libavfilter/f_cue.c

   1 /*
   2  * Copyright (c) 2018 Marton Balint
   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
  21 #include "config_components.h"
  22
  23 #include "libavutil/opt.h"
  24 #include "libavutil/time.h"
  25 #include "audio.h"
  26 #include "avfilter.h"
  27 #include "filters.h"
  28 #include "video.h"
  29
  30 typedef struct CueContext {
  31     const AVClass *class;
  32     int64_t first_pts;
  33     int64_t cue;
  34     int64_t preroll;
  35     int64_t buffer;
  36     int status;
  37 } CueContext;
  38
  39 static int activate(AVFilterContext *ctx)
  40 {
  41     AVFilterLink *inlink = ctx->inputs[0];
  42     AVFilterLink *outlink = ctx->outputs[0];
  43     CueContext *s = ctx->priv;
  44
  45     FF_FILTER_FORWARD_STATUS_BACK(outlink, inlink);
  46
  47     if (ff_inlink_queued_frames(inlink)) {
  48         AVFrame *frame = ff_inlink_peek_frame(inlink, 0);
  49         int64_t pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q);
  50
  51         if (!s->status) {
  52             s->first_pts = pts;
  53             s->status++;
  54         }
  55         if (s->status == 1) {
  56             if (pts - s->first_pts < s->preroll) {
  57                 int ret = ff_inlink_consume_frame(inlink, &frame);
  58                 if (ret < 0)
  59                     return ret;
  60                 return ff_filter_frame(outlink, frame);
  61             }
  62             s->first_pts = pts;
  63             s->status++;
  64         }
  65         if (s->status == 2) {
  66             frame = ff_inlink_peek_frame(inlink, ff_inlink_queued_frames(inlink) - 1);
  67             pts = av_rescale_q(frame->pts, inlink->time_base, AV_TIME_BASE_Q);
  68             if (!(pts - s->first_pts < s->buffer && (av_gettime() - s->cue) < 0))
  69                 s->status++;
  70         }
  71         if (s->status == 3) {
  72             int64_t diff;
  73             while ((diff = (av_gettime() - s->cue)) < 0)
  74                 av_usleep(av_clip(-diff / 2, 100, 1000000));
  75             s->status++;
  76         }
  77         if (s->status == 4) {
  78             int ret = ff_inlink_consume_frame(inlink, &frame);
  79             if (ret < 0)
  80                 return ret;
  81             return ff_filter_frame(outlink, frame);
  82         }
  83     }
  84
  85     FF_FILTER_FORWARD_STATUS(inlink, outlink);
  86     FF_FILTER_FORWARD_WANTED(outlink, inlink);
  87
  88     return FFERROR_NOT_READY;
  89 }
  90
  91 #define OFFSET(x) offsetof(CueContext, x)
  92 #define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_FILTERING_PARAM
  93 static const AVOption options[] = {
  94     { "cue", "cue unix timestamp in microseconds", OFFSET(cue), AV_OPT_TYPE_INT64, { .i64 = 0 }, 0, INT64_MAX, FLAGS },
  95     { "preroll", "preroll duration in seconds", OFFSET(preroll), AV_OPT_TYPE_DURATION, { .i64 = 0 }, 0, INT64_MAX, FLAGS },
  96     { "buffer", "buffer duration in seconds", OFFSET(buffer), AV_OPT_TYPE_DURATION, { .i64 = 0 }, 0, INT64_MAX, FLAGS },
  97     { NULL }
  98 };
  99
 100 AVFILTER_DEFINE_CLASS_EXT(cue_acue, "(a)cue", options);
 101
 102 #if CONFIG_CUE_FILTER
 103 const FFFilter ff_vf_cue = {
 104     .p.name        = "cue",
 105     .p.description = NULL_IF_CONFIG_SMALL("Delay filtering to match a cue."),
 106     .p.priv_class  = &cue_acue_class,
 107     .priv_size   = sizeof(CueContext),
 108     FILTER_INPUTS(ff_video_default_filterpad),
 109     FILTER_OUTPUTS(ff_video_default_filterpad),
 110     .activate    = activate,
 111 };
 112 #endif /* CONFIG_CUE_FILTER */
 113
 114 #if CONFIG_ACUE_FILTER
 115 const FFFilter ff_af_acue = {
 116     .p.name        = "acue",
 117     .p.description = NULL_IF_CONFIG_SMALL("Delay filtering to match a cue."),
 118     .p.priv_class  = &cue_acue_class,
 119     .p.flags       = AVFILTER_FLAG_METADATA_ONLY,
 120     .priv_size   = sizeof(CueContext),
 121     FILTER_INPUTS(ff_audio_default_filterpad),
 122     FILTER_OUTPUTS(ff_audio_default_filterpad),
 123     .activate    = activate,
 124 };
 125 #endif /* CONFIG_ACUE_FILTER */