[FFmpeg-cvslog] avcodec/avcodec: Sanitize options before using them

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at gmail.com> | Tue Mar 16 20:01:52 2021 +0100| [746796ceb49b3dab88d3c05f26c2406eceadf4ed] | committer: Andreas Rheinhardt

avcodec/avcodec: Sanitize options before using them

This is how it is supposed to happen, yet when using frame threading,
the codec's init function has been called before preinit. This can lead
to crashes when e.g. using unsupported lowres values for decoders
together with frame threading.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at gmail.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=746796ceb49b3dab88d3c05f26c2406eceadf4ed
---

 libavcodec/avcodec.c | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/libavcodec/avcodec.c b/libavcodec/avcodec.c
index 13fe3d4ebf..b3940b97e0 100644
--- a/libavcodec/avcodec.c
+++ b/libavcodec/avcodec.c
@@ -315,6 +315,13 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
         avctx->time_base.den = avctx->sample_rate;
     }
 
+    if (av_codec_is_encoder(avctx->codec))
+        ret = ff_encode_preinit(avctx);
+    else
+        ret = ff_decode_preinit(avctx);
+    if (ret < 0)
+        goto free_and_end;
+
     if (!HAVE_THREADS)
         av_log(avctx, AV_LOG_WARNING, "Warning: not compiled with thread support, using thread emulation\n");
 
@@ -336,13 +343,6 @@ int attribute_align_arg avcodec_open2(AVCodecContext *avctx, const AVCodec *code
     if (!HAVE_THREADS && !(codec->caps_internal & FF_CODEC_CAP_AUTO_THREADS))
         avctx->thread_count = 1;
 
-    if (av_codec_is_encoder(avctx->codec))
-        ret = ff_encode_preinit(avctx);
-    else
-        ret = ff_decode_preinit(avctx);
-    if (ret < 0)
-        goto free_and_end;
-
     if (   avctx->codec->init && (!(avctx->active_thread_type&FF_THREAD_FRAME)
         || avci->frame_thread_encoder)) {
         ret = avctx->codec->init(avctx);