libavutil/channel_layout.c

   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 channel layout utility functions
  24  */
  25
  26 #include <stdint.h>
  27
  28 #include "avstring.h"
  29 #include "avutil.h"
  30 #include "channel_layout.h"
  31 #include "common.h"
  32
  33 static const char * const channel_names[] = {
  34     [0]  = "FL",        /* front left */
  35     [1]  = "FR",        /* front right */
  36     [2]  = "FC",        /* front center */
  37     [3]  = "LFE",       /* low frequency */
  38     [4]  = "BL",        /* back left */
  39     [5]  = "BR",        /* back right */
  40     [6]  = "FLC",       /* front left-of-center  */
  41     [7]  = "FRC",       /* front right-of-center */
  42     [8]  = "BC",        /* back-center */
  43     [9]  = "SL",        /* side left */
  44     [10] = "SR",        /* side right */
  45     [11] = "TC",        /* top center */
  46     [12] = "TFL",       /* top front left */
  47     [13] = "TFC",       /* top front center */
  48     [14] = "TFR",       /* top front right */
  49     [15] = "TBL",       /* top back left */
  50     [16] = "TBC",       /* top back center */
  51     [17] = "TBR",       /* top back right */
  52     [29] = "DL",        /* downmix left */
  53     [30] = "DR",        /* downmix right */
  54     [31] = "WL",        /* wide left */
  55     [32] = "WR",        /* wide right */
  56     [33] = "SDL",       /* surround direct left */
  57     [34] = "SDR",       /* surround direct right */
  58     [35] = "LFE2",      /* low frequency 2 */
  59 };
  60
  61 static const char *get_channel_name(int channel_id)
  62 {
  63     if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
  64         return NULL;
  65     return channel_names[channel_id];
  66 }
  67
  68 static const struct {
  69     const char *name;
  70     int         nb_channels;
  71     uint64_t     layout;
  72 } channel_layout_map[] = {
  73     { "mono",        1,  AV_CH_LAYOUT_MONO },
  74     { "stereo",      2,  AV_CH_LAYOUT_STEREO },
  75     { "stereo",      2,  AV_CH_LAYOUT_STEREO_DOWNMIX },
  76     { "2.1",         3,  AV_CH_LAYOUT_2POINT1 },
  77     { "3.0",         3,  AV_CH_LAYOUT_SURROUND },
  78     { "3.0(back)",   3,  AV_CH_LAYOUT_2_1 },
  79     { "3.1",         4,  AV_CH_LAYOUT_3POINT1 },
  80     { "4.0",         4,  AV_CH_LAYOUT_4POINT0 },
  81     { "quad",        4,  AV_CH_LAYOUT_QUAD },
  82     { "quad(side)",  4,  AV_CH_LAYOUT_2_2 },
  83     { "4.1",         5,  AV_CH_LAYOUT_4POINT1 },
  84     { "5.0",         5,  AV_CH_LAYOUT_5POINT0 },
  85     { "5.0",         5,  AV_CH_LAYOUT_5POINT0_BACK },
  86     { "5.1",         6,  AV_CH_LAYOUT_5POINT1 },
  87     { "5.1",         6,  AV_CH_LAYOUT_5POINT1_BACK },
  88     { "6.0",         6,  AV_CH_LAYOUT_6POINT0 },
  89     { "6.0(front)",  6,  AV_CH_LAYOUT_6POINT0_FRONT },
  90     { "hexagonal",   6,  AV_CH_LAYOUT_HEXAGONAL },
  91     { "6.1",         7,  AV_CH_LAYOUT_6POINT1 },
  92     { "6.1",         7,  AV_CH_LAYOUT_6POINT1_BACK },
  93     { "6.1(front)",  7,  AV_CH_LAYOUT_6POINT1_FRONT },
  94     { "7.0",         7,  AV_CH_LAYOUT_7POINT0 },
  95     { "7.0(front)",  7,  AV_CH_LAYOUT_7POINT0_FRONT },
  96     { "7.1",         8,  AV_CH_LAYOUT_7POINT1 },
  97     { "7.1(wide)",   8,  AV_CH_LAYOUT_7POINT1_WIDE },
  98     { "7.1(wide)",   8,  AV_CH_LAYOUT_7POINT1_WIDE_BACK },
  99     { "octagonal",   8,  AV_CH_LAYOUT_OCTAGONAL },
 100     { "hexadecagonal", 16, AV_CH_LAYOUT_HEXADECAGONAL },
 101     { "downmix",     2,  AV_CH_LAYOUT_STEREO_DOWNMIX, },
 102     { 0 }
 103 };
 104
 105 static uint64_t get_channel_layout_single(const char *name, int name_len)
 106 {
 107     int i;
 108     char *end;
 109     int64_t layout;
 110
 111     for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map) - 1; i++) {
 112         if (strlen(channel_layout_map[i].name) == name_len &&
 113             !memcmp(channel_layout_map[i].name, name, name_len))
 114             return channel_layout_map[i].layout;
 115     }
 116     for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
 117         if (channel_names[i] &&
 118             strlen(channel_names[i]) == name_len &&
 119             !memcmp(channel_names[i], name, name_len))
 120             return (int64_t)1 << i;
 121     i = strtol(name, &end, 10);
 122     if (end - name == name_len ||
 123         (end + 1 - name == name_len && *end  == 'c'))
 124         return av_get_default_channel_layout(i);
 125     layout = strtoll(name, &end, 0);
 126     if (end - name == name_len)
 127         return FFMAX(layout, 0);
 128     return 0;
 129 }
 130
 131 uint64_t av_get_channel_layout(const char *name)
 132 {
 133     const char *n, *e;
 134     const char *name_end = name + strlen(name);
 135     int64_t layout = 0, layout_single;
 136
 137     for (n = name; n < name_end; n = e + 1) {
 138         for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
 139         layout_single = get_channel_layout_single(n, e - n);
 140         if (!layout_single)
 141             return 0;
 142         layout |= layout_single;
 143     }
 144     return layout;
 145 }
 146
 147 void av_get_channel_layout_string(char *buf, int buf_size,
 148                                   int nb_channels, uint64_t channel_layout)
 149 {
 150     int i;
 151
 152     if (nb_channels <= 0)
 153         nb_channels = av_get_channel_layout_nb_channels(channel_layout);
 154
 155     for (i = 0; channel_layout_map[i].name; i++)
 156         if (nb_channels    == channel_layout_map[i].nb_channels &&
 157             channel_layout == channel_layout_map[i].layout) {
 158             av_strlcpy(buf, channel_layout_map[i].name, buf_size);
 159             return;
 160         }
 161
 162     snprintf(buf, buf_size, "%d channels", nb_channels);
 163     if (channel_layout) {
 164         int i, ch;
 165         av_strlcat(buf, " (", buf_size);
 166         for (i = 0, ch = 0; i < 64; i++) {
 167             if ((channel_layout & (UINT64_C(1) << i))) {
 168                 const char *name = get_channel_name(i);
 169                 if (name) {
 170                     if (ch > 0)
 171                         av_strlcat(buf, "|", buf_size);
 172                     av_strlcat(buf, name, buf_size);
 173                 }
 174                 ch++;
 175             }
 176         }
 177         av_strlcat(buf, ")", buf_size);
 178     }
 179 }
 180
 181 int av_get_channel_layout_nb_channels(uint64_t channel_layout)
 182 {
 183     return av_popcount64(channel_layout);
 184 }
 185
 186 uint64_t av_get_default_channel_layout(int nb_channels)
 187 {
 188     switch(nb_channels) {
 189     case 1: return AV_CH_LAYOUT_MONO;
 190     case 2: return AV_CH_LAYOUT_STEREO;
 191     case 3: return AV_CH_LAYOUT_SURROUND;
 192     case 4: return AV_CH_LAYOUT_QUAD;
 193     case 5: return AV_CH_LAYOUT_5POINT0;
 194     case 6: return AV_CH_LAYOUT_5POINT1;
 195     case 7: return AV_CH_LAYOUT_6POINT1;
 196     case 8: return AV_CH_LAYOUT_7POINT1;
 197     case 16: return AV_CH_LAYOUT_HEXADECAGONAL;
 198     default: return 0;
 199     }
 200 }
 201
 202 int av_get_channel_layout_channel_index(uint64_t channel_layout,
 203                                         uint64_t channel)
 204 {
 205     if (!(channel_layout & channel) ||
 206         av_get_channel_layout_nb_channels(channel) != 1)
 207         return AVERROR(EINVAL);
 208     channel_layout &= channel - 1;
 209     return av_get_channel_layout_nb_channels(channel_layout);
 210 }
 211
 212 const char *av_get_channel_name(uint64_t channel)
 213 {
 214     int i;
 215     if (av_get_channel_layout_nb_channels(channel) != 1)
 216         return NULL;
 217     for (i = 0; i < 64; i++)
 218         if ((1ULL<<i) & channel)
 219             return get_channel_name(i);
 220     return NULL;
 221 }
 222
 223 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
 224 {
 225     int i;
 226
 227     if (av_get_channel_layout_nb_channels(channel_layout) <= index)
 228         return 0;
 229
 230     for (i = 0; i < 64; i++) {
 231         if ((1ULL << i) & channel_layout && !index--)
 232             return 1ULL << i;
 233     }
 234     return 0;
 235 }