From 4b657a1b1eedcf38bcf36e89a2f4be6f76b5ce09 Mon Sep 17 00:00:00 2001
From: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Date: Fri, 24 Apr 2015 00:01:43 +0200
Subject: [PATCH] alac: reject rice_limit 0 if compression is used

If rice_limit is 0, k can be 0 in decode_scalar, which calls show_bits(gb, k).

Signed-off-by: Andreas Cadhalpun <Andreas.Cadhalpun@googlemail.com>
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
---
 libavcodec/alac.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/libavcodec/alac.c b/libavcodec/alac.c
index ffd2d77d7c..ada7c73c55 100644
--- a/libavcodec/alac.c
+++ b/libavcodec/alac.c
@@ -316,6 +316,11 @@ static int decode_element(AVCodecContext *avctx, AVFrame *frame, int ch_index,
         int lpc_quant[2];
         int rice_history_mult[2];
 
+        if (!alac->rice_limit) {
+            avpriv_request_sample(alac->avctx, "Compression with rice limit 0");
+            return AVERROR(ENOSYS);
+        }
+
         decorr_shift       = get_bits(&alac->gb, 8);
         decorr_left_weight = get_bits(&alac->gb, 8);