134 lines
4.3 KiB
C
134 lines
4.3 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 Libav.
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*
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* Libav 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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* Libav 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 Libav; 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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* @file
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* audio conversion routines
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*/
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#include "avstring.h"
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#include "avutil.h"
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#include "audioconvert.h"
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static const char * const 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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};
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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];
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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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int64_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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{ "4.0", 4, AV_CH_LAYOUT_4POINT0 },
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{ "quad", 4, AV_CH_LAYOUT_QUAD },
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{ "5.0", 5, AV_CH_LAYOUT_5POINT0 },
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{ "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
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{ "5.1", 6, AV_CH_LAYOUT_5POINT1 },
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{ "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
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{ "5.1+downmix", 8, AV_CH_LAYOUT_5POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
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{ "7.1", 8, AV_CH_LAYOUT_7POINT1 },
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{ "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
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{ "7.1+downmix", 10, AV_CH_LAYOUT_7POINT1|AV_CH_LAYOUT_STEREO_DOWNMIX, },
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{ 0 }
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};
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int64_t av_get_channel_layout(const char *name)
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{
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int i = 0;
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do {
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if (!strcmp(channel_layout_map[i].name, name))
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return channel_layout_map[i].layout;
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i++;
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} while (channel_layout_map[i].name);
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return 0;
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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, int64_t channel_layout)
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{
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int i;
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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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for (i = 0; channel_layout_map[i].name; 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_strlcpy(buf, channel_layout_map[i].name, buf_size);
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return;
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}
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snprintf(buf, buf_size, "%d channels", nb_channels);
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if (channel_layout) {
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int i, ch;
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av_strlcat(buf, " (", buf_size);
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for (i = 0, ch = 0; i < 64; i++) {
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if ((channel_layout & (1L << 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_strlcat(buf, "|", buf_size);
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av_strlcat(buf, name, buf_size);
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}
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ch++;
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}
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}
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av_strlcat(buf, ")", buf_size);
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}
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}
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int av_get_channel_layout_nb_channels(int64_t channel_layout)
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{
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int count;
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uint64_t x = channel_layout;
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for (count = 0; x; count++)
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x &= x-1; // unset lowest set bit
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return count;
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}
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