FFmpeg
http_multiclient.c
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1 /*
2  * Copyright (c) 2015 Stephan Holljes
3  *
4  * Permission is hereby granted, free of charge, to any person obtaining a copy
5  * of this software and associated documentation files (the "Software"), to deal
6  * in the Software without restriction, including without limitation the rights
7  * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
8  * copies of the Software, and to permit persons to whom the Software is
9  * furnished to do so, subject to the following conditions:
10  *
11  * The above copyright notice and this permission notice shall be included in
12  * all copies or substantial portions of the Software.
13  *
14  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
15  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
16  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
17  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
18  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
19  * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
20  * THE SOFTWARE.
21  */
22 
23 /**
24  * @file
25  * libavformat multi-client network API usage example.
26  *
27  * @example http_multiclient.c
28  * This example will serve a file without decoding or demuxing it over http.
29  * Multiple clients can connect and will receive the same file.
30  */
31 
32 #include <libavformat/avformat.h>
33 #include <libavutil/opt.h>
34 #include <unistd.h>
35 
36 static void process_client(AVIOContext *client, const char *in_uri)
37 {
39  uint8_t buf[1024];
40  int ret, n, reply_code;
41  uint8_t *resource = NULL;
42  while ((ret = avio_handshake(client)) > 0) {
43  av_opt_get(client, "resource", AV_OPT_SEARCH_CHILDREN, &resource);
44  // check for strlen(resource) is necessary, because av_opt_get()
45  // may return empty string.
46  if (resource && strlen(resource))
47  break;
48  av_freep(&resource);
49  }
50  if (ret < 0)
51  goto end;
52  av_log(client, AV_LOG_TRACE, "resource=%p\n", resource);
53  if (resource && resource[0] == '/' && !strcmp((resource + 1), in_uri)) {
54  reply_code = 200;
55  } else {
56  reply_code = AVERROR_HTTP_NOT_FOUND;
57  }
58  if ((ret = av_opt_set_int(client, "reply_code", reply_code, AV_OPT_SEARCH_CHILDREN)) < 0) {
59  av_log(client, AV_LOG_ERROR, "Failed to set reply_code: %s.\n", av_err2str(ret));
60  goto end;
61  }
62  av_log(client, AV_LOG_TRACE, "Set reply code to %d\n", reply_code);
63 
64  while ((ret = avio_handshake(client)) > 0);
65 
66  if (ret < 0)
67  goto end;
68 
69  fprintf(stderr, "Handshake performed.\n");
70  if (reply_code != 200)
71  goto end;
72  fprintf(stderr, "Opening input file.\n");
73  if ((ret = avio_open2(&input, in_uri, AVIO_FLAG_READ, NULL, NULL)) < 0) {
74  av_log(input, AV_LOG_ERROR, "Failed to open input: %s: %s.\n", in_uri,
75  av_err2str(ret));
76  goto end;
77  }
78  for(;;) {
79  n = avio_read(input, buf, sizeof(buf));
80  if (n < 0) {
81  if (n == AVERROR_EOF)
82  break;
83  av_log(input, AV_LOG_ERROR, "Error reading from input: %s.\n",
84  av_err2str(n));
85  break;
86  }
87  avio_write(client, buf, n);
88  avio_flush(client);
89  }
90 end:
91  fprintf(stderr, "Flushing client\n");
92  avio_flush(client);
93  fprintf(stderr, "Closing client\n");
94  avio_close(client);
95  fprintf(stderr, "Closing input\n");
96  avio_close(input);
97  av_freep(&resource);
98 }
99 
100 int main(int argc, char **argv)
101 {
103  AVIOContext *client = NULL, *server = NULL;
104  const char *in_uri, *out_uri;
105  int ret, pid;
107  if (argc < 3) {
108  printf("usage: %s input http://hostname[:port]\n"
109  "API example program to serve http to multiple clients.\n"
110  "\n", argv[0]);
111  return 1;
112  }
113 
114  in_uri = argv[1];
115  out_uri = argv[2];
116 
118 
119  if ((ret = av_dict_set(&options, "listen", "2", 0)) < 0) {
120  fprintf(stderr, "Failed to set listen mode for server: %s\n", av_err2str(ret));
121  return ret;
122  }
123  if ((ret = avio_open2(&server, out_uri, AVIO_FLAG_WRITE, NULL, &options)) < 0) {
124  fprintf(stderr, "Failed to open server: %s\n", av_err2str(ret));
125  return ret;
126  }
127  fprintf(stderr, "Entering main loop.\n");
128  for(;;) {
129  if ((ret = avio_accept(server, &client)) < 0)
130  goto end;
131  fprintf(stderr, "Accepted client, forking process.\n");
132  // XXX: Since we don't reap our children and don't ignore signals
133  // this produces zombie processes.
134  pid = fork();
135  if (pid < 0) {
136  perror("Fork failed");
137  ret = AVERROR(errno);
138  goto end;
139  }
140  if (pid == 0) {
141  fprintf(stderr, "In child.\n");
142  process_client(client, in_uri);
143  avio_close(server);
144  exit(0);
145  }
146  if (pid > 0)
147  avio_close(client);
148  }
149 end:
150  avio_close(server);
151  if (ret < 0 && ret != AVERROR_EOF) {
152  fprintf(stderr, "Some errors occurred: %s\n", av_err2str(ret));
153  return 1;
154  }
155  return 0;
156 }
#define NULL
Definition: coverity.c:32
int main(int argc, char **argv)
Bytestream IO Context.
Definition: avio.h:161
void av_log_set_level(int level)
Set the log level.
Definition: log.c:385
#define AVIO_FLAG_READ
read-only
Definition: avio.h:674
#define AVIO_FLAG_WRITE
write-only
Definition: avio.h:675
#define AVERROR_HTTP_NOT_FOUND
Definition: error.h:79
int avio_accept(AVIOContext *s, AVIOContext **c)
Accept and allocate a client context on a server context.
Definition: aviobuf.c:1318
uint8_t
AVOptions.
#define AV_LOG_TRACE
Extremely verbose debugging, useful for libav* development.
Definition: log.h:202
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
int avformat_network_init(void)
Do global initialization of network libraries.
Definition: utils.c:5040
#define AVERROR_EOF
End of file.
Definition: error.h:55
void avio_write(AVIOContext *s, const unsigned char *buf, int size)
Definition: aviobuf.c:218
#define av_log(a,...)
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:650
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
int avio_close(AVIOContext *s)
Close the resource accessed by the AVIOContext s and free it.
Definition: aviobuf.c:1217
int av_opt_set_int(void *obj, const char *name, int64_t val, int search_flags)
Definition: opt.c:568
#define AV_OPT_SEARCH_CHILDREN
Search in possible children of the given object first.
Definition: opt.h:557
#define av_err2str(errnum)
Convenience macro, the return value should be used only directly in function arguments but never stan...
Definition: error.h:119
int n
Definition: avisynth_c.h:760
static void process_client(AVIOContext *client, const char *in_uri)
void * buf
Definition: avisynth_c.h:766
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:70
void avio_flush(AVIOContext *s)
Force flushing of buffered data.
Definition: aviobuf.c:238
int avio_open2(AVIOContext **s, const char *url, int flags, const AVIOInterruptCB *int_cb, AVDictionary **options)
Create and initialize a AVIOContext for accessing the resource indicated by url.
Definition: aviobuf.c:1211
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some input
int avio_handshake(AVIOContext *c)
Perform one step of the protocol handshake to accept a new client.
Definition: aviobuf.c:1330
Main libavformat public API header.
const OptionDef options[]
Definition: ffmpeg_opt.c:3374
int av_opt_get(void *obj, const char *name, int search_flags, uint8_t **out_val)
Definition: opt.c:761
printf("static const uint8_t my_array[100] = {\n")
#define av_freep(p)
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