fixed top_field_first support when encoding

Originally committed as revision 2600 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 5 insertions, 1 deletions

diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
index 8591877d37..9d4658d0c6 100644
--- a/libavcodec/mpeg12.c
+++ b/libavcodec/mpeg12.c
@@ -448,7 +448,11 @@ void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
         }
         put_bits(&s->pb, 2, s->intra_dc_precision);
         put_bits(&s->pb, 2, s->picture_structure= PICT_FRAME);
-        put_bits(&s->pb, 1, s->top_field_first);
+        if (s->progressive_sequence) {
+            put_bits(&s->pb, 1, 0); /* no repeat */
+        } else {
+            put_bits(&s->pb, 1, s->current_picture_ptr->top_field_first);
+        }
         /* XXX: optimize the generation of this flag with entropy
            measures */
         s->frame_pred_frame_dct = s->progressive_sequence;