X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=src%2Fcore%2Fao_viterbi.c;h=69e9c1f5b7da393f9757e9b88b6448a1cf95b31d;hb=09761fe0f6ed40ff74317fbb47d6a74068fb4ce4;hp=bb93bc83b798540782e928a8c5ac4e0bf448c0fb;hpb=b292c14790fc225029cba3f80ce8ad6c5652bc4e;p=fw%2Faltos

diff --git a/src/core/ao_viterbi.c b/src/core/ao_viterbi.c
index bb93bc83..69e9c1f5 100644
--- a/src/core/ao_viterbi.c
+++ b/src/core/ao_viterbi.c
@@ -55,16 +55,19 @@ struct ao_soft_sym {
 #define NUM_HIST	8
 #define MOD_HIST(b)	((b) & 7)
 
+#define V_0		0xc0
+#define V_1		0x40
+
 static const struct ao_soft_sym ao_fec_decode_table[NUM_STATE][2] = {
 /* next        0              1	         state */
-	{ { 0x00, 0x00 }, { 0xff, 0xff } } ,	/* 000 */
-	{ { 0x00, 0xff }, { 0xff, 0x00 } },	/* 001 */
-	{ { 0xff, 0xff }, { 0x00, 0x00 } },	/* 010 */
-	{ { 0xff, 0x00 }, { 0x00, 0xff } },	/* 011 */
-	{ { 0xff, 0xff }, { 0x00, 0x00 } },	/* 100 */
-	{ { 0xff, 0x00 }, { 0x00, 0xff } },	/* 101 */
-	{ { 0x00, 0x00 }, { 0xff, 0xff } },	/* 110 */
-	{ { 0x00, 0xff }, { 0xff, 0x00 } }	/* 111 */
+	{ { V_0, V_0 }, { V_1, V_1 } } ,	/* 000 */
+	{ { V_0, V_1 }, { V_1, V_0 } },	/* 001 */
+	{ { V_1, V_1 }, { V_0, V_0 } },	/* 010 */
+	{ { V_1, V_0 }, { V_0, V_1 } },	/* 011 */
+	{ { V_1, V_1 }, { V_0, V_0 } },	/* 100 */
+	{ { V_1, V_0 }, { V_0, V_1 } },	/* 101 */
+	{ { V_0, V_0 }, { V_1, V_1 } },	/* 110 */
+	{ { V_0, V_1 }, { V_1, V_0 } }	/* 111 */
 };
 
 static inline uint8_t
@@ -88,7 +91,7 @@ ao_cost(struct ao_soft_sym a, struct ao_soft_sym b)
  */
 
 uint8_t
-ao_fec_decode(uint8_t *in, uint16_t len, uint8_t *out)
+ao_fec_decode(uint8_t *in, uint16_t len, uint8_t *out, uint8_t out_len, uint16_t (*callback)())
 {
 	static uint16_t	cost[2][NUM_STATE];		/* path cost */
 	static uint16_t	bits[2][NUM_STATE];		/* save bits to quickly output them */
@@ -102,6 +105,7 @@ ao_fec_decode(uint8_t *in, uint16_t len, uint8_t *out)
 	const uint8_t	*whiten = ao_fec_whiten_table;
 	uint16_t	interleave;			/* input byte array index */
 	struct ao_soft_sym	s;			/* input symbol pair */
+	uint16_t	avail;
 
 	p = 0;
 	for (state = 0; state < NUM_STATE; state++) {
@@ -110,11 +114,22 @@ ao_fec_decode(uint8_t *in, uint16_t len, uint8_t *out)
 	}
 	cost[0][0] = 0;
 
+	if (callback)
+		avail = 0;
+	else
+		avail = len;
+
 	o = 0;
 	for (i = 0; i < len; i += 2) {
 		b = i/2;
 		n = p ^ 1;
 
+		if (!avail) {
+			avail = callback();
+			if (!avail)
+				break;
+		}
+
 		/* Fetch one pair of input bytes, de-interleaving
 		 * the input.
 		 */
@@ -200,7 +215,10 @@ ao_fec_decode(uint8_t *in, uint16_t len, uint8_t *out)
 			printf ("\tbit %3d min_cost %5d old bit %3d old_state %x bits %02x whiten %0x\n",
 				i/2, min_cost, o + 8, min_state, (bits[p][min_state] >> dist) & 0xff, *whiten);
 #endif
-			*out++ = (bits[p][min_state] >> dist) ^ *whiten++;
+			if (out_len) {
+				*out++ = (bits[p][min_state] >> dist) ^ *whiten++;
+				--out_len;
+			}
 			o += 8;
 		}
 	}