avcodec/h264_slice: use H264_SEI_FpaType enum constants

Cosmetic change.
Signed-off-by: James Almer <jamrial@gmail.com>

libavcodec/h264_slice.c

@@ -1205,28 +1205,28 @@ static int h264_export_frame_props(H264Context *h)
         AVStereo3D *stereo = av_stereo3d_create_side_data(cur->f);
         if (stereo) {
         switch (fp->arrangement_type) {
-        case 0:
+        case H264_SEI_FPA_TYPE_CHECKERBOARD:
             stereo->type = AV_STEREO3D_CHECKERBOARD;
             break;
-        case 1:
+        case H264_SEI_FPA_TYPE_INTERLEAVE_COLUMN:
             stereo->type = AV_STEREO3D_COLUMNS;
             break;
-        case 2:
+        case H264_SEI_FPA_TYPE_INTERLEAVE_ROW:
             stereo->type = AV_STEREO3D_LINES;
             break;
-        case 3:
+        case H264_SEI_FPA_TYPE_SIDE_BY_SIDE:
             if (fp->quincunx_sampling_flag)
                 stereo->type = AV_STEREO3D_SIDEBYSIDE_QUINCUNX;
             else
                 stereo->type = AV_STEREO3D_SIDEBYSIDE;
             break;
-        case 4:
+        case H264_SEI_FPA_TYPE_TOP_BOTTOM:
             stereo->type = AV_STEREO3D_TOPBOTTOM;
             break;
-        case 5:
+        case H264_SEI_FPA_TYPE_INTERLEAVE_TEMPORAL:
             stereo->type = AV_STEREO3D_FRAMESEQUENCE;
             break;
-        case 6:
+        case H264_SEI_FPA_TYPE_2D:
             stereo->type = AV_STEREO3D_2D;
             break;
         }
@@ -1234,7 +1234,7 @@ static int h264_export_frame_props(H264Context *h)
         if (fp->content_interpretation_type == 2)
             stereo->flags = AV_STEREO3D_FLAG_INVERT;
 
-        if (fp->arrangement_type == 5) {
+        if (fp->arrangement_type == H264_SEI_FPA_TYPE_INTERLEAVE_TEMPORAL) {
             if (fp->current_frame_is_frame0_flag)
                 stereo->view = AV_STEREO3D_VIEW_LEFT;
             else