2 * Copyright (c) 2010 S.N. Hemanth Meenakshisundaram <smeenaks@ucsd.edu>
3 * Copyright (c) 2011 Stefano Sabatini
4 * Copyright (c) 2011 Mina Nagy Zaki
6 * This file is part of FFmpeg.
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.
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.
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
25 * sample format and channel layout conversion audio filter
28 #include "libavutil/avstring.h"
29 #include "libswresample/swresample.h"
35 enum AVSampleFormat out_sample_fmt;
37 struct SwrContext *swr;
40 static av_cold int init(AVFilterContext *ctx, const char *args0, void *opaque)
42 AConvertContext *aconvert = ctx->priv;
43 char *arg, *ptr = NULL;
45 char *args = av_strdup(args0);
47 aconvert->out_sample_fmt = AV_SAMPLE_FMT_NONE;
48 aconvert->out_chlayout = 0;
50 if ((arg = av_strtok(args, ":", &ptr)) && strcmp(arg, "auto")) {
51 if ((ret = ff_parse_sample_format(&aconvert->out_sample_fmt, arg, ctx)) < 0)
54 if ((arg = av_strtok(NULL, ":", &ptr)) && strcmp(arg, "auto")) {
55 if ((ret = ff_parse_channel_layout(&aconvert->out_chlayout, arg, ctx)) < 0)
64 static av_cold void uninit(AVFilterContext *ctx)
66 AConvertContext *aconvert = ctx->priv;
67 swr_free(&aconvert->swr);
70 static int query_formats(AVFilterContext *ctx)
72 AVFilterFormats *formats = NULL;
73 AConvertContext *aconvert = ctx->priv;
74 AVFilterLink *inlink = ctx->inputs[0];
75 AVFilterLink *outlink = ctx->outputs[0];
76 AVFilterChannelLayouts *layouts;
78 avfilter_formats_ref(avfilter_make_all_formats(AVMEDIA_TYPE_AUDIO),
79 &inlink->out_formats);
80 if (aconvert->out_sample_fmt != AV_SAMPLE_FMT_NONE) {
82 avfilter_add_format(&formats, aconvert->out_sample_fmt);
83 avfilter_formats_ref(formats, &outlink->in_formats);
85 avfilter_formats_ref(avfilter_make_all_formats(AVMEDIA_TYPE_AUDIO),
86 &outlink->in_formats);
88 ff_channel_layouts_ref(ff_all_channel_layouts(),
89 &inlink->out_channel_layouts);
90 if (aconvert->out_chlayout != 0) {
92 ff_add_channel_layout(&layouts, aconvert->out_chlayout);
93 ff_channel_layouts_ref(layouts, &outlink->in_channel_layouts);
95 ff_channel_layouts_ref(ff_all_channel_layouts(),
96 &outlink->in_channel_layouts);
101 static int config_output(AVFilterLink *outlink)
104 AVFilterContext *ctx = outlink->src;
105 AVFilterLink *inlink = ctx->inputs[0];
106 AConvertContext *aconvert = ctx->priv;
107 char buf1[64], buf2[64];
109 /* if not specified in args, use the format and layout of the output */
110 if (aconvert->out_sample_fmt == AV_SAMPLE_FMT_NONE)
111 aconvert->out_sample_fmt = outlink->format;
112 if (aconvert->out_chlayout == 0)
113 aconvert->out_chlayout = outlink->channel_layout;
115 aconvert->swr = swr_alloc_set_opts(aconvert->swr,
116 aconvert->out_chlayout, aconvert->out_sample_fmt, inlink->sample_rate,
117 inlink->channel_layout, inlink->format, inlink->sample_rate,
120 return AVERROR(ENOMEM);
121 ret = swr_init(aconvert->swr);
125 av_get_channel_layout_string(buf1, sizeof(buf1),
126 -1, inlink ->channel_layout);
127 av_get_channel_layout_string(buf2, sizeof(buf2),
128 -1, outlink->channel_layout);
129 av_log(ctx, AV_LOG_INFO,
130 "fmt:%s cl:%s -> fmt:%s cl:%s\n",
131 av_get_sample_fmt_name(inlink ->format), buf1,
132 av_get_sample_fmt_name(outlink->format), buf2);
137 static void filter_samples(AVFilterLink *inlink, AVFilterBufferRef *insamplesref)
139 AConvertContext *aconvert = inlink->dst->priv;
140 const int n = insamplesref->audio->nb_samples;
141 AVFilterLink *const outlink = inlink->dst->outputs[0];
142 AVFilterBufferRef *outsamplesref = ff_get_audio_buffer(outlink, AV_PERM_WRITE, n);
144 swr_convert(aconvert->swr, outsamplesref->data, n,
145 (void *)insamplesref->data, n);
147 avfilter_copy_buffer_ref_props(outsamplesref, insamplesref);
148 outsamplesref->audio->channel_layout = outlink->channel_layout;
150 ff_filter_samples(outlink, outsamplesref);
151 avfilter_unref_buffer(insamplesref);
154 AVFilter avfilter_af_aconvert = {
156 .description = NULL_IF_CONFIG_SMALL("Convert the input audio to sample_fmt:channel_layout."),
157 .priv_size = sizeof(AConvertContext),
160 .query_formats = query_formats,
162 .inputs = (const AVFilterPad[]) {{ .name = "default",
163 .type = AVMEDIA_TYPE_AUDIO,
164 .filter_samples = filter_samples,
165 .min_perms = AV_PERM_READ, },
167 .outputs = (const AVFilterPad[]) {{ .name = "default",
168 .type = AVMEDIA_TYPE_AUDIO,
169 .config_props = config_output, },