FFmpeg: libavfilter/af_aconvert.c Source File

FFmpeg
af_aconvert.c
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1 /*
2  * Copyright (c) 2010 S.N. Hemanth Meenakshisundaram <smeenaks@ucsd.edu>
3  * Copyright (c) 2011 Stefano Sabatini
4  * Copyright (c) 2011 Mina Nagy Zaki
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 /**
24  * @file
25  * sample format and channel layout conversion audio filter
26  */
27 
28 #include "libavutil/channel_layout.h"
29 #include "libavutil/opt.h"
30 #include "libswresample/swresample.h"
31 #include "avfilter.h"
32 #include "audio.h"
33 #include "internal.h"
34 
35  typedef struct {
36   const AVClass *class;
37   enum AVSampleFormat out_sample_fmt;
38   int64_t out_chlayout;
39   struct SwrContext *swr;
40   char *format_str;
41   char *channel_layout_str;
42 } AConvertContext;
43 
44  #define OFFSET(x) offsetof(AConvertContext, x)
45  #define A AV_OPT_FLAG_AUDIO_PARAM
46  #define F AV_OPT_FLAG_FILTERING_PARAM
47  static const AVOption aconvert_options[] = {
48  { "sample_fmt", "", OFFSET(format_str), AV_OPT_TYPE_STRING, .flags = A|F },
49  { "channel_layout", "", OFFSET(channel_layout_str), AV_OPT_TYPE_STRING, .flags = A|F },
50  { NULL }
51 };
52 
53 AVFILTER_DEFINE_CLASS(aconvert);
54 
55  static av_cold int init(AVFilterContext *ctx)
56 {
57  AConvertContext *aconvert = ctx->priv;
58  int ret = 0;
59 
60  av_log(ctx, AV_LOG_WARNING, "This filter is deprecated, use aformat instead\n");
61 
62  aconvert->out_sample_fmt = AV_SAMPLE_FMT_NONE;
63  aconvert->out_chlayout = 0;
64 
65  if (aconvert->format_str && strcmp(aconvert->format_str, "auto") &&
66  (ret = ff_parse_sample_format(&aconvert->out_sample_fmt, aconvert->format_str, ctx)) < 0)
67  return ret;
68  if (aconvert->channel_layout_str && strcmp(aconvert->channel_layout_str, "auto"))
69  return ff_parse_channel_layout(&aconvert->out_chlayout, NULL, aconvert->channel_layout_str, ctx);
70  return ret;
71 }
72 
73  static av_cold void uninit(AVFilterContext *ctx)
74 {
75  AConvertContext *aconvert = ctx->priv;
76  swr_free(&aconvert->swr);
77 }
78 
79  static int query_formats(AVFilterContext *ctx)
80 {
81  AVFilterFormats *formats = NULL;
82  AConvertContext *aconvert = ctx->priv;
83  AVFilterLink *inlink = ctx->inputs[0];
84  AVFilterLink *outlink = ctx->outputs[0];
85  AVFilterChannelLayouts *layouts;
86 
87  ff_formats_ref(ff_all_formats(AVMEDIA_TYPE_AUDIO),
88  &inlink->out_formats);
89  if (aconvert->out_sample_fmt != AV_SAMPLE_FMT_NONE) {
90  formats = NULL;
91  ff_add_format(&formats, aconvert->out_sample_fmt);
92  ff_formats_ref(formats, &outlink->in_formats);
93  } else
94  ff_formats_ref(ff_all_formats(AVMEDIA_TYPE_AUDIO),
95  &outlink->in_formats);
96 
97  ff_channel_layouts_ref(ff_all_channel_layouts(),
98  &inlink->out_channel_layouts);
99  if (aconvert->out_chlayout != 0) {
100  layouts = NULL;
101  ff_add_channel_layout(&layouts, aconvert->out_chlayout);
102  ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);
103  } else
104  ff_channel_layouts_ref(ff_all_channel_layouts(),
105  &outlink->in_channel_layouts);
106 
107  return 0;
108 }
109 
110  static int config_output(AVFilterLink *outlink)
111 {
112  int ret;
113  AVFilterContext *ctx = outlink->src;
114  AVFilterLink *inlink = ctx->inputs[0];
115  AConvertContext *aconvert = ctx->priv;
116  char buf1[64], buf2[64];
117 
118  /* if not specified in args, use the format and layout of the output */
119  if (aconvert->out_sample_fmt == AV_SAMPLE_FMT_NONE)
120  aconvert->out_sample_fmt = outlink->format;
121  if (aconvert->out_chlayout == 0)
122  aconvert->out_chlayout = outlink->channel_layout;
123 
124  aconvert->swr = swr_alloc_set_opts(aconvert->swr,
125  aconvert->out_chlayout, aconvert->out_sample_fmt, inlink->sample_rate,
126  inlink->channel_layout, inlink->format, inlink->sample_rate,
127  0, ctx);
128  if (!aconvert->swr)
129  return AVERROR(ENOMEM);
130  ret = swr_init(aconvert->swr);
131  if (ret < 0)
132  return ret;
133 
134  av_get_channel_layout_string(buf1, sizeof(buf1),
135  -1, inlink ->channel_layout);
136  av_get_channel_layout_string(buf2, sizeof(buf2),
137  -1, outlink->channel_layout);
138  av_log(ctx, AV_LOG_VERBOSE,
139  "fmt:%s cl:%s -> fmt:%s cl:%s\n",
140  av_get_sample_fmt_name(inlink ->format), buf1,
141  av_get_sample_fmt_name(outlink->format), buf2);
142 
143  return 0;
144 }
145 
146  static int filter_frame(AVFilterLink *inlink, AVFrame *insamplesref)
147 {
148  AConvertContext *aconvert = inlink->dst->priv;
149  const int n = insamplesref->nb_samples;
150  AVFilterLink *const outlink = inlink->dst->outputs[0];
151  AVFrame *outsamplesref = ff_get_audio_buffer(outlink, n);
152  int ret;
153 
154  if (!outsamplesref)
155  return AVERROR(ENOMEM);
156  swr_convert(aconvert->swr, outsamplesref->extended_data, n,
157  (void *)insamplesref->extended_data, n);
158 
159  av_frame_copy_props(outsamplesref, insamplesref);
160  av_frame_set_channels(outsamplesref, outlink->channels);
161  outsamplesref->channel_layout = outlink->channel_layout;
162 
163  ret = ff_filter_frame(outlink, outsamplesref);
164  av_frame_free(&insamplesref);
165  return ret;
166 }
167 
168  static const AVFilterPad aconvert_inputs[] = {
169  {
170  .name = "default",
171  .type = AVMEDIA_TYPE_AUDIO,
172  .filter_frame = filter_frame,
173  },
174  { NULL }
175 };
176 
177  static const AVFilterPad aconvert_outputs[] = {
178  {
179  .name = "default",
180  .type = AVMEDIA_TYPE_AUDIO,
181  .config_props = config_output,
182  },
183  { NULL }
184 };
185 
186  AVFilter avfilter_af_aconvert = {
187  .name = "aconvert",
188  .description = NULL_IF_CONFIG_SMALL("Convert the input audio to sample_fmt:channel_layout."),
189  .priv_size = sizeof(AConvertContext),
190  .priv_class = &aconvert_class,
191  .init = init,
192  .uninit = uninit,
193  .query_formats = query_formats,
194  .inputs = aconvert_inputs,
195  .outputs = aconvert_outputs,
196 };
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