mpeg1 bframe encoding patch by (Raphaël LEGRAND) with some modifications by me

Originally committed as revision 1551 to svn://svn.ffmpeg.org/ffmpeg/trunk

4 files changed, 194 insertions, 48 deletions

diff --git a/libavcodec/motion_est.c b/libavcodec/motion_est.c
index 89f814b924..5814cb33cf 100644
--- a/libavcodec/motion_est.c
+++ b/libavcodec/motion_est.c
@@ -1493,12 +1493,13 @@ void ff_estimate_b_frame_motion(MpegEncContext * s,
     fbmin= bidir_refine(s, mb_x, mb_y) + penalty_factor;
 //printf("%d %d %d %d\n", dmin, fmin, bmin, fbmin);
     {
-        int score= dmin;
-        type=MB_TYPE_DIRECT;
+        int score= fmin;
+        type = MB_TYPE_FORWARD;
         
-        if(fmin<score){
-            score=fmin;
-            type= MB_TYPE_FORWARD; 
+        // RAL: No MB_TYPE_DIRECT in MPEG-1 video (only MPEG-4)
+        if (s->codec_id != CODEC_ID_MPEG1VIDEO && dmin <= score){
+            score = dmin;
+            type = MB_TYPE_DIRECT;
         }
         if(bmin<score){
             score=bmin;
@@ -1643,21 +1644,32 @@ void ff_fix_long_b_mvs(MpegEncContext * s, int16_t (*mv_table)[2], int f_code, i
     int y;
     UINT8 * fcode_tab= s->fcode_tab;
 
+    // RAL: 8 in MPEG-1, 16 in MPEG-4
+    int range = (((s->codec_id == CODEC_ID_MPEG1VIDEO) ? 8 : 16) << f_code);
+
     /* clip / convert to intra 16x16 type MVs */
     for(y=0; y<s->mb_height; y++){
         int x;
         int xy= (y+1)* (s->mb_width+2)+1;
         int i= y*s->mb_width;
-        for(x=0; x<s->mb_width; x++){
-            if(   fcode_tab[mv_table[xy][0] + MAX_MV] > f_code
-               || fcode_tab[mv_table[xy][0] + MAX_MV] == 0){
-                if(mv_table[xy][0]>0) mv_table[xy][0]=  (16<<f_code)-1;
-                else                  mv_table[xy][0]= -(16<<f_code);
+        for(x=0; x<s->mb_width; x++)
+            {
+            if (s->mb_type[i] & type)    // RAL: "type" test added...
+                {
+                if (fcode_tab[mv_table[xy][0] + MAX_MV] > f_code || fcode_tab[mv_table[xy][0] + MAX_MV] == 0)
+                    {
+                    if(mv_table[xy][0]>0) 
+                        mv_table[xy][0]=  range-1;
+                    else
+                        mv_table[xy][0]= -range;
+                    }
+                if (fcode_tab[mv_table[xy][1] + MAX_MV] > f_code || fcode_tab[mv_table[xy][1] + MAX_MV] == 0)
+                    {
+                    if(mv_table[xy][1]>0) 
+                        mv_table[xy][1]=  range-1;
+                    else                  
+                        mv_table[xy][1]= -range;
             }
-            if(   fcode_tab[mv_table[xy][1] + MAX_MV] > f_code
-               || fcode_tab[mv_table[xy][1] + MAX_MV] == 0){
-                if(mv_table[xy][1]>0) mv_table[xy][1]=  (16<<f_code)-1;
-                else                  mv_table[xy][1]= -(16<<f_code);
             }
             xy++;
             i++;
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 9c32aa493c..52ab5094de 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -50,7 +50,7 @@
 static void mpeg1_encode_block(MpegEncContext *s, 
                          DCTELEM *block, 
                          int component);
-static void mpeg1_encode_motion(MpegEncContext *s, int val);
+static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code);    // RAL: f_code parameter added
 static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
 static inline int mpeg1_decode_block_inter(MpegEncContext *s, 
                               DCTELEM *block, 
@@ -332,18 +332,27 @@ void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
     /* mpeg1 picture header */
     put_header(s, PICTURE_START_CODE);
     /* temporal reference */
-    put_bits(&s->pb, 10, (s->fake_picture_number - 
+
+    // RAL: s->picture_number instead of s->fake_picture_number
+    put_bits(&s->pb, 10, (s->picture_number - 
                           s->gop_picture_number) & 0x3ff); 
     s->fake_picture_number++;
     
     put_bits(&s->pb, 3, s->pict_type);
     put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
     
-    if (s->pict_type == P_TYPE) {
+    // RAL: Forward f_code also needed for B frames
+    if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
         put_bits(&s->pb, 1, 0); /* half pel coordinates */
         put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
     }
     
+    // RAL: Backward f_code necessary for B frames
+    if (s->pict_type == B_TYPE) {
+        put_bits(&s->pb, 1, 0); /* half pel coordinates */
+        put_bits(&s->pb, 3, s->b_code); /* backward_f_code */
+        }
+
     put_bits(&s->pb, 1, 0); /* extra bit picture */
     
     /* only one slice */
@@ -368,10 +377,11 @@ void mpeg1_encode_mb(MpegEncContext *s,
             cbp |= 1 << (5 - i);
     }
 
-    /* skip macroblock, except if first or last macroblock of a slice */
-    if ((cbp | motion_x | motion_y) == 0 &&
-        (!((mb_x | mb_y) == 0 ||
-           (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
+    // RAL: Skipped macroblocks for B frames...
+    if (cbp == 0 && (!((mb_x | mb_y) == 0 || (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1))) && 
+        ((s->pict_type == P_TYPE && (motion_x | motion_y) == 0) ||
+        (s->pict_type == B_TYPE && s->mv_dir == s->last_mv_dir && (((s->mv_dir & MV_DIR_FORWARD) ? ((s->mv[0][0][0] - s->last_mv[0][0][0])|(s->mv[0][0][1] - s->last_mv[0][0][1])) : 0) |
+        ((s->mv_dir & MV_DIR_BACKWARD) ? ((s->mv[1][0][0] - s->last_mv[1][0][0])|(s->mv[1][0][1] - s->last_mv[1][0][1])) : 0)) == 0))) {
         s->mb_incr++;
         s->qscale -= s->dquant;
         s->skip_count++;
@@ -398,18 +408,19 @@ void mpeg1_encode_mb(MpegEncContext *s,
             }
             s->misc_bits+= get_bits_diff(s);
             s->i_count++;
-        } else {
-            if (s->mb_intra) {
-                if(s->dquant && cbp){
-                    put_bits(&s->pb, 6, 0x01);
-                    put_bits(&s->pb, 5, s->qscale);
-                }else{
-                    put_bits(&s->pb, 5, 0x03);
-                    s->qscale -= s->dquant;
-                }
-                s->misc_bits+= get_bits_diff(s);
-                s->i_count++;
-            } else {
+        } else if (s->mb_intra) {
+            if(s->dquant && cbp){
+                put_bits(&s->pb, 6, 0x01);
+                put_bits(&s->pb, 5, s->qscale);
+            }else{
+                put_bits(&s->pb, 5, 0x03);
+                s->qscale -= s->dquant;
+            }
+            s->misc_bits+= get_bits_diff(s);
+            s->i_count++;
+            s->last_mv[0][0][0] = 
+            s->last_mv[0][0][1] = 0;
+        } else if (s->pict_type == P_TYPE) { 
                 if (cbp != 0) {
                     if (motion_x == 0 && motion_y == 0) {
                         if(s->dquant){
@@ -428,21 +439,106 @@ void mpeg1_encode_mb(MpegEncContext *s,
                             put_bits(&s->pb, 1, 1); /* motion + cbp */
                         }
                         s->misc_bits+= get_bits_diff(s);
-                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
-                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
+                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
+                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
                         s->mv_bits+= get_bits_diff(s);
                         put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
                     }
                 } else {
                     put_bits(&s->pb, 3, 1); /* motion only */
-                    mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]); 
-                    mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]); 
+                    mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code);    // RAL: f_code parameter added
+                    mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code);    // RAL: f_code parameter added
                     s->qscale -= s->dquant;
                     s->mv_bits+= get_bits_diff(s);
                 }
                 s->f_count++;
+        } else
+            {    // RAL: All the following bloc added for B frames:
+                if (cbp != 0)
+                    {    // With coded bloc pattern
+                    if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
+                        {    // Bi-directional motion
+                        if (s->dquant)
+                            {    // With QScale
+                            put_bits(&s->pb, 5, 2);
+                            put_bits(&s->pb, 5, s->qscale);
+                            }
+                        else    // Without QScale
+                            put_bits(&s->pb, 2, 3);
+                        s->misc_bits += get_bits_diff(s);
+                        mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
+                        mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
+                        mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
+                        mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
+                        s->b_count++;
+                        s->f_count++;
+                        s->mv_bits += get_bits_diff(s);
+                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
+                        }
+                    else if (s->mv_dir == MV_DIR_BACKWARD)
+                        {    // Backward motion
+                        if (s->dquant)
+                            {    // With QScale
+                            put_bits(&s->pb, 6, 2);
+                            put_bits(&s->pb, 5, s->qscale);
+                            }
+                        else    // Without QScale
+                            put_bits(&s->pb, 3, 3);
+                        s->misc_bits += get_bits_diff(s);
+                        mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code); 
+                        mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code); 
+                        s->b_count++;
+                        s->mv_bits += get_bits_diff(s);
+                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
+                        }
+                    else if (s->mv_dir == MV_DIR_FORWARD)
+                        {    // Forward motion
+                        if (s->dquant)
+                            {    // With QScale
+                            put_bits(&s->pb, 6, 3);
+                            put_bits(&s->pb, 5, s->qscale);
+                            }
+                        else    // Without QScale
+                            put_bits(&s->pb, 4, 3);
+                        s->misc_bits += get_bits_diff(s);
+                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); 
+                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); 
+                        s->f_count++;
+                        s->mv_bits += get_bits_diff(s);
+                        put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
+                        }
+                    }
+                else
+                    {    // No coded bloc pattern
+                    if (s->mv_dir == (MV_DIR_FORWARD | MV_DIR_BACKWARD))
+                        {    // Bi-directional motion
+                        put_bits(&s->pb, 2, 2); /* backward & forward motion */
+                        mpeg1_encode_motion(s, s->mv[0][0][0] - s->last_mv[0][0][0], s->f_code);
+                        mpeg1_encode_motion(s, s->mv[0][0][1] - s->last_mv[0][0][1], s->f_code);
+                        mpeg1_encode_motion(s, s->mv[1][0][0] - s->last_mv[1][0][0], s->b_code);
+                        mpeg1_encode_motion(s, s->mv[1][0][1] - s->last_mv[1][0][1], s->b_code);
+                        s->b_count++;
+                        s->f_count++;
+                        }
+                    else if (s->mv_dir == MV_DIR_BACKWARD)
+                        {    // Backward motion
+                        put_bits(&s->pb, 3, 2); /* backward motion only */
+                        mpeg1_encode_motion(s, motion_x - s->last_mv[1][0][0], s->b_code); 
+                        mpeg1_encode_motion(s, motion_y - s->last_mv[1][0][1], s->b_code); 
+                        s->b_count++;
+                        }
+                    else if (s->mv_dir == MV_DIR_FORWARD)
+                        {    // Forward motion
+                        put_bits(&s->pb, 4, 2); /* forward motion only */
+                        mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0], s->f_code); 
+                        mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1], s->f_code); 
+                        s->f_count++;
+                        }
+                    s->qscale -= s->dquant;
+                    s->mv_bits += get_bits_diff(s);
+                    }
+            // End of bloc from RAL
             }
-        }
         for(i=0;i<6;i++) {
             if (cbp & (1 << (5 - i))) {
                 mpeg1_encode_block(s, block[i], i);
@@ -454,11 +550,22 @@ void mpeg1_encode_mb(MpegEncContext *s,
         else
             s->p_tex_bits+= get_bits_diff(s);
     }
-    s->last_mv[0][0][0] = motion_x;
-    s->last_mv[0][0][1] = motion_y;
+
+    // RAL: By this:
+    if (s->mv_dir & MV_DIR_FORWARD)
+        {
+        s->last_mv[0][0][0]= s->mv[0][0][0];
+        s->last_mv[0][0][1]= s->mv[0][0][1];
+        }
+    if (s->mv_dir & MV_DIR_BACKWARD)
+        {
+        s->last_mv[1][0][0]= s->mv[1][0][0];
+        s->last_mv[1][0][1]= s->mv[1][0][1];
+        }
 }
 
-static void mpeg1_encode_motion(MpegEncContext *s, int val)
+// RAL: Parameter added: f_or_b_code
+static void mpeg1_encode_motion(MpegEncContext *s, int val, int f_or_b_code)
 {
     int code, bit_size, l, m, bits, range, sign;
 
@@ -469,7 +576,7 @@ static void mpeg1_encode_motion(MpegEncContext *s, int val)
                  mbMotionVectorTable[0][1], 
                  mbMotionVectorTable[0][0]); 
     } else {
-        bit_size = s->f_code - 1;
+        bit_size = f_or_b_code - 1;
         range = 1 << bit_size;
         /* modulo encoding */
         l = 16 * range;
@@ -492,9 +599,13 @@ static void mpeg1_encode_motion(MpegEncContext *s, int val)
             bits = val & (range - 1);
             sign = 1;
         }
+
+        assert(code > 0 && code <= 16);
+
         put_bits(&s->pb,
                  mbMotionVectorTable[code][1], 
                  mbMotionVectorTable[code][0]); 
+
         put_bits(&s->pb, 1, sign);
         if (bit_size > 0) {
             put_bits(&s->pb, bit_size, bits);
diff --git a/libavcodec/mpegvideo.c b/libavcodec/mpegvideo.c
index 15bd0249b0..34687d735e 100644
--- a/libavcodec/mpegvideo.c
+++ b/libavcodec/mpegvideo.c
@@ -2872,7 +2872,8 @@ static void encode_picture(MpegEncContext *s, int picture_number)
 
 #ifdef CONFIG_RISKY
     /* we need to initialize some time vars before we can encode b-frames */
-    if (s->h263_pred && !s->h263_msmpeg4)
+    // RAL: Condition added for MPEG1VIDEO
+    if (s->codec_id == CODEC_ID_MPEG1VIDEO || (s->h263_pred && !s->h263_msmpeg4))
         ff_set_mpeg4_time(s, s->picture_number); 
 #endif
         
@@ -2965,12 +2966,24 @@ static void encode_picture(MpegEncContext *s, int picture_number)
 //printf("Scene change detected, encoding as I Frame %d %d\n", s->current_picture.mb_var_sum, s->current_picture.mc_mb_var_sum);
     }
 
-    if(s->pict_type==P_TYPE || s->pict_type==S_TYPE) 
+    if(s->pict_type==P_TYPE || s->pict_type==S_TYPE) {
         s->f_code= ff_get_best_fcode(s, s->p_mv_table, MB_TYPE_INTER);
+        
+        // RAL: Next call moved into that bloc
         ff_fix_long_p_mvs(s);
+    }
+
+    // RAL: All this bloc changed
     if(s->pict_type==B_TYPE){
-        s->f_code= ff_get_best_fcode(s, s->b_forw_mv_table, MB_TYPE_FORWARD);
-        s->b_code= ff_get_best_fcode(s, s->b_back_mv_table, MB_TYPE_BACKWARD);
+        int a, b;
+
+        a = ff_get_best_fcode(s, s->b_forw_mv_table, MB_TYPE_FORWARD);
+        b = ff_get_best_fcode(s, s->b_bidir_forw_mv_table, MB_TYPE_BIDIR);
+        s->f_code = FFMAX(a, b);
+
+        a = ff_get_best_fcode(s, s->b_back_mv_table, MB_TYPE_BACKWARD);
+        b = ff_get_best_fcode(s, s->b_bidir_back_mv_table, MB_TYPE_BIDIR);
+        s->b_code = FFMAX(a, b);
 
         ff_fix_long_b_mvs(s, s->b_forw_mv_table, s->f_code, MB_TYPE_FORWARD);
         ff_fix_long_b_mvs(s, s->b_back_mv_table, s->b_code, MB_TYPE_BACKWARD);
@@ -3064,6 +3077,10 @@ static void encode_picture(MpegEncContext *s, int picture_number)
     s->mb_incr = 1;
     s->last_mv[0][0][0] = 0;
     s->last_mv[0][0][1] = 0;
+    s->last_mv[1][0][0] = 0;
+    s->last_mv[1][0][1] = 0;
+     
+    s->last_mv_dir = 0;
 
 #ifdef CONFIG_RISKY
     if (s->codec_id==CODEC_ID_H263 || s->codec_id==CODEC_ID_H263P)
@@ -3227,7 +3244,7 @@ static void encode_picture(MpegEncContext *s, int picture_number)
                                  &dmin, &next_block, mx, my);
                 }
                 if(mb_type&MB_TYPE_INTRA){
-                    s->mv_dir = MV_DIR_FORWARD;
+                    s->mv_dir = 0;
                     s->mv_type = MV_TYPE_16X16;
                     s->mb_intra= 1;
                     s->mv[0][0][0] = 0;
@@ -3348,7 +3365,7 @@ static void encode_picture(MpegEncContext *s, int picture_number)
                 
                 switch(mb_type){
                 case MB_TYPE_INTRA:
-                    s->mv_dir = MV_DIR_FORWARD;
+                    s->mv_dir = 0;
                     s->mb_intra= 1;
                     motion_x= s->mv[0][0][0] = 0;
                     motion_y= s->mv[0][0][1] = 0;
@@ -3405,8 +3422,13 @@ static void encode_picture(MpegEncContext *s, int picture_number)
                     motion_x=motion_y=0; //gcc warning fix
                     printf("illegal MB type\n");
                 }
+
                 encode_mb(s, motion_x, motion_y);
+
+                // RAL: Update last macrobloc type
+                s->last_mv_dir = s->mv_dir;
             }
+
             /* clean the MV table in IPS frames for direct mode in B frames */
             if(s->mb_intra /* && I,P,S_TYPE */){
                 s->p_mv_table[xy][0]=0;
diff --git a/libavcodec/mpegvideo.h b/libavcodec/mpegvideo.h
index 7ecc6fd38c..91a4525785 100644
--- a/libavcodec/mpegvideo.h
+++ b/libavcodec/mpegvideo.h
@@ -508,6 +508,7 @@ typedef struct MpegEncContext {
     /* Mpeg1 specific */
     int fake_picture_number; /* picture number at the bitstream frame rate */
     int gop_picture_number;  /* index of the first picture of a GOP based on fake_pic_num & mpeg1 specific */
+    int last_mv_dir;         /* last mv_dir, used for b frame encoding */
     
     /* MPEG2 specific - I wish I had not to support this mess. */
     int progressive_sequence;