From 985a5fd7aac7a39cf9f9502f9e8e06ef216e1d35 Mon Sep 17 00:00:00 2001
From: Joshua Colp <jcolp@digium.com>
Date: Wed, 26 Apr 2017 10:38:31 +0000
Subject: [PATCH] frame: Better handle interpolated frames.

Interpolated frames are frames which contain a number of
samples but have no actual data. Audiohooks did not
handle this case when translating an incoming frame into
signed linear. It assumed that a frame would always contain
media when it may not. If this occurs audiohooks will now
immediately return and not act on the frame.

As well for users of ast_trans_frameout the function has
been changed to be a bit more sane and ensure that the data
pointer on a frame is set to NULL if no data is actually
on the frame. This allows the various spots in Asterisk that
check for an interpolated frame based on the presence of a
data pointer to work as expected.

ASTERISK-26926

Change-Id: I7fa22f631fa28d540722ed789ce28e84c7f8662b
---
 main/audiohook.c | 9 +++++++++
 main/translate.c | 6 ++++++
 2 files changed, 15 insertions(+)

diff --git a/main/audiohook.c b/main/audiohook.c
index 986f11f846..2cba2de6e2 100644
--- a/main/audiohook.c
+++ b/main/audiohook.c
@@ -945,6 +945,15 @@ static struct ast_frame *audio_audiohook_write_list(struct ast_channel *chan, st
 	if (!(middle_frame = audiohook_list_translate_to_slin(audiohook_list, direction, start_frame))) {
 		return frame;
 	}
+
+	/* If the translation resulted in an interpolated frame then immediately return as audiohooks
+	 * rely on actual media being present to do things.
+	 */
+	if (!middle_frame->data.ptr) {
+		ast_frfree(middle_frame);
+		return start_frame;
+	}
+
 	samples = middle_frame->samples;
 
 	/*
diff --git a/main/translate.c b/main/translate.c
index 168a72a4bd..f2aa5886b2 100644
--- a/main/translate.c
+++ b/main/translate.c
@@ -442,8 +442,14 @@ struct ast_frame *ast_trans_frameout(struct ast_trans_pvt *pvt,
 	}
 	if (datalen) {
 		f->datalen = datalen;
+		f->data.ptr = pvt->outbuf.c;
 	} else {
 		f->datalen = pvt->datalen;
+		if (!f->datalen) {
+			f->data.ptr = NULL;
+		} else {
+			f->data.ptr = pvt->outbuf.c;
+		}
 		pvt->datalen = 0;
 	}
 
-- 
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