[FFmpeg-cvslog] avcodec/ansi: Check initial dimensions

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sat Sep 19 21:17:32 2020 +0200| [949f0a6be974e4083f8e130c2d6870ef26f0eece] | committer: Michael Niedermayer

avcodec/ansi: Check initial dimensions

Fixes: Timeout (minutes to less than 1sec)
Fixes: 25682/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_ANSI_fuzzer-6320712032452608

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=949f0a6be974e4083f8e130c2d6870ef26f0eece
---

 libavcodec/ansi.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/libavcodec/ansi.c b/libavcodec/ansi.c
index 272185230d..3a461eec26 100644
--- a/libavcodec/ansi.c
+++ b/libavcodec/ansi.c
@@ -475,6 +475,11 @@ static av_cold int decode_close(AVCodecContext *avctx)
     return 0;
 }
 
+static const AVCodecDefault ansi_defaults[] = {
+    { "max_pixels", "640*480" },
+    { NULL },
+};
+
 AVCodec ff_ansi_decoder = {
     .name           = "ansi",
     .long_name      = NULL_IF_CONFIG_SMALL("ASCII/ANSI art"),
@@ -486,4 +491,5 @@ AVCodec ff_ansi_decoder = {
     .decode         = decode_frame,
     .capabilities   = AV_CODEC_CAP_DR1,
     .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
+    .defaults       = ansi_defaults,
 };