处理YUVNV21数据到RGB数据

 1 #define YG 18997 /* round(1.164 * 64 * 256 * 256 / 257) */
 2 #define YGB -1160 /* 1.164 * 64 * -16 + 64 / 2 */
 3
 4 #define UB -128 /* max(-128, round(-2.018 * 64)) */
 5 #define UG 25 /* round(0.391 * 64) */
 6 #define VG 52 /* round(0.813 * 64) */
 7 #define VR -102 /* round(-1.596 * 64) */
 8
 9 #define BB (UB * 128            + YGB)
10 #define BG (UG * 128 + VG * 128 + YGB)
11 #define BR            (VR * 128 + YGB)
12
13 typedef unsigned char sd_uint8;
14 typedef unsigned long sd_uint32;
15 typedef signed long sd_int32;
16
17 sd_int32 clamp0(sd_int32 v) { return ((-(v) >> 31) & (v)); }
18 sd_int32 clamp255(sd_int32 v) { return (((255 - (v)) >> 31) | (v)) & 255; }
19 sd_uint32 Clamp(sd_int32 val) { int v = clamp0(val); return (sd_uint32)(clamp255(v)); }
20
21 void YuvPixel(
22     sd_uint8 y,
23     sd_uint8 u,
24     sd_uint8 v,
25     sd_uint8* b,
26     sd_uint8* g,
27     sd_uint8* r
28     ){
29     sd_uint32 y1 = (sd_uint32)(y * 0x0101 * YG) >> 16;
30     *r = Clamp((sd_int32)(-(u * UB) + y1 + BB) >> 6);
31     *g = Clamp((sd_int32)(-(v * VG + u * UG) + y1 + BG) >> 6);
32     *b = Clamp((sd_int32)(-(v * VR) + y1 + BR) >> 6);
33 }
34 void NV21ToARGBRow_C(
35     const sd_uint8* src_y,
36     const sd_uint8* src_vu,
37     sd_uint8* rgb_buf,
38     int width
39     ){
40     int x;
41     for ( x = 0; x < width - 1; x += 2 ) {
42         YuvPixel(src_y[0], src_vu[1], src_vu[0], rgb_buf + 0, rgb_buf + 1, rgb_buf + 2);
43         rgb_buf[3] = 255;
44         YuvPixel(src_y[1], src_vu[1], src_vu[0], rgb_buf + 4, rgb_buf + 5, rgb_buf + 6);
45         rgb_buf[7] = 255;
46         src_y += 2;
47         src_vu += 2;
48         rgb_buf += 8;
49     }
50     if ( width & 1 ) {
51         YuvPixel(src_y[0], src_vu[1], src_vu[0], rgb_buf + 0, rgb_buf + 1, rgb_buf + 2);
52         rgb_buf[3] = 255;
53     }
54 }
55 int NV21ToARGB(
56     const sd_uint8* src_y,
57     int src_stride_y,
58     const sd_uint8* src_uv,
59     int src_stride_uv,
60     sd_uint8* dst_argb,
61     int dst_stride_argb,
62     int width,
63     int height
64     ){
65     int y;
66     if ( !src_y || !src_uv || !dst_argb || width <= 0 || height == 0 ) { return -1; }
67     for ( y = 0; y < height; ++y ) {
68         NV21ToARGBRow_C(src_y, src_uv, dst_argb, width);
69         dst_argb += dst_stride_argb;
70         src_y += src_stride_y;
71         if ( y & 1 ) {
72             src_uv += src_stride_uv;
73         }
74     }
75     return 0;
76 }
77 int ConvertToARGB(
78     const sd_uint8* sample, // 原图的地址
79     sd_uint8* crop_argb, // RGBA的地址
80     int argb_stride, //  should be width * 4 or width must be 1 right
81     int crop_x, // 裁剪的x坐标
82     int crop_y, // 裁剪的y坐标
83     int src_width, // 原图的宽度
84     int src_height, // 原图的高度
85     int crop_width, // 裁剪的宽度
86     int crop_height // 裁剪的高度
87     ){
88     const sd_uint8* src;
89     const sd_uint8* src_uv;
90     int aligned_src_width = (src_width + 1) & ~1;
91     src = sample + (src_width * crop_y + crop_x);
92     src_uv = sample + aligned_src_width * (src_height + crop_y / 2) + crop_x;
93     // Call NV12 but with u and v parameters swapped.
94     return NV21ToARGB(src, src_width, src_uv, aligned_src_width, crop_argb, argb_stride, crop_width, crop_height);
95 }