1 /*
2 * Copyright (c) 2012 Andrey Utkin
3 * Copyright (c) 2012 Stefano Sabatini
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 * Filter that changes number of samples on single output operation
25 */
26
27 #include "libavutil/avassert.h"
28 #include "libavutil/channel_layout.h"
29 #include "libavutil/opt.h"
30 #include "avfilter.h"
31 #include "audio.h"
32 #include "filters.h"
33 #include "internal.h"
34 #include "formats.h"
35
36 typedef struct ASNSContext {
37 const AVClass *class;
38 int nb_out_samples; ///< how many samples to output
39 int pad;
40 } ASNSContext;
41
42 #define OFFSET(x) offsetof(ASNSContext, x)
43 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
44
45 static const AVOption asetnsamples_options[] = {
46 { "nb_out_samples", "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
47 { "n", "set the number of per-frame output samples", OFFSET(nb_out_samples), AV_OPT_TYPE_INT, {.i64=1024}, 1, INT_MAX, FLAGS },
48 { "pad", "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
49 { "p", "pad last frame with zeros", OFFSET(pad), AV_OPT_TYPE_BOOL, {.i64=1}, 0, 1, FLAGS },
50 { NULL }
51 };
52
53 AVFILTER_DEFINE_CLASS(asetnsamples);
54
activate(AVFilterContext * ctx)55 static int activate(AVFilterContext *ctx)
56 {
57 AVFilterLink *inlink = ctx->inputs[0];
58 AVFilterLink *outlink = ctx->outputs[0];
59 ASNSContext *s = ctx->priv;
60 AVFrame *frame = NULL, *pad_frame;
61 int ret;
62
63 FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
64
65 ret = ff_inlink_consume_samples(inlink, s->nb_out_samples, s->nb_out_samples, &frame);
66 if (ret < 0)
67 return ret;
68
69 if (ret > 0) {
70 if (!s->pad || frame->nb_samples == s->nb_out_samples) {
71 ret = ff_filter_frame(outlink, frame);
72 if (ff_inlink_queued_samples(inlink) >= s->nb_out_samples)
73 ff_filter_set_ready(ctx, 100);
74 return ret;
75 }
76
77 pad_frame = ff_get_audio_buffer(outlink, s->nb_out_samples);
78 if (!pad_frame) {
79 av_frame_free(&frame);
80 return AVERROR(ENOMEM);
81 }
82
83 ret = av_frame_copy_props(pad_frame, frame);
84 if (ret < 0) {
85 av_frame_free(&pad_frame);
86 av_frame_free(&frame);
87 return ret;
88 }
89
90 av_samples_copy(pad_frame->extended_data, frame->extended_data,
91 0, 0, frame->nb_samples, frame->channels, frame->format);
92 av_samples_set_silence(pad_frame->extended_data, frame->nb_samples,
93 s->nb_out_samples - frame->nb_samples, frame->channels,
94 frame->format);
95 av_frame_free(&frame);
96 return ff_filter_frame(outlink, pad_frame);
97 }
98
99 FF_FILTER_FORWARD_STATUS(inlink, outlink);
100 FF_FILTER_FORWARD_WANTED(outlink, inlink);
101
102 return FFERROR_NOT_READY;
103 }
104
105 static const AVFilterPad asetnsamples_inputs[] = {
106 {
107 .name = "default",
108 .type = AVMEDIA_TYPE_AUDIO,
109 },
110 { NULL }
111 };
112
113 static const AVFilterPad asetnsamples_outputs[] = {
114 {
115 .name = "default",
116 .type = AVMEDIA_TYPE_AUDIO,
117 },
118 { NULL }
119 };
120
121 AVFilter ff_af_asetnsamples = {
122 .name = "asetnsamples",
123 .description = NULL_IF_CONFIG_SMALL("Set the number of samples for each output audio frames."),
124 .priv_size = sizeof(ASNSContext),
125 .priv_class = &asetnsamples_class,
126 .inputs = asetnsamples_inputs,
127 .outputs = asetnsamples_outputs,
128 .activate = activate,
129 };
130