subviewer: sanitize packets.

The data does not contain timing or trailing line breaks anymore. In
addition to being less idiotic, it is consistent with other codecs and
thus allows more switches between formats and codecs. It also fixes the
issue of the trailing line returns being simple \n instead of CRLF in
the ASS rectangle dialogue (this is the reason of the FATE update).

1 files changed, 10 insertions, 5 deletions

diff --git a/libavcodec/subviewerdec.c b/libavcodec/subviewerdec.c
index 0e8be90e78..7580cbe679 100644
--- a/libavcodec/subviewerdec.c
+++ b/libavcodec/subviewerdec.c
@@ -31,17 +31,13 @@
 static int subviewer_event_to_ass(AVBPrint *buf, const char *p)
 {
     while (*p) {
-        char c;
-
-        if (sscanf(p, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1)
-            p += strcspn(p, "\n") + 1;
         if (!strncmp(p, "[br]", 4)) {
             av_bprintf(buf, "\\N");
             p += 4;
         } else {
             if (p[0] == '\n' && p[1])
                 av_bprintf(buf, "\\N");
-            else if (*p != '\r')
+            else if (*p != '\n' && *p != '\r')
                 av_bprint_chars(buf, *p, 1);
             p++;
         }
@@ -54,10 +50,19 @@ static int subviewer_event_to_ass(AVBPrint *buf, const char *p)
 static int subviewer_decode_frame(AVCodecContext *avctx,
                                   void *data, int *got_sub_ptr, AVPacket *avpkt)
 {
+    char c;
     AVSubtitle *sub = data;
     const char *ptr = avpkt->data;
     AVBPrint buf;
 
+    /* To be removed later */
+    if (sscanf(ptr, "%*u:%*u:%*u.%*u,%*u:%*u:%*u.%*u%c", &c) == 1) {
+        av_log(avctx, AV_LOG_ERROR, "AVPacket is not clean (contains timing "
+               "information). You need to upgrade your libavformat or "
+               "sanitize your packet.\n");
+        return AVERROR_INVALIDDATA;
+    }
+
     av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
     // note: no need to rescale pts & duration since they are in the same
     // timebase as ASS (1/100)