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| Rev | Author | Line No. | Line |
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| 4349 | Serge | 1 | /* |
| 2 | * The simplest AC-3 encoder |
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| 3 | * Copyright (c) 2000 Fabrice Bellard |
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| 4 | * Copyright (c) 2006-2010 Justin Ruggles |
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| 5 | * Copyright (c) 2006-2010 Prakash Punnoor |
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| 6 | * |
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| 7 | * This file is part of FFmpeg. |
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| 8 | * |
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| 9 | * FFmpeg is free software; you can redistribute it and/or |
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| 10 | * modify it under the terms of the GNU Lesser General Public |
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| 11 | * License as published by the Free Software Foundation; either |
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| 12 | * version 2.1 of the License, or (at your option) any later version. |
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| 13 | * |
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| 14 | * FFmpeg is distributed in the hope that it will be useful, |
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| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 17 | * Lesser General Public License for more details. |
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| 18 | * |
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| 19 | * You should have received a copy of the GNU Lesser General Public |
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| 20 | * License along with FFmpeg; if not, write to the Free Software |
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| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 22 | */ |
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| 23 | |||
| 24 | /** |
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| 25 | * @file |
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| 26 | * floating-point AC-3 encoder. |
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| 27 | */ |
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| 28 | |||
| 29 | #define CONFIG_AC3ENC_FLOAT 1 |
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| 30 | #include "internal.h" |
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| 31 | #include "ac3enc.h" |
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| 32 | #include "eac3enc.h" |
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| 33 | #include "kbdwin.h" |
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| 34 | |||
| 35 | |||
| 36 | #if CONFIG_AC3_ENCODER |
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| 37 | #define AC3ENC_TYPE AC3ENC_TYPE_AC3 |
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| 38 | #include "ac3enc_opts_template.c" |
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| 39 | static const AVClass ac3enc_class = { |
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| 40 | .class_name = "AC-3 Encoder", |
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| 41 | .item_name = av_default_item_name, |
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| 42 | .option = ac3_options, |
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| 43 | .version = LIBAVUTIL_VERSION_INT, |
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| 44 | }; |
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| 45 | #endif |
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| 46 | |||
| 47 | #include "ac3enc_template.c" |
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| 48 | |||
| 49 | |||
| 50 | /** |
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| 51 | * Finalize MDCT and free allocated memory. |
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| 52 | * |
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| 53 | * @param s AC-3 encoder private context |
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| 54 | */ |
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| 55 | av_cold void ff_ac3_float_mdct_end(AC3EncodeContext *s) |
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| 56 | { |
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| 57 | ff_mdct_end(&s->mdct); |
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| 58 | av_freep(&s->mdct_window); |
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| 59 | } |
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| 60 | |||
| 61 | |||
| 62 | /** |
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| 63 | * Initialize MDCT tables. |
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| 64 | * |
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| 65 | * @param s AC-3 encoder private context |
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| 66 | * @return 0 on success, negative error code on failure |
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| 67 | */ |
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| 68 | av_cold int ff_ac3_float_mdct_init(AC3EncodeContext *s) |
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| 69 | { |
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| 70 | float *window; |
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| 71 | int i, n, n2; |
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| 72 | |||
| 73 | n = 1 << 9; |
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| 74 | n2 = n >> 1; |
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| 75 | |||
| 76 | window = av_malloc(n * sizeof(*window)); |
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| 77 | if (!window) { |
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| 78 | av_log(s->avctx, AV_LOG_ERROR, "Cannot allocate memory.\n"); |
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| 79 | return AVERROR(ENOMEM); |
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| 80 | } |
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| 81 | ff_kbd_window_init(window, 5.0, n2); |
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| 82 | for (i = 0; i < n2; i++) |
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| 83 | window[n-1-i] = window[i]; |
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| 84 | s->mdct_window = window; |
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| 85 | |||
| 86 | return ff_mdct_init(&s->mdct, 9, 0, -2.0 / n); |
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| 87 | } |
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| 88 | |||
| 89 | |||
| 90 | /* |
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| 91 | * Apply KBD window to input samples prior to MDCT. |
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| 92 | */ |
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| 93 | static void apply_window(void *dsp, float *output, |
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| 94 | const float *input, const float *window, |
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| 95 | unsigned int len) |
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| 96 | { |
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| 97 | AVFloatDSPContext *fdsp = dsp; |
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| 98 | fdsp->vector_fmul(output, input, window, len); |
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| 99 | } |
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| 100 | |||
| 101 | |||
| 102 | /* |
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| 103 | * Normalize the input samples. |
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| 104 | * Not needed for the floating-point encoder. |
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| 105 | */ |
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| 106 | static int normalize_samples(AC3EncodeContext *s) |
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| 107 | { |
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| 108 | return 0; |
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| 109 | } |
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| 110 | |||
| 111 | |||
| 112 | /* |
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| 113 | * Scale MDCT coefficients from float to 24-bit fixed-point. |
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| 114 | */ |
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| 115 | static void scale_coefficients(AC3EncodeContext *s) |
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| 116 | { |
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| 117 | int chan_size = AC3_MAX_COEFS * s->num_blocks; |
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| 118 | int cpl = s->cpl_on; |
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| 119 | s->ac3dsp.float_to_fixed24(s->fixed_coef_buffer + (chan_size * !cpl), |
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| 120 | s->mdct_coef_buffer + (chan_size * !cpl), |
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| 121 | chan_size * (s->channels + cpl)); |
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| 122 | } |
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| 123 | |||
| 124 | static void sum_square_butterfly(AC3EncodeContext *s, float sum[4], |
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| 125 | const float *coef0, const float *coef1, |
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| 126 | int len) |
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| 127 | { |
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| 128 | s->ac3dsp.sum_square_butterfly_float(sum, coef0, coef1, len); |
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| 129 | } |
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| 130 | |||
| 131 | /* |
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| 132 | * Clip MDCT coefficients to allowable range. |
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| 133 | */ |
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| 134 | static void clip_coefficients(DSPContext *dsp, float *coef, unsigned int len) |
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| 135 | { |
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| 136 | dsp->vector_clipf(coef, coef, COEF_MIN, COEF_MAX, len); |
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| 137 | } |
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| 138 | |||
| 139 | |||
| 140 | /* |
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| 141 | * Calculate a single coupling coordinate. |
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| 142 | */ |
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| 143 | static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl) |
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| 144 | { |
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| 145 | float coord = 0.125; |
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| 146 | if (energy_cpl > 0) |
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| 147 | coord *= sqrtf(energy_ch / energy_cpl); |
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| 148 | return FFMIN(coord, COEF_MAX); |
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| 149 | } |
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| 150 | |||
| 151 | |||
| 152 | #if CONFIG_AC3_ENCODER |
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| 153 | AVCodec ff_ac3_encoder = { |
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| 154 | .name = "ac3", |
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| 155 | .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"), |
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| 156 | .type = AVMEDIA_TYPE_AUDIO, |
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| 157 | .id = AV_CODEC_ID_AC3, |
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| 158 | .priv_data_size = sizeof(AC3EncodeContext), |
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| 159 | .init = ff_ac3_encode_init, |
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| 160 | .encode2 = ff_ac3_float_encode_frame, |
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| 161 | .close = ff_ac3_encode_close, |
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| 162 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, |
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| 163 | AV_SAMPLE_FMT_NONE }, |
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| 164 | .priv_class = &ac3enc_class, |
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| 165 | .channel_layouts = ff_ac3_channel_layouts, |
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| 166 | .defaults = ac3_defaults, |
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| 167 | }; |
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| 168 | #endif |