diff --git a/configure b/configure
index eb41868f51..700de7460d 100755
--- a/configure
+++ b/configure
@@ -855,7 +855,7 @@ if test "$sdl" = "no" ; then
 fi
 
 if test "$debug" = "yes"; then
-	CFLAGS="$CFLAGS -g"
+	CFLAGS="-g $CFLAGS"
 fi
 
 if test "$optimize" = "small"; then
@@ -868,7 +868,7 @@ if test "$optimize" = "yes"; then
 	CFLAGS="$CFLAGS -O5"
 	LDFLAGS="$LDFLAGS -O5"
     else
-	CFLAGS="$CFLAGS -O3"
+	CFLAGS="-O3 $CFLAGS"
     fi
 fi
 
diff --git a/ffserver.c b/ffserver.c
index 4fb1fdeebf..20f2b23724 100644
--- a/ffserver.c
+++ b/ffserver.c
@@ -1468,7 +1468,7 @@ static int http_parse_request(HTTPContext *c)
                 if (eol) {
                     if (eol[-1] == '\r')
                         eol--;
-                    http_log("%.*s\n", eol - logline, logline);
+                    http_log("%.*s\n", (int) (eol - logline), logline);
                     c->suppress_log = 1;
                 }
             }
diff --git a/libavcodec/4xm.c b/libavcodec/4xm.c
index 6544d88d0f..304453d6f1 100644
--- a/libavcodec/4xm.c
+++ b/libavcodec/4xm.c
@@ -354,7 +354,7 @@ static int decode_p_frame(FourXContext *f, uint8_t *buf, int length){
     }
     
     if(bitstream_size != (get_bits_count(&f->gb)+31)/32*4)
-        av_log(f->avctx, AV_LOG_ERROR, " %d %d %d bytes left\n", 
+        av_log(f->avctx, AV_LOG_ERROR, " %d %zd %zd bytes left\n", 
             bitstream_size - (get_bits_count(&f->gb)+31)/32*4, 
             bytestream_size - (f->bytestream - (buf + 20 + bitstream_size + wordstream_size)),
             wordstream_size - (((uint8_t*)f->wordstream) - (buf + 20 + bitstream_size))
diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 44a115858d..62743b3ef6 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -1895,6 +1895,7 @@ void avcodec_string(char *buf, int buf_size, AVCodecContext *enc, int encode);
 
 void avcodec_get_context_defaults(AVCodecContext *s);
 AVCodecContext *avcodec_alloc_context(void);
+void avcodec_get_frame_defaults(AVFrame *pic);
 AVFrame *avcodec_alloc_frame(void);
 
 int avcodec_default_get_buffer(AVCodecContext *s, AVFrame *pic);
diff --git a/libavcodec/dv.c b/libavcodec/dv.c
index 6b7ca1d8d2..22d966dd8d 100644
--- a/libavcodec/dv.c
+++ b/libavcodec/dv.c
@@ -113,7 +113,7 @@ static int dvvideo_init(AVCodecContext *avctx)
 	    return -ENOMEM;
 	}
 	for (i=0; i<12*27; i++)
-	    (int)dv_anchor[i] = i;
+	    dv_anchor[i] = (void*)(size_t)i;
 	
         /* NOTE: as a trick, we use the fact the no codes are unused
            to accelerate the parsing of partial codes */
@@ -896,7 +896,7 @@ static inline void dv_encode_video_segment(DVVideoContext *s,
 static int dv_decode_mt(AVCodecContext *avctx, void* sl)
 {
     DVVideoContext *s = avctx->priv_data;
-    int slice = (int)sl;
+    int slice = (size_t)sl;
     dv_decode_video_segment(s, &s->buf[((slice/27)*6+(slice/3)+slice*5+7)*80],
 	                    &s->sys->video_place[slice*5]);
     return 0;
@@ -905,7 +905,7 @@ static int dv_decode_mt(AVCodecContext *avctx, void* sl)
 static int dv_encode_mt(AVCodecContext *avctx, void* sl)
 {
     DVVideoContext *s = avctx->priv_data;
-    int slice = (int)sl;
+    int slice = (size_t)sl;
     dv_encode_video_segment(s, &s->buf[((slice/27)*6+(slice/3)+slice*5+7)*80],
 	                    &s->sys->video_place[slice*5]);
     return 0;
diff --git a/libavcodec/flac.c b/libavcodec/flac.c
index 5f87cff922..38e09363ab 100644
--- a/libavcodec/flac.c
+++ b/libavcodec/flac.c
@@ -753,7 +753,6 @@ static int flac_decode_close(AVCodecContext *avctx)
 }
 
 static void flac_flush(AVCodecContext *avctx){
-    int i;
     FLACContext *s = avctx->priv_data;
 
     s->bitstream_size=
diff --git a/libavcodec/interplayvideo.c b/libavcodec/interplayvideo.c
index 06816ba3e9..48410f0364 100644
--- a/libavcodec/interplayvideo.c
+++ b/libavcodec/interplayvideo.c
@@ -846,7 +846,7 @@ static void ipvideo_decode_opcodes(IpvideoContext *s)
     }
     if ((s->stream_ptr != s->stream_end) &&
         (s->stream_ptr + 1 != s->stream_end)) {
-        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %d bytes left over\n",
+        av_log(s->avctx, AV_LOG_ERROR, " Interplay video: decode finished with %zd bytes left over\n",
             s->stream_end - s->stream_ptr);
     }
 }
diff --git a/libavcodec/motion_est.c b/libavcodec/motion_est.c
index 5132487cf3..f52f6e150d 100644
--- a/libavcodec/motion_est.c
+++ b/libavcodec/motion_est.c
@@ -774,10 +774,6 @@ static inline int h263_mv4_search(MpegEncContext *s, int mx, int my, int shift)
     int same=1;
     const int stride= s->linesize;
     const int uvstride= s->uvlinesize;
-    const int xmin= s->me.xmin;
-    const int ymin= s->me.ymin;
-    const int xmax= s->me.xmax;
-    const int ymax= s->me.ymax;
 
     for(block=0; block<4; block++){
         int mx4, my4;
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 4d2943a6cd..e4f5f26825 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -242,7 +242,7 @@ static void mpeg1_encode_sequence_header(MpegEncContext *s)
 {
         unsigned int vbv_buffer_size;
         unsigned int fps, v;
-        int n, i;
+        int i;
         uint64_t time_code;
         float best_aspect_error= 1E10;
         float aspect_ratio= av_q2d(s->avctx->sample_aspect_ratio);
@@ -954,7 +954,7 @@ static VLC mb_ptype_vlc;
 static VLC mb_btype_vlc;
 static VLC mb_pat_vlc;
 
-static void init_vlcs()
+static void init_vlcs(void)
 {
     static int done = 0;
 
@@ -2821,7 +2821,7 @@ static int mpeg_decode_frame(AVCodecContext *avctx,
         input_size = buf_end - buf_ptr;
 
         if(avctx->debug & FF_DEBUG_STARTCODE){
-            av_log(avctx, AV_LOG_DEBUG, "%3X at %d left %d\n", start_code, buf_ptr-buf, input_size);
+            av_log(avctx, AV_LOG_DEBUG, "%3X at %zd left %d\n", start_code, buf_ptr-buf, input_size);
         }
 
                 /* prepare data for next start code */
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 28b20c319b..a786f8ab75 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -3382,7 +3382,6 @@ static void encode_mb(MpegEncContext *s, int motion_x, int motion_y)
     int dct_offset   = s->linesize*8; //default for progressive frames
     uint8_t *ptr_y, *ptr_cb, *ptr_cr;
     int wrap_y, wrap_c;
-    int emu=0;
     
     for(i=0; i<6; i++) skip_dct[i]=0;
     
@@ -4580,7 +4579,6 @@ static void merge_context_after_encode(MpegEncContext *dst, MpegEncContext *src)
 
 static void encode_picture(MpegEncContext *s, int picture_number)
 {
-    int mb_x, mb_y;
     int i, j;
     int bits;
 
@@ -5141,7 +5139,6 @@ static int dct_quantize_refine(MpegEncContext *s, //FIXME breaks denoise?
     int prev_run=0;
     int prev_level=0;
     int qmul, qadd, start_i, last_non_zero, i, dc;
-    const int esc_length= s->ac_esc_length;
     uint8_t * length;
     uint8_t * last_length;
     int lambda;
@@ -5249,7 +5246,6 @@ STOP_TIMER("init rem[]")
 #endif
     for(;;){
         int best_score=s->dsp.try_8x8basis(rem, weight, basis[0], 0);
-        int nochange_score= best_score;
         int best_coeff=0;
         int best_change=0;
         int run2, best_unquant_change, analyze_gradient;
diff --git a/libavformat/file.c b/libavformat/file.c
index 83f2e42ae1..00837c8fbb 100644
--- a/libavformat/file.c
+++ b/libavformat/file.c
@@ -50,26 +50,26 @@ static int file_open(URLContext *h, const char *filename, int flags)
     fd = open(filename, access, 0666);
     if (fd < 0)
         return -ENOENT;
-    h->priv_data = (void *)fd;
+    h->priv_data = (void *)(size_t)fd;
     return 0;
 }
 
 static int file_read(URLContext *h, unsigned char *buf, int size)
 {
-    int fd = (int)h->priv_data;
+    int fd = (size_t)h->priv_data;
     return read(fd, buf, size);
 }
 
 static int file_write(URLContext *h, unsigned char *buf, int size)
 {
-    int fd = (int)h->priv_data;
+    int fd = (size_t)h->priv_data;
     return write(fd, buf, size);
 }
 
 /* XXX: use llseek */
 static offset_t file_seek(URLContext *h, offset_t pos, int whence)
 {
-    int fd = (int)h->priv_data;
+    int fd = (size_t)h->priv_data;
 #ifdef CONFIG_WIN32
     return _lseeki64(fd, pos, whence);
 #else
@@ -79,7 +79,7 @@ static offset_t file_seek(URLContext *h, offset_t pos, int whence)
 
 static int file_close(URLContext *h)
 {
-    int fd = (int)h->priv_data;
+    int fd = (size_t)h->priv_data;
     return close(fd);
 }
 
@@ -106,19 +106,19 @@ static int pipe_open(URLContext *h, const char *filename, int flags)
 #if defined(CONFIG_WIN32) || defined(CONFIG_OS2) || defined(__CYGWIN__)
     setmode(fd, O_BINARY);
 #endif
-    h->priv_data = (void *)fd;
+    h->priv_data = (void *)(size_t)fd;
     return 0;
 }
 
 static int pipe_read(URLContext *h, unsigned char *buf, int size)
 {
-    int fd = (int)h->priv_data;
+    int fd = (size_t)h->priv_data;
     return read(fd, buf, size);
 }
 
 static int pipe_write(URLContext *h, unsigned char *buf, int size)
 {
-    int fd = (int)h->priv_data;
+    int fd = (size_t)h->priv_data;
     return write(fd, buf, size);
 }
 
diff --git a/libavformat/framehook.h b/libavformat/framehook.h
index 61b65e489a..ed24c66bae 100644
--- a/libavformat/framehook.h
+++ b/libavformat/framehook.h
@@ -24,6 +24,6 @@ extern FrameHookRelease Release;
 
 extern int frame_hook_add(int argc, char *argv[]);
 extern void frame_hook_process(struct AVPicture *pict, enum PixelFormat pix_fmt, int width, int height);
-extern void frame_hook_release();
+extern void frame_hook_release(void);
 
 #endif
diff --git a/libavformat/matroska.c b/libavformat/matroska.c
index f8942aee4b..d36eb0c9cc 100644
--- a/libavformat/matroska.c
+++ b/libavformat/matroska.c
@@ -927,7 +927,7 @@ ebml_read_header (MatroskaDemuxContext *matroska,
                     return res;
                 if (num > sizeof(uint32_t)) {
                     av_log(matroska->ctx, AV_LOG_ERROR,
-                           "IDs of size %llu (> %d) not supported\n",
+                           "IDs of size %llu (> %zu) not supported\n",
 			    num, sizeof(uint32_t));
                     return AVERROR_INVALIDDATA;
                 }
diff --git a/libavformat/movenc.c b/libavformat/movenc.c
index b46ea5cf74..86d65b9c39 100644
--- a/libavformat/movenc.c
+++ b/libavformat/movenc.c
@@ -917,7 +917,7 @@ static int mov_write_header(AVFormatContext *s)
     return 0;
 }
 
-static int Timestamp() {
+static int Timestamp(void) {
     return 1067949799U+(24107*86400); //its the modification time of this line :)
 }
 
diff --git a/libavformat/mpeg.c b/libavformat/mpeg.c
index a5cd8dfae1..092790c69a 100644
--- a/libavformat/mpeg.c
+++ b/libavformat/mpeg.c
@@ -82,10 +82,10 @@ typedef struct {
 static const int lpcm_freq_tab[4] = { 48000, 96000, 44100, 32000 };
 
 #ifdef CONFIG_ENCODERS
-extern AVOutputFormat mpeg1system_mux;
-extern AVOutputFormat mpeg1vcd_mux;
-extern AVOutputFormat mpeg2vob_mux;
-extern AVOutputFormat mpeg2svcd_mux;
+static AVOutputFormat mpeg1system_mux;
+static AVOutputFormat mpeg1vcd_mux;
+static AVOutputFormat mpeg2vob_mux;
+static AVOutputFormat mpeg2svcd_mux;
 
 static int put_pack_header(AVFormatContext *ctx, 
                            uint8_t *buf, int64_t timestamp)