/* * Copyright (c) 2019 Paul B Mahol * * This file is part of FFmpeg. * * FFmpeg is free software; you can redistribute it and/or * modify it under the terms of the GNU Lesser General Public * License as published by the Free Software Foundation; either * version 2.1 of the License, or (at your option) any later version. * * FFmpeg is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public * License along with FFmpeg; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ #include <pocketsphinx/pocketsphinx.h> #include "libavutil/avassert.h" #include "libavutil/avstring.h" #include "libavutil/channel_layout.h" #include "libavutil/opt.h" #include "audio.h" #include "avfilter.h" #include "internal.h" typedef struct ASRContext { const AVClass *class; int rate; char *hmm; char *dict; char *lm; char *lmctl; char *lmname; char *logfn; ps_decoder_t *ps; cmd_ln_t *config; int utt_started; } ASRContext; #define OFFSET(x) offsetof(ASRContext, x) #define FLAGS AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM static const AVOption asr_options[] = { { "rate", "set sampling rate", OFFSET(rate), AV_OPT_TYPE_INT, {.i64=16000}, 0, INT_MAX, .flags = FLAGS }, { "hmm", "set directory containing acoustic model files", OFFSET(hmm), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "dict", "set pronunciation dictionary", OFFSET(dict), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "lm", "set language model file", OFFSET(lm), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "lmctl", "set language model set", OFFSET(lmctl), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "lmname","set which language model to use", OFFSET(lmname), AV_OPT_TYPE_STRING, {.str=NULL}, .flags = FLAGS }, { "logfn", "set output for log messages", OFFSET(logfn), AV_OPT_TYPE_STRING, {.str="/dev/null"}, .flags = FLAGS }, { NULL } }; AVFILTER_DEFINE_CLASS(asr); static int filter_frame(AVFilterLink *inlink, AVFrame *in) { AVFilterContext *ctx = inlink->dst; AVDictionary **metadata = &in->metadata; ASRContext *s = ctx->priv; int have_speech; const char *speech; ps_process_raw(s->ps, (const int16_t *)in->data[0], in->nb_samples, 0, 0); have_speech = ps_get_in_speech(s->ps); if (have_speech && !s->utt_started) s->utt_started = 1; if (!have_speech && s->utt_started) { ps_end_utt(s->ps); speech = ps_get_hyp(s->ps, NULL); if (speech != NULL) av_dict_set(metadata, "lavfi.asr.text", speech, 0); ps_start_utt(s->ps); s->utt_started = 0; } return ff_filter_frame(ctx->outputs[0], in); } static int config_input(AVFilterLink *inlink) { AVFilterContext *ctx = inlink->dst; ASRContext *s = ctx->priv; ps_start_utt(s->ps); return 0; } static av_cold int asr_init(AVFilterContext *ctx) { ASRContext *s = ctx->priv; const float frate = s->rate; char *rate = av_asprintf("%f", frate); const char *argv[] = { "-logfn", s->logfn, "-hmm", s->hmm, "-lm", s->lm, "-lmctl", s->lmctl, "-lmname", s->lmname, "-dict", s->dict, "-samprate", rate, NULL }; s->config = cmd_ln_parse_r(NULL, ps_args(), 14, (char **)argv, 0); av_free(rate); if (!s->config) return AVERROR(ENOMEM); ps_default_search_args(s->config); s->ps = ps_init(s->config); if (!s->ps) return AVERROR(ENOMEM); return 0; } static int query_formats(AVFilterContext *ctx) { ASRContext *s = ctx->priv; int sample_rates[] = { s->rate, -1 }; int ret; AVFilterFormats *formats = NULL; AVFilterChannelLayouts *layout = NULL; if ((ret = ff_add_format (&formats, AV_SAMPLE_FMT_S16 )) < 0 || (ret = ff_set_common_formats (ctx , formats )) < 0 || (ret = ff_add_channel_layout (&layout , AV_CH_LAYOUT_MONO )) < 0 || (ret = ff_set_common_channel_layouts (ctx , layout )) < 0 || (ret = ff_set_common_samplerates (ctx , ff_make_format_list(sample_rates) )) < 0) return ret; return 0; } static av_cold void asr_uninit(AVFilterContext *ctx) { ASRContext *s = ctx->priv; ps_free(s->ps); s->ps = NULL; cmd_ln_free_r(s->config); s->config = NULL; } static const AVFilterPad asr_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, .filter_frame = filter_frame, .config_props = config_input, }, { NULL } }; static const AVFilterPad asr_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_AUDIO, }, { NULL } }; AVFilter ff_af_asr = { .name = "asr", .description = NULL_IF_CONFIG_SMALL("Automatic Speech Recognition."), .priv_size = sizeof(ASRContext), .priv_class = &asr_class, .init = asr_init, .uninit = asr_uninit, .query_formats = query_formats, .inputs = asr_inputs, .outputs = asr_outputs, };