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			287 lines
		
	
	
	
		
			9.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			287 lines
		
	
	
	
		
			9.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
| /*
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|  * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
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|  *
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|  * This file is part of FFmpeg.
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|  *
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|  * FFmpeg is free software; you can redistribute it and/or
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|  * modify it under the terms of the GNU Lesser General Public
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|  * License as published by the Free Software Foundation; either
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|  * version 2.1 of the License, or (at your option) any later version.
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|  *
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|  * FFmpeg is distributed in the hope that it will be useful,
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|  * but WITHOUT ANY WARRANTY; without even the implied warranty of
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|  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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|  * Lesser General Public License for more details.
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|  *
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|  * You should have received a copy of the GNU Lesser General Public
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|  * License along with FFmpeg; if not, write to the Free Software
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|  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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|  */
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| 
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| /**
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|  * @file
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|  * audio channel layout utility functions
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|  */
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| 
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| #include <stdint.h>
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| 
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| #include "avstring.h"
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| #include "avutil.h"
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| #include "channel_layout.h"
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| #include "bprint.h"
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| #include "common.h"
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| 
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| struct channel_name {
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|     const char *name;
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|     const char *description;
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| };
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| 
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| static const struct channel_name channel_names[] = {
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|      [0] = { "FL",        "front left"            },
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|      [1] = { "FR",        "front right"           },
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|      [2] = { "FC",        "front center"          },
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|      [3] = { "LFE",       "low frequency"         },
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|      [4] = { "BL",        "back left"             },
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|      [5] = { "BR",        "back right"            },
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|      [6] = { "FLC",       "front left-of-center"  },
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|      [7] = { "FRC",       "front right-of-center" },
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|      [8] = { "BC",        "back center"           },
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|      [9] = { "SL",        "side left"             },
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|     [10] = { "SR",        "side right"            },
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|     [11] = { "TC",        "top center"            },
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|     [12] = { "TFL",       "top front left"        },
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|     [13] = { "TFC",       "top front center"      },
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|     [14] = { "TFR",       "top front right"       },
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|     [15] = { "TBL",       "top back left"         },
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|     [16] = { "TBC",       "top back center"       },
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|     [17] = { "TBR",       "top back right"        },
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|     [29] = { "DL",        "downmix left"          },
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|     [30] = { "DR",        "downmix right"         },
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|     [31] = { "WL",        "wide left"             },
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|     [32] = { "WR",        "wide right"            },
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|     [33] = { "SDL",       "surround direct left"  },
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|     [34] = { "SDR",       "surround direct right" },
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|     [35] = { "LFE2",      "low frequency 2"       },
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| };
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| 
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| static const char *get_channel_name(int channel_id)
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| {
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|     if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))
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|         return NULL;
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|     return channel_names[channel_id].name;
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| }
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| 
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| static const struct {
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|     const char *name;
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|     int         nb_channels;
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|     uint64_t     layout;
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| } channel_layout_map[] = {
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|     { "mono",        1,  AV_CH_LAYOUT_MONO },
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|     { "stereo",      2,  AV_CH_LAYOUT_STEREO },
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|     { "2.1",         3,  AV_CH_LAYOUT_2POINT1 },
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|     { "3.0",         3,  AV_CH_LAYOUT_SURROUND },
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|     { "3.0(back)",   3,  AV_CH_LAYOUT_2_1 },
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|     { "4.0",         4,  AV_CH_LAYOUT_4POINT0 },
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|     { "quad",        4,  AV_CH_LAYOUT_QUAD },
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|     { "quad(side)",  4,  AV_CH_LAYOUT_2_2 },
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|     { "3.1",         4,  AV_CH_LAYOUT_3POINT1 },
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|     { "5.0",         5,  AV_CH_LAYOUT_5POINT0_BACK },
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|     { "5.0(side)",   5,  AV_CH_LAYOUT_5POINT0 },
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|     { "4.1",         5,  AV_CH_LAYOUT_4POINT1 },
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|     { "5.1",         6,  AV_CH_LAYOUT_5POINT1_BACK },
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|     { "5.1(side)",   6,  AV_CH_LAYOUT_5POINT1 },
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|     { "6.0",         6,  AV_CH_LAYOUT_6POINT0 },
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|     { "6.0(front)",  6,  AV_CH_LAYOUT_6POINT0_FRONT },
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|     { "hexagonal",   6,  AV_CH_LAYOUT_HEXAGONAL },
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|     { "6.1",         7,  AV_CH_LAYOUT_6POINT1 },
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|     { "6.1(back)",   7,  AV_CH_LAYOUT_6POINT1_BACK },
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|     { "6.1(front)",  7,  AV_CH_LAYOUT_6POINT1_FRONT },
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|     { "7.0",         7,  AV_CH_LAYOUT_7POINT0 },
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|     { "7.0(front)",  7,  AV_CH_LAYOUT_7POINT0_FRONT },
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|     { "7.1",         8,  AV_CH_LAYOUT_7POINT1 },
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|     { "7.1(wide)",   8,  AV_CH_LAYOUT_7POINT1_WIDE_BACK },
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|     { "7.1(wide-side)",   8,  AV_CH_LAYOUT_7POINT1_WIDE },
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|     { "octagonal",   8,  AV_CH_LAYOUT_OCTAGONAL },
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|     { "hexadecagonal", 16, AV_CH_LAYOUT_HEXADECAGONAL },
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|     { "downmix",     2,  AV_CH_LAYOUT_STEREO_DOWNMIX, },
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| };
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| 
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| static uint64_t get_channel_layout_single(const char *name, int name_len)
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| {
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|     int i;
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|     char *end;
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|     int64_t layout;
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| 
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|     for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
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|         if (strlen(channel_layout_map[i].name) == name_len &&
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|             !memcmp(channel_layout_map[i].name, name, name_len))
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|             return channel_layout_map[i].layout;
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|     }
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|     for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
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|         if (channel_names[i].name &&
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|             strlen(channel_names[i].name) == name_len &&
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|             !memcmp(channel_names[i].name, name, name_len))
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|             return (int64_t)1 << i;
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| 
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|     errno = 0;
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|     i = strtol(name, &end, 10);
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| 
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|     if (!errno && (end + 1 - name == name_len && *end  == 'c'))
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|         return av_get_default_channel_layout(i);
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| 
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|     errno = 0;
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|     layout = strtoll(name, &end, 0);
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|     if (!errno && end - name == name_len)
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|         return FFMAX(layout, 0);
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|     return 0;
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| }
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| 
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| uint64_t av_get_channel_layout(const char *name)
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| {
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|     const char *n, *e;
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|     const char *name_end = name + strlen(name);
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|     int64_t layout = 0, layout_single;
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| 
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|     for (n = name; n < name_end; n = e + 1) {
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|         for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
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|         layout_single = get_channel_layout_single(n, e - n);
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|         if (!layout_single)
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|             return 0;
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|         layout |= layout_single;
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|     }
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|     return layout;
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| }
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| 
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| int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels)
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| {
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|     int nb = 0;
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|     char *end;
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|     uint64_t layout = av_get_channel_layout(name);
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| 
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|     if (layout) {
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|         *channel_layout = layout;
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|         *nb_channels = av_get_channel_layout_nb_channels(layout);
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|         return 0;
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|     }
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| 
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|     nb = strtol(name, &end, 10);
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|     if (!errno && *end  == 'C' && *(end + 1) == '\0' && nb > 0 && nb < 64) {
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|         *channel_layout = 0;
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|         *nb_channels = nb;
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|         return 0;
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|     }
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| 
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|     return AVERROR(EINVAL);
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| }
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| 
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| void av_bprint_channel_layout(struct AVBPrint *bp,
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|                               int nb_channels, uint64_t channel_layout)
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| {
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|     int i;
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| 
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|     if (nb_channels <= 0)
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|         nb_channels = av_get_channel_layout_nb_channels(channel_layout);
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| 
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|     for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
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|         if (nb_channels    == channel_layout_map[i].nb_channels &&
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|             channel_layout == channel_layout_map[i].layout) {
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|             av_bprintf(bp, "%s", channel_layout_map[i].name);
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|             return;
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|         }
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| 
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|     av_bprintf(bp, "%d channels", nb_channels);
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|     if (channel_layout) {
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|         int i, ch;
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|         av_bprintf(bp, " (");
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|         for (i = 0, ch = 0; i < 64; i++) {
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|             if ((channel_layout & (UINT64_C(1) << i))) {
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|                 const char *name = get_channel_name(i);
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|                 if (name) {
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|                     if (ch > 0)
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|                         av_bprintf(bp, "+");
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|                     av_bprintf(bp, "%s", name);
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|                 }
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|                 ch++;
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|             }
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|         }
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|         av_bprintf(bp, ")");
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|     }
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| }
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| 
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| void av_get_channel_layout_string(char *buf, int buf_size,
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|                                   int nb_channels, uint64_t channel_layout)
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| {
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|     AVBPrint bp;
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| 
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|     av_bprint_init_for_buffer(&bp, buf, buf_size);
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|     av_bprint_channel_layout(&bp, nb_channels, channel_layout);
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| }
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| 
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| int av_get_channel_layout_nb_channels(uint64_t channel_layout)
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| {
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|     return av_popcount64(channel_layout);
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| }
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| 
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| int64_t av_get_default_channel_layout(int nb_channels) {
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|     int i;
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|     for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
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|         if (nb_channels == channel_layout_map[i].nb_channels)
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|             return channel_layout_map[i].layout;
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|     return 0;
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| }
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| 
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| int av_get_channel_layout_channel_index(uint64_t channel_layout,
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|                                         uint64_t channel)
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| {
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|     if (!(channel_layout & channel) ||
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|         av_get_channel_layout_nb_channels(channel) != 1)
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|         return AVERROR(EINVAL);
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|     channel_layout &= channel - 1;
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|     return av_get_channel_layout_nb_channels(channel_layout);
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| }
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| 
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| const char *av_get_channel_name(uint64_t channel)
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| {
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|     int i;
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|     if (av_get_channel_layout_nb_channels(channel) != 1)
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|         return NULL;
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|     for (i = 0; i < 64; i++)
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|         if ((1ULL<<i) & channel)
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|             return get_channel_name(i);
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|     return NULL;
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| }
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| 
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| const char *av_get_channel_description(uint64_t channel)
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| {
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|     int i;
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|     if (av_get_channel_layout_nb_channels(channel) != 1)
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|         return NULL;
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|     for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
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|         if ((1ULL<<i) & channel)
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|             return channel_names[i].description;
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|     return NULL;
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| }
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| 
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| uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
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| {
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|     int i;
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| 
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|     if (av_get_channel_layout_nb_channels(channel_layout) <= index)
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|         return 0;
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| 
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|     for (i = 0; i < 64; i++) {
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|         if ((1ULL << i) & channel_layout && !index--)
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|             return 1ULL << i;
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|     }
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|     return 0;
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| }
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| 
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| int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
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|                                    const char **name)
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| {
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|     if (index >= FF_ARRAY_ELEMS(channel_layout_map))
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|         return AVERROR_EOF;
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|     if (layout) *layout = channel_layout_map[index].layout;
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|     if (name)   *name   = channel_layout_map[index].name;
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|     return 0;
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| }
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