support for mjpeg bottom field first in mov

Originally committed as revision 8192 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavcodec/mjpeg.c

@@ -965,6 +965,13 @@ static int mjpeg_decode_init(AVCodecContext *avctx)
         mjpeg_decode_dht(s);
         /* should check for error - but dunno */
     }
+    if (avctx->extradata_size > 9 &&
+        AV_RL32(avctx->extradata + 4) == MKTAG('f','i','e','l')) {
+        if (avctx->extradata[9] == 6) { /* quicktime icefloe 019 */
+            s->interlace_polarity = 1; /* bottom field first */
+            av_log(avctx, AV_LOG_DEBUG, "mjpeg bottom field first\n");
+        }
+    }
 
     return 0;
 }
@@ -1185,8 +1192,9 @@ static int mjpeg_decode_sof(MJpegDecodeContext *s)
             s->org_height != 0 &&
             s->height < ((s->org_height * 3) / 4)) {
             s->interlaced = 1;
-//            s->bottom_field = (s->interlace_polarity) ? 1 : 0;
-            s->bottom_field = 0;
+            s->bottom_field = s->interlace_polarity;
+            s->picture.interlaced_frame = 1;
+            s->picture.top_field_first = !s->interlace_polarity;
             height *= 2;
         }
 
@@ -1197,7 +1205,7 @@ static int mjpeg_decode_sof(MJpegDecodeContext *s)
         s->first_picture = 0;
     }
 
-    if(s->interlaced && s->bottom_field)
+    if(s->interlaced && (s->bottom_field == !s->interlace_polarity))
         return 0;
 
     /* XXX: not complete test ! */
@@ -2167,7 +2175,7 @@ eoi_parser:
                         if (s->interlaced) {
                             s->bottom_field ^= 1;
                             /* if not bottom field, do not output image yet */
-                            if (s->bottom_field)
+                            if (s->bottom_field == !s->interlace_polarity)
                                 goto not_the_end;
                         }
                         *picture = s->picture;

libavformat/mov.c

@@ -1366,6 +1366,7 @@ static const MOVParseTableEntry mov_default_parse_table[] = {
 { MKTAG( 'e', 'd', 't', 's' ), mov_read_default },
 { MKTAG( 'e', 'l', 's', 't' ), mov_read_elst },
 { MKTAG( 'e', 'n', 'd', 'a' ), mov_read_enda },
+{ MKTAG( 'f', 'i', 'e', 'l' ), mov_read_extradata },
 { MKTAG( 'f', 't', 'y', 'p' ), mov_read_ftyp },
 { MKTAG( 'h', 'd', 'l', 'r' ), mov_read_hdlr },
 { MKTAG( 'j', 'p', '2', 'h' ), mov_read_extradata },