diff --git a/cinelerra-5.1/cinelerra/ffmpeg.C b/cinelerra-5.1/cinelerra/ffmpeg.C
index 70098ca..32867de 100644
--- a/cinelerra-5.1/cinelerra/ffmpeg.C
+++ b/cinelerra-5.1/cinelerra/ffmpeg.C
@@ -1192,10 +1192,19 @@ int FFVideoStream::video_seek(int64_t pos)
 	if( pos == curr_pos-1 && !seeked ) return 0;
 // if close enough, just read up to current
 	int gop = avctx->gop_size;
-	if( gop < 4 ) gop = 4;
+	if( gop < 4 && gop != 0) gop = 4;
 	if( gop > 64 ) gop = 64;
+	if( gop == 0 ) gop = 1;
+	//fprintf(stderr, "GOP: %i \n", gop);
 	int read_limit = curr_pos + 3*gop;
 	if( pos >= curr_pos && pos <= read_limit ) return 0;
+	// fixup for I-only codecs, not sure why it needed with ffmpeg 4.2
+	if (st->codecpar->codec_id == AV_CODEC_ID_DVVIDEO || st->codecpar->codec_id == AV_CODEC_ID_MJPEG || 
+	st->codecpar->codec_id == AV_CODEC_ID_FFVHUFF || st->codecpar->codec_id == AV_CODEC_ID_DNXHD ||
+	st->codecpar->codec_id ==AV_CODEC_ID_HUFFYUV ) {
+	gop = 1;
+	if( seek(pos - 2*gop, frame_rate) < 0 ) return -1;
+	}
 // guarentee preload more than 2*gop frames
 	if( seek(pos - 3*gop, frame_rate) < 0 ) return -1;
 	return 1;