FFmpeg: libavfilter/af_resample.c Source File

FFmpeg

[フレーム]

libavfilter

af_resample.c

Go to the documentation of this file.

1 /*

2 * This file is part of FFmpeg.

3 *

4 * FFmpeg is free software; you can redistribute it and/or

5 * modify it under the terms of the GNU Lesser General Public

6 * License as published by the Free Software Foundation; either

7 * version 2.1 of the License, or (at your option) any later version.

8 *

9 * FFmpeg is distributed in the hope that it will be useful,

10 * but WITHOUT ANY WARRANTY; without even the implied warranty of

11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU

12 * Lesser General Public License for more details.

13 *

14 * You should have received a copy of the GNU Lesser General Public

15 * License along with FFmpeg; if not, write to the Free Software

16 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

17 */

19 /**

20 * @file

21 * sample format and channel layout conversion audio filter

22 */

24 #include "libavutil/avassert.h"

25 #include "libavutil/avstring.h"

26 #include "libavutil/common.h"

27 #include "libavutil/dict.h"

28 #include "libavutil/mathematics.h"

29 #include "libavutil/opt.h"

31 #include "libavresample/avresample.h"

33 #include "audio.h"

34 #include "avfilter.h"

35 #include "formats.h"

36 #include "internal.h"

38 typedef struct ResampleContext {

39 const AVClass *class;

40 AVAudioResampleContext *avr;

41 AVDictionary *options;

43 int64_t next_pts;

45 /* set by filter_frame() to signal an output frame to request_frame() */

46 int got_output;

47 } ResampleContext;

49 static av_cold int init(AVFilterContext *ctx, AVDictionary **opts)

50 {

51 ResampleContext *s = ctx->priv;

52 const AVClass *avr_class = avresample_get_class();

53 AVDictionaryEntry *e = NULL;

55 while ((e = av_dict_get(*opts, "", e, AV_DICT_IGNORE_SUFFIX))) {

56 if (av_opt_find(&avr_class, e->key, NULL, 0,

57 AV_OPT_SEARCH_FAKE_OBJ | AV_OPT_SEARCH_CHILDREN))

58 av_dict_set(&s->options, e->key, e->value, 0);

59 }

61 e = NULL;

62 while ((e = av_dict_get(s->options, "", e, AV_DICT_IGNORE_SUFFIX)))

63 av_dict_set(opts, e->key, NULL, 0);

65 /* do not allow the user to override basic format options */

66 av_dict_set(&s->options, "in_channel_layout", NULL, 0);

67 av_dict_set(&s->options, "out_channel_layout", NULL, 0);

68 av_dict_set(&s->options, "in_sample_fmt", NULL, 0);

69 av_dict_set(&s->options, "out_sample_fmt", NULL, 0);

70 av_dict_set(&s->options, "in_sample_rate", NULL, 0);

71 av_dict_set(&s->options, "out_sample_rate", NULL, 0);

73 return 0;

74 }

76 static av_cold void uninit(AVFilterContext *ctx)

77 {

78 ResampleContext *s = ctx->priv;

80 if (s->avr) {

81 avresample_close(s->avr);

82 avresample_free(&s->avr);

83 }

84 av_dict_free(&s->options);

85 }

87 static int query_formats(AVFilterContext *ctx)

88 {

89 AVFilterLink *inlink = ctx->inputs[0];

90 AVFilterLink *outlink = ctx->outputs[0];

92 AVFilterFormats *in_formats = ff_all_formats(AVMEDIA_TYPE_AUDIO);

93 AVFilterFormats *out_formats = ff_all_formats(AVMEDIA_TYPE_AUDIO);

94 AVFilterFormats *in_samplerates = ff_all_samplerates();

95 AVFilterFormats *out_samplerates = ff_all_samplerates();

96 AVFilterChannelLayouts *in_layouts = ff_all_channel_layouts();

97 AVFilterChannelLayouts *out_layouts = ff_all_channel_layouts();

99 ff_formats_ref(in_formats, &inlink->out_formats);

100 ff_formats_ref(out_formats, &outlink->in_formats);

101

102 ff_formats_ref(in_samplerates, &inlink->out_samplerates);

103 ff_formats_ref(out_samplerates, &outlink->in_samplerates);

104

105 ff_channel_layouts_ref(in_layouts, &inlink->out_channel_layouts);

106 ff_channel_layouts_ref(out_layouts, &outlink->in_channel_layouts);

107

108 return 0;

109 }

110

111 static int config_output(AVFilterLink *outlink)

112 {

113 AVFilterContext *ctx = outlink->src;

114 AVFilterLink *inlink = ctx->inputs[0];

115 ResampleContext *s = ctx->priv;

116 char buf1[64], buf2[64];

117 int ret;

118

119 if (s->avr) {

120 avresample_close(s->avr);

121 avresample_free(&s->avr);

122 }

123

124 if (inlink->channel_layout == outlink->channel_layout &&

125 inlink->sample_rate == outlink->sample_rate &&

126 (inlink->format == outlink->format ||

127 (av_get_channel_layout_nb_channels(inlink->channel_layout) == 1 &&

128 av_get_channel_layout_nb_channels(outlink->channel_layout) == 1 &&

129 av_get_planar_sample_fmt(inlink->format) ==

130 av_get_planar_sample_fmt(outlink->format))))

131 return 0;

132

133 if (!(s->avr = avresample_alloc_context()))

134 return AVERROR(ENOMEM);

135

136 if (s->options) {

137 AVDictionaryEntry *e = NULL;

138 while ((e = av_dict_get(s->options, "", e, AV_DICT_IGNORE_SUFFIX)))

139 av_log(ctx, AV_LOG_VERBOSE, "lavr option: %s=%s\n", e->key, e->value);

140

141 av_opt_set_dict(s->avr, &s->options);

142 }

143

144 av_opt_set_int(s->avr, "in_channel_layout", inlink ->channel_layout, 0);

145 av_opt_set_int(s->avr, "out_channel_layout", outlink->channel_layout, 0);

146 av_opt_set_int(s->avr, "in_sample_fmt", inlink ->format, 0);

147 av_opt_set_int(s->avr, "out_sample_fmt", outlink->format, 0);

148 av_opt_set_int(s->avr, "in_sample_rate", inlink ->sample_rate, 0);

149 av_opt_set_int(s->avr, "out_sample_rate", outlink->sample_rate, 0);

150

151 if ((ret = avresample_open(s->avr)) < 0)

152 return ret;

153

154 outlink->time_base = (AVRational){ 1, outlink->sample_rate };

155 s->next_pts = AV_NOPTS_VALUE;

156

157 av_get_channel_layout_string(buf1, sizeof(buf1),

158 -1, inlink ->channel_layout);

159 av_get_channel_layout_string(buf2, sizeof(buf2),

160 -1, outlink->channel_layout);

161 av_log(ctx, AV_LOG_VERBOSE,

162 "fmt:%s srate:%d cl:%s -> fmt:%s srate:%d cl:%s\n",

163 av_get_sample_fmt_name(inlink ->format), inlink ->sample_rate, buf1,

164 av_get_sample_fmt_name(outlink->format), outlink->sample_rate, buf2);

165

166 return 0;

167 }

168

169 static int request_frame(AVFilterLink *outlink)

170 {

171 AVFilterContext *ctx = outlink->src;

172 ResampleContext *s = ctx->priv;

173 int ret = 0;

174

175 s->got_output = 0;

176 while (ret >= 0 && !s->got_output)

177 ret = ff_request_frame(ctx->inputs[0]);

178

179 /* flush the lavr delay buffer */

180 if (ret == AVERROR_EOF && s->avr) {

181 AVFrame *frame;

182 int nb_samples = av_rescale_rnd(avresample_get_delay(s->avr),

183 outlink->sample_rate,

184 ctx->inputs[0]->sample_rate,

185 AV_ROUND_UP);

186

187 if (!nb_samples)

188 return ret;

189

190 frame = ff_get_audio_buffer(outlink, nb_samples);

191 if (!frame)

192 return AVERROR(ENOMEM);

193

194 ret = avresample_convert(s->avr, frame->extended_data,

195 frame->linesize[0], nb_samples,

196 NULL, 0, 0);

197 if (ret <= 0) {

198 av_frame_free(&frame);

199 return (ret == 0) ? AVERROR_EOF : ret;

200 }

201

202 frame->pts = s->next_pts;

203 return ff_filter_frame(outlink, frame);

204 }

205 return ret;

206 }

207

208 static int filter_frame(AVFilterLink *inlink, AVFrame *in)

209 {

210 AVFilterContext *ctx = inlink->dst;

211 ResampleContext *s = ctx->priv;

212 AVFilterLink *outlink = ctx->outputs[0];

213 int ret;

214

215 if (s->avr) {

216 AVFrame *out;

217 int delay, nb_samples;

218

219 /* maximum possible samples lavr can output */

220 delay = avresample_get_delay(s->avr);

221 nb_samples = av_rescale_rnd(in->nb_samples + delay,

222 outlink->sample_rate, inlink->sample_rate,

223 AV_ROUND_UP);

224

225 out = ff_get_audio_buffer(outlink, nb_samples);

226 if (!out) {

227 ret = AVERROR(ENOMEM);

228 goto fail;

229 }

230

231 ret = avresample_convert(s->avr, out->extended_data, out->linesize[0],

232 nb_samples, in->extended_data, in->linesize[0],

233 in->nb_samples);

234 if (ret <= 0) {

235 av_frame_free(&out);

236 if (ret < 0)

237 goto fail;

238 }

239

240 av_assert0(!avresample_available(s->avr));

241

242 if (s->next_pts == AV_NOPTS_VALUE) {

243 if (in->pts == AV_NOPTS_VALUE) {

244 av_log(ctx, AV_LOG_WARNING, "First timestamp is missing, "

245 "assuming 0.\n");

246 s->next_pts = 0;

247 } else

248 s->next_pts = av_rescale_q(in->pts, inlink->time_base,

249 outlink->time_base);

250 }

251

252 if (ret > 0) {

253 out->nb_samples = ret;

254 if (in->pts != AV_NOPTS_VALUE) {

255 out->pts = av_rescale_q(in->pts, inlink->time_base,

256 outlink->time_base) -

257 av_rescale(delay, outlink->sample_rate,

258 inlink->sample_rate);

259 } else

260 out->pts = s->next_pts;

261

262 s->next_pts = out->pts + out->nb_samples;

263

264 ret = ff_filter_frame(outlink, out);

265 s->got_output = 1;

266 }

267

268 fail:

269 av_frame_free(&in);

270 } else {

271 in->format = outlink->format;

272 ret = ff_filter_frame(outlink, in);

273 s->got_output = 1;

274 }

275

276 return ret;

277 }

278

279 static const AVClass *resample_child_class_next(const AVClass *prev)

280 {

281 return prev ? NULL : avresample_get_class();

282 }

283

284 static void *resample_child_next(void *obj, void *prev)

285 {

286 ResampleContext *s = obj;

287 return prev ? NULL : s->avr;

288 }

289

290 static const AVClass resample_class = {

291 .class_name = "resample",

292 .item_name = av_default_item_name,

293 .version = LIBAVUTIL_VERSION_INT,

294 .child_class_next = resample_child_class_next,

295 .child_next = resample_child_next,

296 };

297

298 static const AVFilterPad avfilter_af_resample_inputs[] = {

299 {

300 .name = "default",

301 .type = AVMEDIA_TYPE_AUDIO,

302 .filter_frame = filter_frame,

303 },

304 { NULL }

305 };

306

307 static const AVFilterPad avfilter_af_resample_outputs[] = {

308 {

309 .name = "default",

310 .type = AVMEDIA_TYPE_AUDIO,

311 .config_props = config_output,

312 .request_frame = request_frame

313 },

314 { NULL }

315 };

316

317 AVFilter avfilter_af_resample = {

318 .name = "resample",

319 .description = NULL_IF_CONFIG_SMALL("Audio resampling and conversion."),

320 .priv_size = sizeof(ResampleContext),

321 .priv_class = &resample_class,

322 .init_dict = init,

323 .uninit = uninit,

324 .query_formats = query_formats,

325 .inputs = avfilter_af_resample_inputs,

326 .outputs = avfilter_af_resample_outputs,

327 };

Generated on Sat Jan 25 2014 19:51:59 for FFmpeg by doxygen 1.8.2