cleanup / messup?

fixes 20% speedloss bug
removes redundant variables from MpegEncContext
release buffers in avcodec_flush_buffers() (untested)

Originally committed as revision 1325 to svn://svn.ffmpeg.org/ffmpeg/trunk

7 files changed, 251 insertions, 134 deletions

diff --git a/libavcodec/avcodec.h b/libavcodec/avcodec.h
index 0dd560e36c..d02c3e7211 100644
--- a/libavcodec/avcodec.h
+++ b/libavcodec/avcodec.h
@@ -5,8 +5,8 @@
 
 #define LIBAVCODEC_VERSION_INT 0x000406
 #define LIBAVCODEC_VERSION     "0.4.6"
-#define LIBAVCODEC_BUILD       4643
-#define LIBAVCODEC_BUILD_STR   "4643"
+#define LIBAVCODEC_BUILD       4644
+#define LIBAVCODEC_BUILD_STR   "4644"
 
 enum CodecID {
     CODEC_ID_NONE, 
@@ -119,7 +119,7 @@ static const int Motion_Est_QTab[] = { ME_ZERO, ME_PHODS, ME_LOG,
                                        ME_X1, ME_EPZS, ME_FULL };
 
 
-#define FF_MAX_B_FRAMES 4
+#define FF_MAX_B_FRAMES 8
 
 /* encoding support
    these flags can be passed in AVCodecContext.flags before initing 
@@ -260,6 +260,19 @@ static const int Motion_Est_QTab[] = { ME_ZERO, ME_PHODS, ME_LOG,
      * decoding: unused\
      */\
     uint64_t error[4];\
+\
+    /**\
+     * type of the buffer (to keep track of who has to dealloc data[*])\
+     * encoding: set by the one who allocs it\
+     * decoding: set by the one who allocs it\
+     * Note: user allocated (direct rendering) & internal buffers can not coexist currently\ 
+     */\
+    int type;\
+
+#define FF_BUFFER_TYPE_INTERNAL 1
+#define FF_BUFFER_TYPE_USER     2 // Direct rendering buffers
+#define FF_BUFFER_TYPE_SHARED   4 // input frame for encoding(wont be dealloced)
+
 
 #define FF_I_TYPE 1 // Intra
 #define FF_P_TYPE 2 // Predicted
diff --git a/libavcodec/h263dec.c b/libavcodec/h263dec.c
index 2ac68060f9..cf90a95714 100644
--- a/libavcodec/h263dec.c
+++ b/libavcodec/h263dec.c
@@ -55,6 +55,7 @@ static int h263_decode_init(AVCodecContext *avctx)
     s->quant_precision=5;
     s->progressive_sequence=1;
     s->decode_mb= ff_h263_decode_mb;
+    s->low_delay= 1;
 
     /* select sub codec */
     switch(avctx->codec->id) {
@@ -64,7 +65,7 @@ static int h263_decode_init(AVCodecContext *avctx)
     case CODEC_ID_MPEG4:
         s->time_increment_bits = 4; /* default value for broken headers */
         s->h263_pred = 1;
-        s->has_b_frames = 1; //default, might be overriden in the vol header during header parsing
+        s->low_delay = 0; //default, might be overriden in the vol header during header parsing
         break;
     case CODEC_ID_MSMPEG4V1:
         s->h263_msmpeg4 = 1;
@@ -430,14 +431,12 @@ retry:
 
         if(s->flags& CODEC_FLAG_LOW_DELAY)
             s->low_delay=1;
-
-        s->has_b_frames= !s->low_delay;
     } else if (s->h263_intel) {
         ret = intel_h263_decode_picture_header(s);
     } else {
         ret = h263_decode_picture_header(s);
     }
-    avctx->has_b_frames= s->has_b_frames;
+    avctx->has_b_frames= !s->low_delay;
 
     if(s->workaround_bugs&FF_BUG_AUTODETECT){
         if(s->avctx->fourcc == ff_get_fourcc("XVIX")) 
@@ -531,7 +530,7 @@ retry:
     s->current_picture.key_frame= s->pict_type == I_TYPE;
 
     /* skip b frames if we dont have reference frames */
-    if(s->num_available_buffers<2 && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
+    if(s->last_picture.data[0]==NULL && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
     /* skip b frames if we are in a hurry */
     if(avctx->hurry_up && s->pict_type==B_TYPE) return get_consumed_bytes(s, buf_size);
     /* skip everything if we are in a hurry>=5 */
@@ -676,7 +675,7 @@ retry:
 
 }
 #endif
-    if(s->pict_type==B_TYPE || (!s->has_b_frames)){
+    if(s->pict_type==B_TYPE || s->low_delay){
         *pict= *(AVVideoFrame*)&s->current_picture;
     } else {
         *pict= *(AVVideoFrame*)&s->last_picture;
@@ -686,9 +685,8 @@ retry:
     /* we substract 1 because it is added on utils.c    */
     avctx->frame_number = s->picture_number - 1;
 
-    /* dont output the last pic after seeking 
-       note we allready added +1 for the current pix in MPV_frame_end(s) */
-    if(s->num_available_buffers>=2 || (!s->has_b_frames))
+    /* dont output the last pic after seeking */
+    if(s->last_picture.data[0] || s->low_delay)
         *data_size = sizeof(AVVideoFrame);
 #ifdef PRINT_FRAME_TIME
 printf("%Ld\n", rdtsc()-time);
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 5058d1d5f5..22c701340c 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -1702,7 +1702,7 @@ eos: //end of slice
 
         MPV_frame_end(s);
 
-        if (s->pict_type == B_TYPE) {
+        if (s->pict_type == B_TYPE || s->low_delay) {
             *pict= *(AVVideoFrame*)&s->current_picture;
         } else {
             s->picture_number++;
@@ -1756,7 +1756,7 @@ static int mpeg1_decode_sequence(AVCodecContext *avctx,
         }
         s->width = width;
         s->height = height;
-        avctx->has_b_frames= s->has_b_frames = 1;
+        avctx->has_b_frames= 1;
         s->avctx = avctx;
         avctx->width = width;
         avctx->height = height;
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 63338012ff..f947634c2c 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -268,40 +268,87 @@ int DCT_common_init(MpegEncContext *s)
 }
 
 /**
- * allocates various arrays for a Picture structure, except the pixels themself.
- * The pixels are allocated/set in te get_buffer()
+ * allocates a Picture
+ * The pixels are allocated/set by calling get_buffer() if shared=0
  */
-static int alloc_picture(MpegEncContext *s, Picture *pic){
-    if (s->encoding) {        
-        CHECKED_ALLOCZ(pic->mb_var   , s->mb_num * sizeof(INT16))
-        CHECKED_ALLOCZ(pic->mc_mb_var, s->mb_num * sizeof(INT16))
-        CHECKED_ALLOCZ(pic->mb_mean  , s->mb_num * sizeof(INT8))
+static int alloc_picture(MpegEncContext *s, Picture *pic, int shared){
+    
+    if(shared){
+        assert(pic->data[0]);
+        assert(pic->type == 0 || pic->type == FF_BUFFER_TYPE_SHARED);
+        pic->type= FF_BUFFER_TYPE_SHARED;
+    }else{
+        int r;
+        
+        assert(!pic->data[0]);
+        
+        r= s->avctx->get_buffer(s->avctx, (AVVideoFrame*)pic);
+        
+        if(r<0 || !pic->age || !pic->type || !pic->data[0]){
+            fprintf(stderr, "get_buffer() failed (%d %d %d %X)\n", r, pic->age, pic->type, (int)pic->data[0]);
+            return -1;
+        }
+
+        if(s->linesize && (s->linesize != pic->linesize[0] || s->uvlinesize != pic->linesize[1])){
+            fprintf(stderr, "get_buffer() failed (stride changed)\n");
+            return -1;
+        }
+
+        if(pic->linesize[1] != pic->linesize[2]){
+            fprintf(stderr, "get_buffer() failed (uv stride missmatch)\n");
+            return -1;
+        }
+
+        s->linesize  = pic->linesize[0];
+        s->uvlinesize= pic->linesize[1];
     }
+    
+    if(pic->qscale_table==NULL){
+        if (s->encoding) {        
+            CHECKED_ALLOCZ(pic->mb_var   , s->mb_num * sizeof(INT16))
+            CHECKED_ALLOCZ(pic->mc_mb_var, s->mb_num * sizeof(INT16))
+            CHECKED_ALLOCZ(pic->mb_mean  , s->mb_num * sizeof(INT8))
+        }
 
-    CHECKED_ALLOCZ(pic->mbskip_table , s->mb_num * sizeof(UINT8)+1) //the +1 is for the slice end check
-    CHECKED_ALLOCZ(pic->qscale_table , s->mb_num * sizeof(UINT8))
-    pic->qstride= s->mb_width;
+        CHECKED_ALLOCZ(pic->mbskip_table , s->mb_num * sizeof(UINT8)+1) //the +1 is for the slice end check
+        CHECKED_ALLOCZ(pic->qscale_table , s->mb_num * sizeof(UINT8))
+        pic->qstride= s->mb_width;
+    }
     
     return 0;
 fail: //for the CHECKED_ALLOCZ macro
     return -1;
 }
 
+/**
+ * deallocates a picture
+ */
 static void free_picture(MpegEncContext *s, Picture *pic){
     int i;
-    
+
+    if(pic->data[0] && pic->type!=FF_BUFFER_TYPE_SHARED){
+        s->avctx->release_buffer(s->avctx, (AVVideoFrame*)pic);
+    }
+
     av_freep(&pic->mb_var);
     av_freep(&pic->mc_mb_var);
     av_freep(&pic->mb_mean);
     av_freep(&pic->mbskip_table);
     av_freep(&pic->qscale_table);
     
-    if(s->avctx->get_buffer == avcodec_default_get_buffer){
+    if(pic->type == FF_BUFFER_TYPE_INTERNAL){
         for(i=0; i<4; i++){
             av_freep(&pic->base[i]);
             pic->data[i]= NULL;
         }
         av_freep(&pic->opaque);
+        pic->type= 0;
+    }else if(pic->type == FF_BUFFER_TYPE_SHARED){
+        for(i=0; i<4; i++){
+            pic->base[i]=
+            pic->data[i]= NULL;
+        }
+        pic->type= 0;        
     }
 }
 
@@ -445,12 +492,6 @@ void MPV_common_end(MpegEncContext *s)
 {
     int i;
 
-    for(i=0; i<MAX_PICTURE_COUNT; i++){
-        if(s->picture[i].data[0]){
-            s->avctx->release_buffer(s->avctx, (AVVideoFrame*)&s->picture[i]);
-        }
-    }
-    
     av_freep(&s->mb_type);
     av_freep(&s->p_mv_table);
     av_freep(&s->b_forw_mv_table);
@@ -572,6 +613,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         if (mjpeg_init(s) < 0)
             return -1;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_H263:
         if (h263_get_picture_format(s->width, s->height) == 7) {
@@ -580,6 +622,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         }
         s->out_format = FMT_H263;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_H263P:
         s->out_format = FMT_H263;
@@ -591,18 +634,19 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->umvplus = 0;
         s->umvplus_dec = 0;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_RV10:
         s->out_format = FMT_H263;
         s->h263_rv10 = 1;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_MPEG4:
         s->out_format = FMT_H263;
         s->h263_pred = 1;
         s->unrestricted_mv = 1;
-        s->has_b_frames= s->max_b_frames ? 1 : 0;
-        s->low_delay= !s->has_b_frames;
+        s->low_delay= s->max_b_frames ? 0 : 1;
         avctx->delay= s->low_delay ? 0 : (s->max_b_frames + 1);
         break;
     case CODEC_ID_MSMPEG4V1:
@@ -612,6 +656,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->unrestricted_mv = 1;
         s->msmpeg4_version= 1;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_MSMPEG4V2:
         s->out_format = FMT_H263;
@@ -620,6 +665,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->unrestricted_mv = 1;
         s->msmpeg4_version= 2;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_MSMPEG4V3:
         s->out_format = FMT_H263;
@@ -628,6 +674,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->unrestricted_mv = 1;
         s->msmpeg4_version= 3;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_WMV1:
         s->out_format = FMT_H263;
@@ -636,6 +683,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->unrestricted_mv = 1;
         s->msmpeg4_version= 4;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     case CODEC_ID_WMV2:
         s->out_format = FMT_H263;
@@ -644,6 +692,7 @@ int MPV_encode_init(AVCodecContext *avctx)
         s->unrestricted_mv = 1;
         s->msmpeg4_version= 5;
         avctx->delay=0;
+        s->low_delay=1;
         break;
     default:
         return -1;
@@ -770,10 +819,30 @@ static void draw_edges_c(UINT8 *buf, int wrap, int width, int height, int w)
     }
 }
 
+static int find_unused_picture(MpegEncContext *s, int shared){
+    int i;
+    
+    if(shared){
+        for(i=0; i<MAX_PICTURE_COUNT; i++){
+            if(s->picture[i].data[0]==NULL && s->picture[i].type==0) break;
+        }
+    }else{
+        for(i=0; i<MAX_PICTURE_COUNT; i++){
+            if(s->picture[i].data[0]==NULL && s->picture[i].type!=0) break;
+        }
+        for(i=0; i<MAX_PICTURE_COUNT; i++){
+            if(s->picture[i].data[0]==NULL) break;
+        }
+    }
+
+    assert(i<MAX_PICTURE_COUNT);
+    return i;
+}
+
 /* generic function for encode/decode called before a frame is coded/decoded */
 int MPV_frame_start(MpegEncContext *s, AVCodecContext *avctx)
 {
-    int i, r;
+    int i;
     AVVideoFrame *pic;
 
     s->mb_skiped = 0;
@@ -781,6 +850,7 @@ int MPV_frame_start(MpegEncContext *s, AVCodecContext *avctx)
     /* mark&release old frames */
     if (s->pict_type != B_TYPE && s->last_picture.data[0]) {
         for(i=0; i<MAX_PICTURE_COUNT; i++){
+//printf("%8X %d %d %X %X\n", s->picture[i].data[0], s->picture[i].type, i, s->next_picture.data[0], s->last_picture.data[0]);
             if(s->picture[i].data[0] == s->last_picture.data[0]){
 //                s->picture[i].reference=0;
                 avctx->release_buffer(avctx, (AVVideoFrame*)&s->picture[i]);
@@ -802,28 +872,13 @@ int MPV_frame_start(MpegEncContext *s, AVCodecContext *avctx)
     }
 alloc:
     if(!s->encoding){
-        /* find unused Picture */
-        for(i=0; i<MAX_PICTURE_COUNT; i++){
-            if(s->picture[i].data[0]==NULL) break;
-        }
-        assert(i<MAX_PICTURE_COUNT);
+        i= find_unused_picture(s, 0);
     
         pic= (AVVideoFrame*)&s->picture[i];
         pic->reference= s->pict_type != B_TYPE;
         pic->coded_picture_number= s->current_picture.coded_picture_number+1;
         
-        r= avctx->get_buffer(avctx, pic);
-    
-        if(r<0 || (s->linesize && (s->linesize != pic->linesize[0] || s->uvlinesize != pic->linesize[1]))){
-            fprintf(stderr, "get_buffer() failed (stride changed), bye bye\n");
-            return -1;
-        }
-
-        s->linesize  = pic->linesize[0];
-        s->uvlinesize= pic->linesize[1];
-    
-        if(pic->qscale_table==NULL)
-            alloc_picture(s, (Picture*)pic);
+        alloc_picture(s, (Picture*)pic, 0);
 
         s->current_picture= s->picture[i];
     }
@@ -873,8 +928,6 @@ void MPV_frame_end(MpegEncContext *s)
     s->last_pict_type    = s->pict_type;
     if(s->pict_type!=B_TYPE){
         s->last_non_b_pict_type= s->pict_type;
-        s->num_available_buffers++;
-        if(s->num_available_buffers>2) s->num_available_buffers= 2;
     }
     
     s->current_picture.quality= s->qscale; //FIXME get average of qscale_table
@@ -892,7 +945,7 @@ void MPV_frame_end(MpegEncContext *s)
 
     /* release non refernce frames */
     for(i=0; i<MAX_PICTURE_COUNT; i++){
-        if(s->picture[i].data[0] && !s->picture[i].reference)
+        if(s->picture[i].data[0] && !s->picture[i].reference /*&& s->picture[i].type!=FF_BUFFER_TYPE_SHARED*/)
             s->avctx->release_buffer(s->avctx, (AVVideoFrame*)&s->picture[i]);
     }
 }
@@ -930,81 +983,81 @@ static int get_intra_count(MpegEncContext *s, uint8_t *src, uint8_t *ref, int st
     return acc;
 }
 
+
 static int load_input_picture(MpegEncContext *s, AVVideoFrame *pic_arg){
     AVVideoFrame *pic;
-    int i,r;
+    int i;
     const int encoding_delay= s->max_b_frames;
+    int direct=1;
 
-    /* find unused Picture */
-    for(i=0; i<MAX_PICTURE_COUNT; i++){
-        if(s->picture[i].data[0]==NULL) break;
-    }
-    assert(i<MAX_PICTURE_COUNT);
-        
-    pic= (AVVideoFrame*)&s->picture[i];
-    pic->reference= 1;
+    if(encoding_delay && !(s->flags&CODEC_FLAG_INPUT_PRESERVED)) direct=0;
+    if(pic_arg->linesize[0] != s->linesize) direct=0;
+    if(pic_arg->linesize[1] != s->uvlinesize) direct=0;
+    if(pic_arg->linesize[2] != s->uvlinesize) direct=0;
+  
+//    printf("%d %d %d %d\n",pic_arg->linesize[0], pic_arg->linesize[1], s->linesize, s->uvlinesize);
     
-//    assert(avctx->get_buffer == default_get_buffer || avctx->get_buffer==NULL);
-    r= s->avctx->get_buffer(s->avctx, pic);
+    if(direct){
+        i= find_unused_picture(s, 1);
 
-    if(r<0 || (s->linesize && (s->linesize != pic->linesize[0] || s->uvlinesize != pic->linesize[1]))){
-        fprintf(stderr, "get_buffer() failed (stride changed), bye bye\n");
-        return -1;
-    }
-    
-    assert(s->linesize==0   || s->linesize  ==pic->linesize[0]);
-    assert(s->uvlinesize==0 || s->uvlinesize==pic->linesize[1]);
-    assert(pic->linesize[1] == pic->linesize[2]);
-    s->linesize  = pic->linesize[0];
-    s->uvlinesize= pic->linesize[1];
+        pic= (AVVideoFrame*)&s->picture[i];
+        pic->reference= 1;
     
-    if(pic->qscale_table==NULL)
-        alloc_picture(s, (Picture*)pic);
+        for(i=0; i<4; i++){
+            pic->data[i]= pic_arg->data[i];
+            pic->linesize[i]= pic_arg->linesize[i];
+        }
+        alloc_picture(s, (Picture*)pic, 1);
+    }else{
+        i= find_unused_picture(s, 0);
 
-//    assert(s->input_picture[0]==NULL || s->input_picture[0]->data[0]==NULL);
-    
-    if(s->input_picture[encoding_delay])
-        pic->display_picture_number= s->input_picture[encoding_delay]->display_picture_number + 1;
-//printf("dpn2:%d\n", pic->display_picture_number);
+        pic= (AVVideoFrame*)&s->picture[i];
+        pic->reference= 1;
 
-    /* shift buffer entries */
-    for(i=1; i<MAX_PICTURE_COUNT /*s->encoding_delay+1*/; i++)
-        s->input_picture[i-1]= s->input_picture[i];
-        
-    s->input_picture[encoding_delay]= (Picture*)pic;
-    pic->pict_type= pic_arg->pict_type;
-    pic->quality= pic_arg->quality;
-    
-    if(   pic->data[0] == pic_arg->data[0] 
-       && pic->data[1] == pic_arg->data[1]
-       && pic->data[2] == pic_arg->data[2]){
+        alloc_picture(s, (Picture*)pic, 0);
+
+        if(   pic->data[0] == pic_arg->data[0] 
+           && pic->data[1] == pic_arg->data[1]
+           && pic->data[2] == pic_arg->data[2]){
        // empty
-    }else{
-        int h_chroma_shift, v_chroma_shift;
+        }else{
+            int h_chroma_shift, v_chroma_shift;
         
-        avcodec_get_chroma_sub_sample(s->avctx->pix_fmt, &h_chroma_shift, &v_chroma_shift);
+            avcodec_get_chroma_sub_sample(s->avctx->pix_fmt, &h_chroma_shift, &v_chroma_shift);
         
-        for(i=0; i<3; i++){
-            int src_stride= pic_arg->linesize[i];
-            int dst_stride= i ? s->uvlinesize : s->linesize;
-            int h_shift= i ? h_chroma_shift : 0;
-            int v_shift= i ? v_chroma_shift : 0;
-            int w= s->width >>h_shift;
-            int h= s->height>>v_shift;
-            uint8_t *src= pic_arg->data[i];
-            uint8_t *dst= pic->data[i] + 16;
+            for(i=0; i<3; i++){
+                int src_stride= pic_arg->linesize[i];
+                int dst_stride= i ? s->uvlinesize : s->linesize;
+                int h_shift= i ? h_chroma_shift : 0;
+                int v_shift= i ? v_chroma_shift : 0;
+                int w= s->width >>h_shift;
+                int h= s->height>>v_shift;
+                uint8_t *src= pic_arg->data[i];
+                uint8_t *dst= pic->data[i];
             
-            if(src_stride==dst_stride)
-                memcpy(dst, src, src_stride*h);
-            else{
-                while(h--){
-                    memcpy(dst, src, w);
-                    dst += dst_stride;
-                    src += src_stride;
+                if(src_stride==dst_stride)
+                    memcpy(dst, src, src_stride*h);
+                else{
+                    while(h--){
+                        memcpy(dst, src, w);
+                        dst += dst_stride;
+                        src += src_stride;
+                    }
                 }
             }
         }
     }
+    pic->quality= pic_arg->quality;
+    pic->pict_type= pic_arg->pict_type;
+    
+    if(s->input_picture[encoding_delay])
+        pic->display_picture_number= s->input_picture[encoding_delay]->display_picture_number + 1;
+
+    /* shift buffer entries */
+    for(i=1; i<MAX_PICTURE_COUNT /*s->encoding_delay+1*/; i++)
+        s->input_picture[i-1]= s->input_picture[i];
+        
+    s->input_picture[encoding_delay]= (Picture*)pic;
 
     return 0;
 }
@@ -1016,7 +1069,7 @@ static void select_input_picture(MpegEncContext *s){
 
     if(s->reordered_input_picture[0])
         coded_pic_num= s->reordered_input_picture[0]->coded_picture_number + 1;
-//printf("cpn:%d\n", coded_pic_num);
+
     for(i=1; i<MAX_PICTURE_COUNT; i++)
         s->reordered_input_picture[i-1]= s->reordered_input_picture[i];
     s->reordered_input_picture[MAX_PICTURE_COUNT-1]= NULL;
@@ -1039,7 +1092,7 @@ static void select_input_picture(MpegEncContext *s){
                     if(i + 1 >= s->rc_context.num_entries) break;
                 }
             }
-        
+
             if(s->input_picture[0]->pict_type){
                 /* user selected pict_type */
                 for(b_frames=0; b_frames<s->max_b_frames+1; b_frames++){
@@ -1056,8 +1109,8 @@ static void select_input_picture(MpegEncContext *s){
                 for(i=1; i<s->max_b_frames+1; i++){
                     if(s->input_picture[i]->b_frame_score==0){
                         s->input_picture[i]->b_frame_score= 
-                            get_intra_count(s, s->input_picture[i  ]->data[0] + 16, 
-                                               s->input_picture[i-1]->data[0] + 16, s->linesize) + 1;
+                            get_intra_count(s, s->input_picture[i  ]->data[0], 
+                                               s->input_picture[i-1]->data[0], s->linesize) + 1;
                     }
                 }
                 for(i=0; i<s->max_b_frames; i++){
@@ -1097,14 +1150,38 @@ static void select_input_picture(MpegEncContext *s){
     }
     
     if(s->reordered_input_picture[0]){
-        if(s->reordered_input_picture[0]->pict_type==B_TYPE){
-            s->reordered_input_picture[0]->reference=0;
+       s->reordered_input_picture[0]->reference= s->reordered_input_picture[0]->pict_type!=B_TYPE;
+
+        if(s->reordered_input_picture[0]->type == FF_BUFFER_TYPE_SHARED){
+            int i= find_unused_picture(s, 0);
+            Picture *pic= &s->picture[i];
+
+            s->new_picture= *s->reordered_input_picture[0];
+
+            /* mark us unused / free shared pic */
+            for(i=0; i<4; i++)
+                s->reordered_input_picture[0]->data[i]= NULL;
+            s->reordered_input_picture[0]->type= 0;
+            
+            pic->pict_type = s->reordered_input_picture[0]->pict_type;
+            pic->quality   = s->reordered_input_picture[0]->quality;
+            pic->coded_picture_number = s->reordered_input_picture[0]->coded_picture_number;
+            pic->reference = s->reordered_input_picture[0]->reference;
+            
+            alloc_picture(s, pic, 0);
+
+            s->current_picture= *pic;
+        }else{
+            assert(   s->reordered_input_picture[0]->type==FF_BUFFER_TYPE_USER 
+                   || s->reordered_input_picture[0]->type==FF_BUFFER_TYPE_INTERNAL);
+            
+            s->new_picture= *s->reordered_input_picture[0];
+
+            for(i=0; i<4; i++){
+                s->reordered_input_picture[0]->data[i]-=16; //FIXME dirty
+            }
+            s->current_picture= *s->reordered_input_picture[0];
         }
-        s->current_picture= *s->reordered_input_picture[0];
-        s->new_picture= s->current_picture;
-        s->new_picture.data[0]+=16;
-        s->new_picture.data[1]+=16;
-        s->new_picture.data[2]+=16;
     
         s->picture_number= s->new_picture.display_picture_number;
 //printf("dpn:%d\n", s->picture_number);
@@ -2231,7 +2308,7 @@ static int pix_diff_vcmp16x8(UINT8 *s1, UINT8*s2, int stride){ //FIXME move to d
 
 void ff_draw_horiz_band(MpegEncContext *s){
     if (    s->avctx->draw_horiz_band 
-        && (s->num_available_buffers>=1 || (!s->has_b_frames)) ) {
+        && (s->last_picture.data[0] || s->low_delay) ) {
         UINT8 *src_ptr[3];
         int y, h, offset;
         y = s->mb_y * 16;
@@ -2244,7 +2321,7 @@ void ff_draw_horiz_band(MpegEncContext *s){
         else
             offset = y * s->linesize;
 
-        if(s->pict_type==B_TYPE || (!s->has_b_frames)){
+        if(s->pict_type==B_TYPE || s->low_delay){
             src_ptr[0] = s->current_picture.data[0] + offset;
             src_ptr[1] = s->current_picture.data[1] + (offset >> 2);
             src_ptr[2] = s->current_picture.data[2] + (offset >> 2);
diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
index fad4f8eaf1..fe5abff083 100644
--- a/libavcodec/mpegvideo.h
+++ b/libavcodec/mpegvideo.h
@@ -185,7 +185,6 @@ typedef struct MpegEncContext {
     Picture next_picture;       /* previous picture (for bidir pred) */
     Picture new_picture;        /* source picture for encoding */
     Picture current_picture;    /* buffer to store the decompressed current picture */
-    int num_available_buffers;   /* is 0 at the start & after seeking, after the first I frame its 1 after next I/P 2 */
     int last_dc[3];              /* last DC values for MPEG1 */
     INT16 *dc_val[3];            /* used for mpeg4 DC prediction, all 3 arrays must be continuous */
     int y_dc_scale, c_dc_scale;
@@ -254,7 +253,6 @@ typedef struct MpegEncContext {
     UINT16 (*mv_penalty)[MAX_MV*2+1]; /* amount of bits needed to encode a MV, used for ME */
     UINT8 *fcode_tab; /* smallest fcode needed for each MV */
 
-    int has_b_frames;
     int no_rounding; /* apply no rounding to motion compensation (MPEG4, msmpeg4, ...) 
                         for b-frames rounding mode is allways 0 */
 
diff --git a/libavcodec/svq1.c b/libavcodec/svq1.c
index 86ebd73825..929dece2ae 100644
--- a/libavcodec/svq1.c
+++ b/libavcodec/svq1.c
@@ -1179,7 +1179,7 @@ static int svq1_decode_init(AVCodecContext *avctx)
     s->height = (avctx->height+3)&~3;
     s->codec_id= avctx->codec->id;
     avctx->pix_fmt = PIX_FMT_YUV410P;
-    avctx->has_b_frames= s->has_b_frames=1; // not true, but DP frames and these behave like unidirectional b frames
+    avctx->has_b_frames= 1; // not true, but DP frames and these behave like unidirectional b frames
     s->flags= avctx->flags;
     if (MPV_common_init(s) < 0) return -1;
     return 0;
diff --git a/libavcodec/utils.c b/libavcodec/utils.c
index bc7da83efe..768e8b6546 100644
--- a/libavcodec/utils.c
+++ b/libavcodec/utils.c
@@ -125,6 +125,9 @@ int avcodec_default_get_buffer(AVCodecContext *s, AVVideoFrame *pic){
     const int width = s->width;
     const int height= s->height;
     DefaultPicOpaque *opaque;
+    
+    assert(pic->data[0]==NULL);
+    assert(pic->type==0 || pic->type==FF_TYPE_INTERNAL);
 
     if(pic->opaque){
         opaque= (DefaultPicOpaque *)pic->opaque;
@@ -186,13 +189,14 @@ int avcodec_default_get_buffer(AVCodecContext *s, AVVideoFrame *pic){
             memset(pic->base[i], 128, pic->linesize[i]*h>>v_shift);
         
             if(s->flags&CODEC_FLAG_EMU_EDGE)
-                pic->data[i] = pic->base[i];
+                pic->data[i] = pic->base[i] + 16; //FIXME 16
             else
-                pic->data[i] = pic->base[i] + (pic->linesize[i]*EDGE_WIDTH>>v_shift) + (EDGE_WIDTH>>h_shift);
+                pic->data[i] = pic->base[i] + (pic->linesize[i]*EDGE_WIDTH>>v_shift) + (EDGE_WIDTH>>h_shift) + 16; //FIXME 16
             
             opaque->data[i]= pic->data[i];
         }
         pic->age= 256*256*256*64;
+        pic->type= FF_BUFFER_TYPE_INTERNAL;
     }
 
     return 0;
@@ -201,6 +205,8 @@ int avcodec_default_get_buffer(AVCodecContext *s, AVVideoFrame *pic){
 void avcodec_default_release_buffer(AVCodecContext *s, AVVideoFrame *pic){
     int i;
     
+    assert(pic->type==FF_BUFFER_TYPE_INTERNAL);
+    
     for(i=0; i<3; i++)
         pic->data[i]=NULL;
 //printf("R%X\n", pic->opaque);
@@ -642,14 +648,39 @@ void avcodec_init(void)
     //dsputil_init();
 }
 
-/* this should be called after seeking and before trying to decode the next frame */
+/* this can be called after seeking and before trying to decode the next keyframe */
 void avcodec_flush_buffers(AVCodecContext *avctx)
 {
+    int i;
     MpegEncContext *s = avctx->priv_data;
-    s->num_available_buffers=0;
+    
+    switch(avctx->codec_id){
+    case CODEC_ID_MPEG1VIDEO:
+    case CODEC_ID_H263:
+    case CODEC_ID_RV10:
+    case CODEC_ID_MJPEG:
+    case CODEC_ID_MJPEGB:
+    case CODEC_ID_MPEG4:
+    case CODEC_ID_MSMPEG4V1:
+    case CODEC_ID_MSMPEG4V2:
+    case CODEC_ID_MSMPEG4V3:
+    case CODEC_ID_WMV1:
+    case CODEC_ID_WMV2:
+    case CODEC_ID_H263P:
+    case CODEC_ID_H263I:
+    case CODEC_ID_SVQ1:
+        for(i=0; i<MAX_PICTURE_COUNT; i++){
+           if(s->picture[i].data[0] && (   s->picture[i].type == FF_BUFFER_TYPE_INTERNAL
+                                        || s->picture[i].type == FF_BUFFER_TYPE_USER))
+            avctx->release_buffer(avctx, (AVVideoFrame*)&s->picture[i]);
+        }
+        break;
+    default:
+        //FIXME
+        break;
+    }
 }
 
-
 static int raw_encode_init(AVCodecContext *s)
 {
     return 0;