Decouple bit context from h264 context in decode_ref_pic_marking()

(done in order to implement slice-level parallel decoding)
Patch by Andreas Öman % andreas olebyn nu %
Original thread:
Date: Jun 15, 2007 10:10 PM
Subject: [FFmpeg-devel] [PATCH] h264 parallelized, (was: Parallelized h264 proof-of-concept)

Originally committed as revision 9371 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/h264.c

@@ -4006,13 +4006,13 @@ static int execute_ref_pic_marking(H264Context *h, MMCO *mmco, int mmco_count){
     return 0;
 }
 
-static int decode_ref_pic_marking(H264Context *h){
+static int decode_ref_pic_marking(H264Context *h, GetBitContext *gb){
     MpegEncContext * const s = &h->s;
     int i;
 
     if(h->nal_unit_type == NAL_IDR_SLICE){ //FIXME fields
-        s->broken_link= get_bits1(&s->gb) -1;
-        h->mmco[0].long_index= get_bits1(&s->gb) - 1; // current_long_term_idx
+        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_index= 0;
         else{
@@ -4020,20 +4020,20 @@ static int decode_ref_pic_marking(H264Context *h){
             h->mmco_index= 1;
         }
     }else{
-        if(get_bits1(&s->gb)){ // adaptive_ref_pic_marking_mode_flag
+        if(get_bits1(gb)){ // adaptive_ref_pic_marking_mode_flag
             for(i= 0; i<MAX_MMCO_COUNT; i++) {
-                MMCOOpcode opcode= get_ue_golomb(&s->gb);;
+                MMCOOpcode opcode= get_ue_golomb(gb);
 
                 h->mmco[i].opcode= opcode;
                 if(opcode==MMCO_SHORT2UNUSED || opcode==MMCO_SHORT2LONG){
-                    h->mmco[i].short_frame_num= (h->frame_num - get_ue_golomb(&s->gb) - 1) & ((1<<h->sps.log2_max_frame_num)-1); //FIXME fields
+                    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){
                         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(&s->gb);
+                    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){
                         av_log(h->s.avctx, AV_LOG_ERROR, "illegal long ref in memory management control operation %d\n", opcode);
                         return -1;
@@ -4416,7 +4416,7 @@ static int decode_slice_header(H264Context *h){
         h->use_weight = 0;
 
     if(s->current_picture.reference)
-        decode_ref_pic_marking(h);
+        decode_ref_pic_marking(h, &s->gb);
 
     if(FRAME_MBAFF)
         fill_mbaff_ref_list(h);