Libav 0.7.1
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00001 /* 00002 * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at> 00003 * 00004 * This file is part of Libav. 00005 * 00006 * Libav is free software; you can redistribute it and/or 00007 * modify it under the terms of the GNU Lesser General Public 00008 * License as published by the Free Software Foundation; either 00009 * version 2.1 of the License, or (at your option) any later version. 00010 * 00011 * Libav is distributed in the hope that it will be useful, 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00014 * Lesser General Public License for more details. 00015 * 00016 * You should have received a copy of the GNU Lesser General Public 00017 * License along with Libav; if not, write to the Free Software 00018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00019 */ 00020 00026 #include "avstring.h" 00027 #include "avutil.h" 00028 #include "audioconvert.h" 00029 00030 static const char * const channel_names[] = { 00031 "FL", "FR", "FC", "LFE", "BL", "BR", "FLC", "FRC", 00032 "BC", "SL", "SR", "TC", "TFL", "TFC", "TFR", "TBL", 00033 "TBC", "TBR", 00034 [29] = "DL", 00035 [30] = "DR", 00036 }; 00037 00038 static const char *get_channel_name(int channel_id) 00039 { 00040 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names)) 00041 return NULL; 00042 return channel_names[channel_id]; 00043 } 00044 00045 static const struct { 00046 const char *name; 00047 int nb_channels; 00048 int64_t layout; 00049 } channel_layout_map[] = { 00050 { "mono", 1, AV_CH_LAYOUT_MONO }, 00051 { "stereo", 2, AV_CH_LAYOUT_STEREO }, 00052 { "4.0", 4, AV_CH_LAYOUT_4POINT0 }, 00053 { "quad", 4, AV_CH_LAYOUT_QUAD }, 00054 { "5.0", 5, AV_CH_LAYOUT_5POINT0 }, 00055 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK }, 00056 { "5.1", 6, AV_CH_LAYOUT_5POINT1 }, 00057 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK }, 00058 { "5.1+downmix", 8, AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, }, 00059 { "7.1", 8, AV_CH_LAYOUT_7POINT1 }, 00060 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE }, 00061 { "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, }, 00062 { 0 } 00063 }; 00064 00065 int64_t av_get_channel_layout(const char *name) 00066 { 00067 int i = 0; 00068 do { 00069 if (!strcmp(channel_layout_map[i].name, name)) 00070 return channel_layout_map[i].layout; 00071 i++; 00072 } while (channel_layout_map[i].name); 00073 00074 return 0; 00075 } 00076 00077 void av_get_channel_layout_string(char *buf, int buf_size, 00078 int nb_channels, int64_t channel_layout) 00079 { 00080 int i; 00081 00082 if (nb_channels <= 0) 00083 nb_channels = av_get_channel_layout_nb_channels(channel_layout); 00084 00085 for (i = 0; channel_layout_map[i].name; i++) 00086 if (nb_channels == channel_layout_map[i].nb_channels && 00087 channel_layout == channel_layout_map[i].layout) { 00088 av_strlcpy(buf, channel_layout_map[i].name, buf_size); 00089 return; 00090 } 00091 00092 snprintf(buf, buf_size, "%d channels", nb_channels); 00093 if (channel_layout) { 00094 int i,ch; 00095 av_strlcat(buf, " (", buf_size); 00096 for(i=0,ch=0; i<64; i++) { 00097 if ((channel_layout & (1L<<i))) { 00098 const char *name = get_channel_name(i); 00099 if (name) { 00100 if (ch>0) av_strlcat(buf, "|", buf_size); 00101 av_strlcat(buf, name, buf_size); 00102 } 00103 ch++; 00104 } 00105 } 00106 av_strlcat(buf, ")", buf_size); 00107 } 00108 } 00109 00110 int av_get_channel_layout_nb_channels(int64_t channel_layout) 00111 { 00112 int count; 00113 uint64_t x = channel_layout; 00114 for (count = 0; x; count++) 00115 x &= x-1; // unset lowest set bit 00116 return count; 00117 }