- More work on preliminary bit rate control, just to be able to get an

average variance for picture's MBs so we can adjust qscale on the MB layer.

Originally committed as revision 294 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/motion_est.c

@@ -400,7 +400,7 @@ int estimate_motion(MpegEncContext * s,
     UINT8 *pix, *ppix;
     int sum, varc, vard, mx, my, range, dmin, xx, yy;
     int xmin, ymin, xmax, ymax;
-
+    
     range = 8 * (1 << (s->f_code - 1));
     /* XXX: temporary kludge to avoid overflow for msmpeg4 */
     if (s->out_format == FMT_H263 && !s->h263_msmpeg4)
@@ -458,9 +458,12 @@ int estimate_motion(MpegEncContext * s,
     vard = vard >> 8;
     sum = sum >> 8;
     varc = (varc >> 8) - (sum * sum);
+    
+    s->avg_mb_var += varc;
+     
 #if 0
-    printf("varc=%d (sum=%d) vard=%d mx=%d my=%d\n",
-	   varc, sum, vard, mx - xx, my - yy);
+    printf("varc=%4d avg_var=%4d (sum=%4d) vard=%4d mx=%2d my=%2d\n",
+	   varc, s->avg_mb_var, sum, vard, mx - xx, my - yy);
 #endif
     if (vard <= 64 || vard < varc) {
         if (s->full_search != ME_ZERO) {

libavcodec/mpegvideo.c

@@ -115,6 +115,7 @@ int MPV_common_init(MpegEncContext *s)
 #endif
     s->mb_width = (s->width + 15) / 16;
     s->mb_height = (s->height + 15) / 16;
+    s->mb_num = s->mb_width * s->mb_height;
     s->linesize = s->mb_width * 16 + 2 * EDGE_WIDTH;
 
     for(i=0;i<3;i++) {
@@ -149,7 +150,7 @@ int MPV_common_init(MpegEncContext *s)
     
     if (s->encoding) {
         /* Allocate MB type table */
-        s->mb_type = malloc(s->mb_width * s->mb_height * sizeof(char));
+        s->mb_type = malloc(s->mb_num * sizeof(char));
         if (s->mb_type == NULL) {
             perror("malloc");
             goto fail;
@@ -157,8 +158,8 @@ int MPV_common_init(MpegEncContext *s)
     
         /* Allocate MV table */
         /* By now we just have one MV per MB */
-        s->mv_table[0] = malloc(s->mb_width * s->mb_height * sizeof(INT16));
-        s->mv_table[1] = malloc(s->mb_width * s->mb_height * sizeof(INT16));
+        s->mv_table[0] = malloc(s->mb_num * sizeof(INT16));
+        s->mv_table[1] = malloc(s->mb_num * sizeof(INT16));
         if (s->mv_table[1] == NULL || s->mv_table[0] == NULL) {
             perror("malloc");
             goto fail;
@@ -204,17 +205,17 @@ int MPV_common_init(MpegEncContext *s)
             goto fail;
 
         /* which mb is a intra block */
-        s->mbintra_table = av_mallocz(s->mb_width * s->mb_height);
+        s->mbintra_table = av_mallocz(s->mb_num);
         if (!s->mbintra_table)
             goto fail;
-        memset(s->mbintra_table, 1, s->mb_width * s->mb_height);
+        memset(s->mbintra_table, 1, s->mb_num);
     }
     /* default structure is frame */
     s->picture_structure = PICT_FRAME;
 
     /* init macroblock skip table */
     if (!s->encoding) {
-        s->mbskip_table = av_mallocz(s->mb_width * s->mb_height);
+        s->mbskip_table = av_mallocz(s->mb_num);
         if (!s->mbskip_table)
             goto fail;
     }
@@ -960,22 +961,12 @@ static void encode_picture(MpegEncContext *s, int picture_number)
         else
             s->gob_index = 4;
     }
-        
+    
+    /* Reset the average MB variance */
+    s->avg_mb_var = 0;
+    
+    /* Estimate motion for every MB */
     for(mb_y=0; mb_y < s->mb_height; mb_y++) {
-        /* Put GOB header based on RTP MTU */
-        /* TODO: Put all this stuff in a separate generic function */
-        if (s->rtp_mode) {
-            if (!mb_y) {
-                s->ptr_lastgob = s->pb.buf;
-                s->ptr_last_mb_line = s->pb.buf;
-            } else if (s->out_format == FMT_H263 && !s->h263_pred && !s->h263_msmpeg4 && !(mb_y % s->gob_index)) {
-                last_gob = h263_encode_gob_header(s, mb_y);
-                if (last_gob) {
-                    s->first_gob_line = 1;
-                }
-            }
-        }
-        
         for(mb_x=0; mb_x < s->mb_width; mb_x++) {
             s->mb_x = mb_x;
             s->mb_y = mb_y;
@@ -995,7 +986,25 @@ static void encode_picture(MpegEncContext *s, int picture_number)
             s->mv_table[0][mb_y * s->mb_width + mb_x] = motion_x;
             s->mv_table[1][mb_y * s->mb_width + mb_x] = motion_y;
         }
-                    
+    }
+    
+    s->avg_mb_var = s->avg_mb_var / s->mb_num;        
+    
+    for(mb_y=0; mb_y < s->mb_height; mb_y++) {
+        /* Put GOB header based on RTP MTU */
+        /* TODO: Put all this stuff in a separate generic function */
+        if (s->rtp_mode) {
+            if (!mb_y) {
+                s->ptr_lastgob = s->pb.buf;
+                s->ptr_last_mb_line = s->pb.buf;
+            } else if (s->out_format == FMT_H263 && !s->h263_pred && !s->h263_msmpeg4 && !(mb_y % s->gob_index)) {
+                last_gob = h263_encode_gob_header(s, mb_y);
+                if (last_gob) {
+                    s->first_gob_line = 1;
+                }
+            }
+        }
+        
         for(mb_x=0; mb_x < s->mb_width; mb_x++) {
 
             s->mb_x = mb_x;

libavcodec/mpegvideo.h

@@ -58,8 +58,9 @@ typedef struct MpegEncContext {
     int context_initialized;
     int picture_number;
     int fake_picture_number; /* picture number at the bitstream frame rate */
-    int gop_picture_number; /* index of the first picture of a GOP */
+    int gop_picture_number;  /* index of the first picture of a GOP */
     int mb_width, mb_height;
+    int mb_num;                /* number of MBs of a picture */
     int linesize;              /* line size, in bytes, may be different from width */
     UINT8 *new_picture[3];     /* picture to be compressed */
     UINT8 *last_picture[3];    /* previous picture */
@@ -136,6 +137,7 @@ typedef struct MpegEncContext {
     /* bit rate control */
     int I_frame_bits;    /* wanted number of bits per I frame */
     int P_frame_bits;    /* same for P frame */
+    int avg_mb_var;        /* average MB variance for current frame */
     INT64 wanted_bits;
     INT64 total_bits;