lavfi: add lavr-based audio resampling filter.
[libav.git] / libavfilter / af_resample.c
1 /*
2 *
3 * This file is part of Libav.
4 *
5 * Libav is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * Libav is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with Libav; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20 /**
21 * @file
22 * sample format and channel layout conversion audio filter
23 */
24
25 #include "libavutil/avassert.h"
26 #include "libavutil/avstring.h"
27 #include "libavutil/mathematics.h"
28 #include "libavutil/opt.h"
29
30 #include "libavresample/avresample.h"
31
32 #include "audio.h"
33 #include "avfilter.h"
34 #include "internal.h"
35
36 typedef struct ResampleContext {
37 AVAudioResampleContext *avr;
38
39 int64_t next_pts;
40 } ResampleContext;
41
42 static av_cold void uninit(AVFilterContext *ctx)
43 {
44 ResampleContext *s = ctx->priv;
45
46 if (s->avr) {
47 avresample_close(s->avr);
48 avresample_free(&s->avr);
49 }
50 }
51
52 static int query_formats(AVFilterContext *ctx)
53 {
54 AVFilterLink *inlink = ctx->inputs[0];
55 AVFilterLink *outlink = ctx->outputs[0];
56
57 AVFilterFormats *in_formats = avfilter_all_formats(AVMEDIA_TYPE_AUDIO);
58 AVFilterFormats *out_formats = avfilter_all_formats(AVMEDIA_TYPE_AUDIO);
59
60 avfilter_formats_ref(in_formats, &inlink->out_formats);
61 avfilter_formats_ref(out_formats, &outlink->in_formats);
62
63 return 0;
64 }
65
66 static int config_output(AVFilterLink *outlink)
67 {
68 AVFilterContext *ctx = outlink->src;
69 AVFilterLink *inlink = ctx->inputs[0];
70 ResampleContext *s = ctx->priv;
71 char buf1[64], buf2[64];
72 int ret;
73
74 if (s->avr) {
75 avresample_close(s->avr);
76 avresample_free(&s->avr);
77 }
78
79 if (inlink->channel_layout == outlink->channel_layout &&
80 inlink->sample_rate == outlink->sample_rate &&
81 inlink->format == outlink->format)
82 return 0;
83
84 if (!(s->avr = avresample_alloc_context()))
85 return AVERROR(ENOMEM);
86
87 av_opt_set_int(s->avr, "in_channel_layout", inlink ->channel_layout, 0);
88 av_opt_set_int(s->avr, "out_channel_layout", outlink->channel_layout, 0);
89 av_opt_set_int(s->avr, "in_sample_fmt", inlink ->format, 0);
90 av_opt_set_int(s->avr, "out_sample_fmt", outlink->format, 0);
91 av_opt_set_int(s->avr, "in_sample_rate", inlink ->sample_rate, 0);
92 av_opt_set_int(s->avr, "out_sample_rate", outlink->sample_rate, 0);
93
94 /* if both the input and output formats are s16 or u8, use s16 as
95 the internal sample format */
96 if (av_get_bytes_per_sample(inlink->format) <= 2 &&
97 av_get_bytes_per_sample(outlink->format) <= 2)
98 av_opt_set_int(s->avr, "internal_sample_fmt", AV_SAMPLE_FMT_S16P, 0);
99
100 if ((ret = avresample_open(s->avr)) < 0)
101 return ret;
102
103 outlink->time_base = (AVRational){ 1, outlink->sample_rate };
104 s->next_pts = AV_NOPTS_VALUE;
105
106 av_get_channel_layout_string(buf1, sizeof(buf1),
107 -1, inlink ->channel_layout);
108 av_get_channel_layout_string(buf2, sizeof(buf2),
109 -1, outlink->channel_layout);
110 av_log(ctx, AV_LOG_VERBOSE,
111 "fmt:%s srate: %d cl:%s -> fmt:%s srate: %d cl:%s\n",
112 av_get_sample_fmt_name(inlink ->format), inlink ->sample_rate, buf1,
113 av_get_sample_fmt_name(outlink->format), outlink->sample_rate, buf2);
114
115 return 0;
116 }
117
118 static int request_frame(AVFilterLink *outlink)
119 {
120 AVFilterContext *ctx = outlink->src;
121 ResampleContext *s = ctx->priv;
122 int ret = avfilter_request_frame(ctx->inputs[0]);
123
124 /* flush the lavr delay buffer */
125 if (ret == AVERROR_EOF && s->avr) {
126 AVFilterBufferRef *buf;
127 int nb_samples = av_rescale_rnd(avresample_get_delay(s->avr),
128 outlink->sample_rate,
129 ctx->inputs[0]->sample_rate,
130 AV_ROUND_UP);
131
132 if (!nb_samples)
133 return ret;
134
135 buf = ff_get_audio_buffer(outlink, AV_PERM_WRITE, nb_samples);
136 if (!buf)
137 return AVERROR(ENOMEM);
138
139 ret = avresample_convert(s->avr, (void**)buf->extended_data,
140 buf->linesize[0], nb_samples,
141 NULL, 0, 0);
142 if (ret <= 0) {
143 avfilter_unref_buffer(buf);
144 return (ret == 0) ? AVERROR_EOF : ret;
145 }
146
147 buf->pts = s->next_pts;
148 ff_filter_samples(outlink, buf);
149 return 0;
150 }
151 return ret;
152 }
153
154 static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *buf)
155 {
156 AVFilterContext *ctx = inlink->dst;
157 ResampleContext *s = ctx->priv;
158 AVFilterLink *outlink = ctx->outputs[0];
159
160 if (s->avr) {
161 AVFilterBufferRef *buf_out;
162 int delay, nb_samples, ret;
163
164 /* maximum possible samples lavr can output */
165 delay = avresample_get_delay(s->avr);
166 nb_samples = av_rescale_rnd(buf->audio->nb_samples + delay,
167 outlink->sample_rate, inlink->sample_rate,
168 AV_ROUND_UP);
169
170 buf_out = ff_get_audio_buffer(outlink, AV_PERM_WRITE, nb_samples);
171 ret = avresample_convert(s->avr, (void**)buf_out->extended_data,
172 buf_out->linesize[0], nb_samples,
173 (void**)buf->extended_data, buf->linesize[0],
174 buf->audio->nb_samples);
175
176 av_assert0(!avresample_available(s->avr));
177
178 if (s->next_pts == AV_NOPTS_VALUE) {
179 if (buf->pts == AV_NOPTS_VALUE) {
180 av_log(ctx, AV_LOG_WARNING, "First timestamp is missing, "
181 "assuming 0.\n");
182 s->next_pts = 0;
183 } else
184 s->next_pts = av_rescale_q(buf->pts, inlink->time_base,
185 outlink->time_base);
186 }
187
188 if (ret > 0) {
189 buf_out->audio->nb_samples = ret;
190 if (buf->pts != AV_NOPTS_VALUE) {
191 buf_out->pts = av_rescale_q(buf->pts, inlink->time_base,
192 outlink->time_base) -
193 av_rescale(delay, outlink->sample_rate,
194 inlink->sample_rate);
195 } else
196 buf_out->pts = s->next_pts;
197
198 s->next_pts = buf_out->pts + buf_out->audio->nb_samples;
199
200 ff_filter_samples(outlink, buf_out);
201 }
202 avfilter_unref_buffer(buf);
203 } else
204 ff_filter_samples(outlink, buf);
205 }
206
207 AVFilter avfilter_af_resample = {
208 .name = "resample",
209 .description = NULL_IF_CONFIG_SMALL("Audio resampling and conversion."),
210 .priv_size = sizeof(ResampleContext),
211
212 .uninit = uninit,
213 .query_formats = query_formats,
214
215 .inputs = (const AVFilterPad[]) {{ .name = "default",
216 .type = AVMEDIA_TYPE_AUDIO,
217 .filter_samples = filter_samples,
218 .min_perms = AV_PERM_READ },
219 { .name = NULL}},
220 .outputs = (const AVFilterPad[]) {{ .name = "default",
221 .type = AVMEDIA_TYPE_AUDIO,
222 .config_props = config_output,
223 .request_frame = request_frame },
224 { .name = NULL}},
225 };