[FFmpeg-devel] [PATCH] Implement PAFF in H.264

Jeff Downs heydowns
Mon Oct 1 22:32:26 CEST 2007


Hi,

Attached are new versions of the PAFF implementation patches.
As in prior posts, the three patches are to be applied in order.

paff-cosmetics.patch & paff-mmcorename.patch have not changed since last 
posting. Changed slightly since Michael approved. See previous post for 
details on what changed.

See prior posts for overall description of paff-noindent-substance.patch. 
Changes since last post:

1. valid_structure member of Picture has been removed; now uses reference 
   member as it was intended.
2. Fixed blocky effects near edges observed in some clips (manifested when 
   second field in pair predicts against first; fixed by drawing edges for 
   first field after decode).
3. Includes modified version of Neil Brown's fix for IDR fields.


Known limitations (detailed in prior postings):
1. Error concealer is disabled pending augmentation to handle interlacing 
   after base PAFF implementation is finished.
2. Many PAFF samples will trigger errors in ref pic reordering 
   (abs_diff_pic_num overflow). This is not a PAFF problem. I have a fix 
   for posting in separate thread.

Knowing it will take time for complete review/accept, I'd appreciate 
short-term comments on any additional splitting/cleaning needed.

	-Jeff
-------------- next part --------------
Index: libavcodec/h264.h
===================================================================
--- libavcodec/h264.h	(revision 10633)
+++ libavcodec/h264.h	(working copy)
@@ -84,8 +84,8 @@
     int poc_cycle_length;              ///< num_ref_frames_in_pic_order_cnt_cycle
     int ref_frame_count;               ///< num_ref_frames
     int gaps_in_frame_num_allowed_flag;
-    int mb_width;                      ///< frame_width_in_mbs_minus1 + 1
-    int mb_height;                     ///< frame_height_in_mbs_minus1 + 1
+    int mb_width;                      ///< pic_width_in_mbs_minus1 + 1
+    int mb_height;                     ///< pic_height_in_map_units_minus1 + 1
     int frame_mbs_only_flag;
     int mb_aff;                        ///<mb_adaptive_frame_field_flag
     int direct_8x8_inference_flag;
@@ -323,8 +323,9 @@
     unsigned int list_count;
     Picture *short_ref[32];
     Picture *long_ref[32];
-    Picture default_ref_list[2][32];
+    Picture default_ref_list[2][32]; ///< base reference list for all slices of a coded picture
     Picture ref_list[2][48];     ///< 0..15: frame refs, 16..47: mbaff field refs
+                                 ///< Reordered version of default_ref_list according to picture reordering in slice header
     Picture *delayed_pic[18]; //FIXME size?
     Picture *delayed_output_pic;
 
Index: libavcodec/mpegvideo.h
===================================================================
--- libavcodec/mpegvideo.h	(revision 10633)
+++ libavcodec/mpegvideo.h	(working copy)
@@ -138,8 +138,9 @@
 
     int field_poc[2];           ///< h264 top/bottom POC
     int poc;                    ///< h264 frame POC
-    int frame_num;              ///< h264 frame_num
-    int pic_id;                 ///< h264 pic_num or long_term_pic_idx
+    int frame_num;              ///< h264 frame_num (raw frame_num from slice header)
+    int pic_id;                 ///< h264 pic_num (short -> no wrap version of pic_num,
+                                ///<   pic_num & max_pic_num; long -> long_pic_num)
     int long_ref;               ///< 1->long term reference 0->short term reference
     int ref_poc[2][16];         ///< h264 POCs of the frames used as reference
     int ref_count[2];           ///< number of entries in ref_poc
-------------- next part --------------
Index: libavcodec/h264.c
===================================================================
--- libavcodec/h264.c	(revision 10633)
+++ libavcodec/h264.c	(working copy)
@@ -3228,47 +3228,47 @@
 
     for(i=0; i<mmco_count; i++){
         if(s->avctx->debug&FF_DEBUG_MMCO)
-            av_log(h->s.avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode, h->mmco[i].short_frame_num, h->mmco[i].long_index);
+            av_log(h->s.avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode, h->mmco[i].short_pic_num, h->mmco[i].long_arg);
 
         switch(mmco[i].opcode){
         case MMCO_SHORT2UNUSED:
-            pic= remove_short(h, mmco[i].short_frame_num);
+            pic= remove_short(h, mmco[i].short_pic_num);
             if(pic)
                 unreference_pic(h, pic);
             else if(s->avctx->debug&FF_DEBUG_MMCO)
                 av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: remove_short() failure\n");
             break;
         case MMCO_SHORT2LONG:
-            pic= remove_long(h, mmco[i].long_index);
+            pic= remove_long(h, mmco[i].long_arg);
             if(pic) unreference_pic(h, pic);
 
-            h->long_ref[ mmco[i].long_index ]= remove_short(h, mmco[i].short_frame_num);
-            if (h->long_ref[ mmco[i].long_index ]){
-                h->long_ref[ mmco[i].long_index ]->long_ref=1;
+            h->long_ref[ mmco[i].long_arg ]= remove_short(h, mmco[i].short_pic_num);
+            if (h->long_ref[ mmco[i].long_arg ]){
+                h->long_ref[ mmco[i].long_arg ]->long_ref=1;
                 h->long_ref_count++;
             }
             break;
         case MMCO_LONG2UNUSED:
-            pic= remove_long(h, mmco[i].long_index);
+            pic= remove_long(h, mmco[i].long_arg);
             if(pic)
                 unreference_pic(h, pic);
             else if(s->avctx->debug&FF_DEBUG_MMCO)
                 av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: remove_long() failure\n");
             break;
         case MMCO_LONG:
-            pic= remove_long(h, mmco[i].long_index);
+            pic= remove_long(h, mmco[i].long_arg);
             if(pic) unreference_pic(h, pic);
 
-            h->long_ref[ mmco[i].long_index ]= s->current_picture_ptr;
-            h->long_ref[ mmco[i].long_index ]->long_ref=1;
+            h->long_ref[ mmco[i].long_arg ]= s->current_picture_ptr;
+            h->long_ref[ mmco[i].long_arg ]->long_ref=1;
             h->long_ref_count++;
 
             current_is_long=1;
             break;
         case MMCO_SET_MAX_LONG:
-            assert(mmco[i].long_index <= 16);
+            assert(mmco[i].long_arg <= 16);
             // just remove the long term which index is greater than new max
-            for(j = mmco[i].long_index; j<16; j++){
+            for(j = mmco[i].long_arg; j<16; j++){
                 pic = remove_long(h, j);
                 if (pic) unreference_pic(h, pic);
             }
@@ -3313,8 +3313,8 @@
 
     if(h->nal_unit_type == NAL_IDR_SLICE){ //FIXME fields
         s->broken_link= get_bits1(gb) -1;
-        h->mmco[0].long_index= get_bits1(gb) - 1; // current_long_term_idx
-        if(h->mmco[0].long_index == -1)
+        h->mmco[0].long_arg= get_bits1(gb) - 1; // current_long_term_idx
+        if(h->mmco[0].long_arg == -1)
             h->mmco_index= 0;
         else{
             h->mmco[0].opcode= MMCO_LONG;
@@ -3327,19 +3327,19 @@
 
                 h->mmco[i].opcode= opcode;
                 if(opcode==MMCO_SHORT2UNUSED || opcode==MMCO_SHORT2LONG){
-                    h->mmco[i].short_frame_num= (h->frame_num - get_ue_golomb(gb) - 1) & ((1<<h->sps.log2_max_frame_num)-1); //FIXME fields
-/*                    if(h->mmco[i].short_frame_num >= h->short_ref_count || h->short_ref[ h->mmco[i].short_frame_num ] == NULL){
+                    h->mmco[i].short_pic_num= (h->frame_num - get_ue_golomb(gb) - 1) & ((1<<h->sps.log2_max_frame_num)-1); //FIXME fields
+/*                    if(h->mmco[i].short_pic_num >= h->short_ref_count || h->short_ref[ h->mmco[i].short_pic_num ] == NULL){
                         av_log(s->avctx, AV_LOG_ERROR, "illegal short ref in memory management control operation %d\n", mmco);
                         return -1;
                     }*/
                 }
                 if(opcode==MMCO_SHORT2LONG || opcode==MMCO_LONG2UNUSED || opcode==MMCO_LONG || opcode==MMCO_SET_MAX_LONG){
                     unsigned int long_index= get_ue_golomb(gb);
-                    if(/*h->mmco[i].long_index >= h->long_ref_count || h->long_ref[ h->mmco[i].long_index ] == NULL*/ long_index >= 16){
+                    if(/*h->mmco[i].long_arg >= h->long_ref_count || h->long_ref[ h->mmco[i].long_arg ] == NULL*/ long_index >= 16){
                         av_log(h->s.avctx, AV_LOG_ERROR, "illegal long ref in memory management control operation %d\n", opcode);
                         return -1;
                     }
-                    h->mmco[i].long_index= long_index;
+                    h->mmco[i].long_arg= long_index;
                 }
 
                 if(opcode > (unsigned)MMCO_LONG){
@@ -3355,7 +3355,7 @@
 
             if(h->long_ref_count + h->short_ref_count == h->sps.ref_frame_count){ //FIXME fields
                 h->mmco[0].opcode= MMCO_SHORT2UNUSED;
-                h->mmco[0].short_frame_num= h->short_ref[ h->short_ref_count - 1 ]->frame_num;
+                h->mmco[0].short_pic_num= h->short_ref[ h->short_ref_count - 1 ]->frame_num;
                 h->mmco_index= 1;
             }else
                 h->mmco_index= 0;
Index: libavcodec/h264.h
===================================================================
--- libavcodec/h264.h	(revision 10633)
+++ libavcodec/h264.h	(working copy)
@@ -151,8 +151,8 @@
  */
 typedef struct MMCO{
     MMCOOpcode opcode;
-    int short_frame_num;
-    int long_index;
+    int short_pic_num;  ///< pic_num without wrapping (pic_num & max_pic_num)
+    int long_arg;  ///< index, pic_num, or num long refs depending on opcode
 } MMCO;
 
 /**
-------------- next part --------------
--- ../ffmpeg-cosmetics/libavcodec/h264.c	2007-10-01 14:02:06.000000000 -0400
+++ libavcodec/h264.c	2007-10-01 15:56:22.000000000 -0400
@@ -175,11 +175,11 @@
     if(for_deblock && (h->slice_num == 1 || h->slice_table[mb_xy] == h->slice_table[mb_xy-s->mb_stride]) && !FRAME_MBAFF)
         return;
 
     //wow what a mess, why didn't they simplify the interlacing&intra stuff, i can't imagine that these complex rules are worth it
 
-    top_xy     = mb_xy  - s->mb_stride;
+    top_xy     = mb_xy  - (s->mb_stride << FIELD_PICTURE);
     topleft_xy = top_xy - 1;
     topright_xy= top_xy + 1;
     left_xy[1] = left_xy[0] = mb_xy-1;
     left_block[0]= 0;
     left_block[1]= 1;
@@ -1701,11 +1701,11 @@
     int extra_height= h->emu_edge_height;
     int emu=0;
     const int full_mx= mx>>2;
     const int full_my= my>>2;
     const int pic_width  = 16*s->mb_width;
-    const int pic_height = 16*s->mb_height >> MB_MBAFF;
+    const int pic_height = 16*s->mb_height >> (MB_MBAFF || FIELD_PICTURE);
 
     if(!pic->data[0]) //FIXME this is unacceptable, some senseable error concealment must be done for missing reference frames
         return;
 
     if(mx&7) extra_width -= 3;
@@ -1725,11 +1725,11 @@
         qpix_op[luma_xy](dest_y + delta, src_y + delta, h->mb_linesize);
     }
 
     if(ENABLE_GRAY && s->flags&CODEC_FLAG_GRAY) return;
 
-    if(MB_MBAFF){
+    if(MB_MBAFF || FIELD_PICTURE){
         // chroma offset when predicting from a field of opposite parity
         my += 2 * ((s->mb_y & 1) - (h->ref_cache[list][scan8[n]] & 1));
         emu |= (my>>3) < 0 || (my>>3) + 8 >= (pic_height>>1);
     }
     src_cb= pic->data[1] + (mx>>3) + (my>>3)*h->mb_uvlinesize;
@@ -1760,11 +1760,11 @@
 
     dest_y  += 2*x_offset + 2*y_offset*h->  mb_linesize;
     dest_cb +=   x_offset +   y_offset*h->mb_uvlinesize;
     dest_cr +=   x_offset +   y_offset*h->mb_uvlinesize;
     x_offset += 8*s->mb_x;
-    y_offset += 8*(s->mb_y >> MB_MBAFF);
+    y_offset += 8*(s->mb_y >> (MB_MBAFF || FIELD_PICTURE));
 
     if(list0){
         Picture *ref= &h->ref_list[0][ h->ref_cache[0][ scan8[n] ] ];
         mc_dir_part(h, ref, n, square, chroma_height, delta, 0,
                            dest_y, dest_cb, dest_cr, x_offset, y_offset,
@@ -1793,11 +1793,11 @@
 
     dest_y  += 2*x_offset + 2*y_offset*h->  mb_linesize;
     dest_cb +=   x_offset +   y_offset*h->mb_uvlinesize;
     dest_cr +=   x_offset +   y_offset*h->mb_uvlinesize;
     x_offset += 8*s->mb_x;
-    y_offset += 8*(s->mb_y >> MB_MBAFF);
+    y_offset += 8*(s->mb_y >> (MB_MBAFF || FIELD_PICTURE));
 
     if(list0 && list1){
         /* don't optimize for luma-only case, since B-frames usually
          * use implicit weights => chroma too. */
         uint8_t *tmp_cb = s->obmc_scratchpad;
@@ -2247,10 +2247,11 @@
     int i;
 
     if(MPV_frame_start(s, s->avctx) < 0)
         return -1;
     ff_er_frame_start(s);
+    s->current_picture_ptr->key_frame= 0;
 
     assert(s->linesize && s->uvlinesize);
 
     for(i=0; i<16; i++){
         h->block_offset[i]= 4*((scan8[i] - scan8[0])&7) + 4*s->linesize*((scan8[i] - scan8[0])>>3);
@@ -2755,20 +2756,138 @@
     if (is_complex)
         hl_decode_mb_complex(h);
     else hl_decode_mb_simple(h);
 }
 
+static void pic_as_field(Picture *pic, const int bottom){
+    int i;
+    for (i = 0; i < 4; ++i) {
+        if (bottom)
+            pic->data[i] += pic->linesize[i];
+        pic->linesize[i] *= 2;
+    }
+}
+
+static int split_field_copy(Picture *dest, Picture *src,
+                            int parity, int id_add){
+    int match = (src->reference & parity) != 0;
+
+    if (match) {
+        *dest = *src;
+        pic_as_field(dest, parity == PICT_BOTTOM_FIELD);
+        dest->pic_id *= 2;
+        dest->pic_id += id_add;
+    }
+
+    return match;
+}
+
+/**
+ * Split one reference list into field parts, interleaving by parity
+ * as per H.264 spec section 8.2.4.2.5. Output fields have their data pointers
+ * set to look at the actual start of data for that field.
+ *
+ * @param dest output list
+ * @param dest_len maximum number of fields to put in dest
+ * @param src the source reference list containing fields and/or field pairs
+ *            (aka short_ref/long_ref, or
+ *             refFrameListXShortTerm/refFrameListLongTerm in spec-speak)
+ * @param src_len number of Picture's in source (pairs and unmatched fields)
+ * @param parity the parity of the picture being decoded/needing
+ *        these ref pics (PICT_{TOP,BOTTOM}_FIELD)
+ * @return number of fields placed in dest
+ */
+static int split_field_half_ref_list(Picture *dest, int dest_len,
+                                     Picture *src,  int src_len,  int parity){
+    int same_i, opp_i;
+    int i;
+    int same;
+    int out_i;
+
+    same_i = 0;
+    opp_i = 0;
+    same = 1;
+    out_i = 0;
+
+    while (out_i < dest_len) {
+        if (same && same_i < src_len) {
+            i = split_field_copy(dest + out_i, src + same_i, parity, 1);
+            same = !i;
+            same_i++;
+
+        } else if (opp_i < src_len) {
+            i = split_field_copy(dest + out_i, src + opp_i,
+                                 PICT_FRAME - parity, 0);
+            same = i;
+            opp_i++;
+
+        } else {
+            break;
+        }
+        out_i += i;
+    }
+
+    return out_i;
+}
+
+/**
+ * Split the reference frame list into a reference field list.
+ * This implements H.264 spec 8.2.4.2.5 for a combined input list.
+ * The input list contains both reference field pairs and
+ * unmatched reference fields; it is ordered as spec describes
+ * RefPicListX for frames in 8.2.4.2.1 and 8.2.4.2.3, except that
+ * unmatched field pairs are also present. Conceptually this is equivalent
+ * to concatenation of refFrameListXShortTerm with refFrameListLongTerm.
+ *
+ * @param dest output reference list where ordered fields are to be placed
+ * @param dest_len max number of fields to place at dest
+ * @param src source reference list, as described above
+ * @param src_len number of pictures (pairs and unmatched fields) in src
+ * @param parity parity of field being currently decoded
+ *        (one of PICT_{TOP,BOTTOM}_FIELD)
+ * @param long_i index into src array that holds first long reference picture,
+ *        or src_len if no long refs present.
+ */
+static int split_field_ref_list(Picture *dest, int dest_len,
+                                Picture *src,  int src_len,
+                                int parity,    int long_i){
+
+    int i = split_field_half_ref_list(dest, dest_len, src, long_i, parity);
+    dest += i;
+    dest_len -= i;
+
+    i += split_field_half_ref_list(dest, dest_len, src + long_i,
+                                   src_len - long_i, parity);
+    return i;
+}
+
 /**
  * fills the default_ref_list.
  */
 static int fill_default_ref_list(H264Context *h){
     MpegEncContext * const s = &h->s;
     int i;
     int smallest_poc_greater_than_current = -1;
+    int structure_sel;
     Picture sorted_short_ref[32];
+    Picture field_entry_list[2][32];
+    Picture *frame_list[2];
+
+    if (!FIELD_PICTURE) {
+        structure_sel = 0;
+        frame_list[0] = h->default_ref_list[0];
+        frame_list[1] = h->default_ref_list[1];
+    } else {
+        structure_sel = PICT_FRAME;
+        frame_list[0] = field_entry_list[0];
+        frame_list[1] = field_entry_list[1];
+    }
 
     if(h->slice_type==B_TYPE){
+        int list;
+        int len[2];
+        int short_len[2];
         int out_i;
         int limit= INT_MIN;
 
         /* sort frame according to poc in B slice */
         for(out_i=0; out_i<h->short_ref_count; out_i++){
@@ -2792,75 +2911,97 @@
                 if (h->short_ref[best_i]->poc >= s->current_picture_ptr->poc) {
                     smallest_poc_greater_than_current = out_i;
                 }
             }
         }
-    }
 
-    if(s->picture_structure == PICT_FRAME){
-        if(h->slice_type==B_TYPE){
-            int list;
             tprintf(h->s.avctx, "current poc: %d, smallest_poc_greater_than_current: %d\n", s->current_picture_ptr->poc, smallest_poc_greater_than_current);
 
             // find the largest poc
             for(list=0; list<2; list++){
                 int index = 0;
                 int j= -99;
                 int step= list ? -1 : 1;
 
                 for(i=0; i<h->short_ref_count && index < h->ref_count[list]; i++, j+=step) {
+                    int sel;
                     while(j<0 || j>= h->short_ref_count){
                         if(j != -99 && step == (list ? -1 : 1))
                             return -1;
                         step = -step;
                         j= smallest_poc_greater_than_current + (step>>1);
                     }
-                    if(sorted_short_ref[j].reference != 3) continue;
-                    h->default_ref_list[list][index  ]= sorted_short_ref[j];
-                    h->default_ref_list[list][index++].pic_id= sorted_short_ref[j].frame_num;
+                    sel = sorted_short_ref[j].reference | structure_sel;
+                    if(sel != PICT_FRAME) continue;
+                    frame_list[list][index  ]= sorted_short_ref[j];
+                    frame_list[list][index++].pic_id= sorted_short_ref[j].frame_num;
                 }
+                short_len[list] = index;
 
                 for(i = 0; i < 16 && index < h->ref_count[ list ]; i++){
+                    int sel;
                     if(h->long_ref[i] == NULL) continue;
-                    if(h->long_ref[i]->reference != 3) continue;
+                    sel = h->long_ref[i]->reference | structure_sel;
+                    if(sel != PICT_FRAME) continue;
 
-                    h->default_ref_list[ list ][index  ]= *h->long_ref[i];
-                    h->default_ref_list[ list ][index++].pic_id= i;;
+                    frame_list[ list ][index  ]= *h->long_ref[i];
+                    frame_list[ list ][index++].pic_id= i;;
                 }
+                len[list] = index;
 
                 if(list && (smallest_poc_greater_than_current<=0 || smallest_poc_greater_than_current>=h->short_ref_count) && (1 < index)){
                     // swap the two first elements of L1 when
                     // L0 and L1 are identical
-                    Picture temp= h->default_ref_list[1][0];
-                    h->default_ref_list[1][0] = h->default_ref_list[1][1];
-                    h->default_ref_list[1][1] = temp;
+                    Picture temp= frame_list[1][0];
+                    frame_list[1][0] = frame_list[1][1];
+                    frame_list[1][1] = temp;
                 }
 
-                if(index < h->ref_count[ list ])
-                    memset(&h->default_ref_list[list][index], 0, sizeof(Picture)*(h->ref_count[ list ] - index));
             }
+
+            for(list=0; list<2; list++){
+                if (s->picture_structure != PICT_FRAME)
+                    len[list] = split_field_ref_list(h->default_ref_list[list],
+                                                     h->ref_count[list],
+                                                     frame_list[list],
+                                                     len[list],
+                                                     s->picture_structure,
+                                                     short_len[list]);
+
+                if(len[list] < h->ref_count[ list ])
+                    memset(&h->default_ref_list[list][len[list]], 0, sizeof(Picture)*(h->ref_count[ list ] - len[list]));
+            }
+
+
         }else{
             int index=0;
+            int short_len;
             for(i=0; i<h->short_ref_count; i++){
-                if(h->short_ref[i]->reference != 3) continue; //FIXME refernce field shit
-                h->default_ref_list[0][index  ]= *h->short_ref[i];
-                h->default_ref_list[0][index++].pic_id= h->short_ref[i]->frame_num;
+                int sel;
+                sel = h->short_ref[i]->reference | structure_sel;
+                if(sel != PICT_FRAME) continue;
+                frame_list[0][index  ]= *h->short_ref[i];
+                frame_list[0][index++].pic_id= h->short_ref[i]->frame_num;
             }
+            short_len = index;
             for(i = 0; i < 16; i++){
+                int sel;
                 if(h->long_ref[i] == NULL) continue;
-                if(h->long_ref[i]->reference != 3) continue;
-                h->default_ref_list[0][index  ]= *h->long_ref[i];
-                h->default_ref_list[0][index++].pic_id= i;;
+                sel = h->long_ref[i]->reference | structure_sel;
+                if(sel != PICT_FRAME) continue;
+                frame_list[0][index  ]= *h->long_ref[i];
+                frame_list[0][index++].pic_id= i;;
             }
+
+            if (s->picture_structure != PICT_FRAME)
+                index = split_field_ref_list(h->default_ref_list[0],
+                                             h->ref_count[0], frame_list[0],
+                                             index, s->picture_structure,
+                                             short_len);
+
             if(index < h->ref_count[0])
                 memset(&h->default_ref_list[0][index], 0, sizeof(Picture)*(h->ref_count[0] - index));
-        }
-    }else{ //FIELD
-        if(h->slice_type==B_TYPE){
-        }else{
-            //FIXME second field balh
-        }
     }
 #ifdef TRACE
     for (i=0; i<h->ref_count[0]; i++) {
         tprintf(h->s.avctx, "List0: %s fn:%d 0x%p\n", (h->default_ref_list[0][i].long_ref ? "LT" : "ST"), h->default_ref_list[0][i].pic_id, h->default_ref_list[0][i].data[0]);
     }
@@ -2876,11 +3017,11 @@
 static void print_short_term(H264Context *h);
 static void print_long_term(H264Context *h);
 
 static int decode_ref_pic_list_reordering(H264Context *h){
     MpegEncContext * const s = &h->s;
-    int list, index;
+    int list, index, pic_structure;
 
     print_short_term(h);
     print_long_term(h);
     if(h->slice_type==I_TYPE || h->slice_type==SI_TYPE) return 0; //FIXME move before func
 
@@ -2903,41 +3044,78 @@
                     av_log(h->s.avctx, AV_LOG_ERROR, "reference count overflow\n");
                     return -1;
                 }
 
                 if(reordering_of_pic_nums_idc<3){
+                    int bot;
                     if(reordering_of_pic_nums_idc<2){
                         const unsigned int abs_diff_pic_num= get_ue_golomb(&s->gb) + 1;
+                        int frame_num;
 
                         if(abs_diff_pic_num >= h->max_pic_num){
                             av_log(h->s.avctx, AV_LOG_ERROR, "abs_diff_pic_num overflow\n");
                             return -1;
                         }
 
                         if(reordering_of_pic_nums_idc == 0) pred-= abs_diff_pic_num;
                         else                                pred+= abs_diff_pic_num;
                         pred &= h->max_pic_num - 1;
 
+                        if (FIELD_PICTURE) {
+                            frame_num = pred >> 1;
+                            if (pred & 1) {
+                                pic_structure = s->picture_structure;
+                                bot = (s->picture_structure == PICT_BOTTOM_FIELD);
+                            } else {
+                                pic_structure = PICT_FRAME - s->picture_structure;
+                                bot = (s->picture_structure == PICT_TOP_FIELD);
+                            }
+                        } else {
+                            frame_num = pred;
+                            pic_structure = PICT_FRAME;
+                            bot = 0;
+                        }
+
                         for(i= h->short_ref_count-1; i>=0; i--){
                             ref = h->short_ref[i];
-                            assert(ref->reference == 3);
+                            assert(ref->reference);
                             assert(!ref->long_ref);
-                            if(ref->data[0] != NULL && ref->frame_num == pred && ref->long_ref == 0) // ignore non existing pictures by testing data[0] pointer
+                            if(ref->data[0] != NULL &&
+                                   ref->frame_num == frame_num &&
+                                   (ref->reference & pic_structure) &&
+                                   ref->long_ref == 0) // ignore non existing pictures by testing data[0] pointer
                                 break;
                         }
                         if(i>=0)
-                            ref->pic_id= ref->frame_num;
+                            ref->pic_id= pred;
                     }else{
+                        int long_idx;
                         pic_id= get_ue_golomb(&s->gb); //long_term_pic_idx
-                        if(pic_id>31){
+
+                        if (FIELD_PICTURE) {
+                            long_idx = pic_id >> 1;
+                            if (pic_id & 1) {
+                                pic_structure = s->picture_structure;
+                                bot = (s->picture_structure == PICT_BOTTOM_FIELD);
+                            } else {
+                                pic_structure = PICT_FRAME - s->picture_structure;
+                                bot = (s->picture_structure == PICT_TOP_FIELD);
+                            }
+                        } else {
+                            long_idx = pic_id;
+                            pic_structure = PICT_FRAME;
+                            bot = 0;
+                        }
+
+                        if(long_idx>31){
                             av_log(h->s.avctx, AV_LOG_ERROR, "long_term_pic_idx overflow\n");
                             return -1;
                         }
-                        ref = h->long_ref[pic_id];
-                        if(ref){
+                        ref = h->long_ref[long_idx];
+                        assert(!(ref && !ref->reference));
+                        if(ref && (ref->reference & pic_structure)){
                             ref->pic_id= pic_id;
-                            assert(ref->reference == 3);
                             assert(ref->long_ref);
                             i=0;
                         }else{
                             i=-1;
                         }
@@ -2953,10 +3131,12 @@
                         }
                         for(; i > index; i--){
                             h->ref_list[list][i]= h->ref_list[list][i-1];
                         }
                         h->ref_list[list][index]= *ref;
+                        if (FIELD_PICTURE)
+                            pic_as_field(&h->ref_list[list][index], bot);
                     }
                 }else{
                     av_log(h->s.avctx, AV_LOG_ERROR, "illegal reordering_of_pic_nums_idc\n");
                     return -1;
                 }
@@ -3091,40 +3271,55 @@
                 h->implicit_weight[ref0][ref1] = 32;
         }
     }
 }
 
-static inline void unreference_pic(H264Context *h, Picture *pic){
+/**
+ * Mark a picture as no longer needed for reference. The refmask
+ * argument allows unreferencing of individual fields or the whole frame.
+ * If the picture becomes entirely unreferenced, but is being held for
+ * display purposes, it is marked as such.
+ * @param refmask mask of fields to unreference; the mask is bitwise
+ *                anded with the reference marking of pic
+ * @return non-zero if pic becomes entirely unreferenced (except possibly
+ *         for display purposes) zero if one of the fields remains in
+ *         reference
+ */
+static inline int unreference_pic(H264Context *h, Picture *pic, int refmask){
     int i;
-    pic->reference=0;
+    if (pic->reference &= refmask) {
+        return 0;
+    } else {
     if(pic == h->delayed_output_pic)
         pic->reference=DELAYED_PIC_REF;
     else{
         for(i = 0; h->delayed_pic[i]; i++)
             if(pic == h->delayed_pic[i]){
                 pic->reference=DELAYED_PIC_REF;
                 break;
             }
     }
+        return 1;
+    }
 }
 
 /**
  * instantaneous decoder refresh.
  */
 static void idr(H264Context *h){
     int i;
 
     for(i=0; i<16; i++){
         if (h->long_ref[i] != NULL) {
-            unreference_pic(h, h->long_ref[i]);
+            unreference_pic(h, h->long_ref[i], 0);
             h->long_ref[i]= NULL;
         }
     }
     h->long_ref_count=0;
 
     for(i=0; i<h->short_ref_count; i++){
-        unreference_pic(h, h->short_ref[i]);
+        unreference_pic(h, h->short_ref[i], 0);
         h->short_ref[i]= NULL;
     }
     h->short_ref_count=0;
 }
 
@@ -3141,47 +3336,90 @@
         h->delayed_output_pic->reference= 0;
     h->delayed_output_pic= NULL;
     idr(h);
     if(h->s.current_picture_ptr)
         h->s.current_picture_ptr->reference= 0;
+    h->s.first_field= 0;
 }
 
 /**
- *
- * @return the removed picture or NULL if an error occurs
+ * Find a Picture in the short term reference list by frame number.
+ * @param frame_num frame number to search for
+ * @param idx the index into h->short_ref where returned picture is found
+ *            undefined if no picture found.
+ * @return pointer to the found picture, or NULL if no pic with the provided
+ *                 frame number is found
  */
-static Picture * remove_short(H264Context *h, int frame_num){
+static Picture * find_short(H264Context *h, int frame_num, int *idx){
     MpegEncContext * const s = &h->s;
     int i;
 
-    if(s->avctx->debug&FF_DEBUG_MMCO)
-        av_log(h->s.avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
-
     for(i=0; i<h->short_ref_count; i++){
         Picture *pic= h->short_ref[i];
         if(s->avctx->debug&FF_DEBUG_MMCO)
             av_log(h->s.avctx, AV_LOG_DEBUG, "%d %d %p\n", i, pic->frame_num, pic);
-        if(pic->frame_num == frame_num){
-            h->short_ref[i]= NULL;
-            if (--h->short_ref_count)
-                memmove(&h->short_ref[i], &h->short_ref[i+1], (h->short_ref_count - i)*sizeof(Picture*));
+        if(pic->frame_num == frame_num) {
+            *idx = i;
             return pic;
         }
     }
     return NULL;
 }
 
 /**
+ * Remove a picture from the short term reference list by its index in
+ * that list.  This does no checking on the provided index; it is assumed
+ * to be valid. Other list entries are shifted down.
+ * @param i index into h->short_ref of picture to remove.
+ */
+static void remove_short_at_index(H264Context *h, int i){
+    assert(i > 0 && i < h->short_ref_count);
+    h->short_ref[i]= NULL;
+    if (--h->short_ref_count)
+        memmove(&h->short_ref[i], &h->short_ref[i+1], (h->short_ref_count - i)*sizeof(Picture*));
+}
+
+/**
+ *
+ * @return the removed picture or NULL if an error occurs
+ */
+static Picture * remove_short(H264Context *h, int frame_num){
+    MpegEncContext * const s = &h->s;
+    Picture *pic;
+    int i;
+
+    if(s->avctx->debug&FF_DEBUG_MMCO)
+        av_log(h->s.avctx, AV_LOG_DEBUG, "remove short %d count %d\n", frame_num, h->short_ref_count);
+
+    pic = find_short(h, frame_num, &i);
+    if (pic)
+        remove_short_at_index(h, i);
+
+    return pic;
+}
+
+/**
+ * Remove a picture from the long term reference list by its index in
+ * that list.  This does no checking on the provided index; it is assumed
+ * to be valid. The removed entry is set to NULL. Other entries are unaffected.
+ * @param i index into h->long_ref of picture to remove.
+ */
+static void remove_long_at_index(H264Context *h, int i){
+    h->long_ref[i]= NULL;
+    h->long_ref_count--;
+}
+
+/**
  *
  * @return the removed picture or NULL if an error occurs
  */
 static Picture * remove_long(H264Context *h, int i){
     Picture *pic;
 
     pic= h->long_ref[i];
-    h->long_ref[i]= NULL;
-    if(pic) h->long_ref_count--;
+    if (pic)
+        remove_long_at_index(h, i);
 
     return pic;
 }
 
 /**
@@ -3218,11 +3456,11 @@
  * Executes the reference picture marking (memory management control operations).
  */
 static int execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
     MpegEncContext * const s = &h->s;
     int i, j;
-    int current_is_long=0;
+    int current_ref_assigned=0;
     Picture *pic;
 
     if((s->avctx->debug&FF_DEBUG_MMCO) && mmco_count==0)
         av_log(h->s.avctx, AV_LOG_DEBUG, "no mmco here\n");
 
@@ -3230,78 +3468,148 @@
         if(s->avctx->debug&FF_DEBUG_MMCO)
             av_log(h->s.avctx, AV_LOG_DEBUG, "mmco:%d %d %d\n", h->mmco[i].opcode, h->mmco[i].short_pic_num, h->mmco[i].long_arg);
 
         switch(mmco[i].opcode){
         case MMCO_SHORT2UNUSED:
-            pic= remove_short(h, mmco[i].short_pic_num);
-            if(pic)
-                unreference_pic(h, pic);
-            else if(s->avctx->debug&FF_DEBUG_MMCO)
-                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: remove_short() failure\n");
+            if(s->avctx->debug&FF_DEBUG_MMCO)
+                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: unref short %d count %d\n", h->mmco[i].short_pic_num, h->short_ref_count);
+            pic = find_short(h, mmco[i].short_pic_num >> FIELD_PICTURE, &j);
+            if (pic) {
+                int mask = (!FIELD_PICTURE || mmco[i].short_pic_num & 1) ?
+                         ~s->picture_structure : s->picture_structure;
+                if (unreference_pic(h, pic, mask))
+                    remove_short_at_index(h, j);
+            } else if(s->avctx->debug&FF_DEBUG_MMCO)
+                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: unref short failure\n");
             break;
         case MMCO_SHORT2LONG:
-            pic= remove_long(h, mmco[i].long_arg);
-            if(pic) unreference_pic(h, pic);
+            if (FIELD_PICTURE && mmco[i].long_arg < h->long_ref_count &&
+                    h->long_ref[mmco[i].long_arg]->frame_num ==
+                                              mmco[i].short_pic_num / 2) {
+                /* do nothing, we've already moved this field pair. */
+            } else {
+                int frame_num = mmco[i].short_pic_num >> FIELD_PICTURE;
 
-            h->long_ref[ mmco[i].long_arg ]= remove_short(h, mmco[i].short_pic_num);
+                pic= remove_long(h, mmco[i].long_arg);
+                if(pic) unreference_pic(h, pic, 0);
+
+                h->long_ref[ mmco[i].long_arg ]= remove_short(h, frame_num);
             if (h->long_ref[ mmco[i].long_arg ]){
                 h->long_ref[ mmco[i].long_arg ]->long_ref=1;
                 h->long_ref_count++;
             }
+            }
             break;
         case MMCO_LONG2UNUSED:
-            pic= remove_long(h, mmco[i].long_arg);
-            if(pic)
-                unreference_pic(h, pic);
-            else if(s->avctx->debug&FF_DEBUG_MMCO)
-                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: remove_long() failure\n");
+            j = mmco[i].long_arg >> FIELD_PICTURE;
+            pic = h->long_ref[j];
+            if (pic) {
+                int mask = (!FIELD_PICTURE || mmco[i].long_arg & 1) ?
+                         ~s->picture_structure : s->picture_structure;
+                if (unreference_pic(h, pic, mask))
+                    remove_long_at_index(h, j);
+            } else if(s->avctx->debug&FF_DEBUG_MMCO)
+                av_log(h->s.avctx, AV_LOG_DEBUG, "mmco: unref long failure\n");
             break;
         case MMCO_LONG:
+            j = 1;
+            if (FIELD_PICTURE && !s->first_field) {
+                if (h->long_ref[mmco[i].long_arg] == s->current_picture_ptr) {
+                    /* Just mark second field as referenced */
+                    j = 0;
+                } else if (s->current_picture_ptr->reference) {
+                    /* First field in pair is in short term list or
+                     * at a different long term index.
+                     * This is not allowed; see 7.4.3, notes 2 and 3.
+                     * Report the problem and keep the pair where it is,
+                     * and mark this field valid.
+                     */
+                    av_log(h->s.avctx, AV_LOG_ERROR,
+                        "illegal long term reference assignment for second "
+                        "field in complementary field pair (first field is "
+                        "short term or has non-matching long index)\n");
+                    j = 0;
+                }
+            }
+
+            if (j) {
             pic= remove_long(h, mmco[i].long_arg);
-            if(pic) unreference_pic(h, pic);
+            if(pic) unreference_pic(h, pic, 0);
 
             h->long_ref[ mmco[i].long_arg ]= s->current_picture_ptr;
             h->long_ref[ mmco[i].long_arg ]->long_ref=1;
             h->long_ref_count++;
+            }
 
-            current_is_long=1;
+            s->current_picture_ptr->reference |= s->picture_structure;
+            current_ref_assigned=1;
             break;
         case MMCO_SET_MAX_LONG:
             assert(mmco[i].long_arg <= 16);
             // just remove the long term which index is greater than new max
             for(j = mmco[i].long_arg; j<16; j++){
                 pic = remove_long(h, j);
-                if (pic) unreference_pic(h, pic);
+                if (pic) unreference_pic(h, pic, 0);
             }
             break;
         case MMCO_RESET:
             while(h->short_ref_count){
                 pic= remove_short(h, h->short_ref[0]->frame_num);
-                if(pic) unreference_pic(h, pic);
+                if(pic) unreference_pic(h, pic, 0);
             }
             for(j = 0; j < 16; j++) {
                 pic= remove_long(h, j);
-                if(pic) unreference_pic(h, pic);
+                if(pic) unreference_pic(h, pic, 0);
             }
             break;
         default: assert(0);
         }
     }
 
-    if(!current_is_long){
+    if (!current_ref_assigned && FIELD_PICTURE &&
+            !s->first_field && s->current_picture_ptr->reference) {
+
+        /* Second field of complementary field pair; the first field of
+         * which is already referenced. If short referenced, it
+         * should be first entry in short_ref. If not, it must exist
+         * in long_ref; trying to put it on the short list here is an
+         * error in the encoded bit stream (ref: 7.4.3, NOTE 2 and 3).
+         * If on neither list, we have a problem elsewhere
+         */
+        if (h->short_ref_count && h->short_ref[0] == s->current_picture_ptr) {
+            /* Just mark the second field valid */
+            s->current_picture_ptr->reference = PICT_FRAME;
+        } else if (s->current_picture_ptr->long_ref) {
+            av_log(h->s.avctx, AV_LOG_ERROR, "illegal short term reference "
+                                             "assignment for second field "
+                                             "in complementary field pair "
+                                             "(first field is long term)\n");
+        } else {
+            av_log(h->s.avctx, AV_LOG_ERROR, "problem in internal reference "
+                                             "list handling; marking second "
+                                             "field in pair finds first field "
+                                             "in reference, but not in any "
+                                             "ref list\n");
+            s->current_picture_ptr->reference = 0;
+        }
+        current_ref_assigned = 1;
+    }
+
+    if(!current_ref_assigned){
         pic= remove_short(h, s->current_picture_ptr->frame_num);
         if(pic){
-            unreference_pic(h, pic);
+            unreference_pic(h, pic, 0);
             av_log(h->s.avctx, AV_LOG_ERROR, "illegal short term buffer state detected\n");
         }
 
         if(h->short_ref_count)
             memmove(&h->short_ref[1], &h->short_ref[0], h->short_ref_count*sizeof(Picture*));
 
         h->short_ref[0]= s->current_picture_ptr;
         h->short_ref[0]->long_ref=0;
         h->short_ref_count++;
+        s->current_picture_ptr->reference |= s->picture_structure;
     }
 
     print_short_term(h);
     print_long_term(h);
     return 0;
@@ -3325,23 +3633,23 @@
             for(i= 0; i<MAX_MMCO_COUNT; i++) {
                 MMCOOpcode opcode= get_ue_golomb(gb);
 
                 h->mmco[i].opcode= opcode;
                 if(opcode==MMCO_SHORT2UNUSED || opcode==MMCO_SHORT2LONG){
-                    h->mmco[i].short_pic_num= (h->frame_num - get_ue_golomb(gb) - 1) & ((1<<h->sps.log2_max_frame_num)-1); //FIXME fields
+                    h->mmco[i].short_pic_num= (h->curr_pic_num - get_ue_golomb(gb) - 1) & (h->max_pic_num - 1);
 /*                    if(h->mmco[i].short_pic_num >= h->short_ref_count || h->short_ref[ h->mmco[i].short_pic_num ] == NULL){
                         av_log(s->avctx, AV_LOG_ERROR, "illegal short ref in memory management control operation %d\n", mmco);
                         return -1;
                     }*/
                 }
                 if(opcode==MMCO_SHORT2LONG || opcode==MMCO_LONG2UNUSED || opcode==MMCO_LONG || opcode==MMCO_SET_MAX_LONG){
-                    unsigned int long_index= get_ue_golomb(gb);
-                    if(/*h->mmco[i].long_arg >= h->long_ref_count || h->long_ref[ h->mmco[i].long_arg ] == NULL*/ long_index >= 16){
+                    unsigned int long_arg= get_ue_golomb(gb);
+                    if(long_arg >= 32 || (long_arg >= 16 && !(opcode == MMCO_LONG2UNUSED && FIELD_PICTURE))){
                         av_log(h->s.avctx, AV_LOG_ERROR, "illegal long ref in memory management control operation %d\n", opcode);
                         return -1;
                     }
-                    h->mmco[i].long_arg= long_index;
+                    h->mmco[i].long_arg= long_arg;
                 }
 
                 if(opcode > (unsigned)MMCO_LONG){
                     av_log(h->s.avctx, AV_LOG_ERROR, "illegal memory management control operation %d\n", opcode);
                     return -1;
@@ -3351,14 +3659,21 @@
             }
             h->mmco_index= i;
         }else{
             assert(h->long_ref_count + h->short_ref_count <= h->sps.ref_frame_count);
 
-            if(h->long_ref_count + h->short_ref_count == h->sps.ref_frame_count){ //FIXME fields
+            if(h->long_ref_count + h->short_ref_count == h->sps.ref_frame_count &&
+                    !(FIELD_PICTURE && !s->first_field && s->current_picture_ptr->reference)) {
                 h->mmco[0].opcode= MMCO_SHORT2UNUSED;
                 h->mmco[0].short_pic_num= h->short_ref[ h->short_ref_count - 1 ]->frame_num;
                 h->mmco_index= 1;
+                if (FIELD_PICTURE) {
+                    h->mmco[0].short_pic_num *= 2;
+                    h->mmco[1].opcode= MMCO_SHORT2UNUSED;
+                    h->mmco[1].short_pic_num= h->mmco[0].short_pic_num + 1;
+                    h->mmco_index= 2;
+                }
             }else
                 h->mmco_index= 0;
         }
     }
 
@@ -3442,15 +3757,19 @@
         }
         field_poc[0]= poc;
         field_poc[1]= poc;
     }
 
-    if(s->picture_structure != PICT_BOTTOM_FIELD)
+    if(s->picture_structure != PICT_BOTTOM_FIELD) {
         s->current_picture_ptr->field_poc[0]= field_poc[0];
-    if(s->picture_structure != PICT_TOP_FIELD)
+        s->current_picture_ptr->poc = field_poc[0];
+    }
+    if(s->picture_structure != PICT_TOP_FIELD) {
         s->current_picture_ptr->field_poc[1]= field_poc[1];
-    if(s->picture_structure == PICT_FRAME) // FIXME field pix?
+        s->current_picture_ptr->poc = field_poc[1];
+    }
+    if(!FIELD_PICTURE || !s->first_field)
         s->current_picture_ptr->poc= FFMIN(field_poc[0], field_poc[1]);
 
     return 0;
 }
 
@@ -3512,10 +3831,11 @@
     memcpy(dst->block_offset,     src->block_offset, sizeof(dst->block_offset));
     dst->s.current_picture_ptr  = src->s.current_picture_ptr;
     dst->s.current_picture      = src->s.current_picture;
     dst->s.linesize             = src->s.linesize;
     dst->s.uvlinesize           = src->s.uvlinesize;
+    dst->s.first_field          = src->s.first_field;
 
     dst->prev_poc_msb           = src->prev_poc_msb;
     dst->prev_poc_lsb           = src->prev_poc_lsb;
     dst->prev_frame_num_offset  = src->prev_frame_num_offset;
     dst->prev_frame_num         = src->prev_frame_num;
@@ -3539,24 +3859,27 @@
  *
  * @return 0 if okay, <0 if an error occured, 1 if decoding must not be multithreaded
  */
 static int decode_slice_header(H264Context *h, H264Context *h0){
     MpegEncContext * const s = &h->s;
+    MpegEncContext * const s0 = &h0->s;
     unsigned int first_mb_in_slice;
     unsigned int pps_id;
     int num_ref_idx_active_override_flag;
     static const uint8_t slice_type_map[5]= {P_TYPE, B_TYPE, I_TYPE, SP_TYPE, SI_TYPE};
     unsigned int slice_type, tmp, i;
     int default_ref_list_done = 0;
+    int last_pic_structure;
 
     s->dropable= h->nal_ref_idc == 0;
 
     first_mb_in_slice= get_ue_golomb(&s->gb);
 
     if((s->flags2 & CODEC_FLAG2_CHUNKS) && first_mb_in_slice == 0){
         h0->current_slice = 0;
-        s->current_picture_ptr= NULL;
+        if (!s0->first_field)
+            s->current_picture_ptr= NULL;
     }
 
     slice_type= get_ue_golomb(&s->gb);
     if(slice_type > 9){
         av_log(h->s.avctx, AV_LOG_ERROR, "slice type too large (%d) at %d %d\n", h->slice_type, s->mb_x, s->mb_y);
@@ -3621,10 +3944,11 @@
     if (!s->context_initialized) {
         if(h != h0)
             return -1;  // we cant (re-)initialize context during parallel decoding
         if (MPV_common_init(s) < 0)
             return -1;
+        s->first_field = 0;
 
         init_scan_tables(h);
         alloc_tables(h);
 
         for(i = 1; i < s->avctx->thread_count; i++) {
@@ -3659,26 +3983,69 @@
 
     h->frame_num= get_bits(&s->gb, h->sps.log2_max_frame_num);
 
     h->mb_mbaff = 0;
     h->mb_aff_frame = 0;
+    last_pic_structure = s0->picture_structure;
     if(h->sps.frame_mbs_only_flag){
         s->picture_structure= PICT_FRAME;
     }else{
         if(get_bits1(&s->gb)) { //field_pic_flag
             s->picture_structure= PICT_TOP_FIELD + get_bits1(&s->gb); //bottom_field_flag
-            av_log(h->s.avctx, AV_LOG_ERROR, "PAFF interlacing is not implemented\n");
         } else {
             s->picture_structure= PICT_FRAME;
             h->mb_aff_frame = h->sps.mb_aff;
         }
     }
 
     if(h0->current_slice == 0){
-        if(frame_start(h) < 0)
+        /* See if we have a decoded first field looking for a pair... */
+        if (s0->first_field) {
+            assert(s0->current_picture_ptr);
+            assert(s0->current_picture_ptr->data[0]);
+            assert(s0->current_picture_ptr->reference != DELAYED_PIC_REF);
+
+            /* figure out if we have a complementary field pair */
+            if (!FIELD_PICTURE || s->picture_structure == last_pic_structure) {
+                /*
+                 * Previous field is unmatched. Don't display it, but let it
+                 * remain for reference if marked as such.
+                 */
+                s0->current_picture_ptr = NULL;
+                s0->first_field = FIELD_PICTURE;
+
+            } else {
+                if (h->nal_ref_idc &&
+                        s0->current_picture_ptr->reference &&
+                        s0->current_picture_ptr->frame_num != h->frame_num) {
+                    /*
+                     * This and previous field were reference, but had
+                     * different frame_nums. Consider this field first in
+                     * pair. Throw away previous field except for reference
+                     * purposes.
+                     */
+                    s0->first_field = 1;
+                    s0->current_picture_ptr = NULL;
+
+                } else {
+                    /* Second field in complementary pair */
+                    s0->first_field = 0;
+                }
+            }
+
+        } else {
+            /* Frame or first field in a potentially complementary pair */
+            assert(!s0->current_picture_ptr);
+            s0->first_field = FIELD_PICTURE;
+        }
+
+        if((!FIELD_PICTURE || s0->first_field) && frame_start(h) < 0) {
+            s0->first_field = 0;
             return -1;
+        }
     }
+
     if(h != h0)
         clone_slice(h, h0);
 
     s->current_picture_ptr->frame_num= h->frame_num; //FIXME frame_num cleanup
 
@@ -3688,17 +4055,22 @@
         av_log(h->s.avctx, AV_LOG_ERROR, "first_mb_in_slice overflow\n");
         return -1;
     }
     s->resync_mb_x = s->mb_x = first_mb_in_slice % s->mb_width;
     s->resync_mb_y = s->mb_y = (first_mb_in_slice / s->mb_width) << h->mb_aff_frame;
+    if (FIELD_PICTURE) {
+        s->resync_mb_y = s->mb_y = s->mb_y * 2;
+        if (s->picture_structure == PICT_BOTTOM_FIELD)
+            s->resync_mb_y = s->mb_y = s->mb_y + 1;
+    }
     assert(s->mb_y < s->mb_height);
 
     if(s->picture_structure==PICT_FRAME){
         h->curr_pic_num=   h->frame_num;
         h->max_pic_num= 1<< h->sps.log2_max_frame_num;
     }else{
-        h->curr_pic_num= 2*h->frame_num;
+        h->curr_pic_num= 2*h->frame_num + 1;
         h->max_pic_num= 1<<(h->sps.log2_max_frame_num + 1);
     }
 
     if(h->nal_unit_type == NAL_IDR_SLICE){
         get_ue_golomb(&s->gb); /* idr_pic_id */
@@ -3730,11 +4102,11 @@
     h->ref_count[1]= h->pps.ref_count[1];
 
     if(h->slice_type == P_TYPE || h->slice_type == SP_TYPE || h->slice_type == B_TYPE){
         if(h->slice_type == B_TYPE){
             h->direct_spatial_mv_pred= get_bits1(&s->gb);
-            if(h->sps.mb_aff && h->direct_spatial_mv_pred)
+            if(h->mb_aff_frame && h->direct_spatial_mv_pred)
                 av_log(h->s.avctx, AV_LOG_ERROR, "MBAFF + spatial direct mode is not implemented\n");
         }
         num_ref_idx_active_override_flag= get_bits1(&s->gb);
 
         if(num_ref_idx_active_override_flag){
@@ -3850,11 +4222,11 @@
 
     h0->last_slice_type = slice_type;
     h->slice_num = ++h0->current_slice;
 
     h->emu_edge_width= (s->flags&CODEC_FLAG_EMU_EDGE) ? 0 : 16;
-    h->emu_edge_height= FRAME_MBAFF ? 0 : h->emu_edge_width;
+    h->emu_edge_height= (FRAME_MBAFF || FIELD_PICTURE) ? 0 : h->emu_edge_width;
 
     if(s->avctx->debug&FF_DEBUG_PICT_INFO){
         av_log(h->s.avctx, AV_LOG_DEBUG, "slice:%d %s mb:%d %c pps:%u frame:%d poc:%d/%d ref:%d/%d qp:%d loop:%d:%d:%d weight:%d%s\n",
                h->slice_num,
                (s->picture_structure==PICT_FRAME ? "F" : s->picture_structure==PICT_TOP_FIELD ? "T" : "B"),
@@ -4748,10 +5120,12 @@
             mbb_xy = mb_x + (mb_y-1)*s->mb_stride;
     }else{
         int mb_xy = mb_x + mb_y*s->mb_stride;
         mba_xy = mb_xy - 1;
         mbb_xy = mb_xy - s->mb_stride;
+        if (FIELD_PICTURE)
+            mbb_xy -= s->mb_stride;
     }
 
     if( h->slice_table[mba_xy] == h->slice_num && !IS_SKIP( s->current_picture.mb_type[mba_xy] ))
         ctx++;
     if( h->slice_table[mbb_xy] == h->slice_num && !IS_SKIP( s->current_picture.mb_type[mbb_xy] ))
@@ -4835,19 +5209,13 @@
     if( cbp_a == 2 ) ctx++;
     if( cbp_b == 2 ) ctx += 2;
     return 1 + get_cabac_noinline( &h->cabac, &h->cabac_state[77 + ctx] );
 }
 static int decode_cabac_mb_dqp( H264Context *h) {
-    MpegEncContext * const s = &h->s;
-    int mbn_xy;
     int   ctx = 0;
     int   val = 0;
 
-    if( s->mb_x > 0 )
-        mbn_xy = s->mb_x + s->mb_y*s->mb_stride - 1;
-    else
-        mbn_xy = s->mb_width - 1 + (s->mb_y-1)*s->mb_stride;
 
     if( h->last_qscale_diff != 0 )
         ctx++;
 
     while( get_cabac_noinline( &h->cabac, &h->cabac_state[60 + ctx] ) ) {
@@ -5198,10 +5566,12 @@
             h->top_mb_xy -= s->mb_stride;
         }
         if (left_mb_frame_flag != curr_mb_frame_flag) {
             h->left_mb_xy[0] = pair_xy - 1;
         }
+    } else if (FIELD_PICTURE) {
+        h->top_mb_xy -= s->mb_stride;
     }
     return;
 }
 
 /**
@@ -6433,11 +6803,11 @@
 
             if( ++s->mb_x >= s->mb_width ) {
                 s->mb_x = 0;
                 ff_draw_horiz_band(s, 16*s->mb_y, 16);
                 ++s->mb_y;
-                if(FRAME_MBAFF) {
+                if(FRAME_MBAFF || FIELD_PICTURE) {
                     ++s->mb_y;
                 }
             }
 
             if( eos || s->mb_y >= s->mb_height ) {
@@ -6470,11 +6840,11 @@
 
             if(++s->mb_x >= s->mb_width){
                 s->mb_x=0;
                 ff_draw_horiz_band(s, 16*s->mb_y, 16);
                 ++s->mb_y;
-                if(FRAME_MBAFF) {
+                if(FRAME_MBAFF || FIELD_PICTURE) {
                     ++s->mb_y;
                 }
                 if(s->mb_y >= s->mb_height){
                     tprintf(s->avctx, "slice end %d %d\n", get_bits_count(&s->gb), s->gb.size_in_bits);
 
@@ -7047,10 +7417,12 @@
 
         /* pull back stuff from slices to master context */
         hx = h->thread_context[context_count - 1];
         s->mb_x = hx->s.mb_x;
         s->mb_y = hx->s.mb_y;
+        s->dropable = hx->s.dropable;
+        s->picture_structure = hx->s.picture_structure;
         for(i = 1; i < context_count; i++)
             h->s.error_count += h->thread_context[i]->s.error_count;
     }
 }
 
@@ -7069,11 +7441,12 @@
         av_log(NULL, AV_LOG_ERROR,"%02X ", buf[i]);
     }
 #endif
     if(!(s->flags2 & CODEC_FLAG2_CHUNKS)){
         h->current_slice = 0;
-        s->current_picture_ptr= NULL;
+        if (!s->first_field)
+            s->current_picture_ptr= NULL;
     }
 
     for(;;){
         int consumed;
         int dst_length;
@@ -7148,11 +7521,11 @@
             hx->s.data_partitioning = 0;
 
             if((err = decode_slice_header(hx, h)))
                break;
 
-            s->current_picture_ptr->key_frame= (hx->nal_unit_type == NAL_IDR_SLICE);
+            s->current_picture_ptr->key_frame|= (hx->nal_unit_type == NAL_IDR_SLICE);
             if(hx->redundant_pic_count==0 && hx->s.hurry_up < 5
                && (avctx->skip_frame < AVDISCARD_NONREF || hx->nal_ref_idc)
                && (avctx->skip_frame < AVDISCARD_BIDIR  || hx->slice_type!=B_TYPE)
                && (avctx->skip_frame < AVDISCARD_NONKEY || hx->slice_type==I_TYPE)
                && avctx->skip_frame < AVDISCARD_ALL)
@@ -7366,21 +7739,39 @@
         s->current_picture_ptr->qscale_type= FF_QSCALE_TYPE_H264;
         s->current_picture_ptr->pict_type= s->pict_type;
 
         h->prev_frame_num_offset= h->frame_num_offset;
         h->prev_frame_num= h->frame_num;
-        if(s->current_picture_ptr->reference & s->picture_structure){
+        if(!s->dropable) {
             h->prev_poc_msb= h->poc_msb;
             h->prev_poc_lsb= h->poc_lsb;
             execute_ref_pic_marking(h, h->mmco, h->mmco_index);
         }
 
-        ff_er_frame_end(s);
+        /*
+         * FIXME: Error handling code does not seem to support interlaced
+         * when slices span multiple rows
+         * The ff_er_add_slice calls don't work right for bottom
+         * fields; they cause massive erroneous error concealing
+         * Error marking covers both fields (top and bottom).
+         * This causes a mismatched s->error_count
+         * and a bad error table. Further, the error count goes to
+         * INT_MAX when called for bottom field, because mb_y is
+         * past end by one (callers fault) and resync_mb_y != 0
+         * causes problems for the first MB line, too.
+         */
+        if (!FIELD_PICTURE)
+            ff_er_frame_end(s);
 
         MPV_frame_end(s);
 
-    //FIXME do something with unavailable reference frames
+        if (s->first_field) {
+            /* Wait for second field. */
+            *data_size = 0;
+
+        } else {
+        //FIXME do something with unavailable reference frames
 
 #if 0 //decode order
         *data_size = sizeof(AVFrame);
 #else
         /* Sort B-frames into display order */
@@ -7446,10 +7837,11 @@
 
         if(out)
             *pict= *(AVFrame*)out;
         else
             av_log(avctx, AV_LOG_DEBUG, "no picture\n");
+        }
     }
 
     assert(pict->data[0] || !*data_size);
     ff_print_debug_info(s, pict);
 //printf("out %d\n", (int)pict->data[0]);
--- ../ffmpeg-cosmetics/libavcodec/h264.h	2007-09-24 17:07:39.000000000 -0400
+++ libavcodec/h264.h	2007-09-24 17:08:08.000000000 -0400
@@ -57,14 +57,16 @@
 
 #ifdef ALLOW_INTERLACE
 #define MB_MBAFF h->mb_mbaff
 #define MB_FIELD h->mb_field_decoding_flag
 #define FRAME_MBAFF h->mb_aff_frame
+#define FIELD_PICTURE (s->picture_structure != PICT_FRAME)
 #else
 #define MB_MBAFF 0
 #define MB_FIELD 0
 #define FRAME_MBAFF 0
+#define FIELD_PICTURE 0
 #undef  IS_INTERLACED
 #define IS_INTERLACED(mb_type) 0
 #endif
 
 /**
@@ -281,11 +283,11 @@
     int frame_num_offset;         ///< for POC type 2
     int prev_frame_num_offset;    ///< for POC type 2
     int prev_frame_num;           ///< frame_num of the last pic for POC type 1/2
 
     /**
-     * frame_num for frames or 2*frame_num for field pics.
+     * frame_num for frames or 2*frame_num+1 for field pics.
      */
     int curr_pic_num;
 
     /**
      * max_frame_num or 2*max_frame_num for field pics.
--- ../ffmpeg-cosmetics/libavcodec/mpegvideo.c	2007-09-26 15:22:59.000000000 -0400
+++ libavcodec/mpegvideo.c	2007-10-01 15:25:45.000000000 -0400
@@ -952,11 +952,11 @@
         goto alloc;
     }
 
     assert(s->pict_type == I_TYPE || (s->last_picture_ptr && s->last_picture_ptr->data[0]));
 
-    if(s->picture_structure!=PICT_FRAME){
+    if(s->picture_structure!=PICT_FRAME && s->out_format != FMT_H264){
         int i;
         for(i=0; i<4; i++){
             if(s->picture_structure == PICT_BOTTOM_FIELD){
                  s->current_picture.data[i] += s->current_picture.linesize[i];
             }



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