[FFmpeg-devel] [PATCH v2] hevc: Fix memory leak related to a53_caption data

[Will Kelleher]

On 04/08, Will Kelleher wrote:
> 
> The leak is...continuous.  We only noticed it during long running decode
> operations because the amount is small, but it definitely adds up.
>
Hi all,

I finally got some time to revisit this.

In the simple case where we are not decoding the HEVC bitstream, the
parser never frees the caption data.  This patch adds a function
similar to what the H.264 decoder is using to free SEI data. This
gets called near the top of each parse_nal_units run to clear any
SEI data from the previous picture.

This is almost a copy-paste from the H.264 solution.

I would love to get this in, because anyone using an HEVC input with
bitstream caption data is going to see this leak.

Thanks,

will

-------------- next part --------------
>From d2aa2530b7d808c3710db7b627b96f4159bef460 Mon Sep 17 00:00:00 2001
From: Will Kelleher <wkelleher at gogoair.com>
Date: Thu, 7 Apr 2016 08:58:31 -0500
Subject: [PATCH] hevc: Fix memory leak related to a53_caption data

Signed-off-by: Will Kelleher <wkelleher at gogoair.com>
---
 libavcodec/hevc.c        | 2 ++
 libavcodec/hevc.h        | 9 +++++++++
 libavcodec/hevc_parser.c | 2 ++
 libavcodec/hevc_sei.c    | 7 +++++++
 4 files changed, 20 insertions(+)

diff --git a/libavcodec/hevc.c b/libavcodec/hevc.c
index d1aa0b0..b478065 100644
--- a/libavcodec/hevc.c
+++ b/libavcodec/hevc.c
@@ -3155,6 +3155,8 @@ static av_cold int hevc_init_context(AVCodecContext *avctx)
     s->context_initialized = 1;
     s->eos = 0;
 
+    ff_hevc_reset_sei(s);
+
     return 0;
 
 fail:
diff --git a/libavcodec/hevc.h b/libavcodec/hevc.h
index f44fa49..be91010 100644
--- a/libavcodec/hevc.h
+++ b/libavcodec/hevc.h
@@ -1054,6 +1054,15 @@ void ff_hevc_hls_mvd_coding(HEVCContext *s, int x0, int y0, int log2_cb_size);
 int ff_hevc_encode_nal_vps(HEVCVPS *vps, unsigned int id,
                            uint8_t *buf, int buf_size);
 
+/**
+ * Reset SEI values that are stored on the Context.
+ * e.g. Caption data that was extracted during NAL
+ * parsing.
+ *
+ * @param s HEVCContext.
+ */
+void ff_hevc_reset_sei(HEVCContext *s);
+
 extern const uint8_t ff_hevc_qpel_extra_before[4];
 extern const uint8_t ff_hevc_qpel_extra_after[4];
 extern const uint8_t ff_hevc_qpel_extra[4];
diff --git a/libavcodec/hevc_parser.c b/libavcodec/hevc_parser.c
index 1227358..b5633f1 100644
--- a/libavcodec/hevc_parser.c
+++ b/libavcodec/hevc_parser.c
@@ -211,6 +211,8 @@ static inline int parse_nal_units(AVCodecParserContext *s, const uint8_t *buf,
 
     h->avctx = avctx;
 
+    ff_hevc_reset_sei(h);
+
     if (!buf_size)
         return 0;
 
diff --git a/libavcodec/hevc_sei.c b/libavcodec/hevc_sei.c
index 40685fe..59c5941 100644
--- a/libavcodec/hevc_sei.c
+++ b/libavcodec/hevc_sei.c
@@ -373,3 +373,10 @@ int ff_hevc_decode_nal_sei(HEVCContext *s)
     } while (more_rbsp_data(&s->HEVClc->gb));
     return 1;
 }
+
+void ff_hevc_reset_sei(HEVCContext *s)
+{
+    s->a53_caption_size = 0;
+    av_freep(&s->a53_caption);
+}
+
-- 
2.8.0