Switch multicast distribution system to round-robin mode

Send one packet from each eraseblock in turn, rather than all packets
for one eraseblock together. This means that bursts of loss are evenly
spread between blocks. It also makes the client side a bit more complex
if you can't assume that there's anywhere except the flash to store its
intermediate data.

Signed-off-by: David Woodhouse <dwmw2@infradead.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/fec.c b/fec.c
index e374dfe..09e8453 100644
--- a/fec.c
+++ b/fec.c
@@ -742,6 +742,25 @@ fec_encode(struct fec_parms *code, gf *src[], gf *fec, int index, int sz)
 	    index, code->n - 1 );
 }
 
+void fec_encode_linear(struct fec_parms *code, gf *src, gf *fec, int index, int sz)
+{
+    int i, k = code->k ;
+    gf *p ;
+
+    if (GF_BITS > 8)
+	sz /= 2 ;
+
+    if (index < k)
+	    bcopy(src + (index * sz), fec, sz*sizeof(gf) ) ;
+    else if (index < code->n) {
+	p = &(code->enc_matrix[index*k] );
+	bzero(fec, sz*sizeof(gf));
+	for (i = 0; i < k ; i++)
+	    addmul(fec, src + (i * sz), p[i], sz ) ;
+    } else
+	fprintf(stderr, "Invalid index %d (max %d)\n",
+	    index, code->n - 1 );
+}
 /*
  * shuffle move src packets in their position
  */