TT#14008 fix TLS-send-only w/o recording scenario

Provide a standard output format if no other outputs are configured, so
that the decoder has something to work with. Applicable to TLS-send-only
scenarios without recording.

Change-Id: I627bb7af3f3033e1025009c21a4da6991e491dcf
(cherry picked from commit 9ba0dd9aea)

recording-daemon/decoder.c

@@ -79,6 +79,8 @@ decode_t *decoder_new(const char *payload_str, const char *format, int ptime, ou
 			out_format = outp->requested_format;
 		output_config(outp, &out_format, &out_format);
 	}
+	else
+		out_format.format = AV_SAMPLE_FMT_S16; // needed for TLS-only scenarios
 
 	str fmtp;
 	str_init(&fmtp, (char *) format);