stream_dvd: better .ifo probing

stream_dvd.c includes a pseudo-protocol that recognizes .IFO files, and
plays them using libdvdread. This was relatively lazy, and could perhaps
easily trigger with files that just had the .ifo extension.

Make the checks stricter, and even probe the file header. Apparently the
first bytes in an .ifo file are always "DVDVIDEO-VTS", so check for
this.

Refuse to load the main "video_ts.ifo". The plan is to use stream_dvdnav
for it.

This also removes at least 1 memory leak.

1 files changed, 29 insertions, 0 deletions

diff --git a/stream/stream_dvd_common.c b/stream/stream_dvd_common.c
index a9a6895384..99e9067621 100644
--- a/stream/stream_dvd_common.c
+++ b/stream/stream_dvd_common.c
@@ -21,6 +21,9 @@
 #include <unistd.h>
 #include <stdio.h>
 #include <string.h>
+#include <strings.h>
+#include <assert.h>
+
 #include <libavutil/intreadwrite.h>
 
 #include "config.h"
@@ -42,6 +45,7 @@
 #include "osdep/io.h"
 
 #include "common/msg.h"
+#include "misc/bstr.h"
 #include "stream_dvd_common.h"
 
 const char * const dvd_audio_stream_types[8] = { "ac3","unknown","mpeg1","mpeg2ext","lpcm","unknown","dts" };
@@ -134,3 +138,28 @@ int mp_dvdtimetomsec(dvd_time_t *dt)
     msec += (((dt->frame_u & 0x30) >> 3) * 5 + (dt->frame_u & 0x0f)) * 100000 / framerate;
   return msec;
 }
+
+// Check if this is likely to be an .ifo or similar file.
+int dvd_probe(const char *path, const char *ext, const char *sig)
+{
+    if (!bstr_case_endswith(bstr0(path), bstr0(ext)))
+        return false;
+
+    FILE *temp = fopen(path, "rb");
+    if (!temp)
+        return false;
+
+    bool r = false;
+
+    char data[50];
+
+    assert(strlen(sig) <= sizeof(data));
+
+    if (fread(data, 50, 1, temp) == 1) {
+        if (memcmp(data, sig, strlen(sig)) == 0)
+            r = true;
+    }
+
+    fclose(temp);
+    return r;
+}