channel_layout.c 9.8 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", 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. { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },
  99. };
  100. #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
  101. static uint64_t get_channel_layout_single(const char *name, int name_len, int compat)
  102. #else
  103. static uint64_t get_channel_layout_single(const char *name, int name_len)
  104. #endif
  105. {
  106. int i;
  107. char *end;
  108. int64_t layout;
  109. for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {
  110. if (strlen(channel_layout_map[i].name) == name_len &&
  111. !memcmp(channel_layout_map[i].name, name, name_len))
  112. return channel_layout_map[i].layout;
  113. }
  114. for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
  115. if (channel_names[i].name &&
  116. strlen(channel_names[i].name) == name_len &&
  117. !memcmp(channel_names[i].name, name, name_len))
  118. return (int64_t)1 << i;
  119. i = strtol(name, &end, 10);
  120. #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
  121. if (compat) {
  122. if (end - name == name_len ||
  123. (end + 1 - name == name_len && *end == 'c')) {
  124. layout = av_get_default_channel_layout(i);
  125. if (end - name == name_len) {
  126. av_log(NULL, AV_LOG_WARNING,
  127. "Single channel layout '%.*s' is interpreted as a number of channels, "
  128. "switch to the syntax '%.*sc' otherwise it will be interpreted as a "
  129. "channel layout number in a later version\n",
  130. name_len, name, name_len, name);
  131. return layout;
  132. }
  133. }
  134. } else {
  135. #endif
  136. if ((end + 1 - name == name_len && *end == 'c'))
  137. return av_get_default_channel_layout(i);
  138. #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
  139. }
  140. #endif
  141. layout = strtoll(name, &end, 0);
  142. if (end - name == name_len)
  143. return FFMAX(layout, 0);
  144. return 0;
  145. }
  146. #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
  147. uint64_t ff_get_channel_layout(const char *name, int compat)
  148. #else
  149. uint64_t av_get_channel_layout(const char *name)
  150. #endif
  151. {
  152. const char *n, *e;
  153. const char *name_end = name + strlen(name);
  154. int64_t layout = 0, layout_single;
  155. for (n = name; n < name_end; n = e + 1) {
  156. for (e = n; e < name_end && *e != '+' && *e != '|'; e++);
  157. #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
  158. layout_single = get_channel_layout_single(n, e - n, compat);
  159. #else
  160. layout_single = get_channel_layout_single(n, e - n);
  161. #endif
  162. if (!layout_single)
  163. return 0;
  164. layout |= layout_single;
  165. }
  166. return layout;
  167. }
  168. #if FF_API_GET_CHANNEL_LAYOUT_COMPAT
  169. uint64_t av_get_channel_layout(const char *name)
  170. {
  171. return ff_get_channel_layout(name, 1);
  172. }
  173. #endif
  174. void av_bprint_channel_layout(struct AVBPrint *bp,
  175. int nb_channels, uint64_t channel_layout)
  176. {
  177. int i;
  178. if (nb_channels <= 0)
  179. nb_channels = av_get_channel_layout_nb_channels(channel_layout);
  180. for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
  181. if (nb_channels == channel_layout_map[i].nb_channels &&
  182. channel_layout == channel_layout_map[i].layout) {
  183. av_bprintf(bp, "%s", channel_layout_map[i].name);
  184. return;
  185. }
  186. av_bprintf(bp, "%d channels", nb_channels);
  187. if (channel_layout) {
  188. int i, ch;
  189. av_bprintf(bp, " (");
  190. for (i = 0, ch = 0; i < 64; i++) {
  191. if ((channel_layout & (UINT64_C(1) << i))) {
  192. const char *name = get_channel_name(i);
  193. if (name) {
  194. if (ch > 0)
  195. av_bprintf(bp, "+");
  196. av_bprintf(bp, "%s", name);
  197. }
  198. ch++;
  199. }
  200. }
  201. av_bprintf(bp, ")");
  202. }
  203. }
  204. void av_get_channel_layout_string(char *buf, int buf_size,
  205. int nb_channels, uint64_t channel_layout)
  206. {
  207. AVBPrint bp;
  208. av_bprint_init_for_buffer(&bp, buf, buf_size);
  209. av_bprint_channel_layout(&bp, nb_channels, channel_layout);
  210. }
  211. int av_get_channel_layout_nb_channels(uint64_t channel_layout)
  212. {
  213. return av_popcount64(channel_layout);
  214. }
  215. int64_t av_get_default_channel_layout(int nb_channels) {
  216. int i;
  217. for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)
  218. if (nb_channels == channel_layout_map[i].nb_channels)
  219. return channel_layout_map[i].layout;
  220. return 0;
  221. }
  222. int av_get_channel_layout_channel_index(uint64_t channel_layout,
  223. uint64_t channel)
  224. {
  225. if (!(channel_layout & channel) ||
  226. av_get_channel_layout_nb_channels(channel) != 1)
  227. return AVERROR(EINVAL);
  228. channel_layout &= channel - 1;
  229. return av_get_channel_layout_nb_channels(channel_layout);
  230. }
  231. const char *av_get_channel_name(uint64_t channel)
  232. {
  233. int i;
  234. if (av_get_channel_layout_nb_channels(channel) != 1)
  235. return NULL;
  236. for (i = 0; i < 64; i++)
  237. if ((1ULL<<i) & channel)
  238. return get_channel_name(i);
  239. return NULL;
  240. }
  241. const char *av_get_channel_description(uint64_t channel)
  242. {
  243. int i;
  244. if (av_get_channel_layout_nb_channels(channel) != 1)
  245. return NULL;
  246. for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)
  247. if ((1ULL<<i) & channel)
  248. return channel_names[i].description;
  249. return NULL;
  250. }
  251. uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)
  252. {
  253. int i;
  254. if (av_get_channel_layout_nb_channels(channel_layout) <= index)
  255. return 0;
  256. for (i = 0; i < 64; i++) {
  257. if ((1ULL << i) & channel_layout && !index--)
  258. return 1ULL << i;
  259. }
  260. return 0;
  261. }
  262. int av_get_standard_channel_layout(unsigned index, uint64_t *layout,
  263. const char **name)
  264. {
  265. if (index >= FF_ARRAY_ELEMS(channel_layout_map))
  266. return AVERROR_EOF;
  267. if (layout) *layout = channel_layout_map[index].layout;
  268. if (name) *name = channel_layout_map[index].name;
  269. return 0;
  270. }