lavc/psd: Interpret DUOTONE as GRAYSCALE.

This is what gimp, ImageMagick and FreeImage do and what the
Adobe Photoshop file format specification suggests.
Fixes a sample from ticket #6045.

Reviewed-by: Martin Vignali

libavcodec/psd.c

@@ -352,6 +352,8 @@ static int decode_frame(AVCodecContext *avctx, void *data,
             return AVERROR_PATCHWELCOME;
         }
         break;
+    case PSD_DUOTONE:
+        av_log(avctx, AV_LOG_WARNING, "ignoring unknwon duotone specification.\n");
     case PSD_GRAYSCALE:
         if (s->channel_count == 1) {
             if (s->channel_depth == 8) {

libavcodec/version.h

@@ -29,7 +29,7 @@
 
 #define LIBAVCODEC_VERSION_MAJOR  57
 #define LIBAVCODEC_VERSION_MINOR  71
-#define LIBAVCODEC_VERSION_MICRO 100
+#define LIBAVCODEC_VERSION_MICRO 101
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \