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1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU Lesser General Public
6  * License as published by the Free Software Foundation; either
7  * version 2.1 of the License, or (at your option) any later version.
8  *
9  * FFmpeg is distributed in the hope that it will be useful,
10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12  * Lesser General Public License for more details.
13  *
14  * You should have received a copy of the GNU Lesser General Public
15  * License along with FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18 
19 /**
20  * @file
21  * Bauer stereo-to-binaural filter
22  */
23 
24 #include <bs2b.h>
25 
26 #include "libavutil/channel_layout.h"
27 #include "libavutil/common.h"
28 #include "libavutil/opt.h"
29 
30 #include "audio.h"
31 #include "avfilter.h"
32 #include "formats.h"
33 #include "internal.h"
34 
35 typedef void (*filter_func)(t_bs2bdp bs2bdp, uint8_t *sample, int n);
36 
37 typedef struct Bs2bContext {
38     const AVClass *class;
39 
40     int profile;
41     int fcut;
42     int feed;
43 
44     t_bs2bdp bs2bp;
45 
46     filter_func filter;
47 } Bs2bContext;
48 
49 #define OFFSET(x) offsetof(Bs2bContext, x)
50 #define A AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
51 
52 static const AVOption bs2b_options[] = {
53     { "profile", "Apply a pre-defined crossfeed level",
54             OFFSET(profile), AV_OPT_TYPE_INT, { .i64 = BS2B_DEFAULT_CLEVEL }, 0, INT_MAX, A, "profile" },
55         { "default", "default profile", 0, AV_OPT_TYPE_CONST, { .i64 = BS2B_DEFAULT_CLEVEL }, 0, 0, A, "profile" },
56         { "cmoy",    "Chu Moy circuit", 0, AV_OPT_TYPE_CONST, { .i64 = BS2B_CMOY_CLEVEL    }, 0, 0, A, "profile" },
57         { "jmeier",  "Jan Meier circuit", 0, AV_OPT_TYPE_CONST, { .i64 = BS2B_JMEIER_CLEVEL  }, 0, 0, A, "profile" },
58     { "fcut", "Set cut frequency (in Hz)",
59             OFFSET(fcut), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, BS2B_MAXFCUT, A },
60     { "feed", "Set feed level (in Hz)",
61             OFFSET(feed), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, BS2B_MAXFEED, A },
62     { NULL },
63 };
64 
65 AVFILTER_DEFINE_CLASS(bs2b);
66 
init(AVFilterContext * ctx)67 static av_cold int init(AVFilterContext *ctx)
68 {
69     Bs2bContext *bs2b = ctx->priv;
70 
71     if (!(bs2b->bs2bp = bs2b_open()))
72         return AVERROR(ENOMEM);
73 
74     bs2b_set_level(bs2b->bs2bp, bs2b->profile);
75 
76     if (bs2b->fcut)
77         bs2b_set_level_fcut(bs2b->bs2bp, bs2b->fcut);
78 
79     if (bs2b->feed)
80         bs2b_set_level_feed(bs2b->bs2bp, bs2b->feed);
81 
82     return 0;
83 }
84 
uninit(AVFilterContext * ctx)85 static av_cold void uninit(AVFilterContext *ctx)
86 {
87     Bs2bContext *bs2b = ctx->priv;
88 
89     if (bs2b->bs2bp)
90         bs2b_close(bs2b->bs2bp);
91 }
92 
query_formats(AVFilterContext * ctx)93 static int query_formats(AVFilterContext *ctx)
94 {
95     AVFilterChannelLayouts *layouts = NULL;
96 
97     static const enum AVSampleFormat sample_fmts[] = {
98         AV_SAMPLE_FMT_U8,
99         AV_SAMPLE_FMT_S16,
100         AV_SAMPLE_FMT_S32,
101         AV_SAMPLE_FMT_FLT,
102         AV_SAMPLE_FMT_DBL,
103         AV_SAMPLE_FMT_NONE,
104     };
105     int ret;
106 
107     if (ff_add_channel_layout(&layouts, &(AVChannelLayout)AV_CHANNEL_LAYOUT_STEREO) != 0)
108         return AVERROR(ENOMEM);
109     ret = ff_set_common_channel_layouts(ctx, layouts);
110     if (ret < 0)
111         return ret;
112 
113     ret = ff_set_common_formats_from_list(ctx, sample_fmts);
114     if (ret < 0)
115         return ret;
116 
117     return ff_set_common_all_samplerates(ctx);
118 }
119 
filter_frame(AVFilterLink * inlink,AVFrame * frame)120 static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
121 {
122     int ret;
123     AVFrame *out_frame;
124 
125     Bs2bContext     *bs2b = inlink->dst->priv;
126     AVFilterLink *outlink = inlink->dst->outputs[0];
127 
128     if (av_frame_is_writable(frame)) {
129         out_frame = frame;
130     } else {
131         out_frame = ff_get_audio_buffer(outlink, frame->nb_samples);
132         if (!out_frame) {
133             av_frame_free(&frame);
134             return AVERROR(ENOMEM);
135         }
136         av_frame_copy(out_frame, frame);
137         ret = av_frame_copy_props(out_frame, frame);
138         if (ret < 0) {
139             av_frame_free(&out_frame);
140             av_frame_free(&frame);
141             return ret;
142         }
143     }
144 
145     bs2b->filter(bs2b->bs2bp, out_frame->extended_data[0], out_frame->nb_samples);
146 
147     if (frame != out_frame)
148         av_frame_free(&frame);
149 
150     return ff_filter_frame(outlink, out_frame);
151 }
152 
config_output(AVFilterLink * outlink)153 static int config_output(AVFilterLink *outlink)
154 {
155     AVFilterContext *ctx = outlink->src;
156     Bs2bContext    *bs2b = ctx->priv;
157     AVFilterLink *inlink = ctx->inputs[0];
158 
159     int srate = inlink->sample_rate;
160 
161     switch (inlink->format) {
162     case AV_SAMPLE_FMT_U8:
163         bs2b->filter = (filter_func) bs2b_cross_feed_u8;
164         break;
165     case AV_SAMPLE_FMT_S16:
166         bs2b->filter = (filter_func) bs2b_cross_feed_s16;
167         break;
168     case AV_SAMPLE_FMT_S32:
169         bs2b->filter = (filter_func) bs2b_cross_feed_s32;
170         break;
171     case AV_SAMPLE_FMT_FLT:
172         bs2b->filter = (filter_func) bs2b_cross_feed_f;
173         break;
174     case AV_SAMPLE_FMT_DBL:
175         bs2b->filter = (filter_func) bs2b_cross_feed_d;
176         break;
177     default:
178         return AVERROR_BUG;
179     }
180 
181     if ((srate < BS2B_MINSRATE) || (srate > BS2B_MAXSRATE))
182         return AVERROR(ENOSYS);
183 
184     bs2b_set_srate(bs2b->bs2bp, srate);
185 
186     return 0;
187 }
188 
189 static const AVFilterPad bs2b_inputs[] = {
190     {
191         .name           = "default",
192         .type           = AVMEDIA_TYPE_AUDIO,
193         .filter_frame   = filter_frame,
194     },
195 };
196 
197 static const AVFilterPad bs2b_outputs[] = {
198     {
199         .name           = "default",
200         .type           = AVMEDIA_TYPE_AUDIO,
201         .config_props   = config_output,
202     },
203 };
204 
205 const AVFilter ff_af_bs2b = {
206     .name           = "bs2b",
207     .description    = NULL_IF_CONFIG_SMALL("Bauer stereo-to-binaural filter."),
208     .priv_size      = sizeof(Bs2bContext),
209     .priv_class     = &bs2b_class,
210     .init           = init,
211     .uninit         = uninit,
212     FILTER_INPUTS(bs2b_inputs),
213     FILTER_OUTPUTS(bs2b_outputs),
214     FILTER_QUERY_FUNC(query_formats),
215 };
216