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