fixes crash during dtmf

During the processing of Cisco dtmf the dtmf samples were
not being calculated correctly.  In an attempt to determine
what sample rate was being used, a NULL frame was processed
which caused a crash.  This patch resolves this.

(closes issue #17248)
Reported by: falves11
Patches:
      issue_17248.diff uploaded by dvossel (license 671)

git-svn-id: https://origsvn.digium.com/svn/asterisk/trunk@264114 65c4cc65-6c06-0410-ace0-fbb531ad65f3

diff --git a/res/res_rtp_asterisk.c b/res/res_rtp_asterisk.c
index af1f1eb..07f7bf3 100644 (file)
--- a/res/res_rtp_asterisk.c
+++ b/res/res_rtp_asterisk.c
@@ -1502,10 +1502,11 @@ static struct ast_frame *process_dtmf_cisco(struct ast_rtp_instance *instance, u
                }
        } else if ((rtp->resp == resp) && !power) {
                f = create_dtmf_frame(instance, AST_FRAME_DTMF_END, ast_rtp_instance_get_prop(instance, AST_RTP_PROPERTY_DTMF_COMPENSATE));
-               f->samples = rtp->dtmfsamples * (rtp_get_rate(f->subclass.codec) / 1000);
+               f->samples = rtp->dtmfsamples * (rtp->lastrxformat ? (rtp_get_rate(rtp->lastrxformat) / 1000) : 8);
                rtp->resp = 0;
        } else if (rtp->resp == resp)
-               rtp->dtmfsamples += 20 * (rtp_get_rate(f->subclass.codec) / 1000);
+               rtp->dtmfsamples += 20 * (rtp->lastrxformat ? (rtp_get_rate(rtp->lastrxformat) / 1000) : 8);
+
        rtp->dtmf_timeout = 0;
 
        return f;