swscale: unscaled rgb48 <-> bgr48

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libswscale/rgb2rgb.c

@@ -26,6 +26,7 @@
 #include <inttypes.h>
 
 #include "libavutil/bswap.h"
+#include "libavutil/intreadwrite.h"
 #include "config.h"
 #include "rgb2rgb.h"
 #include "swscale.h"
@@ -333,3 +334,21 @@ DEFINE_SHUFFLE_BYTES(0, 3, 2, 1)
 DEFINE_SHUFFLE_BYTES(1, 2, 3, 0)
 DEFINE_SHUFFLE_BYTES(3, 0, 1, 2)
 DEFINE_SHUFFLE_BYTES(3, 2, 1, 0)
+
+#define DEFINE_RGB48TOBGR48(ie, oe)                                     \
+void rgb48tobgr48_ ## ie ## oe(const uint8_t *src,                      \
+                               uint8_t *dst, int src_size)              \
+{                                                                       \
+    uint16_t *d = (uint16_t *)dst;                                      \
+    uint16_t *s = (uint16_t *)src;                                      \
+    int i, num_pixels = src_size >> 1;                                  \
+                                                                        \
+    for (i = 0; i < num_pixels; i += 3) {                               \
+        AV_W ## oe ## 16(&d[i    ], AV_R ## ie ## 16(&s[i + 2]));       \
+        AV_W ## oe ## 16(&d[i + 1], AV_R ## ie ## 16(&s[i + 1]));       \
+        AV_W ## oe ## 16(&d[i + 2], AV_R ## ie ## 16(&s[i    ]));       \
+    }                                                                   \
+}
+
+DEFINE_RGB48TOBGR48(L, L)
+DEFINE_RGB48TOBGR48(L, B)

libswscale/rgb2rgb.h

@@ -52,6 +52,8 @@ extern void (*rgb32tobgr15)(const uint8_t *src, uint8_t *dst, int src_size);
 
 extern void (*shuffle_bytes_2103)(const uint8_t *src, uint8_t *dst, int src_size);
 
+void rgb48tobgr48_LL(const uint8_t *src, uint8_t *dst, int src_size);
+void rgb48tobgr48_LB(const uint8_t *src, uint8_t *dst, int src_size);
 void    rgb24to32(const uint8_t *src, uint8_t *dst, int src_size);
 void    rgb32to24(const uint8_t *src, uint8_t *dst, int src_size);
 void rgb16tobgr32(const uint8_t *src, uint8_t *dst, int src_size);

libswscale/swscale_unscaled.c

@@ -521,6 +521,13 @@ static int planarRgbToRgbWrapper(SwsContext *c, const uint8_t *src[],
         || (x) == PIX_FMT_ABGR   \
         )
 
+#define isRGB48(x) (                \
+           (x) == PIX_FMT_RGB48LE   \
+        || (x) == PIX_FMT_RGB48BE   \
+        || (x) == PIX_FMT_BGR48LE   \
+        || (x) == PIX_FMT_BGR48BE   \
+        )
+
 /* {RGB,BGR}{15,16,24,32,32_1} -> {RGB,BGR}{15,16,24,32} */
 typedef void (* rgbConvFn) (const uint8_t *, uint8_t *, int);
 static rgbConvFn findRgbConvFn(SwsContext *c)
@@ -554,6 +561,15 @@ static rgbConvFn findRgbConvFn(SwsContext *c)
               || CONV_IS(RGBA, BGRA)) conv = shuffle_bytes_2103;
         else if (CONV_IS(BGRA, ABGR)
               || CONV_IS(RGBA, ARGB)) conv = shuffle_bytes_3012;
+    } else if (isRGB48(srcFormat) && isRGB48(dstFormat)) {
+        if      (CONV_IS(RGB48LE, BGR48LE)
+              || CONV_IS(BGR48LE, RGB48LE)
+              || CONV_IS(RGB48BE, BGR48BE)
+              || CONV_IS(BGR48BE, RGB48BE)) conv = rgb48tobgr48_LL;
+        else if (CONV_IS(RGB48LE, BGR48BE)
+              || CONV_IS(BGR48LE, RGB48BE)
+              || CONV_IS(RGB48BE, BGR48LE)
+              || CONV_IS(BGR48BE, RGB48LE)) conv = rgb48tobgr48_LB;
     } else
     /* BGR -> BGR */
     if ((isBGRinInt(srcFormat) && isBGRinInt(dstFormat)) ||