2 * This file is part of FFmpeg.
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.
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.
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
21 * sample format and channel layout conversion audio filter
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"
38 typedef struct ResampleContext {
40 AVAudioResampleContext *avr;
41 AVDictionary *options;
45 /* set by filter_frame() to signal an output frame to request_frame() */
49 static av_cold int init(AVFilterContext *ctx, AVDictionary **opts)
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);
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);
76 static av_cold void uninit(AVFilterContext *ctx)
78 ResampleContext *s = ctx->priv;
81 avresample_close(s->avr);
82 avresample_free(&s->avr);
84 av_dict_free(&s->options);
87 static int query_formats(AVFilterContext *ctx)
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);
102 ff_formats_ref(in_samplerates, &inlink->out_samplerates);
103 ff_formats_ref(out_samplerates, &outlink->in_samplerates);
105 ff_channel_layouts_ref(in_layouts, &inlink->out_channel_layouts);
106 ff_channel_layouts_ref(out_layouts, &outlink->in_channel_layouts);
111 static int config_output(AVFilterLink *outlink)
113 AVFilterContext *ctx = outlink->src;
114 AVFilterLink *inlink = ctx->inputs[0];
115 ResampleContext *s = ctx->priv;
116 char buf1[64], buf2[64];
120 avresample_close(s->avr);
121 avresample_free(&s->avr);
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))))
133 if (!(s->avr = avresample_alloc_context()))
134 return AVERROR(ENOMEM);
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);
141 av_opt_set_dict(s->avr, &s->options);
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);
151 if ((ret = avresample_open(s->avr)) < 0)
154 outlink->time_base = (AVRational){ 1, outlink->sample_rate };
155 s->next_pts = AV_NOPTS_VALUE;
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);
169 static int request_frame(AVFilterLink *outlink)
171 AVFilterContext *ctx = outlink->src;
172 ResampleContext *s = ctx->priv;
176 while (ret >= 0 && !s->got_output)
177 ret = ff_request_frame(ctx->inputs[0]);
179 /* flush the lavr delay buffer */
180 if (ret == AVERROR_EOF && s->avr) {
182 int nb_samples = av_rescale_rnd(avresample_get_delay(s->avr),
183 outlink->sample_rate,
184 ctx->inputs[0]->sample_rate,
190 frame = ff_get_audio_buffer(outlink, nb_samples);
192 return AVERROR(ENOMEM);
194 ret = avresample_convert(s->avr, frame->extended_data,
195 frame->linesize[0], nb_samples,
198 av_frame_free(&frame);
199 return (ret == 0) ? AVERROR_EOF : ret;
202 frame->pts = s->next_pts;
203 return ff_filter_frame(outlink, frame);
208 static int filter_frame(AVFilterLink *inlink, AVFrame *in)
210 AVFilterContext *ctx = inlink->dst;
211 ResampleContext *s = ctx->priv;
212 AVFilterLink *outlink = ctx->outputs[0];
217 int delay, nb_samples;
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,
225 out = ff_get_audio_buffer(outlink, nb_samples);
227 ret = AVERROR(ENOMEM);
231 ret = avresample_convert(s->avr, out->extended_data, out->linesize[0],
232 nb_samples, in->extended_data, in->linesize[0],
240 av_assert0(!avresample_available(s->avr));
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, "
248 s->next_pts = av_rescale_q(in->pts, inlink->time_base,
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);
260 out->pts = s->next_pts;
262 s->next_pts = out->pts + out->nb_samples;
264 ret = ff_filter_frame(outlink, out);
271 in->format = outlink->format;
272 ret = ff_filter_frame(outlink, in);
279 static const AVClass *resample_child_class_next(const AVClass *prev)
281 return prev ? NULL : avresample_get_class();
284 static void *resample_child_next(void *obj, void *prev)
286 ResampleContext *s = obj;
287 return prev ? NULL : s->avr;
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,
298 static const AVFilterPad avfilter_af_resample_inputs[] = {
301 .type = AVMEDIA_TYPE_AUDIO,
302 .filter_frame = filter_frame,
307 static const AVFilterPad avfilter_af_resample_outputs[] = {
310 .type = AVMEDIA_TYPE_AUDIO,
311 .config_props = config_output,
312 .request_frame = request_frame
317 AVFilter avfilter_af_resample = {
319 .description = NULL_IF_CONFIG_SMALL("Audio resampling and conversion."),
320 .priv_size = sizeof(ResampleContext),
321 .priv_class = &resample_class,
324 .query_formats = query_formats,
325 .inputs = avfilter_af_resample_inputs,
326 .outputs = avfilter_af_resample_outputs,