aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/ac3enc_fixed.c
blob: 80aa98c69173ec6f145de7898088e7f48aaa4dea (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
/*
 * The simplest AC-3 encoder
 * Copyright (c) 2000 Fabrice Bellard
 * Copyright (c) 2006-2010 Justin Ruggles <justin.ruggles@gmail.com>
 * Copyright (c) 2006-2010 Prakash Punnoor <prakash@punnoor.de>
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * fixed-point AC-3 encoder.
 */

#define AC3ENC_FLOAT 0
#define FFT_FLOAT 0
#include "internal.h"
#include "audiodsp.h"
#include "ac3enc.h"
#include "eac3enc.h"
#include "kbdwin.h"

static void sum_square_butterfly(AC3EncodeContext *s, int64_t sum[4],
                                 const int32_t *coef0, const int32_t *coef1,
                                 int len)
{
    s->ac3dsp.sum_square_butterfly_int32(sum, coef0, coef1, len);
}

/*
 * Clip MDCT coefficients to allowable range.
 */
static void clip_coefficients(AudioDSPContext *adsp, int32_t *coef,
                              unsigned int len)
{
    adsp->vector_clip_int32(coef, coef, COEF_MIN, COEF_MAX, len);
}


/*
 * Calculate a single coupling coordinate.
 */
static CoefType calc_cpl_coord(CoefSumType energy_ch, CoefSumType energy_cpl)
{
    if (energy_cpl <= COEF_MAX) {
        return 1048576;
    } else {
        uint64_t coord   = energy_ch / (energy_cpl >> 24);
        uint32_t coord32 = FFMIN(coord, 1073741824);
        coord32          = ff_sqrt(coord32) << 9;
        return FFMIN(coord32, COEF_MAX);
    }
}


#include "ac3enc_template.c"


/**
 * Finalize MDCT and free allocated memory.
 *
 * @param s  AC-3 encoder private context
 */
static av_cold void ac3_fixed_mdct_end(AC3EncodeContext *s)
{
    ff_mdct_end(&s->mdct);
}

/**
 * Initialize MDCT tables.
 *
 * @param s  AC-3 encoder private context
 * @return   0 on success, negative error code on failure
 */
static av_cold int ac3_fixed_mdct_init(AC3EncodeContext *s)
{
    float fwin[AC3_BLOCK_SIZE];

    int32_t *iwin = av_malloc_array(AC3_BLOCK_SIZE, sizeof(*iwin));
    if (!iwin)
        return AVERROR(ENOMEM);

    ff_kbd_window_init(fwin, 5.0, AC3_BLOCK_SIZE);
    for (int i = 0; i < AC3_BLOCK_SIZE; i++)
        iwin[i] = lrintf(fwin[i] * (1 << 22));

    s->mdct_window = iwin;

    s->fdsp = avpriv_alloc_fixed_dsp(s->avctx->flags & AV_CODEC_FLAG_BITEXACT);
    if (!s->fdsp)
        return AVERROR(ENOMEM);

    return ff_mdct_init(&s->mdct, 9, 0, -1.0);
}


static av_cold int ac3_fixed_encode_init(AVCodecContext *avctx)
{
    AC3EncodeContext *s = avctx->priv_data;
    s->fixed_point = 1;
    s->mdct_end                = ac3_fixed_mdct_end;
    s->mdct_init               = ac3_fixed_mdct_init;
    s->allocate_sample_buffers = allocate_sample_buffers;
    return ff_ac3_encode_init(avctx);
}


const AVCodec ff_ac3_fixed_encoder = {
    .name            = "ac3_fixed",
    .long_name       = NULL_IF_CONFIG_SMALL("ATSC A/52A (AC-3)"),
    .type            = AVMEDIA_TYPE_AUDIO,
    .id              = AV_CODEC_ID_AC3,
    .capabilities    = AV_CODEC_CAP_DR1,
    .priv_data_size  = sizeof(AC3EncodeContext),
    .init            = ac3_fixed_encode_init,
    .encode2         = ff_ac3_fixed_encode_frame,
    .close           = ff_ac3_encode_close,
    .sample_fmts     = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S32P,
                                                      AV_SAMPLE_FMT_NONE },
    .priv_class      = &ff_ac3enc_class,
    .caps_internal   = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
    .supported_samplerates = ff_ac3_sample_rate_tab,
    .channel_layouts = ff_ac3_channel_layouts,
    .defaults        = ff_ac3_enc_defaults,
};