FFmpeg
asrc_hilbert.c
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1 /*
2  * Copyright (c) 2018 Paul B Mahol
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public License
8  * as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14  * GNU Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public License
17  * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
22 #include "libavutil/mem.h"
23 #include "libavutil/opt.h"
24 #include "audio.h"
25 #include "avfilter.h"
26 #include "formats.h"
27 #include "filters.h"
28 #include "window_func.h"
29 
30 typedef struct HilbertContext {
31  const AVClass *class;
32 
34  int nb_taps;
36  int win_func;
37 
38  float *taps;
41 
42 #define OFFSET(x) offsetof(HilbertContext, x)
43 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
44 
45 static const AVOption hilbert_options[] = {
46  { "sample_rate", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, FLAGS },
47  { "r", "set sample rate", OFFSET(sample_rate), AV_OPT_TYPE_INT, {.i64=44100}, 1, INT_MAX, FLAGS },
48  { "taps", "set number of taps", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=22051}, 11, UINT16_MAX, FLAGS },
49  { "t", "set number of taps", OFFSET(nb_taps), AV_OPT_TYPE_INT, {.i64=22051}, 11, UINT16_MAX, FLAGS },
50  { "nb_samples", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
51  { "n", "set the number of samples per requested frame", OFFSET(nb_samples), AV_OPT_TYPE_INT, {.i64 = 1024}, 1, INT_MAX, FLAGS },
52  WIN_FUNC_OPTION("win_func", OFFSET(win_func), FLAGS, WFUNC_BLACKMAN),
53  WIN_FUNC_OPTION("w", OFFSET(win_func), FLAGS, WFUNC_BLACKMAN),
54  {NULL}
55 };
56 
57 AVFILTER_DEFINE_CLASS(hilbert);
58 
60 {
61  HilbertContext *s = ctx->priv;
62 
63  if (!(s->nb_taps & 1)) {
64  av_log(s, AV_LOG_ERROR, "Number of taps %d must be odd length.\n", s->nb_taps);
65  return AVERROR(EINVAL);
66  }
67 
68  return 0;
69 }
70 
72 {
73  HilbertContext *s = ctx->priv;
74 
75  av_freep(&s->taps);
76 }
77 
79  AVFilterFormatsConfig **cfg_in,
80  AVFilterFormatsConfig **cfg_out)
81 {
82  HilbertContext *s = ctx->priv;
83  static const AVChannelLayout chlayouts[] = { AV_CHANNEL_LAYOUT_MONO, { 0 } };
84  int sample_rates[] = { s->sample_rate, -1 };
85  static const enum AVSampleFormat sample_fmts[] = {
88  };
89  int ret = ff_set_common_formats_from_list2(ctx, cfg_in, cfg_out, sample_fmts);
90  if (ret < 0)
91  return ret;
92 
93  ret = ff_set_common_channel_layouts_from_list2(ctx, cfg_in, cfg_out, chlayouts);
94  if (ret < 0)
95  return ret;
96 
97  return ff_set_common_samplerates_from_list2(ctx, cfg_in, cfg_out, sample_rates);
98 }
99 
100 static av_cold int config_props(AVFilterLink *outlink)
101 {
102  AVFilterContext *ctx = outlink->src;
103  HilbertContext *s = ctx->priv;
104  float overlap;
105  int i;
106 
107  s->taps = av_malloc_array(s->nb_taps, sizeof(*s->taps));
108  if (!s->taps)
109  return AVERROR(ENOMEM);
110 
111  generate_window_func(s->taps, s->nb_taps, s->win_func, &overlap);
112 
113  for (i = 0; i < s->nb_taps; i++) {
114  int k = -(s->nb_taps / 2) + i;
115 
116  if (k & 1) {
117  float pk = M_PI * k;
118 
119  s->taps[i] *= (1.f - cosf(pk)) / pk;
120  } else {
121  s->taps[i] = 0.f;
122  }
123  }
124 
125  s->pts = 0;
126 
127  return 0;
128 }
129 
131 {
132  AVFilterLink *outlink = ctx->outputs[0];
133  HilbertContext *s = ctx->priv;
134  AVFrame *frame;
135  int nb_samples;
136 
137  if (!ff_outlink_frame_wanted(outlink))
138  return FFERROR_NOT_READY;
139 
140  nb_samples = FFMIN(s->nb_samples, s->nb_taps - s->pts);
141  if (nb_samples <= 0) {
142  ff_outlink_set_status(outlink, AVERROR_EOF, s->pts);
143  return 0;
144  }
145 
146  if (!(frame = ff_get_audio_buffer(outlink, nb_samples)))
147  return AVERROR(ENOMEM);
148 
149  memcpy(frame->data[0], s->taps + s->pts, nb_samples * sizeof(float));
150 
151  frame->pts = s->pts;
152  s->pts += nb_samples;
153  return ff_filter_frame(outlink, frame);
154 }
155 
156 static const AVFilterPad hilbert_outputs[] = {
157  {
158  .name = "default",
159  .type = AVMEDIA_TYPE_AUDIO,
160  .config_props = config_props,
161  },
162 };
163 
165  .name = "hilbert",
166  .description = NULL_IF_CONFIG_SMALL("Generate a Hilbert transform FIR coefficients."),
167  .init = init,
168  .uninit = uninit,
169  .activate = activate,
170  .priv_size = sizeof(HilbertContext),
171  .inputs = NULL,
174  .priv_class = &hilbert_class,
175 };
HilbertContext::nb_samples
int nb_samples
Definition: asrc_hilbert.c:35
ff_get_audio_buffer
AVFrame * ff_get_audio_buffer(AVFilterLink *link, int nb_samples)
Request an audio samples buffer with a specific set of permissions.
Definition: audio.c:98
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
opt.h
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1062
sample_fmts
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:948
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:57
FFERROR_NOT_READY
return FFERROR_NOT_READY
Definition: filter_design.txt:204
int64_t
long long int64_t
Definition: coverity.c:34
hilbert_outputs
static const AVFilterPad hilbert_outputs[]
Definition: asrc_hilbert.c:156
uninit
static av_cold void uninit(AVFilterContext *ctx)
Definition: asrc_hilbert.c:71
OFFSET
#define OFFSET(x)
Definition: asrc_hilbert.c:42
sample_rates
static const int sample_rates[]
Definition: dcaenc.h:34
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:389
AVOption
AVOption.
Definition: opt.h:429
ff_set_common_channel_layouts_from_list2
int ff_set_common_channel_layouts_from_list2(const AVFilterContext *ctx, AVFilterFormatsConfig **cfg_in, AVFilterFormatsConfig **cfg_out, const AVChannelLayout *fmts)
Definition: formats.c:920
WIN_FUNC_OPTION
#define WIN_FUNC_OPTION(win_func_opt_name, win_func_offset, flag, default_window_func)
Definition: window_func.h:37
HilbertContext::sample_rate
int sample_rate
Definition: asrc_hilbert.c:33
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:205
query_formats
static av_cold int query_formats(const AVFilterContext *ctx, AVFilterFormatsConfig **cfg_in, AVFilterFormatsConfig **cfg_out)
Definition: asrc_hilbert.c:78
init
static av_cold int init(AVFilterContext *ctx)
Definition: asrc_hilbert.c:59
formats.h
WFUNC_BLACKMAN
@ WFUNC_BLACKMAN
Definition: af_firequalizer.c:39
HilbertContext::pts
int64_t pts
Definition: asrc_hilbert.c:39
cosf
#define cosf(x)
Definition: libm.h:78
ff_asrc_hilbert
const AVFilter ff_asrc_hilbert
Definition: asrc_hilbert.c:164
AVFilterPad
A filter pad used for either input or output.
Definition: filters.h:38
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:209
av_cold
#define av_cold
Definition: attributes.h:90
ff_outlink_set_status
static void ff_outlink_set_status(AVFilterLink *link, int status, int64_t pts)
Set the status field of a link from the source filter.
Definition: filters.h:424
s
#define s(width, name)
Definition: cbs_vp9.c:198
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
HilbertContext::win_func
int win_func
Definition: asrc_hilbert.c:36
filters.h
ff_set_common_samplerates_from_list2
int ff_set_common_samplerates_from_list2(const AVFilterContext *ctx, AVFilterFormatsConfig **cfg_in, AVFilterFormatsConfig **cfg_out, const int *samplerates)
Definition: formats.c:944
ctx
AVFormatContext * ctx
Definition: movenc.c:49
FILTER_OUTPUTS
#define FILTER_OUTPUTS(array)
Definition: filters.h:263
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:75
NULL
#define NULL
Definition: coverity.c:32
generate_window_func
static void generate_window_func(float *lut, int N, int win_func, float *overlap)
Definition: window_func.h:63
inputs
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
Definition: filter_design.txt:243
AVFilterFormatsConfig
Lists of formats / etc.
Definition: avfilter.h:111
hilbert_options
static const AVOption hilbert_options[]
Definition: asrc_hilbert.c:45
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:94
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:317
FLAGS
#define FLAGS
Definition: asrc_hilbert.c:43
AV_SAMPLE_FMT_NONE
@ AV_SAMPLE_FMT_NONE
Definition: samplefmt.h:56
activate
static int activate(AVFilterContext *ctx)
Definition: asrc_hilbert.c:130
M_PI
#define M_PI
Definition: mathematics.h:67
HilbertContext::nb_taps
int nb_taps
Definition: asrc_hilbert.c:34
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:256
av_malloc_array
#define av_malloc_array(a, b)
Definition: tableprint_vlc.h:31
AVSampleFormat
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:55
FILTER_QUERY_FUNC2
#define FILTER_QUERY_FUNC2(func)
Definition: filters.h:239
FFMIN
#define FFMIN(a, b)
Definition: macros.h:49
AVFilterPad::name
const char * name
Pad name.
Definition: filters.h:44
AVFilter
Filter definition.
Definition: avfilter.h:201
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
HilbertContext
Definition: asrc_hilbert.c:30
window_func.h
ff_set_common_formats_from_list2
int ff_set_common_formats_from_list2(const AVFilterContext *ctx, AVFilterFormatsConfig **cfg_in, AVFilterFormatsConfig **cfg_out, const int *fmts)
Definition: formats.c:1016
channel_layout.h
config_props
static av_cold int config_props(AVFilterLink *outlink)
Definition: asrc_hilbert.c:100
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Underlying C type is int.
Definition: opt.h:259
avfilter.h
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(hilbert)
AVFilterContext
An instance of a filter.
Definition: avfilter.h:457
HilbertContext::taps
float * taps
Definition: asrc_hilbert.c:38
mem.h
audio.h
AV_CHANNEL_LAYOUT_MONO
#define AV_CHANNEL_LAYOUT_MONO
Definition: channel_layout.h:392
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:34
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
ff_outlink_frame_wanted
the definition of that something depends on the semantic of the filter The callback must examine the status of the filter s links and proceed accordingly The status of output links is stored in the status_in and status_out fields and tested by the ff_outlink_frame_wanted() function. If this function returns true
AV_SAMPLE_FMT_FLT
@ AV_SAMPLE_FMT_FLT
float
Definition: samplefmt.h:60