avformat/http: allow adjusting the redirect limit

Idea from: BapToutatis and also curl and wget have equivalent options

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/http.c

@@ -156,6 +156,7 @@ typedef struct HTTPContext {
     int nb_redirects;
     int sum_latency; /* divide by nb_requests */
     int max_latency;
+    int max_redirects;
 } HTTPContext;
 
 #define OFFSET(x) offsetof(HTTPContext, x)
@@ -202,6 +203,7 @@ static const AVOption options[] = {
     { "resource", "The resource requested by a client", OFFSET(resource), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, E },
     { "reply_code", "The http status code to return to a client", OFFSET(reply_code), AV_OPT_TYPE_INT, { .i64 = 200}, INT_MIN, 599, E},
     { "short_seek_size", "Threshold to favor readahead over seek.", OFFSET(short_seek_size), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, D },
+    { "max_redirects", "Maximum number of redirects", OFFSET(max_redirects), AV_OPT_TYPE_INT, { .i64 = MAX_REDIRECTS }, 0, INT_MAX, D },
     { NULL }
 };
 
@@ -480,7 +482,7 @@ redo:
         s->new_location) {
         /* url moved, get next */
         ffurl_closep(&s->hd);
-        if (redirects++ >= MAX_REDIRECTS)
+        if (redirects++ >= s->max_redirects)
             return AVERROR(EIO);
 
         if (!s->expires) {