Use a minimum of 8 bytes for the payload bits.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/freedv_fsk.c b/src/freedv_fsk.c
index 69aa8b9..2660ea1 100644
--- a/src/freedv_fsk.c
+++ b/src/freedv_fsk.c
@@ -123,7 +123,8 @@ void freedv_800xa_open(struct freedv *f) {
 
   f->bits_per_codec_frame = codec2_bits_per_frame(f->codec2);
   f->bits_per_modem_frame = f->n_codec_frames * f->bits_per_codec_frame;
-  int n_packed_bytes = ceil((f->bits_per_modem_frame + 7.0) / 8.0) + 1;
+  int n_packed_bytes = ceil((f->bits_per_modem_frame + 7.0) / 8.0) + 1;  /* ~3.5 bits per frame, which needs to be rounded up to 4. */
+  if (n_packed_bytes < 8) n_packed_bytes = 8;
   f->tx_payload_bits = MALLOC(n_packed_bytes);
   assert(f->tx_payload_bits != NULL);
   f->rx_payload_bits = MALLOC(n_packed_bytes);