diff --git a/libavformat/ogg.c b/libavformat/ogg.c
index ae2ea965c7..c127ff747c 100644
--- a/libavformat/ogg.c
+++ b/libavformat/ogg.c
@@ -90,7 +90,7 @@ static int ogg_write_header(AVFormatContext *avfcontext)
 
 static int ogg_write_packet(AVFormatContext *avfcontext,
 			    int stream_index,
-			    unsigned char *buf, int size, int force_pts)
+			    const uint8_t *buf, int size, int64_t force_pts)
 {
     OggContext *context = avfcontext->priv_data ;
     ogg_packet *op ;
@@ -110,7 +110,7 @@ static int ogg_write_packet(AVFormatContext *avfcontext,
 
     while(l < size) {
 	op = (ogg_packet*)(buf + l) ;
-	op->packet = buf + l + sizeof(ogg_packet) ; /* fix data pointer */
+	op->packet = (uint8_t*) buf + l + sizeof( ogg_packet) ; /* fix data pointer */
 
 	if(!context->base_packet_no) { /* this is the first packet */
 	    context->base_packet_no = op->packetno ; 
diff --git a/libavformat/utils.c b/libavformat/utils.c
index a593f42d6c..70c9e6e192 100644
--- a/libavformat/utils.c
+++ b/libavformat/utils.c
@@ -294,7 +294,7 @@ int av_open_input_file(AVFormatContext **ic_ptr, const char *filename,
 {
     AVFormatContext *ic = NULL;
     int err, must_open_file;
-    char buf[PROBE_BUF_SIZE];
+    unsigned char buf[PROBE_BUF_SIZE];
     AVProbeData probe_data, *pd = &probe_data;
 
     ic = av_mallocz(sizeof(AVFormatContext));
@@ -1440,8 +1440,8 @@ int get_frame_filename(char *buf, int buf_size,
                        const char *path, int number)
 {
     const char *p;
-    char *q, buf1[20];
-    int nd, len, c, percentd_found;
+    char *q, buf1[20], c;
+    int nd, len, percentd_found;
 
     q = buf;
     p = path;