Ticket #4566: propagate-metadata-changes-to-icecast-outputs.patch

fftools/ffmpeg.c

@@ -4341 +4341 @@
         av_log(NULL, AV_LOG_INFO, "Press [q] to stop, [?] for help\n");
     }
 
+    // check if metadata propagation is required
+    int propagate_metadata_updates = 0;
+    for (i = 0; i < nb_output_files; i++) {
+        if (strncmp(output_files[i]->ctx->url, "icecast://", 10) == 0) {
+            propagate_metadata_updates = 1;
+            break;
+        }
+    }
+
     timer_start = av_gettime_relative();
 
 #if HAVE_THREADS
@@ -4370 +4379 @@
 
         /* dump report by using the output first video and audio streams */
         print_report(0, timer_start, cur_time);
+
+        for (i = 0; i < nb_input_streams && propagate_metadata_updates; i++) {
+            ist = input_streams[i];
+            if (input_files[ist->file_index]->ctx->event_flags & AVFMT_EVENT_FLAG_METADATA_UPDATED) {
+                input_files[ist->file_index]->ctx->event_flags &= ~AVFMT_EVENT_FLAG_METADATA_UPDATED;
+                av_log(NULL, AV_LOG_TRACE, "Input metadata update detected on stream: %d\n", ist->file_index);
+                for (i = 0; i < nb_output_files; i++) {
+                    av_dict_copy(&output_files[i]->ctx->metadata, input_files[ist->file_index]->ctx->metadata, 0);
+                    output_files[i]->ctx->event_flags |= AVFMT_EVENT_FLAG_METADATA_UPDATED;
+                }
+            }
+        }
     }
 #if HAVE_THREADS
     free_input_threads();

fftools/ffmpeg_opt.c

@@ -33 +33 @@
 #include "opt_common.h"
 
 #include "libavformat/avformat.h"
+#include "libavformat/url.h"
 
 #include "libavcodec/avcodec.h"
 #include "libavcodec/bsf.h"
@@ -2845 +2846 @@
             print_error(filename, err);
             exit_program(1);
         }
+        // set the AVFormatContext parent reference in URLContext
+        if (strncmp(oc->url, "icecast://", 10) == 0) {
+            av_log(NULL, AV_LOG_TRACE, "Set AVFormatContext parent reference in URLContext\n");
+            ((URLContext *)oc->pb->opaque)->ctx = oc;
+        }
     } else if (strcmp(oc->oformat->name, "image2")==0 && !av_filename_number_test(filename))
         assert_file_overwrite(filename);
 

libavformat/icecast.c

@@ -33 +33 @@
     URLContext *hd;
     int send_started;
     char *user;
+    char *metadata_url;
     // Options
     char *content_type;
     char *description;
@@ -163 +164 @@
         goto cleanup;
     }
 
+    // Build URI for metadata updates
+    ff_url_join(h_url, sizeof(h_url),
+                s->tls ? "https" : "http",
+                auth, host, port, "/admin/metadata?mode=updinfo&charset=UTF-8&mount=%s", path);
+    s->metadata_url = av_strdup(h_url);
+
     // Build new URI for passing to http protocol
     ff_url_join(h_url, sizeof(h_url),
                 s->tls ? "https" : "http",
@@ -178 +185 @@
     return ret;
 }
 
+static int metadata_update_interrupt_cb(void *ctx) {
+    return 0;
+}
+
+const AVIOInterruptCB icecast_metadata_int_cb = { metadata_update_interrupt_cb, NULL };
+
+// escape the song name (like bprint_escaped_path but also escapes '&' and '#')
+static void escape_metadata(char *buffer, int size, const char *song) {
+#define NEEDS_ESCAPE(ch) \
+    ((ch) <= ' ' || (ch) >= '\x7f' || \
+     (ch) == '"' || (ch) == '%' || (ch) == '<' || (ch) == '>' || (ch) == '\\' || \
+     (ch) == '^' || (ch) == '`' || (ch) == '{' || (ch) == '}' || (ch) == '|' || \
+     (ch) == '&' || (ch) == '#')
+    char *q = buffer;
+    while (*song && q - buffer < size - 4) {
+        if (song[0] == '%' && av_isxdigit(song[1]) && av_isxdigit(song[2])) {
+            *q++ = *song++;
+            *q++ = *song++;
+            *q++ = *song++;
+        } else if (NEEDS_ESCAPE(*song)) {
+            q += snprintf(q, 4, "%%%02X", (uint8_t)*song++);
+        } else {
+            *q++ = *song++;
+        }
+    }
+    // terminate the string
+    if (q - buffer < size) {
+        *q = '\0';
+    } else {
+        buffer[size - 1] = '\0';
+    }
+}
+
+static void update_metadata(IcecastContext *s, const char *song) {
+    // escape the song name
+    char escaped_song[1024];
+    escape_metadata(&escaped_song, sizeof(escaped_song), song);
+
+    // build the metadata update url
+    char h_url[2048];
+    snprintf(h_url, sizeof(h_url), "%s&song=%s", s->metadata_url, &escaped_song);
+    av_log(s, AV_LOG_TRACE, "StreamTitle update: '%s', url: '%s'\n", song, h_url);
+
+    // call the metadata update url
+    AVDictionary *opt_dict = NULL;
+    av_dict_set(&opt_dict, "auth_type", "basic", 0);
+    if (NOT_EMPTY(s->user_agent))
+        av_dict_set(&opt_dict, "user_agent", s->user_agent, 0);
+    AVIOContext *avio = NULL;
+    int ret = avio_open2(&avio, h_url, AVIO_FLAG_READ, &icecast_metadata_int_cb, &opt_dict);
+    if (ret < 0) {
+        av_log(NULL, AV_LOG_WARNING, "Failed to open metadata update URL \"%s\": %s\n", h_url, av_err2str(ret));
+    }
+    if ((ret = avio_closep(&avio)) < 0) {
+        av_log(NULL, AV_LOG_ERROR, "Error closing metadata update URL \"%s\": %s\n", h_url, av_err2str(ret));
+    }
+    av_dict_free(&opt_dict);
+}
+
 static int icecast_write(URLContext *h, const uint8_t *buf, int size)
 {
     IcecastContext *s = h->priv_data;
@@ -202 +268 @@
             }
         }
     }
+    if (h->ctx && h->ctx->event_flags & AVFMT_EVENT_FLAG_METADATA_UPDATED) {
+        h->ctx->event_flags &= ~AVFMT_EVENT_FLAG_METADATA_UPDATED;
+        AVDictionaryEntry *song_entry = av_dict_get(h->ctx->metadata, "StreamTitle",  NULL, 0);
+        if (song_entry) {
+            update_metadata(s, song_entry->value);
+        }
+    }
     return ffurl_write(s->hd, buf, size);
 }
 

libavformat/url.h

@@ -33 +33 @@
 #define URL_PROTOCOL_FLAG_NETWORK       2 /*< The protocol uses network */
 
 extern const AVClass ffurl_context_class;
+typedef struct AVFormatContext AVFormatContext;
 
 typedef struct URLContext {
     const AVClass *av_class;    /**< information for av_log(). Set by url_open(). */
@@ -48 +49 @@
     const char *protocol_whitelist;
     const char *protocol_blacklist;
     int min_packet_size;        /**< if non zero, the stream is packetized with this min packet size */
+    AVFormatContext *ctx;       /**< reference to the format context */
 } URLContext;
 
 typedef struct URLProtocol {