FFmpeg
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 
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 
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),
137  .inputs = avfilter_vf_fifo_inputs,
138  .outputs = avfilter_vf_fifo_outputs,
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),
165  .inputs = avfilter_af_afifo_inputs,
166  .outputs = avfilter_af_afifo_outputs,
167 };
AVFrame * out
When a specific number of output samples is requested, the partial buffer is stored here...
Definition: fifo.c:46
#define NULL
Definition: coverity.c:32
AVFilter ff_vf_fifo
Definition: fifo.c:131
This structure describes decoded (raw) audio or video data.
Definition: frame.h:308
Buf * last
last buffered frame
Definition: fifo.c:40
static av_cold int init(AVFilterContext *ctx)
Definition: fifo.c:50
static const AVFilterPad avfilter_vf_fifo_inputs[]
Definition: fifo.c:113
Main libavfilter public API header.
static void queue_pop(FifoContext *s)
Definition: fifo.c:88
static av_cold void uninit(AVFilterContext *ctx)
Definition: fifo.c:58
static int add_to_queue(AVFilterLink *inlink, AVFrame *frame)
Definition: fifo.c:72
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
const char * name
Pad name.
Definition: internal.h:60
AVFilterLink ** inputs
array of pointers to input links
Definition: avfilter.h:349
AVFrame * frame
Definition: fifo.c:34
int ff_filter_frame(AVFilterLink *link, AVFrame *frame)
Send a frame of data to the next filter.
Definition: avfilter.c:1091
#define av_cold
Definition: attributes.h:88
Definition: fifo.c:33
AVFilter ff_af_afifo
Definition: fifo.c:159
static const AVFilterPad avfilter_vf_fifo_outputs[]
Definition: fifo.c:122
Buf root
Definition: fifo.c:39
static const AVFilterPad avfilter_af_afifo_inputs[]
Definition: fifo.c:141
A filter pad used for either input or output.
Definition: internal.h:54
struct Buf * next
Definition: fifo.c:35
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
void * priv
private data for use by the filter
Definition: avfilter.h:356
int allocated_samples
number of samples out was allocated for
Definition: fifo.c:47
AVFormatContext * ctx
Definition: movenc.c:48
#define s(width, name)
Definition: cbs_vp9.c:257
static const AVFilterPad outputs[]
Definition: af_acontrast.c:203
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several inputs
static int request_frame(AVFilterLink *outlink)
Definition: fifo.c:97
Filter definition.
Definition: avfilter.h:145
const char * name
Filter name.
Definition: avfilter.h:149
The exact code depends on how similar the blocks are and how related they are to the and needs to apply these operations to the correct inlink or outlink if there are several Macros are available to factor that when no extra processing is inlink
common internal and external API header
#define av_free(p)
static const AVFilterPad avfilter_af_afifo_outputs[]
Definition: fifo.c:150
An instance of a filter.
Definition: avfilter.h:341
#define av_freep(p)
int ff_request_frame(AVFilterLink *link)
Request an input frame from the filter at the other end of the link.
Definition: avfilter.c:407
internal API functions
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
static uint8_t tmp[11]
Definition: aes_ctr.c:26