typefind: Expand the search range for HLS detection

HLS files can have arbitrary extra tags in them, and
those can be quite long lines. We need to search
further than 256 bytes sometimes just to get past the
first few lines of the file. Make the limit 4KB,
which matches a typical input block size and should
hopefully cover every crazy input.

https://bugzilla.gnome.org/show_bug.cgi?id=780559

diff --git a/gst/typefind/gsttypefindfunctions.c b/gst/typefind/gsttypefindfunctions.c
index 90544b3..9ad6667 100644 (file)
--- a/gst/typefind/gsttypefindfunctions.c
+++ b/gst/typefind/gsttypefindfunctions.c
@@ -503,7 +503,8 @@ hls_type_find (GstTypeFind * tf, gpointer unused)
 {
   DataScanCtx c = { 0, NULL, 0 };
 
-  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 7)))
+  /* Minimum useful size is #EXTM3U\n + 1 tag + ':' = 30 bytes */
+  if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 30)))
     return;
 
   if (memcmp (c.data, "#EXTM3U", 7))
@@ -511,8 +512,8 @@ hls_type_find (GstTypeFind * tf, gpointer unused)
 
   data_scan_ctx_advance (tf, &c, 7);
 
-  /* Check only the first 256 bytes */
-  while (c.offset < 256) {
+  /* Check only the first 4KB */
+  while (c.offset < 4096) {
     if (G_UNLIKELY (!data_scan_ctx_ensure_data (tf, &c, 21)))
       return;