FFmpeg
af_asr.c
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1 /*
2  * Copyright (c) 2019 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
8  * License 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 GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <pocketsphinx/pocketsphinx.h>
22 
23 #include "libavutil/avassert.h"
24 #include "libavutil/avstring.h"
26 #include "libavutil/opt.h"
27 #include "audio.h"
28 #include "avfilter.h"
29 #include "internal.h"
30 
31 typedef struct ASRContext {
32  const AVClass *class;
33 
34  int rate;
35  char *hmm;
36  char *dict;
37  char *lm;
38  char *lmctl;
39  char *lmname;
40  char *logfn;
41 
42  ps_decoder_t *ps;
43  cmd_ln_t *config;
44 
46 } ASRContext;
47 
48 #define OFFSET(x) offsetof(ASRContext, x)
49 #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
50 static const AVOption asr_options[] = {
51  { "rate", "set sampling rate", OFFSET(rate), AV_OPT_TYPE_INT, {.i64=16000}, 0, INT_MAX, .flags = FLAGS },
52  { "hmm", "set directory containing acoustic model files", OFFSET(hmm), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
53  { "dict", "set pronunciation dictionary", OFFSET(dict), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
54  { "lm", "set language model file", OFFSET(lm), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
55  { "lmctl", "set language model set", OFFSET(lmctl), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
56  { "lmname","set which language model to use", OFFSET(lmname), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS },
57  { "logfn", "set output for log messages", OFFSET(logfn), AV_OPT_TYPE_STRING, {.str="/dev/null"}, .flags = FLAGS },
58  { NULL }
59 };
60 
62 
64 {
65  AVFilterContext *ctx = inlink->dst;
66  AVDictionary **metadata = &in->metadata;
67  ASRContext *s = ctx->priv;
68  int have_speech;
69  const char *speech;
70 
71  ps_process_raw(s->ps, (const int16_t *)in->data[0], in->nb_samples, 0, 0);
72  have_speech = ps_get_in_speech(s->ps);
73  if (have_speech && !s->utt_started)
74  s->utt_started = 1;
75  if (!have_speech && s->utt_started) {
76  ps_end_utt(s->ps);
77  speech = ps_get_hyp(s->ps, NULL);
78  if (speech != NULL)
79  av_dict_set(metadata, "lavfi.asr.text", speech, 0);
80  ps_start_utt(s->ps);
81  s->utt_started = 0;
82  }
83 
84  return ff_filter_frame(ctx->outputs[0], in);
85 }
86 
88 {
89  AVFilterContext *ctx = inlink->dst;
90  ASRContext *s = ctx->priv;
91 
92  ps_start_utt(s->ps);
93 
94  return 0;
95 }
96 
98 {
99  ASRContext *s = ctx->priv;
100  const float frate = s->rate;
101  char *rate = av_asprintf("%f", frate);
102  const char *argv[] = { "-logfn", s->logfn,
103  "-hmm", s->hmm,
104  "-lm", s->lm,
105  "-lmctl", s->lmctl,
106  "-lmname", s->lmname,
107  "-dict", s->dict,
108  "-samprate", rate,
109  NULL };
110 
111  s->config = cmd_ln_parse_r(NULL, ps_args(), 14, (char **)argv, 0);
112  av_free(rate);
113  if (!s->config)
114  return AVERROR(ENOMEM);
115 
116  ps_default_search_args(s->config);
117  s->ps = ps_init(s->config);
118  if (!s->ps)
119  return AVERROR(ENOMEM);
120 
121  return 0;
122 }
123 
125 {
126  ASRContext *s = ctx->priv;
127  int sample_rates[] = { s->rate, -1 };
128  int ret;
129 
132 
133  if ((ret = ff_add_format (&formats, AV_SAMPLE_FMT_S16 )) < 0 ||
134  (ret = ff_set_common_formats (ctx , formats )) < 0 ||
138  return ret;
139 
140  return 0;
141 }
142 
144 {
145  ASRContext *s = ctx->priv;
146 
147  ps_free(s->ps);
148  s->ps = NULL;
149  cmd_ln_free_r(s->config);
150  s->config = NULL;
151 }
152 
153 static const AVFilterPad asr_inputs[] = {
154  {
155  .name = "default",
156  .type = AVMEDIA_TYPE_AUDIO,
157  .filter_frame = filter_frame,
158  .config_props = config_input,
159  },
160  { NULL }
161 };
162 
163 static const AVFilterPad asr_outputs[] = {
164  {
165  .name = "default",
166  .type = AVMEDIA_TYPE_AUDIO,
167  },
168  { NULL }
169 };
170 
172  .name = "asr",
173  .description = NULL_IF_CONFIG_SMALL("Automatic Speech Recognition."),
174  .priv_size = sizeof(ASRContext),
175  .priv_class = &asr_class,
176  .init = asr_init,
177  .uninit = asr_uninit,
179  .inputs = asr_inputs,
180  .outputs = asr_outputs,
181 };
formats
formats
Definition: signature.h:48
ASRContext::logfn
char * logfn
Definition: af_asr.c:40
query_formats
static int query_formats(AVFilterContext *ctx)
Definition: af_asr.c:124
AVFilterChannelLayouts
A list of supported channel layouts.
Definition: formats.h:86
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
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_make_format_list
AVFilterFormats * ff_make_format_list(const int *fmts)
Create a list of supported formats.
Definition: formats.c:286
ff_filter_frame
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:978
AV_CH_LAYOUT_MONO
#define AV_CH_LAYOUT_MONO
Definition: channel_layout.h:90
inlink
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
Definition: filter_design.txt:212
av_asprintf
char * av_asprintf(const char *fmt,...)
Definition: avstring.c:113
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:303
AVOption
AVOption.
Definition: opt.h:248
asr_options
static const AVOption asr_options[]
Definition: af_asr.c:50
AVDictionary
Definition: dict.c:30
AVFilter::name
const char * name
Filter name.
Definition: avfilter.h:149
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:317
AVFilterFormats
A list of supported formats for one end of a filter link.
Definition: formats.h:65
filter_frame
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
Definition: af_asr.c:63
FLAGS
#define FLAGS
Definition: af_asr.c:49
ASRContext::hmm
char * hmm
Definition: af_asr.c:35
AVFilterPad
A filter pad used for either input or output.
Definition: internal.h:54
ASRContext
Definition: af_asr.c:31
avassert.h
av_cold
#define av_cold
Definition: attributes.h:90
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
ff_set_common_formats
int ff_set_common_formats(AVFilterContext *ctx, AVFilterFormats *formats)
A helper for query_formats() which sets all links to the same list of formats.
Definition: formats.c:580
ASRContext::ps
ps_decoder_t * ps
Definition: af_asr.c:42
ff_add_channel_layout
int ff_add_channel_layout(AVFilterChannelLayouts **l, uint64_t channel_layout)
Definition: formats.c:331
s
#define s(width, name)
Definition: cbs_vp9.c:257
config_input
static int config_input(AVFilterLink *inlink)
Definition: af_asr.c:87
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
outputs
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
ctx
AVFormatContext * ctx
Definition: movenc.c:48
ASRContext::utt_started
int utt_started
Definition: af_asr.c:45
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:67
NULL
#define NULL
Definition: coverity.c:32
asr_init
static av_cold int asr_init(AVFilterContext *ctx)
Definition: af_asr.c:97
ff_add_format
int ff_add_format(AVFilterFormats **avff, int64_t fmt)
Add fmt to the list of media formats contained in *avff.
Definition: formats.c:325
ASRContext::dict
char * dict
Definition: af_asr.c:36
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:117
sample_rates
sample_rates
Definition: ffmpeg_filter.c:156
internal.h
layout
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 layout
Definition: filter_design.txt:18
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:369
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:61
asr_uninit
static av_cold void asr_uninit(AVFilterContext *ctx)
Definition: af_asr.c:143
AVFilterPad::name
const char * name
Pad name.
Definition: internal.h:60
ASRContext::config
cmd_ln_t * config
Definition: af_asr.c:43
AVFilter
Filter definition.
Definition: avfilter.h:145
asr_outputs
static const AVFilterPad asr_outputs[]
Definition: af_asr.c:163
ret
ret
Definition: filter_design.txt:187
channel_layout.h
ASRContext::lmname
char * lmname
Definition: af_asr.c:39
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
avfilter.h
AVFrame::metadata
AVDictionary * metadata
metadata.
Definition: frame.h:572
ASRContext::lmctl
char * lmctl
Definition: af_asr.c:38
AVFilterContext
An instance of a filter.
Definition: avfilter.h:333
AVFILTER_DEFINE_CLASS
AVFILTER_DEFINE_CLASS(asr)
audio.h
av_free
#define av_free(p)
Definition: tableprint_vlc.h:34
av_dict_set
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
ASRContext::rate
int rate
Definition: af_asr.c:34
ff_set_common_samplerates
int ff_set_common_samplerates(AVFilterContext *ctx, AVFilterFormats *samplerates)
Definition: formats.c:568
asr_inputs
static const AVFilterPad asr_inputs[]
Definition: af_asr.c:153
uninit
static av_cold int uninit(AVCodecContext *avctx)
Definition: crystalhd.c:279
avstring.h
OFFSET
#define OFFSET(x)
Definition: af_asr.c:48
AV_OPT_TYPE_STRING
@ AV_OPT_TYPE_STRING
Definition: opt.h:229
ff_af_asr
const AVFilter ff_af_asr
Definition: af_asr.c:171
ASRContext::lm
char * lm
Definition: af_asr.c:37
ff_set_common_channel_layouts
int ff_set_common_channel_layouts(AVFilterContext *ctx, AVFilterChannelLayouts *channel_layouts)
A helper for query_formats() which sets all links to the same list of channel layouts/sample rates.
Definition: formats.c:561