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f_zmq.c
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1 /*
2  * Copyright (c) 2013 Stefano Sabatini
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  * receive commands through libzeromq and broker them to filters
24  */
25 
26 #include <zmq.h>
27 #include "libavutil/avstring.h"
28 #include "libavutil/bprint.h"
29 #include "libavutil/opt.h"
30 #include "avfilter.h"
31 #include "internal.h"
32 #include "avfiltergraph.h"
33 #include "audio.h"
34 #include "video.h"
35 
36 typedef struct {
37  const AVClass *class;
38  void *zmq;
39  void *responder;
40  char *bind_address;
42 } ZMQContext;
43 
44 #define OFFSET(x) offsetof(ZMQContext, x)
45 #define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_VIDEO_PARAM
46 static const AVOption options[] = {
47  { "bind_address", "set bind address", OFFSET(bind_address), AV_OPT_TYPE_STRING, {.str = "tcp://*:5555"}, 0, 0, FLAGS },
48  { "b", "set bind address", OFFSET(bind_address), AV_OPT_TYPE_STRING, {.str = "tcp://*:5555"}, 0, 0, FLAGS },
49  { NULL }
50 };
51 
52 static av_cold int init(AVFilterContext *ctx)
53 {
54  ZMQContext *zmq = ctx->priv;
55 
56  zmq->zmq = zmq_ctx_new();
57  if (!zmq->zmq) {
58  av_log(ctx, AV_LOG_ERROR,
59  "Could not create ZMQ context: %s\n", zmq_strerror(errno));
60  return AVERROR_EXTERNAL;
61  }
62 
63  zmq->responder = zmq_socket(zmq->zmq, ZMQ_REP);
64  if (!zmq->responder) {
65  av_log(ctx, AV_LOG_ERROR,
66  "Could not create ZMQ socket: %s\n", zmq_strerror(errno));
67  return AVERROR_EXTERNAL;
68  }
69 
70  if (zmq_bind(zmq->responder, zmq->bind_address) == -1) {
71  av_log(ctx, AV_LOG_ERROR,
72  "Could not bind ZMQ socket to address '%s': %s\n",
73  zmq->bind_address, zmq_strerror(errno));
74  return AVERROR_EXTERNAL;
75  }
76 
77  zmq->command_count = -1;
78  return 0;
79 }
80 
81 static void av_cold uninit(AVFilterContext *ctx)
82 {
83  ZMQContext *zmq = ctx->priv;
84 
85  zmq_close(zmq->responder);
86  zmq_ctx_destroy(zmq->zmq);
87 }
88 
89 typedef struct {
90  char *target, *command, *arg;
91 } Command;
92 
93 #define SPACES " \f\t\n\r"
94 
95 static int parse_command(Command *cmd, const char *command_str, void *log_ctx)
96 {
97  const char **buf = &command_str;
98 
99  cmd->target = av_get_token(buf, SPACES);
100  if (!cmd->target || !cmd->target[0]) {
101  av_log(log_ctx, AV_LOG_ERROR,
102  "No target specified in command '%s'\n", command_str);
103  return AVERROR(EINVAL);
104  }
105 
106  cmd->command = av_get_token(buf, SPACES);
107  if (!cmd->command || !cmd->command[0]) {
108  av_log(log_ctx, AV_LOG_ERROR,
109  "No command specified in command '%s'\n", command_str);
110  return AVERROR(EINVAL);
111  }
112 
113  cmd->arg = av_get_token(buf, SPACES);
114  return 0;
115 }
116 
117 static int recv_msg(AVFilterContext *ctx, char **buf, int *buf_size)
118 {
119  ZMQContext *zmq = ctx->priv;
120  zmq_msg_t msg;
121  int ret = 0;
122 
123  if (zmq_msg_init(&msg) == -1) {
124  av_log(ctx, AV_LOG_WARNING,
125  "Could not initialize receive message: %s\n", zmq_strerror(errno));
126  return AVERROR_EXTERNAL;
127  }
128 
129  if (zmq_msg_recv(&msg, zmq->responder, ZMQ_DONTWAIT) == -1) {
130  if (errno != EAGAIN)
131  av_log(ctx, AV_LOG_WARNING,
132  "Could not receive message: %s\n", zmq_strerror(errno));
133  ret = AVERROR_EXTERNAL;
134  goto end;
135  }
136 
137  *buf_size = zmq_msg_size(&msg) + 1;
138  *buf = av_malloc(*buf_size);
139  if (!*buf) {
140  ret = AVERROR(ENOMEM);
141  goto end;
142  }
143  memcpy(*buf, zmq_msg_data(&msg), *buf_size);
144  (*buf)[*buf_size-1] = 0;
145 
146 end:
147  zmq_msg_close(&msg);
148  return ret;
149 }
150 
151 static int filter_frame(AVFilterLink *inlink, AVFrame *ref)
152 {
153  AVFilterContext *ctx = inlink->dst;
154  ZMQContext *zmq = ctx->priv;
155 
156  while (1) {
157  char cmd_buf[1024];
158  char *recv_buf, *send_buf;
159  int recv_buf_size;
160  Command cmd = {0};
161  int ret;
162 
163  /* receive command */
164  if (recv_msg(ctx, &recv_buf, &recv_buf_size) < 0)
165  break;
166  zmq->command_count++;
167 
168  /* parse command */
169  if (parse_command(&cmd, recv_buf, ctx) < 0) {
170  av_log(ctx, AV_LOG_ERROR, "Could not parse command #%d\n", zmq->command_count);
171  goto end;
172  }
173 
174  /* process command */
175  av_log(ctx, AV_LOG_VERBOSE,
176  "Processing command #%d target:%s command:%s arg:%s\n",
177  zmq->command_count, cmd.target, cmd.command, cmd.arg);
178  ret = avfilter_graph_send_command(inlink->graph,
179  cmd.target, cmd.command, cmd.arg,
180  cmd_buf, sizeof(cmd_buf),
182  send_buf = av_asprintf("%d %s%s%s",
183  -ret, av_err2str(ret), cmd_buf[0] ? "\n" : "", cmd_buf);
184  if (!send_buf) {
185  ret = AVERROR(ENOMEM);
186  goto end;
187  }
188  av_log(ctx, AV_LOG_VERBOSE,
189  "Sending command reply for command #%d:\n%s\n",
190  zmq->command_count, send_buf);
191  if (zmq_send(zmq->responder, send_buf, strlen(send_buf), 0) == -1)
192  av_log(ctx, AV_LOG_ERROR, "Failed to send reply for command #%d: %s\n",
193  zmq->command_count, zmq_strerror(ret));
194 
195  end:
196  av_freep(&send_buf);
197  av_freep(&recv_buf);
198  recv_buf_size = 0;
199  av_freep(&cmd.target);
200  av_freep(&cmd.command);
201  av_freep(&cmd.arg);
202  }
203 
204  return ff_filter_frame(ctx->outputs[0], ref);
205 }
206 
207 #if CONFIG_ZMQ_FILTER
208 
209 #define zmq_options options
211 
212 static const AVFilterPad zmq_inputs[] = {
213  {
214  .name = "default",
215  .type = AVMEDIA_TYPE_VIDEO,
216  .filter_frame = filter_frame,
217  },
218  { NULL }
219 };
220 
221 static const AVFilterPad zmq_outputs[] = {
222  {
223  .name = "default",
224  .type = AVMEDIA_TYPE_VIDEO,
225  },
226  { NULL }
227 };
228 
229 AVFilter ff_vf_zmq = {
230  .name = "zmq",
231  .description = NULL_IF_CONFIG_SMALL("Receive commands through ZMQ and broker them to filters."),
232  .init = init,
233  .uninit = uninit,
234  .priv_size = sizeof(ZMQContext),
235  .inputs = zmq_inputs,
236  .outputs = zmq_outputs,
237  .priv_class = &zmq_class,
238 };
239 
240 #endif
241 
242 #if CONFIG_AZMQ_FILTER
243 
244 #define azmq_options options
246 
247 static const AVFilterPad azmq_inputs[] = {
248  {
249  .name = "default",
250  .type = AVMEDIA_TYPE_AUDIO,
251  .filter_frame = filter_frame,
252  },
253  { NULL }
254 };
255 
256 static const AVFilterPad azmq_outputs[] = {
257  {
258  .name = "default",
259  .type = AVMEDIA_TYPE_AUDIO,
260  },
261  { NULL }
262 };
263 
264 AVFilter ff_af_azmq = {
265  .name = "azmq",
266  .description = NULL_IF_CONFIG_SMALL("Receive commands through ZMQ and broker them to filters."),
267  .init = init,
268  .uninit = uninit,
269  .priv_size = sizeof(ZMQContext),
270  .inputs = azmq_inputs,
271  .outputs = azmq_outputs,
272  .priv_class = &azmq_class,
273 };
274 
275 #endif