[FFmpeg-cvslog] Revert "avcodec/er: remove check for fields"

[Michael Niedermayer]

ffmpeg | branch: master | Michael Niedermayer <michael at niedermayer.cc> | Sun Apr  9 15:31:32 2023 +0200| [fa618f5f492f94d19dd8d32bcea084523fb4e2d8] | committer: Michael Niedermayer

Revert "avcodec/er: remove check for fields"

Fixes: out of array write on x86-32
Fixes: 57825/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG2VIDEO_fuzzer-6094366187061248
Fixes: 57829/clusterfuzz-testcase-minimized-ffmpeg_AV_CODEC_ID_MPEG2VIDEO_fuzzer-4526419991724032

Found-by: continuous fuzzing process https://github.com/google/oss-fuzz/tree/master/projects/ffmpeg
This reverts commit f7abe92bd7939b6aeeb2393fe141033e733305d4.

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=fa618f5f492f94d19dd8d32bcea084523fb4e2d8
---

 libavcodec/error_resilience.c | 9 ++-------
 libavcodec/error_resilience.h | 1 -
 2 files changed, 2 insertions(+), 8 deletions(-)

diff --git a/libavcodec/error_resilience.c b/libavcodec/error_resilience.c
index bd7050062c..2aa6f1d864 100644
--- a/libavcodec/error_resilience.c
+++ b/libavcodec/error_resilience.c
@@ -805,7 +805,8 @@ void ff_er_frame_start(ERContext *s)
 static int er_supported(ERContext *s)
 {
     if(s->avctx->hwaccel && s->avctx->hwaccel->decode_slice           ||
-       !s->cur_pic.f
+       !s->cur_pic.f                                                  ||
+       s->cur_pic.field_picture
     )
         return 0;
     return 1;
@@ -907,12 +908,6 @@ void ff_er_frame_end(ERContext *s)
                           (s->avctx->skip_top + s->avctx->skip_bottom)) {
         return;
     }
-
-    if (!s->warned_fields && (s->cur_pic.field_picture || s->cur_pic.f->interlaced_frame)) {
-        av_log(s->avctx, AV_LOG_WARNING, "Error concealment is not fully implemented for field pictures.\n");
-        s->warned_fields = 1;
-    }
-
     linesize = s->cur_pic.f->linesize;
 
     if (   s->avctx->codec_id == AV_CODEC_ID_MPEG2VIDEO
diff --git a/libavcodec/error_resilience.h b/libavcodec/error_resilience.h
index 55efacaccc..47cc8a4fc6 100644
--- a/libavcodec/error_resilience.h
+++ b/libavcodec/error_resilience.h
@@ -87,7 +87,6 @@ typedef struct ERContext {
                       int (*mv)[2][4][2],
                       int mb_x, int mb_y, int mb_intra, int mb_skipped);
     void *opaque;
-    int warned_fields;
 } ERContext;
 
 void ff_er_frame_start(ERContext *s);