyMoserEncodeContext; 
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static float pow_table[POW_TABLE_SIZE]; ///< pow(2, i / 2048.0  3.0); 
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static const uint8_t sf_lut[96] = { 
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0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 
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5, 5, 5, 6, 7, 7, 8, 8, 9, 10, 11, 11, 12, 13, 13, 14, 
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15, 15, 16, 17, 17, 18, 19, 19, 20, 21, 22, 22, 23, 24, 25, 26, 
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27, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 
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41, 41, 42, 43, 44, 45, 45, 46, 47, 48, 49, 50, 51, 52, 52, 53, 
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54, 55, 55, 56, 57, 57, 58, 59, 59, 60, 60, 60, 61, 61, 61, 62, 
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}; 
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static const uint8_t sf_delta_lut[78] = { 
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0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 3, 3, 3, 4, 4, 
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4, 5, 5, 5, 6, 6, 7, 7, 8, 8, 9, 10, 10, 11, 11, 12, 
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13, 13, 14, 15, 16, 17, 17, 18, 19, 19, 20, 21, 21, 22, 22, 23, 
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23, 24, 24, 25, 25, 25, 26, 26, 26, 26, 27, 27, 27, 27, 27, 28, 
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28, 28, 28, 28, 28, 29, 29, 29, 29, 29, 29, 29, 29, 30, 
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}; 
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static const uint8_t quant_lut[230] = { 
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0,

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0, 1, 2, 
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0, 1, 2, 3, 4, 5, 6, 
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0, 1, 1, 2, 2, 3, 3, 4, 5, 6, 7, 8, 9, 10, 11, 11, 
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12, 13, 13, 13, 14, 
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0, 1, 1, 2, 2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 7, 8, 
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8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 
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22, 23, 23, 24, 24, 25, 25, 26, 26, 27, 27, 28, 28, 29, 29, 29, 
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30,

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0, 1, 1, 1, 1, 1, 1, 2, 2, 2, 2, 2, 3, 3, 3, 3, 
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4, 4, 4, 5, 5, 5, 6, 6, 7, 7, 7, 8, 8, 9, 9, 9, 
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10, 10, 11, 11, 11, 12, 12, 13, 13, 13, 13, 14, 14, 14, 15, 15, 
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15, 15, 16, 16, 16, 17, 17, 17, 18, 18, 18, 19, 19, 20, 20, 20, 
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21, 21, 22, 22, 23, 23, 24, 25, 26, 26, 27, 28, 29, 30, 31, 32, 
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33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 42, 43, 44, 44, 45, 45, 
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46, 47, 47, 48, 48, 49, 49, 50, 50, 50, 51, 51, 51, 52, 52, 52, 
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53, 53, 53, 54, 54, 54, 55, 55, 55, 56, 56, 56, 57, 57, 57, 57, 
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58, 58, 58, 58, 59, 59, 59, 59, 60, 60, 60, 60, 60, 61, 61, 61, 
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61, 61, 61, 61, 62, 
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}; 
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static const float quant_lut_mul[7] = { 0.0, 0.0, 2.0, 2.0, 5.0, 12.0, 36.6 }; 
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static const float quant_lut_add[7] = { 0.0, 0.0, 2.0, 7.0, 21.0, 56.0, 157.0 }; 
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static const uint8_t quant_lut_offset[8] = { 0, 0, 1, 4, 11, 32, 81, 230 }; 
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void apply_mdct(NellyMoserEncodeContext *s)

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{ 
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DECLARE_ALIGNED_16(float, in_buff[NELLY_SAMPLES]);

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memcpy(in_buff, s>buf[s>bufsel], NELLY_BUF_LEN * sizeof(float)); 
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s>dsp.vector_fmul(in_buff, ff_sine_128, NELLY_BUF_LEN); 
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s>dsp.vector_fmul_reverse(in_buff + NELLY_BUF_LEN, s>buf[s>bufsel] + NELLY_BUF_LEN, ff_sine_128, 
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NELLY_BUF_LEN); 
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ff_mdct_calc(&s>mdct_ctx, s>mdct_out, in_buff); 
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s>dsp.vector_fmul(s>buf[s>bufsel] + NELLY_BUF_LEN, ff_sine_128, NELLY_BUF_LEN); 
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s>dsp.vector_fmul_reverse(s>buf[s>bufsel] + 2 * NELLY_BUF_LEN, s>buf[1  s>bufsel], ff_sine_128, 
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NELLY_BUF_LEN); 
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ff_mdct_calc(&s>mdct_ctx, s>mdct_out + NELLY_BUF_LEN, s>buf[s>bufsel] + NELLY_BUF_LEN); 
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} 
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static av_cold int encode_init(AVCodecContext *avctx) 
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{ 
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NellyMoserEncodeContext *s = avctx>priv_data; 
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int i;

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if (avctx>channels != 1) { 
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av_log(avctx, AV_LOG_ERROR, "Nellymoser supports only 1 channel\n");

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return 1; 
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} 
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if (avctx>sample_rate != 8000 && avctx>sample_rate != 16000 && 
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avctx>sample_rate != 11025 &&

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avctx>sample_rate != 22050 && avctx>sample_rate != 44100 && 
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avctx>strict_std_compliance >= FF_COMPLIANCE_NORMAL) { 
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av_log(avctx, AV_LOG_ERROR, "Nellymoser works only with 8000, 16000, 11025, 22050 and 44100 sample rate\n");

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return 1; 
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} 
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avctx>frame_size = NELLY_SAMPLES; 
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s>avctx = avctx; 
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ff_mdct_init(&s>mdct_ctx, 8, 0, 1.0); 
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dsputil_init(&s>dsp, avctx); 
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/* Generate overlap window */

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ff_sine_window_init(ff_sine_128, 128);

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for (i = 0; i < POW_TABLE_SIZE; i++) 
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pow_table[i] = pow(2, i / 2048.0  3.0 + POW_TABLE_OFFSET); 
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if (s>avctx>trellis) {

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s>opt = av_malloc(NELLY_BANDS * OPT_SIZE * sizeof(float )); 
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s>path = av_malloc(NELLY_BANDS * OPT_SIZE * sizeof(uint8_t));

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} 
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return 0; 
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} 
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static av_cold int encode_end(AVCodecContext *avctx) 
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{ 
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NellyMoserEncodeContext *s = avctx>priv_data; 
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ff_mdct_end(&s>mdct_ctx); 
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if (s>avctx>trellis) {

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av_free(s>opt); 
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av_free(s>path); 
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} 
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return 0; 
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} 
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#define find_best(val, table, LUT, LUT_add, LUT_size) \

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best_idx = \ 
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LUT[av_clip ((lrintf(val) >> 8) + LUT_add, 0, LUT_size  1)]; \ 
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if (fabs(val  table[best_idx]) > fabs(val  table[best_idx + 1])) \ 
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best_idx++; 
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static void get_exponent_greedy(NellyMoserEncodeContext *s, float *cand, int *idx_table) 
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{ 
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int band, best_idx, power_idx = 0; 
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float power_candidate;

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//base exponent

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find_best(cand[0], ff_nelly_init_table, sf_lut, 20, 96); 
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idx_table[0] = best_idx;

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power_idx = ff_nelly_init_table[best_idx]; 
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for (band = 1; band < NELLY_BANDS; band++) { 
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power_candidate = cand[band]  power_idx; 
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find_best(power_candidate, ff_nelly_delta_table, sf_delta_lut, 37, 78); 
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idx_table[band] = best_idx; 
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power_idx += ff_nelly_delta_table[best_idx]; 
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} 
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} 
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static inline float distance(float x, float y, int band) 
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{ 
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//return pow(fabs(xy), 2.0);

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float tmp = x  y;

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return tmp * tmp;

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} 
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static void get_exponent_dynamic(NellyMoserEncodeContext *s, float *cand, int *idx_table) 
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{ 
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int i, j, band, best_idx;

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float power_candidate, best_val;

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float (*opt )[NELLY_BANDS] = s>opt ;

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uint8_t(*path)[NELLY_BANDS] = s>path; 
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for (i = 0; i < NELLY_BANDS * OPT_SIZE; i++) { 
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opt[0][i] = INFINITY;

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} 
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for (i = 0; i < 64; i++) { 
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opt[0][ff_nelly_init_table[i]] = distance(cand[0], ff_nelly_init_table[i], 0); 
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path[0][ff_nelly_init_table[i]] = i;

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} 
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for (band = 1; band < NELLY_BANDS; band++) { 
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int q, c = 0; 
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float tmp;

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int idx_min, idx_max, idx;

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power_candidate = cand[band]; 
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for (q = 1000; !c && q < OPT_SIZE; q <<= 2) { 
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idx_min = FFMAX(0, cand[band]  q);

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idx_max = FFMIN(OPT_SIZE, cand[band  1] + q);

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for (i = FFMAX(0, cand[band  1]  q); i < FFMIN(OPT_SIZE, cand[band  1] + q); i++) { 
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if ( isinf(opt[band  1][i]) ) 
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continue;

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for (j = 0; j < 32; j++) { 
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idx = i + ff_nelly_delta_table[j]; 
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if (idx > idx_max)

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break;

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if (idx >= idx_min) {

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tmp = opt[band  1][i] + distance(idx, power_candidate, band);

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if (opt[band][idx] > tmp) {

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opt[band][idx] = tmp; 
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path[band][idx] = j; 
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c = 1;

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} 
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} 
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} 
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} 
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} 
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assert(c); //FIXME

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} 
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best_val = INFINITY; 
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best_idx = 1;

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band = NELLY_BANDS  1;

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for (i = 0; i < OPT_SIZE; i++) { 
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if (best_val > opt[band][i]) {

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best_val = opt[band][i]; 
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best_idx = i; 
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} 
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} 
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for (band = NELLY_BANDS  1; band >= 0; band) { 
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idx_table[band] = path[band][best_idx]; 
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if (band) {

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best_idx = ff_nelly_delta_table[path[band][best_idx]]; 
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} 
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} 
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} 
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/**

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* Encodes NELLY_SAMPLES samples. It assumes, that samples contains 3 * NELLY_BUF_LEN values

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* @param s encoder context

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* @param output output buffer

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* @param output_size size of output buffer

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*/

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static void encode_block(NellyMoserEncodeContext *s, unsigned char *output, int output_size) 
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{ 
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PutBitContext pb; 
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int i, j, band, block, best_idx, power_idx = 0; 
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float power_val, coeff, coeff_sum;

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float pows[NELLY_FILL_LEN];

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int bits[NELLY_BUF_LEN], idx_table[NELLY_BANDS];

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float cand[NELLY_BANDS];

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apply_mdct(s); 
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init_put_bits(&pb, output, output_size * 8);

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i = 0;

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for (band = 0; band < NELLY_BANDS; band++) { 
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coeff_sum = 0;

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for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) { 
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coeff_sum += s>mdct_out[i ] * s>mdct_out[i ] 
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+ s>mdct_out[i + NELLY_BUF_LEN] * s>mdct_out[i + NELLY_BUF_LEN]; 
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} 
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cand[band] = 
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log(FFMAX(1.0, coeff_sum / (ff_nelly_band_sizes_table[band] << 7))) * 1024.0 / M_LN2; 
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} 
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if (s>avctx>trellis) {

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get_exponent_dynamic(s, cand, idx_table); 
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} else {

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get_exponent_greedy(s, cand, idx_table); 
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} 
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i = 0;

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for (band = 0; band < NELLY_BANDS; band++) { 
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if (band) {

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power_idx += ff_nelly_delta_table[idx_table[band]]; 
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put_bits(&pb, 5, idx_table[band]);

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} else {

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power_idx = ff_nelly_init_table[idx_table[0]];

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put_bits(&pb, 6, idx_table[0]); 
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} 
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power_val = pow_table[power_idx & 0x7FF] / (1 << ((power_idx >> 11) + POW_TABLE_OFFSET)); 
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for (j = 0; j < ff_nelly_band_sizes_table[band]; i++, j++) { 
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s>mdct_out[i] *= power_val; 
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s>mdct_out[i + NELLY_BUF_LEN] *= power_val; 
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pows[i] = power_idx; 
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} 
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} 
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ff_nelly_get_sample_bits(pows, bits); 
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for (block = 0; block < 2; block++) { 
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for (i = 0; i < NELLY_FILL_LEN; i++) { 
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if (bits[i] > 0) { 
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const float *table = ff_nelly_dequantization_table + (1 << bits[i])  1; 
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coeff = s>mdct_out[block * NELLY_BUF_LEN + i]; 
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best_idx = 
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quant_lut[av_clip ( 
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coeff * quant_lut_mul[bits[i]] + quant_lut_add[bits[i]], 
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quant_lut_offset[bits[i]], 
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quant_lut_offset[bits[i]+1]  1 
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)]; 
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if (fabs(coeff  table[best_idx]) > fabs(coeff  table[best_idx + 1])) 
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best_idx++; 
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put_bits(&pb, bits[i], best_idx); 
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} 
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} 
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if (!block)

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put_bits(&pb, NELLY_HEADER_BITS + NELLY_DETAIL_BITS  put_bits_count(&pb), 0);

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} 
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flush_put_bits(&pb); 
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} 
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static int encode_frame(AVCodecContext *avctx, uint8_t *frame, int buf_size, void *data) 
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{ 
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NellyMoserEncodeContext *s = avctx>priv_data; 
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int16_t *samples = data; 
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int i;

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if (s>last_frame)

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return 0; 
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if (data) {

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for (i = 0; i < avctx>frame_size; i++) { 
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s>buf[s>bufsel][i] = samples[i]; 
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} 
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for (; i < NELLY_SAMPLES; i++) {

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s>buf[s>bufsel][i] = 0;

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} 
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s>bufsel = 1  s>bufsel;

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if (!s>have_saved) {

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s>have_saved = 1;

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return 0; 
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} 
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} else {

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memset(s>buf[s>bufsel], 0, sizeof(s>buf[0][0]) * NELLY_BUF_LEN); 
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s>bufsel = 1  s>bufsel;

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s>last_frame = 1;

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} 
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if (s>have_saved) {

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encode_block(s, frame, buf_size); 
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return NELLY_BLOCK_LEN;

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} 
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return 0; 
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} 
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AVCodec nellymoser_encoder = { 
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.name = "nellymoser",

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.type = CODEC_TYPE_AUDIO, 
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.id = CODEC_ID_NELLYMOSER, 
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.priv_data_size = sizeof(NellyMoserEncodeContext),

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.init = encode_init, 
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.encode = encode_frame, 
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.close = encode_end, 
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.capabilities = CODEC_CAP_SMALL_LAST_FRAME  CODEC_CAP_DELAY, 
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.long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),

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}; 