avcodec/mss2: fix chroma dimensions

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavcodec/mss2.c

@@ -421,8 +421,8 @@ static int decode_wmv9(AVCodecContext *avctx, const uint8_t *buf, int buf_size,
 
     if (v->respic == 3) {
         ctx->dsp.upsample_plane(f->data[0], f->linesize[0], w,      h);
-        ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w >> 1, h >> 1);
-        ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w >> 1, h >> 1);
+        ctx->dsp.upsample_plane(f->data[1], f->linesize[1], w+1 >> 1, h+1 >> 1);
+        ctx->dsp.upsample_plane(f->data[2], f->linesize[2], w+1 >> 1, h+1 >> 1);
     } else if (v->respic)
         avpriv_request_sample(v->s.avctx,
                               "Asymmetric WMV9 rectangle subsampling");

tests/ref/fate/mss2-wmv

@@ -70,7 +70,7 @@
 0,         74,         74,        1,   230400, 0xfe47e3c4
 0,         75,         75,        1,   230400, 0xa2e0e721
 0,         76,         76,        1,   230400, 0xde974a42
-0,         77,         77,        1,   230400, 0xe86a376b
+0,         77,         77,        1,   230400, 0x87bf38ba
 0,         78,         78,        1,   230400, 0xd52318fd
 0,         79,         79,        1,   230400, 0x0bbb1526
 0,         80,         80,        1,   230400, 0xa22c5e5e