swscale: add unscaled packed 16 bit per component endianess conversion

libswscale/swscale_unscaled.c

@@ -252,6 +252,27 @@ static void gray8aToPacked24(const uint8_t *src, uint8_t *dst, int num_pixels, c
     }
 }
 
+static int packed_16bpc_bswap(SwsContext *c, const uint8_t* src[],
+                              int srcStride[], int srcSliceY, int srcSliceH,
+                              uint8_t* dst[], int dstStride[])
+{
+    int i, j;
+    int srcstr = srcStride[0] >> 1;
+    int dststr = dstStride[0] >> 1;
+    uint16_t       *dstPtr =       (uint16_t *)dst[0];
+    const uint16_t *srcPtr = (const uint16_t *)src[0];
+
+    for (i = 0; i < srcSliceH; i++) {
+        for (j = 0; j < srcstr; j++) {
+            dstPtr[j] = av_bswap16(srcPtr[j]);
+        }
+        srcPtr += srcstr;
+        dstPtr += dststr;
+    }
+
+    return srcSliceH;
+}
+
 static int palToRgbWrapper(SwsContext *c, const uint8_t* src[], int srcStride[], int srcSliceY,
                            int srcSliceH, uint8_t* dst[], int dstStride[])
 {
@@ -697,6 +718,15 @@ void ff_get_unscaled_swscale(SwsContext *c)
     if (srcFormat==PIX_FMT_BGR24 && (dstFormat==PIX_FMT_YUV420P || dstFormat==PIX_FMT_YUVA420P) && !(flags & SWS_ACCURATE_RND))
         c->swScale= bgr24ToYv12Wrapper;
 
+    /* bswap 16 bits per component packed formats */
+    if ((srcFormat == PIX_FMT_RGB48LE  && dstFormat == PIX_FMT_RGB48BE)  ||
+        (srcFormat == PIX_FMT_RGB48BE  && dstFormat == PIX_FMT_RGB48LE)  ||
+        (srcFormat == PIX_FMT_BGR48LE  && dstFormat == PIX_FMT_BGR48BE)  ||
+        (srcFormat == PIX_FMT_BGR48BE  && dstFormat == PIX_FMT_BGR48LE)  ||
+        (srcFormat == PIX_FMT_GRAY16LE && dstFormat == PIX_FMT_GRAY16BE) ||
+        (srcFormat == PIX_FMT_GRAY16BE && dstFormat == PIX_FMT_GRAY16LE))
+        c->swScale = packed_16bpc_bswap;
+
     /* RGB/BGR -> RGB/BGR (no dither needed forms) */
     if (   isAnyRGB(srcFormat)
         && isAnyRGB(dstFormat)