| Line | Branch | Exec | Source |
|---|---|---|---|
| 1 | /* | ||
| 2 | * The simplest AC-3 encoder | ||
| 3 | * Copyright (c) 2000 Fabrice Bellard | ||
| 4 | * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com> | ||
| 5 | * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de> | ||
| 6 | * | ||
| 7 | * This file is part of FFmpeg. | ||
| 8 | * | ||
| 9 | * FFmpeg is free software; you can redistribute it and/or | ||
| 10 | * modify it under the terms of the GNU Lesser General Public | ||
| 11 | * License as published by the Free Software Foundation; either | ||
| 12 | * version 2.1 of the License, or (at your option) any later version. | ||
| 13 | * | ||
| 14 | * FFmpeg is distributed in the hope that it will be useful, | ||
| 15 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | ||
| 16 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | ||
| 17 | * Lesser General Public License for more details. | ||
| 18 | * | ||
| 19 | * You should have received a copy of the GNU Lesser General Public | ||
| 20 | * License along with FFmpeg; if not, write to the Free Software | ||
| 21 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA | ||
| 22 | */ | ||
| 23 | |||
| 24 | /** | ||
| 25 | * @file | ||
| 26 | * floating-point AC-3 encoder. | ||
| 27 | */ | ||
| 28 | |||
| 29 | #define AC3ENC_FLOAT 1 | ||
| 30 | #include "audiodsp.h" | ||
| 31 | #include "ac3enc.h" | ||
| 32 | #include "codec_internal.h" | ||
| 33 | #include "eac3enc.h" | ||
| 34 | #include "kbdwin.h" | ||
| 35 | |||
| 36 | |||
| 37 | /* | ||
| 38 | * Scale MDCT coefficients from float to 24-bit fixed-point. | ||
| 39 | */ | ||
| 40 | 546 | static void scale_coefficients(AC3EncodeContext *s) | |
| 41 | { | ||
| 42 | 546 | int chan_size = AC3_MAX_COEFS * s->num_blocks; | |
| 43 | 546 | int cpl = s->cpl_on; | |
| 44 | 546 | s->ac3dsp.float_to_fixed24(s->fixed_coef_buffer + (chan_size * !cpl), | |
| 45 | 546 | s->mdct_coef_buffer + (chan_size * !cpl), | |
| 46 | 546 | chan_size * (s->channels + cpl)); | |
| 47 | 546 | } | |
| 48 | |||
| 49 | |||
| 50 | /* | ||
| 51 | * Clip MDCT coefficients to allowable range. | ||
| 52 | */ | ||
| 53 | 3276 | static void clip_coefficients(AudioDSPContext *adsp, float *coef, | |
| 54 | unsigned int len) | ||
| 55 | { | ||
| 56 | 3276 | adsp->vector_clipf(coef, coef, len, COEF_MIN, COEF_MAX); | |
| 57 | 3276 | } | |
| 58 | |||
| 59 | |||
| 60 | /* | ||
| 61 | * Calculate a single coupling coordinate. | ||
| 62 | */ | ||
| 63 | 30736 | static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl) | |
| 64 | { | ||
| 65 | 30736 | float coord = 0.125; | |
| 66 |
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30736 | if (energy_cpl > 0) |
| 67 | 30736 | coord *= sqrtf(energy_ch / energy_cpl); | |
| 68 |
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30736 | return FFMIN(coord, COEF_MAX); |
| 69 | } | ||
| 70 | |||
| 71 | 13104 | static void sum_square_butterfly(AC3EncodeContext *s, float sum[4], | |
| 72 | const float *coef0, const float *coef1, | ||
| 73 | int len) | ||
| 74 | { | ||
| 75 | 13104 | s->ac3dsp.sum_square_butterfly_float(sum, coef0, coef1, len); | |
| 76 | 13104 | } | |
| 77 | |||
| 78 | #include "ac3enc_template.c" | ||
| 79 | |||
| 80 | /** | ||
| 81 | * Initialize MDCT tables. | ||
| 82 | * | ||
| 83 | * @param s AC-3 encoder private context | ||
| 84 | * @return 0 on success, negative error code on failure | ||
| 85 | */ | ||
| 86 | 2 | static av_cold int ac3_float_mdct_init(AC3EncodeContext *s) | |
| 87 | { | ||
| 88 | 2 | const float scale = -2.0 / AC3_WINDOW_SIZE; | |
| 89 | |||
| 90 | 2 | ff_kbd_window_init(s->mdct_window_float, 5.0, AC3_BLOCK_SIZE); | |
| 91 | |||
| 92 | 2 | return av_tx_init(&s->tx, &s->tx_fn, AV_TX_FLOAT_MDCT, 0, | |
| 93 | AC3_BLOCK_SIZE, &scale, 0); | ||
| 94 | } | ||
| 95 | |||
| 96 | |||
| 97 | 2 | av_cold int ff_ac3_float_encode_init(AVCodecContext *avctx) | |
| 98 | { | ||
| 99 | 2 | AC3EncodeContext *s = avctx->priv_data; | |
| 100 | int ret; | ||
| 101 | |||
| 102 | 2 | s->encode_frame = encode_frame; | |
| 103 | 2 | s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT); | |
| 104 |
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2 | if (!s->fdsp) |
| 105 | ✗ | return AVERROR(ENOMEM); | |
| 106 | |||
| 107 | 2 | ret = ac3_float_mdct_init(s); | |
| 108 |
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2 | if (ret < 0) |
| 109 | ✗ | return ret; | |
| 110 | |||
| 111 | 2 | return ff_ac3_encode_init(avctx); | |
| 112 | } | ||
| 113 | |||
| 114 | const FFCodec ff_ac3_encoder = { | ||
| 115 | .p.name = "ac3", | ||
| 116 | CODEC_LONG_NAME("ATSC A/52A (AC-3)"), | ||
| 117 | .p.type = AVMEDIA_TYPE_AUDIO, | ||
| 118 | .p.id = AV_CODEC_ID_AC3, | ||
| 119 | .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_ENCODER_REORDERED_OPAQUE, | ||
| 120 | .priv_data_size = sizeof(AC3EncodeContext), | ||
| 121 | .init = ff_ac3_float_encode_init, | ||
| 122 | FF_CODEC_ENCODE_CB(ff_ac3_encode_frame), | ||
| 123 | .close = ff_ac3_encode_close, | ||
| 124 | .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, | ||
| 125 | AV_SAMPLE_FMT_NONE }, | ||
| 126 | .p.priv_class = &ff_ac3enc_class, | ||
| 127 | .p.supported_samplerates = ff_ac3_sample_rate_tab, | ||
| 128 | .p.ch_layouts = ff_ac3_ch_layouts, | ||
| 129 | .defaults = ff_ac3_enc_defaults, | ||
| 130 | .caps_internal = FF_CODEC_CAP_INIT_CLEANUP, | ||
| 131 | }; | ||
| 132 |