[FFmpeg-cvslog] lavf/spdifenc: Do not overwrite buffer when muxing TrueHD.

[Carl Eugen Hoyos]

ffmpeg | branch: master | Carl Eugen Hoyos <ceffmpeg at gmail.com> | Thu Feb 14 20:16:18 2019 +0100| [5247c4328bb96d1b4e2953eef722833c8dbde358] | committer: Carl Eugen Hoyos

lavf/spdifenc: Do not overwrite buffer when muxing TrueHD.

Fixes ticket #7733.

Tested-by: Moritz Barsnick

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=5247c4328bb96d1b4e2953eef722833c8dbde358
---

 libavformat/spdifenc.c | 9 +++++++--
 1 file changed, 7 insertions(+), 2 deletions(-)

diff --git a/libavformat/spdifenc.c b/libavformat/spdifenc.c
index 9514ff8e10..4307942a44 100644
--- a/libavformat/spdifenc.c
+++ b/libavformat/spdifenc.c
@@ -422,8 +422,13 @@ static int spdif_header_truehd(AVFormatContext *s, AVPacket *pkt)
 
     memcpy(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length],
            pkt->data, pkt->size);
-    memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],
-           0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);
+    if (ctx->hd_buf_count < 23) {
+        memset(&ctx->hd_buf[ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + mat_code_length + pkt->size],
+               0, TRUEHD_FRAME_OFFSET - pkt->size - mat_code_length);
+    } else {
+        size_t padding = MAT_FRAME_SIZE - (ctx->hd_buf_count * TRUEHD_FRAME_OFFSET - BURST_HEADER_SIZE + pkt->size);
+        memset(&ctx->hd_buf[MAT_FRAME_SIZE - padding], 0, padding);
+    }
 
     if (++ctx->hd_buf_count < 24){
         ctx->pkt_offset = 0;