tiffdec: notify user that tile support is missing

Signed-off-by: Stefano Sabatini <stefasab@gmail.com>

libavcodec/tiff.c

@@ -485,6 +485,13 @@ static int tiff_decode_tag(TiffContext *s, const uint8_t *start, const uint8_t *
             return -1;
         }
         break;
+    case TIFF_TILE_BYTE_COUNTS:
+    case TIFF_TILE_LENGTH:
+    case TIFF_TILE_OFFSETS:
+    case TIFF_TILE_WIDTH:
+        av_log(s->avctx, AV_LOG_ERROR, "Tiled images are not supported\n");
+        return AVERROR_PATCHWELCOME;
+        break;
     case TIFF_PREDICTOR:
         s->predictor = value;
         break;

libavcodec/tiff.h

@@ -56,6 +56,10 @@ enum TiffTags{
     TIFF_SOFTWARE_NAME = 0x131,
     TIFF_PREDICTOR = 0x13D,
     TIFF_PAL = 0x140,
+    TIFF_TILE_WIDTH = 0x142,
+    TIFF_TILE_LENGTH = 0x143,
+    TIFF_TILE_OFFSETS = 0x144,
+    TIFF_TILE_BYTE_COUNTS = 0x145,
     TIFF_YCBCR_COEFFICIENTS = 0x211,
     TIFF_YCBCR_SUBSAMPLING = 0x212,
     TIFF_YCBCR_POSITIONING = 0x213,