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dualinput.c
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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 #define MAIN 0
20 #define SECOND 1
21 
22 #include "dualinput.h"
23 #include "libavutil/timestamp.h"
24 
26  AVFilterContext *ctx, AVFrame *mainpic)
27 {
28  int ret;
29 
30  /* Discard obsolete second frames: if there is a next second frame with pts
31  * before the main frame, we can drop the current second. */
32  while (1) {
33  AVFrame *next_overpic = ff_bufqueue_peek(&s->queue[SECOND], 0);
34  if (!next_overpic && s->second_eof && !s->repeatlast) {
36  break;
37  }
38  if (!next_overpic || av_compare_ts(next_overpic->pts, ctx->inputs[SECOND]->time_base,
39  mainpic->pts, ctx->inputs[MAIN]->time_base) > 0)
40  break;
43  s->second_frame = next_overpic;
44  }
45 
46  /* If there is no next frame and no EOF and the second frame is before
47  * the main frame, we can not know yet if it will be superseded. */
48  if (!s->queue[SECOND].available && !s->second_eof &&
50  mainpic->pts, ctx->inputs[MAIN]->time_base) < 0))
51  return AVERROR(EAGAIN);
52 
53  /* At this point, we know that the current second frame extends to the
54  * time of the main frame. */
55  av_dlog(ctx, "main_pts:%s main_pts_time:%s",
56  av_ts2str(mainpic->pts), av_ts2timestr(mainpic->pts, &ctx->inputs[MAIN]->time_base));
57  if (s->second_frame)
58  av_dlog(ctx, " second_pts:%s second_pts_time:%s",
60  av_dlog(ctx, "\n");
61 
62  if (s->second_frame && !ctx->is_disabled)
63  mainpic = s->process(ctx, mainpic, s->second_frame);
64  ret = ff_filter_frame(ctx->outputs[0], mainpic);
65  av_assert1(ret != AVERROR(EAGAIN));
66  s->frame_requested = 0;
67  return ret;
68 }
69 
71 {
72  AVFrame *next_mainpic = ff_bufqueue_peek(&s->queue[MAIN], 0);
73  int ret;
74 
75  if (!next_mainpic)
76  return AVERROR(EAGAIN);
77  if ((ret = try_filter_frame(s, ctx, next_mainpic)) == AVERROR(EAGAIN))
78  return ret;
80  return ret;
81 }
82 
84 {
85  int ret;
86 
87  while (!(ret = try_filter_next_frame(s, ctx)));
88  return ret == AVERROR(EAGAIN) ? 0 : ret;
89 }
90 
92  AVFilterLink *inlink, AVFrame *in)
93 {
94  AVFilterContext *ctx = inlink->dst;
95  int ret;
96 
97  if ((ret = flush_frames(s, ctx)) < 0)
98  return ret;
99  if ((ret = try_filter_frame(s, ctx, in)) < 0) {
100  if (ret != AVERROR(EAGAIN))
101  return ret;
102  ff_bufqueue_add(ctx, &s->queue[MAIN], in);
103  }
104 
105  if (!s->second_frame)
106  return 0;
107  flush_frames(s, ctx);
108 
109  return 0;
110 }
111 
113  AVFilterLink *inlink, AVFrame *in)
114 {
115  AVFilterContext *ctx = inlink->dst;
116  int ret;
117 
118  if ((ret = flush_frames(s, ctx)) < 0)
119  return ret;
120  ff_bufqueue_add(ctx, &s->queue[SECOND], in);
121  ret = try_filter_next_frame(s, ctx);
122  return ret == AVERROR(EAGAIN) ? 0 : ret;
123 }
124 
126 {
127  AVFilterContext *ctx = outlink->src;
128  int input, ret;
129 
130  if (!try_filter_next_frame(s, ctx))
131  return 0;
132  s->frame_requested = 1;
133  while (s->frame_requested) {
134  /* TODO if we had a frame duration, we could guess more accurately */
135  input = !s->second_eof && (s->queue[MAIN].available ||
136  s->queue[SECOND].available < 2) ?
137  SECOND : MAIN;
138  ret = ff_request_frame(ctx->inputs[input]);
139  /* EOF on main is reported immediately */
140  if (ret == AVERROR_EOF && input == SECOND) {
141  s->second_eof = 1;
142  if (s->shortest)
143  return ret;
144  if ((ret = try_filter_next_frame(s, ctx)) != AVERROR(EAGAIN))
145  return ret;
146  ret = 0; /* continue requesting frames on main */
147  }
148  if (ret < 0)
149  return ret;
150  }
151  return 0;
152 }
153 
155 {
159 }