channel_layout.c 9.2 KB

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  1. /*
  2. * Copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
  3. *
  4. * This file is part of FFmpeg.
  5. *
  6. * FFmpeg 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. * FFmpeg 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 FFmpeg; if not, write to the Free Software
  18. * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19. */
  20. /**
  21. * @file
  22. * audio channel layout utility functions
  23. */
  24. #include <stdint.h>
  25. #include "avstring.h"
  26. #include "avutil.h"
  27. #include "channel_layout.h"
  28. #include "bprint.h"
  29. #include "common.h"
  30. struct channel_name {
  31. const char *name;
  32. const char *description;
  33. };
  34. static const struct channel_name channel_names[] = {
  35. [0] = { "FL", "front left" },
  36. [1] = { "FR", "front right" },
  37. [2] = { "FC", "front center" },
  38. [3] = { "LFE", "low frequency" },
  39. [4] = { "BL", "back left" },
  40. [5] = { "BR", "back right" },
  41. [6] = { "FLC", "front left-of-center" },
  42. [7] = { "FRC", "front right-of-center" },
  43. [8] = { "BC", "back center" },
  44. [9] = { "SL", "side left" },
  45. [10] = { "SR", "side right" },
  46. [11] = { "TC", "top center" },
  47. [12] = { "TFL", "top front left" },
  48. [13] = { "TFC", "top front center" },
  49. [14] = { "TFR", "top front right" },
  50. [15] = { "TBL", "top back left" },
  51. [16] = { "TBC", "top back center" },
  52. [17] = { "TBR", "top back right" },
  53. [29] = { "DL", "downmix left" },
  54. [30] = { "DR", "downmix right" },
  55. [31] = { "WL", "wide left" },
  56. [32] = { "WR", "wide right" },
  57. [33] = { "SDL", "surround direct left" },
  58. [34] = { "SDR", "surround direct right" },
  59. [35] = { "LFE2", "low frequency 2" },
  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].name;
  66. }
  67. static const struct {
  68. const char *name;
  69. int nb_channels;
  70. uint64_t layout;
  71. } channel_layout_map[] = {
  72. { "mono", 1, AV_CH_LAYOUT_MONO },
  73. { "stereo", 2, AV_CH_LAYOUT_STEREO },
  74. { "2.1", 3, AV_CH_LAYOUT_2POINT1 },
  75. { "3.0", 3, AV_CH_LAYOUT_SURROUND },
  76. { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },
  77. { "4.0", 4, AV_CH_LAYOUT_4POINT0 },
  78. { "quad", 4, AV_CH_LAYOUT_QUAD },
  79. { "quad(side)", 4, AV_CH_LAYOUT_2_2 },
  80. { "3.1", 4, AV_CH_LAYOUT_3POINT1 },
  81. { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },
  82. { "5.0(side)", 5, AV_CH_LAYOUT_5POINT0 },
  83. { "4.1", 5, AV_CH_LAYOUT_4POINT1 },
  84. { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },
  85. { "5.1(side)", 6, AV_CH_LAYOUT_5POINT1 },
  86. { "6.0", 6, AV_CH_LAYOUT_6POINT0 },
  87. { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },
  88. { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },
  89. { "6.1", 7, AV_CH_LAYOUT_6POINT1 },
  90. { "6.1(back)", 7, AV_CH_LAYOUT_6POINT1_BACK },
  91. { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },
  92. { "7.0", 7, AV_CH_LAYOUT_7POINT0 },
  93. { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },
  94. { "7.1", 8, AV_CH_LAYOUT_7POINT1 },
  95. { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE_BACK },
  96. { "7.1(wide-side)", 8, AV_CH_LAYOUT_7POINT1_WIDE },
  97. { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },
  98. { "hexadecagonal", 16, AV_CH_LAYOUT_HEXADECAGONAL },
  99. { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
  100. };
  101. static uint64_t get_channel_layout_single(const char *name, int name_len)
  102. {
  103. int i;
  104. char *end;
  105. int64_t layout;
  106. for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
  107. if (strlen(channel_layout_map[i].name) == name_len &&
  108. !memcmp(channel_layout_map[i].name, name, name_len))
  109. return channel_layout_map[i].layout;
  110. }
  111. for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
  112. if (channel_names[i].name &&
  113. strlen(channel_names[i].name) == name_len &&
  114. !memcmp(channel_names[i].name, name, name_len))
  115. return (int64_t)1 << i;
  116. errno = 0;
  117. i = strtol(name, &end, 10);
  118. if (!errno && (end + 1 - name == name_len && *end == 'c'))
  119. return av_get_default_channel_layout(i);
  120. errno = 0;
  121. layout = strtoll(name, &end, 0);
  122. if (!errno && end - name == name_len)
  123. return FFMAX(layout, 0);
  124. return 0;
  125. }
  126. uint64_t av_get_channel_layout(const char *name)
  127. {
  128. const char *n, *e;
  129. const char *name_end = name + strlen(name);
  130. int64_t layout = 0, layout_single;
  131. for (n = name; n < name_end; n = e + 1) {
  132. for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
  133. layout_single = get_channel_layout_single(n, e - n);
  134. if (!layout_single)
  135. return 0;
  136. layout |= layout_single;
  137. }
  138. return layout;
  139. }
  140. int av_get_extended_channel_layout(const char *name, uint64_t* channel_layout, int* nb_channels)
  141. {
  142. int nb = 0;
  143. char *end;
  144. uint64_t layout = av_get_channel_layout(name);
  145. if (layout) {
  146. *channel_layout = layout;
  147. *nb_channels = av_get_channel_layout_nb_channels(layout);
  148. return 0;
  149. }
  150. nb = strtol(name, &end, 10);
  151. if (!errno && *end == 'C' && *(end + 1) == '\0' && nb > 0 && nb < 64) {
  152. *channel_layout = 0;
  153. *nb_channels = nb;
  154. return 0;
  155. }
  156. return AVERROR(EINVAL);
  157. }
  158. void av_bprint_channel_layout(struct AVBPrint *bp,
  159. int nb_channels, uint64_t channel_layout)
  160. {
  161. int i;
  162. if (nb_channels <= 0)
  163. nb_channels = av_get_channel_layout_nb_channels(channel_layout);
  164. for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
  165. if (nb_channels == channel_layout_map[i].nb_channels &&
  166. channel_layout == channel_layout_map[i].layout) {
  167. av_bprintf(bp, "%s", channel_layout_map[i].name);
  168. return;
  169. }
  170. av_bprintf(bp, "%d channels", nb_channels);
  171. if (channel_layout) {
  172. int i, ch;
  173. av_bprintf(bp, " (");
  174. for (i = 0, ch = 0; i < 64; i++) {
  175. if ((channel_layout & (UINT64_C(1) << i))) {
  176. const char *name = get_channel_name(i);
  177. if (name) {
  178. if (ch > 0)
  179. av_bprintf(bp, "+");
  180. av_bprintf(bp, "%s", name);
  181. }
  182. ch++;
  183. }
  184. }
  185. av_bprintf(bp, ")");
  186. }
  187. }
  188. void av_get_channel_layout_string(char *buf, int buf_size,
  189. int nb_channels, uint64_t channel_layout)
  190. {
  191. AVBPrint bp;
  192. av_bprint_init_for_buffer(&bp, buf, buf_size);
  193. av_bprint_channel_layout(&bp, nb_channels, channel_layout);
  194. }
  195. int av_get_channel_layout_nb_channels(uint64_t channel_layout)
  196. {
  197. return av_popcount64(channel_layout);
  198. }
  199. int64_t av_get_default_channel_layout(int nb_channels) {
  200. int i;
  201. for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
  202. if (nb_channels == channel_layout_map[i].nb_channels)
  203. return channel_layout_map[i].layout;
  204. return 0;
  205. }
  206. int av_get_channel_layout_channel_index(uint64_t channel_layout,
  207. uint64_t channel)
  208. {
  209. if (!(channel_layout & channel) ||
  210. av_get_channel_layout_nb_channels(channel) != 1)
  211. return AVERROR(EINVAL);
  212. channel_layout &= channel - 1;
  213. return av_get_channel_layout_nb_channels(channel_layout);
  214. }
  215. const char *av_get_channel_name(uint64_t channel)
  216. {
  217. int i;
  218. if (av_get_channel_layout_nb_channels(channel) != 1)
  219. return NULL;
  220. for (i = 0; i < 64; i++)
  221. if ((1ULL<<i) & channel)
  222. return get_channel_name(i);
  223. return NULL;
  224. }
  225. const char *av_get_channel_description(uint64_t channel)
  226. {
  227. int i;
  228. if (av_get_channel_layout_nb_channels(channel) != 1)
  229. return NULL;
  230. for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
  231. if ((1ULL<<i) & channel)
  232. return channel_names[i].description;
  233. return NULL;
  234. }
  235. uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
  236. {
  237. int i;
  238. if (av_get_channel_layout_nb_channels(channel_layout) <= index)
  239. return 0;
  240. for (i = 0; i < 64; i++) {
  241. if ((1ULL << i) & channel_layout && !index--)
  242. return 1ULL << i;
  243. }
  244. return 0;
  245. }
  246. int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
  247. const char **name)
  248. {
  249. if (index >= FF_ARRAY_ELEMS(channel_layout_map))
  250. return AVERROR_EOF;
  251. if (layout) *layout = channel_layout_map[index].layout;
  252. if (name) *name = channel_layout_map[index].name;
  253. return 0;
  254. }