diff --git a/src/h264.c b/src/h264.c
index ba29c5d..34f5025 100644
--- a/src/h264.c
+++ b/src/h264.c
@@ -28,6 +28,7 @@
 #include <assert.h>
 #include <limits.h>
 #include <string.h>
+#include <stdio.h>
 
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -259,6 +260,42 @@ static void h264_va_picture_to_v4l2(struct request_data *driver_data,
 	 * the OUTPUT bitstream — a hypothesis verified empirically by
 	 * running this patch and inspecting the CAPTURE buffer.
 	 */
+	/*
+	 * DEBUG INSTRUMENTATION (0014): dump the raw bytes of
+	 * VAPicture->CurrPic plus sizeof(VAPictureH264) so we can
+	 * tell whether the observed TopFieldOrderCnt=65536 anomaly is
+	 * (a) at the documented byte-offset 12 (ffmpeg-side bug or
+	 * intentional non-spec encoding) or
+	 * (b) at a different offset (libva ABI / VA_PADDING_LOW
+	 * mismatch between ffmpeg's writer and our reader).
+	 *
+	 * Documented VAPictureH264 layout (libva-2.x):
+	 *   offset 0:  VASurfaceID picture_id  (uint32)
+	 *   offset 4:  uint32 frame_idx
+	 *   offset 8:  uint32 flags
+	 *   offset 12: int32 TopFieldOrderCnt
+	 *   offset 16: int32 BottomFieldOrderCnt
+	 *   offset 20+: uint32 va_reserved[VA_PADDING_LOW]
+	 */
+	{
+		const unsigned char *cp = (const unsigned char *)&VAPicture->CurrPic;
+		char hex[32 * 3 + 1] = { 0 };
+		unsigned int i;
+		for (i = 0; i < 32; i++)
+			snprintf(hex + i * 3, 4, " %02x", cp[i]);
+		request_log("VAPictureH264 sizeof=%zu CurrPic[0..31]:%s\n",
+			    sizeof(VAPictureH264), hex);
+		request_log("VAPictureH264 CurrPic field reads: "
+			    "picture_id=0x%08x frame_idx=%u flags=0x%x "
+			    "TopFOC=%d BottomFOC=%d frame_num=%u\n",
+			    (unsigned)VAPicture->CurrPic.picture_id,
+			    (unsigned)VAPicture->CurrPic.frame_idx,
+			    (unsigned)VAPicture->CurrPic.flags,
+			    (int)VAPicture->CurrPic.TopFieldOrderCnt,
+			    (int)VAPicture->CurrPic.BottomFieldOrderCnt,
+			    (unsigned)VAPicture->frame_num);
+	}
+
 	decode->nal_ref_idc = nal_ref_idc;
 	decode->frame_num = VAPicture->frame_num;
 	decode->top_field_order_cnt = VAPicture->CurrPic.TopFieldOrderCnt;