FFmpeg  4.4.5
fifo.c
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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 {
35  struct Buf *next;
36 } Buf;
37 
38 typedef struct FifoContext {
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  */
47  int allocated_samples; ///< number of samples out was allocated for
48 } FifoContext;
49 
51 {
52  FifoContext *s = ctx->priv;
53  s->last = &s->root;
54 
55  return 0;
56 }
57 
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 
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) {
79  return AVERROR(ENOMEM);
80  }
81 
82  s->last = s->last->next;
83  s->last->frame = frame;
84 
85  return 0;
86 }
87 
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 
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 
114  {
115  .name = "default",
116  .type = AVMEDIA_TYPE_VIDEO,
117  .filter_frame = add_to_queue,
118  },
119  { NULL }
120 };
121 
123  {
124  .name = "default",
125  .type = AVMEDIA_TYPE_VIDEO,
126  .request_frame = request_frame,
127  },
128  { NULL }
129 };
130 
132  .name = "fifo",
133  .description = NULL_IF_CONFIG_SMALL("Buffer input images and send them when they are requested."),
134  .init = init,
135  .uninit = uninit,
136  .priv_size = sizeof(FifoContext),
139 };
140 
142  {
143  .name = "default",
144  .type = AVMEDIA_TYPE_AUDIO,
145  .filter_frame = add_to_queue,
146  },
147  { NULL }
148 };
149 
151  {
152  .name = "default",
153  .type = AVMEDIA_TYPE_AUDIO,
154  .request_frame = request_frame,
155  },
156  { NULL }
157 };
158 
160  .name = "afifo",
161  .description = NULL_IF_CONFIG_SMALL("Buffer input frames and send them when they are requested."),
162  .init = init,
163  .uninit = uninit,
164  .priv_size = sizeof(FifoContext),
167 };
static const AVFilterPad inputs[]
Definition: af_acontrast.c:193
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
#define av_cold
Definition: attributes.h:88
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1096
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:408
Main libavfilter public API header.
#define s(width, name)
Definition: cbs_vp9.c:257
common internal and external API header
#define NULL
Definition: coverity.c:32
static AVFrame * frame
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:237
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
static int add_to_queue(AVFilterLink *inlink, AVFrame *frame)
Definition: fifo.c:72
static int request_frame(AVFilterLink *outlink)
Definition: fifo.c:97
AVFilter ff_af_afifo
Definition: fifo.c:159
static const AVFilterPad avfilter_vf_fifo_inputs[]
Definition: fifo.c:113
static av_cold int init(AVFilterContext *ctx)
Definition: fifo.c:50
static av_cold void uninit(AVFilterContext *ctx)
Definition: fifo.c:58
static void queue_pop(FifoContext *s)
Definition: fifo.c:88
static const AVFilterPad avfilter_af_afifo_inputs[]
Definition: fifo.c:141
AVFilter ff_vf_fifo
Definition: fifo.c:131
static const AVFilterPad avfilter_af_afifo_outputs[]
Definition: fifo.c:150
static const AVFilterPad avfilter_vf_fifo_outputs[]
Definition: fifo.c:122
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
An instance of a filter.
Definition: avfilter.h:341
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:349
void * priv
private data for use by the filter
Definition: avfilter.h:356
A filter pad used for either input or output.
Definition: internal.h:54
const char * name
Pad name.
Definition: internal.h:60
Filter definition.
Definition: avfilter.h:145
const char * name
Filter name.
Definition: avfilter.h:149
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
Definition: fifo.c:33
struct Buf * next
Definition: fifo.c:35
AVFrame * frame
Definition: fifo.c:34
int allocated_samples
number of samples out was allocated for
Definition: fifo.c:47
Buf * last
last buffered frame
Definition: fifo.c:40
AVFrame * out
When a specific number of output samples is requested, the partial buffer is stored here.
Definition: fifo.c:46
Buf root
Definition: fifo.c:39
#define av_free(p)
#define av_freep(p)
static uint8_t tmp[11]
Definition: aes_ctr.c:27
AVFormatContext * ctx
Definition: movenc.c:48