diff mbox

[FFmpeg-devel] lavc/truehd_core: Initialize the last bytes of the output buffer

Message ID CAB0OVGo-ca1_3rfDY84F8sxfGHvmy_0Ksn8L_+mqiLwTUgE-8Q@mail.gmail.com
State Superseded
Headers show

Commit Message

Carl Eugen Hoyos Feb. 12, 2019, 11:58 a.m. UTC 
Hi!

The output of truehd_core is currently undeterministic, the last bytes
are uninitialized, valgrind protests if less than 8 bytes are
initialized.
I believe attached patch is simpler than calculating the necessary
write size at the bottom of the function.

Please comment, Carl Eugen
diff mbox

Patch

From e824c88cc15446cc0e3f80672a38f8503333b3a7 Mon Sep 17 00:00:00 2001
From: Carl Eugen Hoyos <ceffmpeg@gmail.com>
Date: Tue, 12 Feb 2019 12:54:31 +0100
Subject: [PATCH] lavc/truehd_core: Initialize the last bytes of the output
 buffer.

Avoids undeterministic output.
---
 libavcodec/truehd_core_bsf.c |    2 ++
 1 file changed, 2 insertions(+)

diff --git a/libavcodec/truehd_core_bsf.c b/libavcodec/truehd_core_bsf.c
index be021af..a78eedc 100644
--- a/libavcodec/truehd_core_bsf.c
+++ b/libavcodec/truehd_core_bsf.c
@@ -117,6 +117,8 @@  static int truehd_core_filter(AVBSFContext *ctx, AVPacket *out)
         out->size -= reduce * 2;
         parity_nibble ^= out->size / 2;
 
+        if (out_size > 8)
+            memset(out->data + out_size - 8, 0, 8);
         if (have_header) {
             memcpy(out->data + 4, in->data + 4, 28);
             out->data[16 + 4] = (out->data[16 + 4] & 0x0f) | (FFMIN(s->hdr.num_substreams, 3) << 4);
-- 
1.7.10.4