implemented frame skipping for libmpeg2 as well as low-quality decoding for low-end systems

CVS patchset: 82
CVS date: 2001/05/26 00:48:47

6 files changed, 113 insertions, 26 deletions

diff --git a/src/libmpeg2/decode.c b/src/libmpeg2/decode.c
index 8feb005dc..044f235f3 100644
--- a/src/libmpeg2/decode.c
+++ b/src/libmpeg2/decode.c
@@ -90,17 +90,14 @@ static inline int parse_chunk (mpeg2dec_t * mpeg2dec, int code,
 	if (((picture->picture_structure == FRAME_PICTURE) ||
 	     (picture->second_field)) ) {
 
+	    picture->current_frame->bFrameBad = mpeg2dec->drop_frame;
+
 	    if (picture->picture_coding_type == B_TYPE) {
-	      picture->current_frame->bFrameBad = mpeg2dec->drop_frame;
-	      picture->current_frame->PTS = mpeg2dec->pts;
-	      mpeg2dec->pts = 0;
 	      mpeg2dec->frames_to_drop = picture->current_frame->draw (picture->current_frame);
 	      picture->current_frame->free (picture->current_frame);
 	      picture->current_frame = NULL;
+	      picture->throwaway_frame = NULL;
 	    } else {
-	      picture->forward_reference_frame->bFrameBad = mpeg2dec->drop_frame;
-	      picture->forward_reference_frame->PTS = mpeg2dec->pts;
-	      mpeg2dec->pts = 0;
 	      mpeg2dec->frames_to_drop = picture->forward_reference_frame->draw (picture->forward_reference_frame);
 	    }
 
@@ -117,8 +114,41 @@ static inline int parse_chunk (mpeg2dec_t * mpeg2dec, int code,
 	    fprintf (stderr, "bad picture header\n");
 	    exit (1);
 	}
-	mpeg2dec->drop_frame = /* FIXME : skip P and I frames too if necc. */
-	    (mpeg2dec->frames_to_drop>0) && (picture->picture_coding_type == B_TYPE);
+
+	/* find out if we want to skip this frame */
+	mpeg2dec->drop_frame = 0;
+
+	picture->skip_non_intra_dct = (mpeg2dec->frames_to_drop>0) ;
+
+	    
+	switch (picture->picture_coding_type) {
+        case B_TYPE:
+          
+          if (mpeg2dec->frames_to_drop>1) {
+            mpeg2dec->drop_frame = 1;
+          } else if (picture->forward_reference_frame->bFrameBad 
+                     || picture->backward_reference_frame->bFrameBad) {
+            mpeg2dec->drop_frame = 1;
+          }
+	  break;
+
+        case P_TYPE:
+          
+          if (mpeg2dec->frames_to_drop>2) {
+            mpeg2dec->drop_frame = 1;
+          } else if (picture->backward_reference_frame->bFrameBad) {
+            mpeg2dec->drop_frame = 1;
+	  }
+	  break;
+
+        case I_TYPE:
+          
+          if (mpeg2dec->frames_to_drop>4) {
+            mpeg2dec->drop_frame = 1;
+	  }
+	  break;
+	}
+
 	break;
 
     case 0xb3:	/* sequence_header_code */
@@ -170,7 +200,7 @@ static inline int parse_chunk (mpeg2dec_t * mpeg2dec, int code,
 					    picture->picture_structure);
 	    else {
 		if (picture->picture_coding_type == B_TYPE)
-		    picture->current_frame =
+		    picture->throwaway_frame = picture->current_frame =
 		        mpeg2dec->output->get_frame (mpeg2dec->output,
 						     picture->coded_picture_width,
 						     picture->coded_picture_height,
@@ -191,6 +221,8 @@ static inline int parse_chunk (mpeg2dec_t * mpeg2dec, int code,
 			picture->backward_reference_frame;
 		    picture->backward_reference_frame = picture->current_frame;
 		}
+		picture->current_frame->PTS = mpeg2dec->pts;
+		mpeg2dec->pts = 0;
 	    }
 	}
 
@@ -268,15 +300,64 @@ int mpeg2_decode_data (mpeg2dec_t * mpeg2dec, uint8_t * current, uint8_t * end,
 void mpeg2_close (mpeg2dec_t * mpeg2dec)
 {
     static uint8_t finalizer[] = {0,0,1,0xb4};
+    picture_t *picture = mpeg2dec->picture;
 
     mpeg2_decode_data (mpeg2dec, finalizer, finalizer+4, 0);
 
-    /* FIXME
-    if (! (mpeg2dec->is_sequence_needed))
-	vo_draw (mpeg2dec->picture->backward_reference_frame);
-	*/
+    if (picture->throwaway_frame) 
+      picture->throwaway_frame->free (picture->throwaway_frame);
+
+    if (picture->forward_reference_frame) 
+      picture->forward_reference_frame->free (picture->forward_reference_frame);
+
+    if (picture->backward_reference_frame) 
+      picture->backward_reference_frame->free (picture->backward_reference_frame);
 
+    /* FIXME
     free (mpeg2dec->chunk_buffer);
     free (mpeg2dec->picture);
+    */
+}
+
+void mpeg2_find_sequence_header (mpeg2dec_t * mpeg2dec,
+				 uint8_t * current, uint8_t * end){
+
+    uint8_t code;
+    picture_t *picture = mpeg2dec->picture;
+
+    while (current != end) {
+	code = mpeg2dec->code;
+	current = copy_chunk (mpeg2dec, current, end);
+	if (current == NULL)
+	    return ;
+
+	if (code == 0xb3) {	/* sequence_header_code */
+	    if (header_process_sequence_header (picture, mpeg2dec->chunk_buffer)) {
+	        fprintf (stderr, "bad sequence header\n");
+		return;
+	    }
+	  
+	    if (mpeg2dec->is_sequence_needed) {
+	        mpeg2dec->is_sequence_needed = 0;
+		picture->forward_reference_frame =
+		    mpeg2dec->output->get_frame (mpeg2dec->output,
+						 picture->coded_picture_width,
+						 picture->coded_picture_height,
+						 picture->aspect_ratio_information,
+						 IMGFMT_YV12,
+						 picture->frame_duration);
+		picture->forward_reference_frame->PTS = 0;
+		picture->backward_reference_frame =
+		    mpeg2dec->output->get_frame (mpeg2dec->output,
+						 picture->coded_picture_width,
+						 picture->coded_picture_height,
+						 picture->aspect_ratio_information,
+						 IMGFMT_YV12,
+						 picture->frame_duration);
+		picture->backward_reference_frame->PTS = 0;
+	    
+	    }
+	}
+    }
 }
 
diff --git a/src/libmpeg2/mpeg2.h b/src/libmpeg2/mpeg2.h
index bca8f61b0..69a4ba03d 100644
--- a/src/libmpeg2/mpeg2.h
+++ b/src/libmpeg2/mpeg2.h
@@ -59,8 +59,10 @@ void mpeg2_init (mpeg2dec_t * mpeg2dec,
 void mpeg2_close (mpeg2dec_t * mpeg2dec);
 
 int mpeg2_decode_data (mpeg2dec_t * mpeg2dec,
-		       uint8_t * data_start, uint8_t * data_end, uint32_t pts);
+		       uint8_t * data_start, uint8_t * data_end, 
+		       uint32_t pts);
+
+void mpeg2_find_sequence_header (mpeg2dec_t * mpeg2dec,
+				 uint8_t * data_start, uint8_t * data_end);
 
-void decode_free_image_buffers (mpeg2dec_t * mpeg2dec) ;
 
-void mpeg2_drop (mpeg2dec_t * mpeg2dec, int flag);
diff --git a/src/libmpeg2/mpeg2_internal.h b/src/libmpeg2/mpeg2_internal.h
index 97c611d1c..bafd7abf9 100644
--- a/src/libmpeg2/mpeg2_internal.h
+++ b/src/libmpeg2/mpeg2_internal.h
@@ -124,6 +124,8 @@ typedef struct picture_s {
 
     int mpeg1;
 
+    int skip_non_intra_dct;
+
     /* these things are not needed by the decoder */
     /* this is a temporary interface, we will build a better one later. */
     int aspect_ratio_information;
diff --git a/src/libmpeg2/slice.c b/src/libmpeg2/slice.c
index 819ff0f65..95c04e79f 100644
--- a/src/libmpeg2/slice.c
+++ b/src/libmpeg2/slice.c
@@ -1011,8 +1011,9 @@ static inline void slice_non_intra_DCT (picture_t * picture, uint8_t * dest,
     if (picture->mpeg1)
 	get_mpeg1_non_intra_block (picture);
     else
-	get_non_intra_block (picture);
-    idct_block_add (picture->DCTblock, dest, stride);
+        get_non_intra_block (picture);
+    if (!picture->skip_non_intra_dct)
+        idct_block_add (picture->DCTblock, dest, stride);
 }
 
 #define MOTION_Y(table,offset_x,offset_y,motion_x,motion_y,		\
@@ -1712,7 +1713,7 @@ void slice_process (picture_t * picture, uint8_t code, uint8_t * buffer)
 		}
 
 		coded_block_pattern = get_coded_block_pattern (picture);
-
+		
 		if (coded_block_pattern & 0x20)
 		    slice_non_intra_DCT (picture, dest[0] + offset,
 					 DCT_stride);
@@ -1733,7 +1734,7 @@ void slice_process (picture_t * picture, uint8_t code, uint8_t * buffer)
 					 stride >> 1);
 		if (coded_block_pattern & 0x1)
 		    slice_non_intra_DCT (picture, dest[2] + (offset >> 1),
-					 stride >> 1);
+					 stride >> 1); 
 	    }
 
 	    picture->dc_dct_pred[0] = picture->dc_dct_pred[1] =
diff --git a/src/video_out/video_out_xv.c b/src/video_out/video_out_xv.c
index 9fe115d37..c62f8ce73 100644
--- a/src/video_out/video_out_xv.c
+++ b/src/video_out/video_out_xv.c
@@ -17,7 +17,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
  *
- * $Id: video_out_xv.c,v 1.21 2001/05/25 10:30:56 f1rmb Exp $
+ * $Id: video_out_xv.c,v 1.22 2001/05/26 00:48:47 guenter Exp $
  * 
  * video_out_xv.c, X11 video extension interface for xine
  *
@@ -151,7 +151,7 @@ static void xv_update_frame_format (vo_driver_t *this_gen, vo_frame_t *frame_gen
 
   if ((frame->width != width) || (frame->height != height) || (frame->format != format)) {
 
-    printf ("video_out_xv: updating frame to %d x %d (ratio=%d, format=%08x)\n",width,height,ratio_code,format);
+    /* printf ("video_out_xv: updating frame to %d x %d (ratio=%d, format=%08x)\n",width,height,ratio_code,format); */
 
     XLockDisplay (this->display); 
 
diff --git a/src/xine-engine/video_out.c b/src/xine-engine/video_out.c
index c1a206a3e..543e141fb 100644
--- a/src/xine-engine/video_out.c
+++ b/src/xine-engine/video_out.c
@@ -17,7 +17,7 @@
  * along with this program; if not, write to the Free Software
  * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA
  *
- * $Id: video_out.c,v 1.8 2001/05/24 23:15:40 f1rmb Exp $
+ * $Id: video_out.c,v 1.9 2001/05/26 00:48:47 guenter Exp $
  *
  */
 
@@ -352,6 +352,7 @@ static int vo_frame_draw (vo_frame_t *img) {
   int32_t        diff;
   uint32_t       cur_vpts;
   uint32_t       pic_vpts ;
+  int            frames_to_skip;
 
   pic_vpts = this->metronom->got_video_frame (this->metronom, img->PTS);
   img->PTS = pic_vpts;
@@ -364,13 +365,13 @@ static int vo_frame_draw (vo_frame_t *img) {
   cur_vpts = this->metronom->get_current_time(this->metronom);
 
   diff = pic_vpts - cur_vpts;
+  frames_to_skip = (-1 * diff) / this->pts_per_frame + 1;
 
   xprintf (VERBOSE|VIDEO,"video_out:: delivery diff : %d\n",diff);
 
   if (cur_vpts>0) {
 
-    if (diff<0) {
-      int frames_to_skip = diff / this->pts_per_frame;
+    if (diff<(-1 * this->pts_per_half_frame)) {
 
       this->num_frames_discarded++;
       xprintf (VERBOSE|VIDEO, "vo_frame_draw: rejected, %d frames to skip\n", frames_to_skip);
@@ -410,7 +411,7 @@ static int vo_frame_draw (vo_frame_t *img) {
     this->num_frames_skipped   = 0;
   }
   
-  return 0; /* no frames to skip */
+  return frames_to_skip;
 }
 
 vo_instance_t *vo_new_instance (vo_driver_t *driver, metronom_t *metronom) {