cmdutils: avoid setting data pointers to invalid values in alloc_buffer()

Fixes bug 352.
(cherry picked from commit 990450c5bf17afc31a81d6225afaac86d0dca5dd)

Conflicts:
	cmdutils.c

Signed-off-by: Anton Khirnov <anton@khirnov.net>

1 files changed, 1 insertions, 1 deletions

diff --git a/avconv.c b/avconv.c
index 90bc49cc88..34507d4d0c 100644
--- a/avconv.c
+++ b/avconv.c
@@ -455,7 +455,7 @@ static int alloc_buffer(InputStream *ist, FrameBuffer **pbuf)
         const int v_shift = i==0 ? 0 : v_chroma_shift;
         if (s->flags & CODEC_FLAG_EMU_EDGE)
             buf->data[i] = buf->base[i];
-        else
+        else if (buf->base[i])
             buf->data[i] = buf->base[i] +
                            FFALIGN((buf->linesize[i]*edge >> v_shift) +
                                    (pixel_size*edge >> h_shift), 32);