[FFmpeg-devel] [PATCH 8/8] doc/example: Add http multi-client example code

[Stephan Holljes]

Signed-off-by: Stephan Holljes <klaxa1337 at googlemail.com>
---
 doc/examples/Makefile           |   1 +
 doc/examples/http_multiclient.c | 139 ++++++++++++++++++++++++++++++++++++++++
 2 files changed, 140 insertions(+)
 create mode 100644 doc/examples/http_multiclient.c

Changes since last version:
  - Use handshake API properly
  - Use perror() to print fork()'s error message. 

diff --git a/doc/examples/Makefile b/doc/examples/Makefile
index 9699f11..8c9501b 100644
--- a/doc/examples/Makefile
+++ b/doc/examples/Makefile
@@ -18,6 +18,7 @@ EXAMPLES=       avio_list_dir                      \
                 extract_mvs                        \
                 filtering_video                    \
                 filtering_audio                    \
+                http_multiclient                   \
                 metadata                           \
                 muxing                             \
                 remuxing                           \
diff --git a/doc/examples/http_multiclient.c b/doc/examples/http_multiclient.c
new file mode 100644
index 0000000..a2293b8
--- /dev/null
+++ b/doc/examples/http_multiclient.c
@@ -0,0 +1,139 @@
+/*
+ * copyright (c) 2015 Stephan Holljes
+ *
+ * This file is part of FFmpeg.
+ *
+ * FFmpeg is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU Lesser General Public
+ * License as published by the Free Software Foundation; either
+ * version 2.1 of the License, or (at your option) any later version.
+ *
+ * FFmpeg is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * libavformat multi-client network API usage example.
+ *
+ * @example http_multiclient.c
+ * This example will serve a file without decoding or demuxing it over http.
+ * Multiple clients can connect and will receive the same file.
+ */
+
+#include <libavformat/avformat.h>
+#include <unistd.h>
+#include <libavutil/opt.h>
+
+void process_client(AVIOContext *client, const char* in_uri)
+{
+    AVIOContext *input = NULL;
+    uint8_t buf[1024];
+    int ret, n, http_code;
+    char *resource;
+    for (;;) {
+        if ((ret = avio_handshake(client)) < 0)
+            goto end;
+        av_opt_get(client, "resource", AV_OPT_SEARCH_CHILDREN, &resource);
+        resource++;
+        av_log(client, AV_LOG_TRACE, "resource=%s\n", resource);
+        if (strcmp(resource, in_uri)) {
+            http_code = 404;
+        } else {
+            http_code = 200;
+        }
+        av_opt_set_int(client, "http_code", http_code, AV_OPT_SEARCH_CHILDREN);
+        if (ret == 0)
+            break;
+    }
+    fprintf(stderr, "Handshake performed.\n");
+    if (http_code != 200)
+        goto end;
+    fprintf(stderr, "Opening input file.\n");
+    if ((ret = avio_open2(&input, in_uri, AVIO_FLAG_READ, NULL, NULL)) < 0) {
+        av_log(input, AV_LOG_ERROR, "Failed to open input: %s\n", in_uri);
+        goto end;
+    }
+    for(;;) {
+        n = avio_read(input, buf, sizeof(buf));
+        if (n < 0) {
+            if (n == AVERROR_EOF)
+                break;
+            av_log(input, AV_LOG_ERROR, "Error reading from input: %s.\n",
+                   av_err2str(n));
+            ret = n;
+            break;
+        }
+        avio_write(client, buf, n);
+        avio_flush(client);
+    }
+end:
+    fprintf(stderr, "Flushing client\n");
+    avio_flush(client);
+    fprintf(stderr, "Closing client\n");
+    avio_close(client);
+    fprintf(stderr, "Closing input\n");
+    avio_close(input);
+}
+
+int main(int argc, char **argv)
+{
+    av_log_set_level(AV_LOG_TRACE);
+    AVDictionary *options = NULL;
+    AVIOContext *client = NULL, *server = NULL;
+    const char *in_uri, *out_uri;
+    int ret, pid;
+    if (argc < 3) {
+        printf("usage: %s input http://hostname[:port]\n"
+               "API example program to serve http to multiple clients.\n"
+               "\n", argv[0]);
+        return 1;
+    }
+
+    in_uri = argv[1];
+    out_uri = argv[2];
+
+    av_register_all();
+    avformat_network_init();
+
+    if ((ret = av_dict_set(&options, "listen", "2", 0)) < 0)
+        goto end;
+    if ((ret = avio_open2(&server, out_uri, AVIO_FLAG_WRITE, NULL, &options)) < 0)
+        goto end;
+    fprintf(stderr, "Entering main loop.\n");
+    for(;;) {
+        if ((ret = avio_accept(server, &client)) < 0)
+            goto end;
+        fprintf(stderr, "Accepted client, forking process.\n");
+        // XXX: Since we don't reap our children and don't ignore signals
+        //      this produces zombie processes.
+        pid = fork();
+        if (pid < 0) {
+            perror("Fork failed");
+            ret = AVERROR(errno);
+            goto end;
+        }
+        if (pid == 0) {
+            fprintf(stderr, "In child.\n");
+            process_client(client, in_uri);
+            avio_close(server);
+            exit(0);
+        }
+        if (pid > 0)
+            avio_close(client);
+    }
+end:
+    avio_close(server);
+    if (ret < 0 && ret != AVERROR_EOF) {
+        fprintf(stderr, "Some errors occured: ");
+        fprintf(stderr, "%s\n", av_err2str(ret));
+        return 1;
+    }
+    return 0;
+}
-- 
2.1.0