[FFmpeg-devel] [PATCH] avcodec/h264dec: get field_order for typical frames

[Paul B Mahol]

This is normally set by parser but parsing is not always enabled.

Signed-off-by: Paul B Mahol <onemda at gmail.com>
---
 libavcodec/h264dec.c | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)

diff --git a/libavcodec/h264dec.c b/libavcodec/h264dec.c
index 00d922fbe9..39142da7af 100644
--- a/libavcodec/h264dec.c
+++ b/libavcodec/h264dec.c
@@ -1018,6 +1018,24 @@ static int h264_decode_frame(AVCodecContext *avctx, void *data,
         }
     }
 
+    if (h->picture_structure == PICT_FRAME) {
+        if (h->ps.sps->pic_struct_present_flag && h->sei.picture_timing.present) {
+            switch (h->sei.picture_timing.pic_struct) {
+            case H264_SEI_PIC_STRUCT_TOP_BOTTOM:
+            case H264_SEI_PIC_STRUCT_TOP_BOTTOM_TOP:
+                avctx->field_order = AV_FIELD_TT;
+                break;
+            case H264_SEI_PIC_STRUCT_BOTTOM_TOP:
+            case H264_SEI_PIC_STRUCT_BOTTOM_TOP_BOTTOM:
+                avctx->field_order = AV_FIELD_BB;
+                break;
+            default:
+                avctx->field_order = AV_FIELD_PROGRESSIVE;
+                break;
+            }
+        }
+    }
+
     av_assert0(pict->buf[0] || !*got_frame);
 
     ff_h264_unref_picture(h, &h->last_pic_for_ec);
-- 
2.17.1