Simplify ptx decoding on big-endian.

Reviewed-by: Reimar Döffinger

libavcodec/ptx.c

@@ -58,7 +58,7 @@ static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
         return -1;
     }
 
-    avctx->pix_fmt = PIX_FMT_RGB555;
+    avctx->pix_fmt = PIX_FMT_RGB555LE;
 
     if (buf_end - buf < offset)
         return AVERROR_INVALIDDATA;
@@ -85,13 +85,7 @@ static int ptx_decode_frame(AVCodecContext *avctx, void *data, int *data_size,
     stride = p->linesize[0];
 
     for (y = 0; y < h && buf_end - buf >= w * bytes_per_pixel; y++) {
-#if HAVE_BIGENDIAN
-        unsigned int x;
-        for (x=0; x<w*bytes_per_pixel; x+=bytes_per_pixel)
-            AV_WN16(ptr+x, AV_RL16(buf+x));
-#else
         memcpy(ptr, buf, w*bytes_per_pixel);
-#endif
         ptr += stride;
         buf += w*bytes_per_pixel;
     }