[asterisk-commits] rizzo: branch rizzo/video_v2 r85282 - /team/rizzo/video_v2/channels/

[SVN commits to the Asterisk project]

Author: rizzo
Date: Wed Oct 10 09:51:01 2007
New Revision: 85282

URL: http://svn.digium.com/view/asterisk?view=rev&rev=85282
Log:
more h261 split...

Modified:
    team/rizzo/video_v2/channels/console_video.c

Modified: team/rizzo/video_v2/channels/console_video.c
URL: http://svn.digium.com/view/asterisk/team/rizzo/video_v2/channels/console_video.c?view=diff&rev=85282&r1=85281&r2=85282
==============================================================================
--- team/rizzo/video_v2/channels/console_video.c (original)
+++ team/rizzo/video_v2/channels/console_video.c Wed Oct 10 09:51:01 2007
@@ -712,6 +712,7 @@
 		//ast_log(LOG_WARNING, "search at %d of %d/%d\n", i, start, len);
 		for (; i < len ; i++) {
 			uint8_t x, rpos, lpos;
+			int rpos_i;	/* index corresponding to rpos */
 			if (d[i] != 0)		/* cannot be in a GBSC */
 				continue;
 			if (i > len - 1)
@@ -724,7 +725,7 @@
 			 * see if we have enough 0 on the left.
 			 * We are guaranteed to end before rpos == 0
 			 */
-			for (rpos = 0x80; rpos; rpos >>= 1)
+			for (rpos = 0x80, rpos_i = 8; rpos; rpos >>= 1, rpos_i--)
 				if (x & rpos)	/* found the '1' bit in GBSC */
 					break;
 			x = d[i-1];		/* now look behind */
@@ -739,8 +740,8 @@
 			if (rpos == 0x80) {	/* lucky case */
 				i = i - 1;
 			} else {	/* XXX to be completed */
-				ast_log(LOG_WARNING, "unaligned GBSC 0x%x\n",
-					rpos);
+				ast_log(LOG_WARNING, "unaligned GBSC 0x%x %d\n",
+					rpos, rpos_i);
 			}
 			break;
 		}
@@ -831,15 +832,22 @@
 	const int pheader_len = 4;
 	uint8_t h261_hdr[4];
 	uint8_t *h = h261_hdr;	/* shorthand */
-
-#define H261_MIN_LEN 4
+	int sbit = 0, ebit = 0;
+
+#define H261_MIN_LEN 10
 	if (len < H261_MIN_LEN)	/* unreasonably small */
 		return NULL;
 
 	bzero(h261_hdr, sizeof(h261_hdr));
-	h[0] = 0x01;	/* sbit = ebit = 0, i=0, v=1, all others 0 */
-
-	for (i = H261_MIN_LEN, start = 0; start < len; start = i, i += 3) {
+
+	/* This is the same code we have in h263, but the maker there is longer.
+	 * We start a few bytes within the bitstream to avoid hitting the marker
+	 * twice. We stop at len-1 because when there are bits to ignore we move
+	 * back the 'start' pointer by 1, and this would cause us to enter the loop
+	 * one more time.
+	 */
+	for (i = H261_MIN_LEN, start = 0; start < len - 1; start = i, i += 4) {
+		int found = 0, found_ebit = 0;	/* last GBSC position found */
 		ast_log(LOG_WARNING, "search at %d of %d/%d\n", i, start, len);
 		for (; i < len ; i++) {
 			uint8_t x, rpos, lpos;
@@ -855,7 +863,7 @@
 			 * see if we have enough 0 on the left.
 			 * We are guaranteed to end before rpos == 0
 			 */
-			for (rpos = 0x80; rpos; rpos >>= 1)
+			for (rpos = 0x80, ebit = 7; rpos; ebit--, rpos >>= 1)
 				if (x & rpos)	/* found the '1' bit in GBSC */
 					break;
 			x = d[i-1];		/* now look behind */
@@ -865,16 +873,23 @@
 			if (lpos)		/* as i said... */
 				continue;
 			/* now we have a GBSC starting somewhere in d[i-1],
-			 * but it might be not byte-aligned
+			 * but it might be not byte-aligned. Just remember it.
 			 */
-			if (rpos == 0x80) {	/* lucky case */
-				i = i - 1;
-			} else {	/* XXX to be completed */
-				ast_log(LOG_WARNING, "unaligned GBSC 0x%x\n",
-					rpos);
-			}
-			break;
+			if (i > out->mtu)	/* too large, stop now */
+				break;
+			found_ebit = ebit;
+			found = i;
+			i += 4;	/* continue forward */
 		}
+		if (i > len) {	/* trim if we went too forward */
+			i = len;
+			ebit = 0;	/* hopefully... should ask the bitstream ? */
+		}
+		if (i > out->mtu && found) {	/* hope the previous one is still ok */
+			i = found;
+			ebit = found_ebit;
+		}
+		ast_log(LOG_WARNING, "found %d of %d/%d\n", i - start, start, len);
 		/* This frame is up to offset i (not inclusive).
 		 * We do not split it yet even if larger than MTU.
 		 */
@@ -883,10 +898,14 @@
 
 		if (!f)
 			break;
-		bcopy(h, f->data, 4);	/* copy the h263 header */
-		/* XXX to do: if not aligned, fix sbit and ebit,
-		 * then move i back by 1 for the next frame
-		 */
+		/* recompute header with I=0, V=1 */
+		h[0] = ( (sbit & 7) << 5 ) | ( (ebit & 7) << 2 ) | 1;
+		bcopy(h, f->data, 4);	/* copy the h261 header */
+		if (ebit) {	/* not aligned, so restart from previous byte */
+			sbit = 8 - ebit;
+			ebit = 0;
+			i--;
+		}
 		if (!cur)
 			first = f;
 		cur = f;
@@ -1393,7 +1412,7 @@
 	pthread_join(env->vthread, NULL);
 	ast_channel_lock(env->owner);
 	env->shutdown = 0;
-	env->vthread = NULL;
+	/* XXX should remove the vthread reference */
 
 	/* uninitialize the local and remote video environments */
 	video_in_uninit(&env->in);