improvements to detc filter:

-> use of 8x8 blocks rather than 16x16 to better localize the search
   for interlacing. this helps detect interlacing in very small
   motions, e.g. mouths in anime.
-> removed some redundant conditions in the logic
-> looser condition for detecting lacing and more forgiving of slight
   mismatches between fields from the two telecine frames to make up
   for quantization noise in low quality encodes.
this code is still mostly experimental but probably better than the
old version, so maybe it should be backported to 0.90...?


git-svn-id: svn://svn.mplayerhq.hu/mplayer/trunk@9661 b3059339-0415-0410-9bf9-f77b7e298cf2

1 files changed, 16 insertions, 15 deletions

diff --git a/libmpcodecs/vf_detc.c b/libmpcodecs/vf_detc.c
index 681a3db792..1fc422b6ef 100644
--- a/libmpcodecs/vf_detc.c
+++ b/libmpcodecs/vf_detc.c
@@ -22,7 +22,7 @@ struct vf_priv_s {
 	int frame;
 	int drop, lastdrop;
 	struct metrics pm;
-	int thres[4];
+	int thres[5];
 	int inframes, outframes;
 	int mode;
 	int (*analyze)(struct vf_priv_s *, mp_image_t *, mp_image_t *);
@@ -92,11 +92,11 @@ static void block_diffs(struct metrics *m, unsigned char *old, unsigned char *ne
 	int x, y, even=0, odd=0, noise, temp;
 	unsigned char *oldp, *newp;
 	m->noise = m->temp = 0;
-	for (x = 15; x; x--) {
+	for (x = 8; x; x--) {
 		oldp = old++;
 		newp = new++;
 		noise = temp = 0;
-		for (y = 8; y; y--) {
+		for (y = 4; y; y--) {
 			even += abs(newp[0]-oldp[0]);
 			odd += abs(newp[ns]-oldp[os]);
 			noise += newp[ns]-newp[0];
@@ -115,8 +115,8 @@ static void diff_planes(struct metrics *m, unsigned char *old, unsigned char *ne
 {
 	int x, y, me=0, mo=0, mn=0, mt=0;
 	struct metrics l;
-	for (y = 0; y < h-15; y += 16) {
-		for (x = 0; x < w-15; x += 16) {
+	for (y = 0; y < h-7; y += 8) {
+		for (x = 0; x < w-7; x += 8) {
 			block_diffs(&l, old+x+y*os, new+x+y*ns, os, ns);
 			if (l.even > me) me = l.even;
 			if (l.odd > mo) mo = l.odd;
@@ -190,8 +190,9 @@ static int analyze_aggressive(struct vf_priv_s *p, mp_image_t *new, mp_image_t *
 	p->pm = m;
 
 	if (p->frame == 4) {
-		if (2*m.noise > m.temp) {
-			if (VERYCLOSE(m.even, pm.odd)) {
+		/* Thres. is to compensate for quantization errors when noise is low */
+		if (m.noise - m.temp > -p->thres[4]) {
+			if (COMPARABLE(m.even, pm.odd)) {
 				//mp_msg(MSGT_VFILTER, MSGL_V, "confirmed field match!\n");
 				return TC_IL2;
 			} else if ((m.even < p->thres[0]) && (m.odd < p->thres[0]) && VERYCLOSE(m.even, m.odd)
@@ -207,9 +208,7 @@ static int analyze_aggressive(struct vf_priv_s *p, mp_image_t *new, mp_image_t *
 		}
 	}
 
-	if (((2*m.even < m.odd) && (5*m.temp < 4*m.noise))
-		|| ((5*m.even < 4*m.odd) && (2*m.temp < m.noise))
-		|| (m.even*m.temp < 2*m.odd*m.noise/5) /* ok? */ ) {
+	if (2*m.even*m.temp < m.odd*m.noise) {
 		mp_msg(MSGT_VFILTER, MSGL_V, "caught telecine sync!\n");
 		p->frame = 3;
 		return TC_IL1;
@@ -239,7 +238,7 @@ static int analyze_aggressive(struct vf_priv_s *p, mp_image_t *new, mp_image_t *
 	case 2:
 		return TC_PROG;
 	case 3:
-		if ((m.even > p->thres[1]) && (5*m.even > 4*m.odd) && (5*m.temp > 4*m.noise)) {
+		if ((m.even > p->thres[1]) && (m.even > m.odd) && (m.temp > m.noise)) {
 			mp_msg(MSGT_VFILTER, MSGL_V, "lost telecine tracking!\n");
 			p->frame = -1;
 			return TC_PROG;
@@ -415,6 +414,7 @@ static void parse_var(struct vf_priv_s *p, char *var)
 	GETVAR(var, "t1", p->thres[1], atoi);
 	GETVAR(var, "t2", p->thres[2], atoi);
 	GETVAR(var, "t3", p->thres[3], atoi);
+	GETVAR(var, "t4", p->thres[4], atoi);
 	GETVAR(var, "fr", p->frame, atoi);
 	GETVAR(var, "am", p->mode, atoi);
 }
@@ -440,10 +440,11 @@ static int open(vf_instance_t *vf, char* args)
 	vf->default_reqs = VFCAP_ACCEPT_STRIDE;
 	vf->priv = p = calloc(1, sizeof(struct vf_priv_s));
 	p->frame = -1;
-	p->thres[0] = 1760;
-	p->thres[1] = 2880;
-	p->thres[2] = 10000;
-	p->thres[3] = 10000;
+	p->thres[0] = 440;
+	p->thres[1] = 720;
+	p->thres[2] = 2500;
+	p->thres[3] = 2500;
+	p->thres[4] = 800;
 	p->drop = 0;
 	p->mode = 1;
 	if (args) parse_args(p, args);