[FFmpeg-cvslog] avformat/sga: improve probing for valid files

[Paul B Mahol]

ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Mon Mar  1 18:37:40 2021 +0100| [498be38e322ce14e1355d8bc5a3d56e239c56958] | committer: Paul B Mahol

avformat/sga: improve probing for valid files

Update variables depending on high four bits of first two bytes.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=498be38e322ce14e1355d8bc5a3d56e239c56958
---

 libavformat/sga.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/libavformat/sga.c b/libavformat/sga.c
index 957ca0f4cd..20da423ebf 100644
--- a/libavformat/sga.c
+++ b/libavformat/sga.c
@@ -75,9 +75,11 @@ static int sga_probe(const AVProbeData *p)
         if (last_left < 0)
             return 0;
         if (sectors && header && last_left == 0) {
-            if (left <= 8)
-                return 0;
-            last_left = left;
+            if (header >> 12) {
+                last_left = left;
+            } else {
+                last_left = left = header;
+            }
         } else if (sectors && header) {
             left = header;
             last_left -= left;