swscale: implement >8bit scaling support.

This means that precision is retained when scaling between sample
formats with >8 bits per component (48bit RGB, 16bit grayscale,
9/10/16bit YUV).

1 files changed, 10 insertions, 0 deletions

diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h
index c1eed8ac96..cfb19d9c13 100644
--- a/libswscale/swscale_internal.h
+++ b/libswscale/swscale_internal.h
@@ -205,6 +205,7 @@ typedef struct SwsContext {
     enum PixelFormat srcFormat;   ///< Source      pixel format.
     int dstFormatBpp;             ///< Number of bits per pixel of the destination pixel format.
     int srcFormatBpp;             ///< Number of bits per pixel of the source      pixel format.
+    int scalingBpp;
     int chrSrcHSubSample;         ///< Binary logarithm of horizontal subsampling factor between luma/alpha and chroma planes in source      image.
     int chrSrcVSubSample;         ///< Binary logarithm of vertical   subsampling factor between luma/alpha and chroma planes in source      image.
     int chrDstHSubSample;         ///< Binary logarithm of horizontal subsampling factor between luma/alpha and chroma planes in destination image.
@@ -446,6 +447,15 @@ typedef struct SwsContext {
     void (*lumConvertRange)(int16_t *dst, int width); ///< Color range conversion function for luma plane if needed.
     void (*chrConvertRange)(int16_t *dst1, int16_t *dst2, int width); ///< Color range conversion function for chroma planes if needed.
 
+    /**
+     * dst[..] = (src[..] << 8) | src[..];
+     */
+    void (*scale8To16Rv)(uint16_t *dst, const uint8_t *src, int len);
+    /**
+     * dst[..] = src[..] >> 4;
+     */
+    void (*scale19To15Fw)(int16_t *dst, const int32_t *src, int len);
+
     int needs_hcscale; ///< Set if there are chroma planes to be converted.
 
 } SwsContext;