Commit | Line | Data |
---|---|---|
2ba45a60 DM |
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 CONFIG_AC3ENC_FLOAT 1 | |
30 | #include "internal.h" | |
31 | #include "audiodsp.h" | |
32 | #include "ac3enc.h" | |
33 | #include "eac3enc.h" | |
34 | #include "kbdwin.h" | |
35 | ||
36 | ||
37 | #define AC3ENC_TYPE AC3ENC_TYPE_AC3 | |
38 | #include "ac3enc_opts_template.c" | |
39 | static const AVClass ac3enc_class = { | |
40 | .class_name = "AC-3 Encoder", | |
41 | .item_name = av_default_item_name, | |
42 | .option = ac3_options, | |
43 | .version = LIBAVUTIL_VERSION_INT, | |
44 | }; | |
45 | ||
46 | #include "ac3enc_template.c" | |
47 | ||
48 | ||
49 | /** | |
50 | * Finalize MDCT and free allocated memory. | |
51 | * | |
52 | * @param s AC-3 encoder private context | |
53 | */ | |
54 | av_cold void ff_ac3_float_mdct_end(AC3EncodeContext *s) | |
55 | { | |
56 | ff_mdct_end(&s->mdct); | |
57 | av_freep(&s->mdct_window); | |
58 | } | |
59 | ||
60 | ||
61 | /** | |
62 | * Initialize MDCT tables. | |
63 | * | |
64 | * @param s AC-3 encoder private context | |
65 | * @return 0 on success, negative error code on failure | |
66 | */ | |
67 | av_cold int ff_ac3_float_mdct_init(AC3EncodeContext *s) | |
68 | { | |
69 | float *window; | |
70 | int i, n, n2; | |
71 | ||
72 | n = 1 << 9; | |
73 | n2 = n >> 1; | |
74 | ||
75 | window = av_malloc_array(n, sizeof(*window)); | |
76 | if (!window) { | |
77 | av_log(s->avctx, AV_LOG_ERROR, "Cannot allocate memory.\n"); | |
78 | return AVERROR(ENOMEM); | |
79 | } | |
80 | ff_kbd_window_init(window, 5.0, n2); | |
81 | for (i = 0; i < n2; i++) | |
82 | window[n-1-i] = window[i]; | |
83 | s->mdct_window = window; | |
84 | ||
85 | return ff_mdct_init(&s->mdct, 9, 0, -2.0 / n); | |
86 | } | |
87 | ||
88 | ||
89 | /* | |
90 | * Normalize the input samples. | |
91 | * Not needed for the floating-point encoder. | |
92 | */ | |
93 | static int normalize_samples(AC3EncodeContext *s) | |
94 | { | |
95 | return 0; | |
96 | } | |
97 | ||
98 | ||
99 | /* | |
100 | * Scale MDCT coefficients from float to 24-bit fixed-point. | |
101 | */ | |
102 | static void scale_coefficients(AC3EncodeContext *s) | |
103 | { | |
104 | int chan_size = AC3_MAX_COEFS * s->num_blocks; | |
105 | int cpl = s->cpl_on; | |
106 | s->ac3dsp.float_to_fixed24(s->fixed_coef_buffer + (chan_size * !cpl), | |
107 | s->mdct_coef_buffer + (chan_size * !cpl), | |
108 | chan_size * (s->channels + cpl)); | |
109 | } | |
110 | ||
111 | static void sum_square_butterfly(AC3EncodeContext *s, float sum[4], | |
112 | const float *coef0, const float *coef1, | |
113 | int len) | |
114 | { | |
115 | s->ac3dsp.sum_square_butterfly_float(sum, coef0, coef1, len); | |
116 | } | |
117 | ||
118 | /* | |
119 | * Clip MDCT coefficients to allowable range. | |
120 | */ | |
121 | static void clip_coefficients(AudioDSPContext *adsp, float *coef, | |
122 | unsigned int len) | |
123 | { | |
124 | adsp->vector_clipf(coef, coef, COEF_MIN, COEF_MAX, len); | |
125 | } | |
126 | ||
127 | ||
128 | /* | |
129 | * Calculate a single coupling coordinate. | |
130 | */ | |
131 | static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl) | |
132 | { | |
133 | float coord = 0.125; | |
134 | if (energy_cpl > 0) | |
135 | coord *= sqrtf(energy_ch / energy_cpl); | |
136 | return FFMIN(coord, COEF_MAX); | |
137 | } | |
138 | ||
139 | av_cold int ff_ac3_float_encode_init(AVCodecContext *avctx) | |
140 | { | |
141 | AC3EncodeContext *s = avctx->priv_data; | |
f6fa7814 DM |
142 | s->fdsp = avpriv_float_dsp_alloc(avctx->flags & CODEC_FLAG_BITEXACT); |
143 | if (!s->fdsp) | |
144 | return AVERROR(ENOMEM); | |
2ba45a60 DM |
145 | return ff_ac3_encode_init(avctx); |
146 | } | |
147 | ||
148 | AVCodec ff_ac3_encoder = { | |
149 | .name = "ac3", | |
150 | .long_name = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"), | |
151 | .type = AVMEDIA_TYPE_AUDIO, | |
152 | .id = AV_CODEC_ID_AC3, | |
153 | .priv_data_size = sizeof(AC3EncodeContext), | |
154 | .init = ff_ac3_float_encode_init, | |
155 | .encode2 = ff_ac3_float_encode_frame, | |
156 | .close = ff_ac3_encode_close, | |
157 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_FLTP, | |
158 | AV_SAMPLE_FMT_NONE }, | |
159 | .priv_class = &ac3enc_class, | |
160 | .channel_layouts = ff_ac3_channel_layouts, | |
161 | .defaults = ac3_defaults, | |
162 | }; |