FFmpeg: libavutil/channel_layout.c Source File

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libavutil

channel_layout.c

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1 /*

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 */

21 /**

22 * @file

23 * audio channel layout utility functions

24 */

26 #include <stdint.h>

28 #include "avstring.h"

29 #include "avutil.h"

30 #include "channel_layout.h"

31 #include "bprint.h"

32 #include "common.h"

34 struct channel_name {

35 const char *name;

36 const char *description;

37 };

39 static const struct channel_name channel_names[] = {

40 [0] = { "FL", "front left" },

41 [1] = { "FR", "front right" },

42 [2] = { "FC", "front center" },

43 [3] = { "LFE", "low frequency" },

44 [4] = { "BL", "back left" },

45 [5] = { "BR", "back right" },

46 [6] = { "FLC", "front left-of-center" },

47 [7] = { "FRC", "front right-of-center" },

48 [8] = { "BC", "back center" },

49 [9] = { "SL", "side left" },

50 [10] = { "SR", "side right" },

51 [11] = { "TC", "top center" },

52 [12] = { "TFL", "top front left" },

53 [13] = { "TFC", "top front center" },

54 [14] = { "TFR", "top front right" },

55 [15] = { "TBL", "top back left" },

56 [16] = { "TBC", "top back center" },

57 [17] = { "TBR", "top back right" },

58 [29] = { "DL", "downmix left" },

59 [30] = { "DR", "downmix right" },

60 [31] = { "WL", "wide left" },

61 [32] = { "WR", "wide right" },

62 [33] = { "SDL", "surround direct left" },

63 [34] = { "SDR", "surround direct right" },

64 [35] = { "LFE2", "low frequency 2" },

65 };

67 static const char *get_channel_name(int channel_id)

68 {

69 if (channel_id < 0 || channel_id >= FF_ARRAY_ELEMS(channel_names))

70 return NULL;

71 return channel_names[channel_id].name;

72 }

74 static const struct {

75 const char *name;

76 int nb_channels;

77 uint64_t layout;

78 } channel_layout_map[] = {

79 { "mono", 1, AV_CH_LAYOUT_MONO },

80 { "stereo", 2, AV_CH_LAYOUT_STEREO },

81 { "2.1", 3, AV_CH_LAYOUT_2POINT1 },

82 { "3.0", 3, AV_CH_LAYOUT_SURROUND },

83 { "3.0(back)", 3, AV_CH_LAYOUT_2_1 },

84 { "4.0", 4, AV_CH_LAYOUT_4POINT0 },

85 { "quad", 4, AV_CH_LAYOUT_QUAD },

86 { "quad(side)", 4, AV_CH_LAYOUT_2_2 },

87 { "3.1", 4, AV_CH_LAYOUT_3POINT1 },

88 { "5.0", 5, AV_CH_LAYOUT_5POINT0_BACK },

89 { "5.0(side)", 5, AV_CH_LAYOUT_5POINT0 },

90 { "4.1", 5, AV_CH_LAYOUT_4POINT1 },

91 { "5.1", 6, AV_CH_LAYOUT_5POINT1_BACK },

92 { "5.1(side)", 6, AV_CH_LAYOUT_5POINT1 },

93 { "6.0", 6, AV_CH_LAYOUT_6POINT0 },

94 { "6.0(front)", 6, AV_CH_LAYOUT_6POINT0_FRONT },

95 { "hexagonal", 6, AV_CH_LAYOUT_HEXAGONAL },

96 { "6.1", 7, AV_CH_LAYOUT_6POINT1 },

97 { "6.1", 7, AV_CH_LAYOUT_6POINT1_BACK },

98 { "6.1(front)", 7, AV_CH_LAYOUT_6POINT1_FRONT },

99 { "7.0", 7, AV_CH_LAYOUT_7POINT0 },

100 { "7.0(front)", 7, AV_CH_LAYOUT_7POINT0_FRONT },

101 { "7.1", 8, AV_CH_LAYOUT_7POINT1 },

102 { "7.1(wide)", 8, AV_CH_LAYOUT_7POINT1_WIDE_BACK },

103 { "7.1(wide-side)", 8, AV_CH_LAYOUT_7POINT1_WIDE },

104 { "octagonal", 8, AV_CH_LAYOUT_OCTAGONAL },

105 { "downmix", 2, AV_CH_LAYOUT_STEREO_DOWNMIX, },

106 };

107

108 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT

109 static uint64_t get_channel_layout_single(const char *name, int name_len, int compat)

110 #else

111 static uint64_t get_channel_layout_single(const char *name, int name_len)

112 #endif

113 {

114 int i;

115 char *end;

116 int64_t layout;

117

118 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++) {

119 if (strlen(channel_layout_map[i].name) == name_len &&

120 !memcmp(channel_layout_map[i].name, name, name_len))

121 return channel_layout_map[i].layout;

122 }

123 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)

124 if (channel_names[i].name &&

125 strlen(channel_names[i].name) == name_len &&

126 !memcmp(channel_names[i].name, name, name_len))

127 return (int64_t)1 << i;

128 i = strtol(name, &end, 10);

129

130 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT

131 if (compat) {

132 if (end - name == name_len ||

133 (end + 1 - name == name_len && *end == 'c')) {

134 layout = av_get_default_channel_layout(i);

135 if (end - name == name_len) {

136 av_log(NULL, AV_LOG_WARNING,

137 "Single channel layout '%.*s' is interpreted as a number of channels, "

138 "switch to the syntax '%.*sc' otherwise it will be interpreted as a "

139 "channel layout number in a later version\n",

140 name_len, name, name_len, name);

141 return layout;

142 }

143 }

144 } else {

145 #endif

146 if ((end + 1 - name == name_len && *end == 'c'))

147 return av_get_default_channel_layout(i);

148 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT

149 }

150 #endif

151

152 layout = strtoll(name, &end, 0);

153 if (end - name == name_len)

154 return FFMAX(layout, 0);

155 return 0;

156 }

157

158 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT

159 uint64_t ff_get_channel_layout(const char *name, int compat)

160 #else

161 uint64_t av_get_channel_layout(const char *name)

162 #endif

163 {

164 const char *n, *e;

165 const char *name_end = name + strlen(name);

166 int64_t layout = 0, layout_single;

167

168 for (n = name; n < name_end; n = e + 1) {

169 for (e = n; e < name_end && *e != '+' && *e != '|'; e++);

170 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT

171 layout_single = get_channel_layout_single(n, e - n, compat);

172 #else

173 layout_single = get_channel_layout_single(n, e - n);

174 #endif

175 if (!layout_single)

176 return 0;

177 layout |= layout_single;

178 }

179 return layout;

180 }

181

182 #if FF_API_GET_CHANNEL_LAYOUT_COMPAT

183 uint64_t av_get_channel_layout(const char *name)

184 {

185 return ff_get_channel_layout(name, 1);

186 }

187 #endif

188

189 void av_bprint_channel_layout(struct AVBPrint *bp,

190 int nb_channels, uint64_t channel_layout)

191 {

192 int i;

193

194 if (nb_channels <= 0)

195 nb_channels = av_get_channel_layout_nb_channels(channel_layout);

196

197 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)

198 if (nb_channels == channel_layout_map[i].nb_channels &&

199 channel_layout == channel_layout_map[i].layout) {

200 av_bprintf(bp, "%s", channel_layout_map[i].name);

201 return;

202 }

203

204 av_bprintf(bp, "%d channels", nb_channels);

205 if (channel_layout) {

206 int i, ch;

207 av_bprintf(bp, " (");

208 for (i = 0, ch = 0; i < 64; i++) {

209 if ((channel_layout & (UINT64_C(1) << i))) {

210 const char *name = get_channel_name(i);

211 if (name) {

212 if (ch > 0)

213 av_bprintf(bp, "+");

214 av_bprintf(bp, "%s", name);

215 }

216 ch++;

217 }

218 }

219 av_bprintf(bp, ")");

220 }

221 }

222

223 void av_get_channel_layout_string(char *buf, int buf_size,

224 int nb_channels, uint64_t channel_layout)

225 {

226 AVBPrint bp;

227

228 av_bprint_init_for_buffer(&bp, buf, buf_size);

229 av_bprint_channel_layout(&bp, nb_channels, channel_layout);

230 }

231

232 int av_get_channel_layout_nb_channels(uint64_t channel_layout)

233 {

234 return av_popcount64(channel_layout);

235 }

236

237 int64_t av_get_default_channel_layout(int nb_channels) {

238 int i;

239 for (i = 0; i < FF_ARRAY_ELEMS(channel_layout_map); i++)

240 if (nb_channels == channel_layout_map[i].nb_channels)

241 return channel_layout_map[i].layout;

242 return 0;

243 }

244

245 int av_get_channel_layout_channel_index(uint64_t channel_layout,

246 uint64_t channel)

247 {

248 if (!(channel_layout & channel) ||

249 av_get_channel_layout_nb_channels(channel) != 1)

250 return AVERROR(EINVAL);

251 channel_layout &= channel - 1;

252 return av_get_channel_layout_nb_channels(channel_layout);

253 }

254

255 const char *av_get_channel_name(uint64_t channel)

256 {

257 int i;

258 if (av_get_channel_layout_nb_channels(channel) != 1)

259 return NULL;

260 for (i = 0; i < 64; i++)

261 if ((1ULL<<i) & channel)

262 return get_channel_name(i);

263 return NULL;

264 }

265

266 const char *av_get_channel_description(uint64_t channel)

267 {

268 int i;

269 if (av_get_channel_layout_nb_channels(channel) != 1)

270 return NULL;

271 for (i = 0; i < FF_ARRAY_ELEMS(channel_names); i++)

272 if ((1ULL<<i) & channel)

273 return channel_names[i].description;

274 return NULL;

275 }

276

277 uint64_t av_channel_layout_extract_channel(uint64_t channel_layout, int index)

278 {

279 int i;

280

281 if (av_get_channel_layout_nb_channels(channel_layout) <= index)

282 return 0;

283

284 for (i = 0; i < 64; i++) {

285 if ((1ULL << i) & channel_layout && !index--)

286 return 1ULL << i;

287 }

288 return 0;

289 }

290

291 int av_get_standard_channel_layout(unsigned index, uint64_t *layout,

292 const char **name)

293 {

294 if (index >= FF_ARRAY_ELEMS(channel_layout_map))

295 return AVERROR_EOF;

296 if (layout) *layout = channel_layout_map[index].layout;

297 if (name) *name = channel_layout_map[index].name;

298 return 0;

299 }

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