1 /*
2 * Copyright (c) 2007 Bobby Bingham
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 /**
22 * @file
23 * FIFO buffering filter
24 */
25
26 #include "libavutil/common.h"
27 #include "libavutil/mathematics.h"
28
29 #include "audio.h"
30 #include "avfilter.h"
31 #include "internal.h"
32
33 typedef struct Buf {
34 AVFrame *frame;
35 struct Buf *next;
36 } Buf;
37
38 typedef struct FifoContext {
39 Buf root;
40 Buf *last; ///< last buffered frame
41
42 /**
43 * When a specific number of output samples is requested, the partial
44 * buffer is stored here
45 */
46 AVFrame *out;
47 int allocated_samples; ///< number of samples out was allocated for
48 } FifoContext;
49
init(AVFilterContext * ctx)50 static av_cold int init(AVFilterContext *ctx)
51 {
52 FifoContext *s = ctx->priv;
53 s->last = &s->root;
54
55 return 0;
56 }
57
uninit(AVFilterContext * ctx)58 static av_cold void uninit(AVFilterContext *ctx)
59 {
60 FifoContext *s = ctx->priv;
61 Buf *buf, *tmp;
62
63 for (buf = s->root.next; buf; buf = tmp) {
64 tmp = buf->next;
65 av_frame_free(&buf->frame);
66 av_free(buf);
67 }
68
69 av_frame_free(&s->out);
70 }
71
add_to_queue(AVFilterLink * inlink,AVFrame * frame)72 static int add_to_queue(AVFilterLink *inlink, AVFrame *frame)
73 {
74 FifoContext *s = inlink->dst->priv;
75
76 s->last->next = av_mallocz(sizeof(Buf));
77 if (!s->last->next) {
78 av_frame_free(&frame);
79 return AVERROR(ENOMEM);
80 }
81
82 s->last = s->last->next;
83 s->last->frame = frame;
84
85 return 0;
86 }
87
queue_pop(FifoContext * s)88 static void queue_pop(FifoContext *s)
89 {
90 Buf *tmp = s->root.next->next;
91 if (s->last == s->root.next)
92 s->last = &s->root;
93 av_freep(&s->root.next);
94 s->root.next = tmp;
95 }
96
request_frame(AVFilterLink * outlink)97 static int request_frame(AVFilterLink *outlink)
98 {
99 FifoContext *s = outlink->src->priv;
100 int ret = 0;
101
102 if (!s->root.next) {
103 if ((ret = ff_request_frame(outlink->src->inputs[0])) < 0)
104 return ret;
105 if (!s->root.next)
106 return 0;
107 }
108 ret = ff_filter_frame(outlink, s->root.next->frame);
109 queue_pop(s);
110 return ret;
111 }
112
113 static const AVFilterPad avfilter_vf_fifo_inputs[] = {
114 {
115 .name = "default",
116 .type = AVMEDIA_TYPE_VIDEO,
117 .filter_frame = add_to_queue,
118 },
119 };
120
121 static const AVFilterPad avfilter_vf_fifo_outputs[] = {
122 {
123 .name = "default",
124 .type = AVMEDIA_TYPE_VIDEO,
125 .request_frame = request_frame,
126 },
127 };
128
129 const AVFilter ff_vf_fifo = {
130 .name = "fifo",
131 .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),
132 .init = init,
133 .uninit = uninit,
134 .priv_size = sizeof(FifoContext),
135 .flags = AVFILTER_FLAG_METADATA_ONLY,
136 FILTER_INPUTS(avfilter_vf_fifo_inputs),
137 FILTER_OUTPUTS(avfilter_vf_fifo_outputs),
138 };
139
140 static const AVFilterPad avfilter_af_afifo_inputs[] = {
141 {
142 .name = "default",
143 .type = AVMEDIA_TYPE_AUDIO,
144 .filter_frame = add_to_queue,
145 },
146 };
147
148 static const AVFilterPad avfilter_af_afifo_outputs[] = {
149 {
150 .name = "default",
151 .type = AVMEDIA_TYPE_AUDIO,
152 .request_frame = request_frame,
153 },
154 };
155
156 const AVFilter ff_af_afifo = {
157 .name = "afifo",
158 .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),
159 .init = init,
160 .uninit = uninit,
161 .priv_size = sizeof(FifoContext),
162 .flags = AVFILTER_FLAG_METADATA_ONLY,
163 FILTER_INPUTS(avfilter_af_afifo_inputs),
164 FILTER_OUTPUTS(avfilter_af_afifo_outputs),
165 };
166