1/*
2 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3 *
4 * This file is part of Libav.
5 *
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21/**
22 * @file
23 * audio conversion routines
24 */
25
26#include "avstring.h"
27#include "avutil.h"
28#include "audioconvert.h"
29
30static const char * const channel_names[] = {
31    [0]  = "FL",        /* front left */
32    [1]  = "FR",        /* front right */
33    [2]  = "FC",        /* front center */
34    [3]  = "LFE",       /* low frequency */
35    [4]  = "BL",        /* back left */
36    [5]  = "BR",        /* back right */
37    [6]  = "FLC",       /* front left-of-center  */
38    [7]  = "FRC",       /* front right-of-center */
39    [8]  = "BC",        /* back-center */
40    [9]  = "SL",        /* side left */
41    [10] = "SR",        /* side right */
42    [11] = "TC",        /* top center */
43    [12] = "TFL",       /* top front left */
44    [13] = "TFC",       /* top front center */
45    [14] = "TFR",       /* top front right */
46    [15] = "TBL",       /* top back left */
47    [16] = "TBC",       /* top back center */
48    [17] = "TBR",       /* top back right */
49    [29] = "DL",        /* downmix left */
50    [30] = "DR",        /* downmix right */
51};
52
53static const char *get_channel_name(int channel_id)
54{
55    if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
56        return NULL;
57    return channel_names[channel_id];
58}
59
60static const struct {
61    const char *name;
62    int         nb_channels;
63    uint64_t     layout;
64} channel_layout_map[] = {
65    { "mono",        1,  AV_CH_LAYOUT_MONO },
66    { "stereo",      2,  AV_CH_LAYOUT_STEREO },
67    { "4.0",         4,  AV_CH_LAYOUT_4POINT0 },
68    { "quad",        4,  AV_CH_LAYOUT_QUAD },
69    { "5.0",         5,  AV_CH_LAYOUT_5POINT0 },
70    { "5.0",         5,  AV_CH_LAYOUT_5POINT0_BACK },
71    { "5.1",         6,  AV_CH_LAYOUT_5POINT1 },
72    { "5.1",         6,  AV_CH_LAYOUT_5POINT1_BACK },
73    { "5.1+downmix", 8,  AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
74    { "7.1",         8,  AV_CH_LAYOUT_7POINT1 },
75    { "7.1(wide)",   8,  AV_CH_LAYOUT_7POINT1_WIDE },
76    { "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
77    { 0 }
78};
79
80uint64_t av_get_channel_layout(const char *name)
81{
82    int i = 0;
83    do {
84        if (!strcmp(channel_layout_map[i].name, name))
85            return channel_layout_map[i].layout;
86        i++;
87    } while (channel_layout_map[i].name);
88
89    return 0;
90}
91
92void av_get_channel_layout_string(char *buf, int buf_size,
93                                  int nb_channels, uint64_t channel_layout)
94{
95    int i;
96
97    if (nb_channels <= 0)
98        nb_channels = av_get_channel_layout_nb_channels(channel_layout);
99
100    for (i = 0; channel_layout_map[i].name; i++)
101        if (nb_channels    == channel_layout_map[i].nb_channels &&
102            channel_layout == channel_layout_map[i].layout) {
103            av_strlcpy(buf, channel_layout_map[i].name, buf_size);
104            return;
105        }
106
107    snprintf(buf, buf_size, "%d channels", nb_channels);
108    if (channel_layout) {
109        int i, ch;
110        av_strlcat(buf, " (", buf_size);
111        for (i = 0, ch = 0; i < 64; i++) {
112            if ((channel_layout & (UINT64_C(1) << i))) {
113                const char *name = get_channel_name(i);
114                if (name) {
115                    if (ch > 0)
116                        av_strlcat(buf, "|", buf_size);
117                    av_strlcat(buf, name, buf_size);
118                }
119                ch++;
120            }
121        }
122        av_strlcat(buf, ")", buf_size);
123    }
124}
125
126int av_get_channel_layout_nb_channels(uint64_t channel_layout)
127{
128    int count;
129    uint64_t x = channel_layout;
130    for (count = 0; x; count++)
131        x &= x-1; // unset lowest set bit
132    return count;
133}
134