FFmpeg: libavfilter/af_aresample.c Source File

FFmpeg
af_aresample.c
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1 /*
2  * Copyright (c) 2011 Stefano Sabatini
3  * Copyright (c) 2011 Mina Nagy Zaki
4  *
5  * This file is part of FFmpeg.
6  *
7  * FFmpeg is free software; you can redistribute it and/or
8  * modify it under the terms of the GNU Lesser General Public
9  * License as published by the Free Software Foundation; either
10  * version 2.1 of the License, or (at your option) any later version.
11  *
12  * FFmpeg is distributed in the hope that it will be useful,
13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15  * Lesser General Public License for more details.
16  *
17  * You should have received a copy of the GNU Lesser General Public
18  * License along with FFmpeg; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
22 /**
23  * @file
24  * resampling audio filter
25  */
26 
27 #include "libavutil/avstring.h"
28 #include "libavutil/channel_layout.h"
29 #include "libavutil/opt.h"
30 #include "libavutil/samplefmt.h"
31 #include "libavutil/avassert.h"
32 #include "libswresample/swresample.h"
33 #include "avfilter.h"
34 #include "audio.h"
35 #include "internal.h"
36 
37  typedef struct {
38   const AVClass *class;
39   int sample_rate_arg;
40   double ratio;
41   struct SwrContext *swr;
42   int64_t next_pts;
43   int req_fullfilled;
44 } AResampleContext;
45 
46  static av_cold int init_dict(AVFilterContext *ctx, AVDictionary **opts)
47 {
48  AResampleContext *aresample = ctx->priv;
49  int ret = 0;
50 
51  aresample->next_pts = AV_NOPTS_VALUE;
52  aresample->swr = swr_alloc();
53  if (!aresample->swr) {
54  ret = AVERROR(ENOMEM);
55  goto end;
56  }
57 
58  if (opts) {
59  AVDictionaryEntry *e = NULL;
60 
61  while ((e = av_dict_get(*opts, "", e, AV_DICT_IGNORE_SUFFIX))) {
62  if ((ret = av_opt_set(aresample->swr, e->key, e->value, 0)) < 0)
63  goto end;
64  }
65  av_dict_free(opts);
66  }
67  if (aresample->sample_rate_arg > 0)
68  av_opt_set_int(aresample->swr, "osr", aresample->sample_rate_arg, 0);
69 end:
70  return ret;
71 }
72 
73  static av_cold void uninit(AVFilterContext *ctx)
74 {
75  AResampleContext *aresample = ctx->priv;
76  swr_free(&aresample->swr);
77 }
78 
79  static int query_formats(AVFilterContext *ctx)
80 {
81  AResampleContext *aresample = ctx->priv;
82  int out_rate = av_get_int(aresample->swr, "osr", NULL);
83  uint64_t out_layout = av_get_int(aresample->swr, "ocl", NULL);
84  enum AVSampleFormat out_format = av_get_int(aresample->swr, "osf", NULL);
85 
86  AVFilterLink *inlink = ctx->inputs[0];
87  AVFilterLink *outlink = ctx->outputs[0];
88 
89  AVFilterFormats *in_formats = ff_all_formats(AVMEDIA_TYPE_AUDIO);
90  AVFilterFormats *out_formats;
91  AVFilterFormats *in_samplerates = ff_all_samplerates();
92  AVFilterFormats *out_samplerates;
93  AVFilterChannelLayouts *in_layouts = ff_all_channel_counts();
94  AVFilterChannelLayouts *out_layouts;
95 
96  ff_formats_ref (in_formats, &inlink->out_formats);
97  ff_formats_ref (in_samplerates, &inlink->out_samplerates);
98  ff_channel_layouts_ref(in_layouts, &inlink->out_channel_layouts);
99 
100  if(out_rate > 0) {
101  out_samplerates = ff_make_format_list((int[]){ out_rate, -1 });
102  } else {
103  out_samplerates = ff_all_samplerates();
104  }
105  ff_formats_ref(out_samplerates, &outlink->in_samplerates);
106 
107  if(out_format != AV_SAMPLE_FMT_NONE) {
108  out_formats = ff_make_format_list((int[]){ out_format, -1 });
109  } else
110  out_formats = ff_all_formats(AVMEDIA_TYPE_AUDIO);
111  ff_formats_ref(out_formats, &outlink->in_formats);
112 
113  if(out_layout) {
114  out_layouts = avfilter_make_format64_list((int64_t[]){ out_layout, -1 });
115  } else
116  out_layouts = ff_all_channel_counts();
117  ff_channel_layouts_ref(out_layouts, &outlink->in_channel_layouts);
118 
119  return 0;
120 }
121 
122 
123  static int config_output(AVFilterLink *outlink)
124 {
125  int ret;
126  AVFilterContext *ctx = outlink->src;
127  AVFilterLink *inlink = ctx->inputs[0];
128  AResampleContext *aresample = ctx->priv;
129  int out_rate;
130  uint64_t out_layout;
131  enum AVSampleFormat out_format;
132  char inchl_buf[128], outchl_buf[128];
133 
134  aresample->swr = swr_alloc_set_opts(aresample->swr,
135  outlink->channel_layout, outlink->format, outlink->sample_rate,
136  inlink->channel_layout, inlink->format, inlink->sample_rate,
137  0, ctx);
138  if (!aresample->swr)
139  return AVERROR(ENOMEM);
140  if (!inlink->channel_layout)
141  av_opt_set_int(aresample->swr, "ich", inlink->channels, 0);
142  if (!outlink->channel_layout)
143  av_opt_set_int(aresample->swr, "och", outlink->channels, 0);
144 
145  ret = swr_init(aresample->swr);
146  if (ret < 0)
147  return ret;
148 
149  out_rate = av_get_int(aresample->swr, "osr", NULL);
150  out_layout = av_get_int(aresample->swr, "ocl", NULL);
151  out_format = av_get_int(aresample->swr, "osf", NULL);
152  outlink->time_base = (AVRational) {1, out_rate};
153 
154  av_assert0(outlink->sample_rate == out_rate);
155  av_assert0(outlink->channel_layout == out_layout || !outlink->channel_layout);
156  av_assert0(outlink->format == out_format);
157 
158  aresample->ratio = (double)outlink->sample_rate / inlink->sample_rate;
159 
160  av_get_channel_layout_string(inchl_buf, sizeof(inchl_buf), inlink ->channels, inlink ->channel_layout);
161  av_get_channel_layout_string(outchl_buf, sizeof(outchl_buf), outlink->channels, outlink->channel_layout);
162 
163  av_log(ctx, AV_LOG_VERBOSE, "ch:%d chl:%s fmt:%s r:%dHz -> ch:%d chl:%s fmt:%s r:%dHz\n",
164  inlink ->channels, inchl_buf, av_get_sample_fmt_name(inlink->format), inlink->sample_rate,
165  outlink->channels, outchl_buf, av_get_sample_fmt_name(outlink->format), outlink->sample_rate);
166  return 0;
167 }
168 
169  static int filter_frame(AVFilterLink *inlink, AVFrame *insamplesref)
170 {
171  AResampleContext *aresample = inlink->dst->priv;
172  const int n_in = insamplesref->nb_samples;
173  int n_out = n_in * aresample->ratio * 2 + 256;
174  AVFilterLink *const outlink = inlink->dst->outputs[0];
175  AVFrame *outsamplesref = ff_get_audio_buffer(outlink, n_out);
176  int ret;
177 
178  if(!outsamplesref)
179  return AVERROR(ENOMEM);
180 
181  av_frame_copy_props(outsamplesref, insamplesref);
182  outsamplesref->format = outlink->format;
183  av_frame_set_channels(outsamplesref, outlink->channels);
184  outsamplesref->channel_layout = outlink->channel_layout;
185  outsamplesref->sample_rate = outlink->sample_rate;
186 
187  if(insamplesref->pts != AV_NOPTS_VALUE) {
188  int64_t inpts = av_rescale(insamplesref->pts, inlink->time_base.num * (int64_t)outlink->sample_rate * inlink->sample_rate, inlink->time_base.den);
189  int64_t outpts= swr_next_pts(aresample->swr, inpts);
190  aresample->next_pts =
191  outsamplesref->pts = ROUNDED_DIV(outpts, inlink->sample_rate);
192  } else {
193  outsamplesref->pts = AV_NOPTS_VALUE;
194  }
195  n_out = swr_convert(aresample->swr, outsamplesref->extended_data, n_out,
196  (void *)insamplesref->extended_data, n_in);
197  if (n_out <= 0) {
198  av_frame_free(&outsamplesref);
199  av_frame_free(&insamplesref);
200  return 0;
201  }
202 
203  outsamplesref->nb_samples = n_out;
204 
205  ret = ff_filter_frame(outlink, outsamplesref);
206  aresample->req_fullfilled= 1;
207  av_frame_free(&insamplesref);
208  return ret;
209 }
210 
211  static int request_frame(AVFilterLink *outlink)
212 {
213  AVFilterContext *ctx = outlink->src;
214  AResampleContext *aresample = ctx->priv;
215  AVFilterLink *const inlink = outlink->src->inputs[0];
216  int ret;
217 
218  aresample->req_fullfilled = 0;
219  do{
220  ret = ff_request_frame(ctx->inputs[0]);
221  }while(!aresample->req_fullfilled && ret>=0);
222 
223  if (ret == AVERROR_EOF) {
224  AVFrame *outsamplesref;
225  int n_out = 4096;
226 
227  outsamplesref = ff_get_audio_buffer(outlink, n_out);
228  if (!outsamplesref)
229  return AVERROR(ENOMEM);
230  n_out = swr_convert(aresample->swr, outsamplesref->extended_data, n_out, 0, 0);
231  if (n_out <= 0) {
232  av_frame_free(&outsamplesref);
233  return (n_out == 0) ? AVERROR_EOF : n_out;
234  }
235 
236  outsamplesref->sample_rate = outlink->sample_rate;
237  outsamplesref->nb_samples = n_out;
238 #if 0
239  outsamplesref->pts = aresample->next_pts;
240  if(aresample->next_pts != AV_NOPTS_VALUE)
241  aresample->next_pts += av_rescale_q(n_out, (AVRational){1 ,outlink->sample_rate}, outlink->time_base);
242 #else
243  outsamplesref->pts = swr_next_pts(aresample->swr, INT64_MIN);
244  outsamplesref->pts = ROUNDED_DIV(outsamplesref->pts, inlink->sample_rate);
245 #endif
246 
247  return ff_filter_frame(outlink, outsamplesref);
248  }
249  return ret;
250 }
251 
252  static const AVClass *resample_child_class_next(const AVClass *prev)
253 {
254  return prev ? NULL : swr_get_class();
255 }
256 
257  static void *resample_child_next(void *obj, void *prev)
258 {
259  AResampleContext *s = obj;
260  return prev ? NULL : s->swr;
261 }
262 
263  #define OFFSET(x) offsetof(AResampleContext, x)
264  #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
265 
266  static const AVOption options[] = {
267  {"sample_rate", NULL, OFFSET(sample_rate_arg), AV_OPT_TYPE_INT, {.i64=0}, 0, INT_MAX, FLAGS },
268  {NULL}
269 };
270 
271  static const AVClass aresample_class = {
272  .class_name = "aresample",
273  .item_name = av_default_item_name,
274  .option = options,
275  .version = LIBAVUTIL_VERSION_INT,
276  .child_class_next = resample_child_class_next,
277  .child_next = resample_child_next,
278 };
279 
280  static const AVFilterPad aresample_inputs[] = {
281  {
282  .name = "default",
283  .type = AVMEDIA_TYPE_AUDIO,
284  .filter_frame = filter_frame,
285  },
286  { NULL }
287 };
288 
289  static const AVFilterPad aresample_outputs[] = {
290  {
291  .name = "default",
292  .config_props = config_output,
293  .request_frame = request_frame,
294  .type = AVMEDIA_TYPE_AUDIO,
295  },
296  { NULL }
297 };
298 
299  AVFilter avfilter_af_aresample = {
300  .name = "aresample",
301  .description = NULL_IF_CONFIG_SMALL("Resample audio data."),
302  .init_dict = init_dict,
303  .uninit = uninit,
304  .query_formats = query_formats,
305  .priv_size = sizeof(AResampleContext),
306  .priv_class = &aresample_class,
307  .inputs = aresample_inputs,
308  .outputs = aresample_outputs,
309 };
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