Fix build with newer FFmpeg.

Index: ip/ffmpeg.c
--- ip/ffmpeg.c.orig
+++ ip/ffmpeg.c
@@ -202,8 +202,10 @@ static int ffmpeg_open(struct input_plugin_data *ip_da
 			break;
 		}
 
+#if LIBAVCODEC_VERSION_INT < AV_VERSION_INT(59, 18, 100)
 		if (codec->capabilities & AV_CODEC_CAP_TRUNCATED)
 			cc->flags |= AV_CODEC_FLAG_TRUNCATED;
+#endif
 
 		if (avcodec_open2(cc, codec, NULL) < 0) {
 			d_print("could not open codec: %d, %s\n", cc->codec_id, avcodec_get_name(cc->codec_id));
