[FFmpeg-cvslog] avformat/dv: Avoid allocation for reading timecode

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Sun Aug  2 00:58:48 2020 +0200| [1fbfa42432b1348944829a51997f1a0d8f11c6bc] | committer: Andreas Rheinhardt

avformat/dv: Avoid allocation for reading timecode

Reviewed-by: Paul B Mahol <onemda at gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=1fbfa42432b1348944829a51997f1a0d8f11c6bc
---

 libavformat/dv.c | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/libavformat/dv.c b/libavformat/dv.c
index 9179e6cec6..d25641daac 100644
--- a/libavformat/dv.c
+++ b/libavformat/dv.c
@@ -470,19 +470,15 @@ static int dv_read_timecode(AVFormatContext *s) {
     int64_t pos = avio_tell(s->pb);
 
     // Read 3 DIF blocks: Header block and 2 Subcode blocks.
-    int partial_frame_size = 3 * 80;
-    uint8_t *partial_frame = av_mallocz(sizeof(*partial_frame) *
-                                        partial_frame_size);
-
+#define PARTIAL_FRAME_SIZE (3 * 80)
+    uint8_t partial_frame[PARTIAL_FRAME_SIZE];
     RawDVContext *c = s->priv_data;
-    if (!partial_frame)
-        return AVERROR(ENOMEM);
 
-    ret = avio_read(s->pb, partial_frame, partial_frame_size);
+    ret = avio_read(s->pb, partial_frame, PARTIAL_FRAME_SIZE);
     if (ret < 0)
         goto finish;
 
-    if (ret < partial_frame_size) {
+    if (ret < PARTIAL_FRAME_SIZE) {
         ret = -1;
         goto finish;
     }
@@ -494,7 +490,6 @@ static int dv_read_timecode(AVFormatContext *s) {
         av_log(s, AV_LOG_ERROR, "Detected timecode is invalid\n");
 
 finish:
-    av_free(partial_frame);
     avio_seek(s->pb, pos, SEEK_SET);
     return ret;
 }