lavc/qsvdec: set complete_frame flags for progressive picture

Set the flag MFX_BITSTREAM_COMPLETE_FRAME when it is a progressive picture.
This can fix vc1 decoding segment fault issues because can't set the start
code correctly.

See: ./avconv -hwaccel qsv -c:v vc1_qsv -i /fate-suite/vc1/SA00040.vc1
-vf "hwdownload, format=nv12" -f rawvideo /dev/null

v2: fix some h264 interlaced clips regression
a. field_order of some h264 interlaced video (e.g: cama3_vtc_b.avc) is marked as AV_FIELD_UNKNOWN
   in h264_parser.c. This is not a completed frames.
   So only set the MFX_BITSTREAM_COMPLETE_FRAME when it is progressive.
b. some clips have both progressive and interlaced frames (e.g.CAPAMA3_Sand_F.264),
   the parsed field_order maybe changed druing the decoding progress.

This patch has been verified for other codecs(mpeg2/hevc/vp8).

Signed-off-by: Zhong Li <zhong.li@intel.com>
Signed-off-by: Maxym Dmytrychenko <maxim.d33@gmail.com>

libavcodec/qsvdec.c

@@ -323,6 +323,8 @@ static int qsv_decode(AVCodecContext *avctx, QSVContext *q,
         bs.DataLength = avpkt->size;
         bs.MaxLength  = bs.DataLength;
         bs.TimeStamp  = avpkt->pts;
+        if (avctx->field_order == AV_FIELD_PROGRESSIVE)
+            bs.DataFlag   |= MFX_BITSTREAM_COMPLETE_FRAME;
     }
 
     sync = av_mallocz(sizeof(*sync));
@@ -516,6 +518,7 @@ int ff_qsv_process_data(AVCodecContext *avctx, QSVContext *q,
                      pkt->data, pkt->size, pkt->pts, pkt->dts,
                      pkt->pos);
 
+    avctx->field_order  = q->parser->field_order;
     /* TODO: flush delayed frames on reinit */
     if (q->parser->format       != q->orig_pix_fmt    ||
         FFALIGN(q->parser->coded_width, 16)  != FFALIGN(avctx->coded_width, 16) ||
@@ -540,7 +543,6 @@ int ff_qsv_process_data(AVCodecContext *avctx, QSVContext *q,
         avctx->height       = q->parser->height;
         avctx->coded_width  = FFALIGN(q->parser->coded_width, 16);
         avctx->coded_height = FFALIGN(q->parser->coded_height, 16);
-        avctx->field_order  = q->parser->field_order;
         avctx->level        = q->avctx_internal->level;
         avctx->profile      = q->avctx_internal->profile;