[FFmpeg-devel] [PATCH] lavf/mov.c: Allocate buffer in case of long metadata entries.

[Thilo Borgmann]

Am 17.10.14 17:03, schrieb Michael Niedermayer:
> [...]
> 
> i think it would be simpler to always allocate with no str_small
> local buffer case.
> Also always allocating 2x the size should avoid the macro

Done & attached.

-Thilo

-------------- next part --------------
>From e374fd065392f7e68fd3d951712a13008dc6fb2f Mon Sep 17 00:00:00 2001
From: Thilo Borgmann <thilo.borgmann at mail.de>
Date: Mon, 20 Oct 2014 13:42:28 +0200
Subject: [PATCH] lavf/mov.c: Allocate buffer in case of long metadata entries.

---
 libavformat/mov.c | 18 ++++++++++++------
 1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/libavformat/mov.c b/libavformat/mov.c
index 4ff46dd..fee76e7 100644
--- a/libavformat/mov.c
+++ b/libavformat/mov.c
@@ -261,10 +261,11 @@ static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
 #ifdef MOV_EXPORT_ALL_METADATA
     char tmp_key[5];
 #endif
-    char str[1024], key2[16], language[4] = {0};
+    char key2[16], language[4] = {0};
+    char *str = NULL;
     const char *key = NULL;
     uint16_t langcode = 0;
-    uint32_t data_type = 0, str_size;
+    uint32_t data_type = 0, str_size, str_size_alloc;
     int (*parse)(MOVContext*, AVIOContext*, unsigned, const char*) = NULL;
 
     switch (atom.type) {
@@ -353,18 +354,21 @@ static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     }
 #endif
 
+    str_size_alloc = str_size << 1; // worst-case requirement for output string in case of utf8 coded input
+    str = av_malloc(str_size_alloc);
+    if (!str)
+        return AVERROR(ENOMEM);
+
     if (!key)
         return 0;
     if (atom.size < 0)
         return AVERROR_INVALIDDATA;
 
-    str_size = FFMIN3(sizeof(str)-1, str_size, atom.size);
-
     if (parse)
         parse(c, pb, str_size, key);
     else {
         if (data_type == 3 || (data_type == 0 && (langcode < 0x400 || langcode == 0x7fff))) { // MAC Encoded
-            mov_read_mac_string(c, pb, str_size, str, sizeof(str));
+            mov_read_mac_string(c, pb, str_size, str, str_size_alloc);
         } else {
             int ret = avio_read(pb, str, str_size);
             if (ret != str_size)
@@ -380,7 +384,9 @@ static int mov_read_udta_string(MOVContext *c, AVIOContext *pb, MOVAtom atom)
     }
     av_dlog(c->fc, "lang \"%3s\" ", language);
     av_dlog(c->fc, "tag \"%s\" value \"%s\" atom \"%.4s\" %d %"PRId64"\n",
-            key, str, (char*)&atom.type, str_size, atom.size);
+            key, str, (char*)&atom.type, str_size_alloc, atom.size);
+
+    av_freep(&str);
 
     return 0;
 }
-- 
1.9.3 (Apple Git-50)