user: Please show me the C implementation that matches the assembly code listed below:

```asm
<v4lconvert_yuyv_to_bgr24>:
  endbr64
  push   %r15
  push   %r14
  push   %r13
  push   %r12
  push   %rbp
  push   %rbx
  mov    %ecx,%ebx
  sub    $0x1,%ebx
  js     L121
  mov    %rsi,%rbp
  mov    %edx,%r12d
  lea    -0x1(%rdx),%eax
  shr    %eax
  lea    0x1(%rax),%eax
  lea    0x0(,%rax,4),%r13
  lea    (%rax,%rax,2),%rax
  add    %rax,%rax
  mov    %rax,-0x8(%rsp)
  mov    $0xffffffff,%r8d
  mov    $0x0,%r10d
  jmp    L95
L63:
  add    $0x6,%rdx
  mov    %r9b,-0x1(%rdx)
  add    $0x4,%rdi
  cmp    %r11,%rdi
  je     L39
L77:
  movzbl 0x1(%rdi),%ecx
  add    $0xffffff80,%ecx
  mov    %ecx,%esi
  shl    $0x7,%esi
  add    %ecx,%esi
  sar    $0x6,%esi
  movzbl 0x3(%rdi),%eax
  add    $0xffffff80,%eax
  lea    (%rax,%rax,1),%r9d
  lea    (%rcx,%rcx,2),%ecx
  lea    (%rcx,%rax,4),%ecx
  add    %r9d,%ecx
  sar    $0x3,%ecx
  add    %r9d,%eax
  sar    %eax
  movzbl (%rdi),%r14d
  movzbl %r14b,%r9d
  add    %esi,%r9d
  mov    %r8d,%r15d
  cmp    $0xff,%r9d
  jg     L23
  add    %esi,%r14d
  test   %r9d,%r9d
  mov    %r14d,%r15d
  cmovs  %r10d,%r15d
L23:
  mov    %r15b,(%rdx)
  movzbl (%rdi),%r14d
  movzbl %r14b,%r9d
  sub    %ecx,%r9d
  mov    %r8d,%r15d
  cmp    $0xff,%r9d
  jg     L57
  sub    %ecx,%r14d
  test   %r9d,%r9d
  mov    %r14d,%r15d
  cmovs  %r10d,%r15d
L57:
  mov    %r15b,0x1(%rdx)
  movzbl (%rdi),%r14d
  movzbl %r14b,%r9d
  add    %eax,%r9d
  mov    %r8d,%r15d
  cmp    $0xff,%r9d
  jg     L69
  add    %eax,%r14d
  test   %r9d,%r9d
  mov    %r14d,%r15d
  cmovs  %r10d,%r15d
L69:
  mov    %r15b,0x2(%rdx)
  movzbl 0x2(%rdi),%r14d
  movzbl %r14b,%r9d
  add    %esi,%r9d
  mov    %r8d,%r15d
  cmp    $0xff,%r9d
  jg     L31
  add    %esi,%r14d
  test   %r9d,%r9d
  mov    %r14d,%r15d
  cmovs  %r10d,%r15d
L31:
  mov    %r15b,0x3(%rdx)
  movzbl 0x2(%rdi),%r9d
  movzbl %r9b,%esi
  sub    %ecx,%esi
  mov    %r8d,%r14d
  cmp    $0xff,%esi
  jg     L92
  sub    %ecx,%r9d
  test   %esi,%esi
  mov    %r9d,%r14d
  cmovs  %r10d,%r14d
L92:
  mov    %r14b,0x4(%rdx)
  movzbl 0x2(%rdi),%esi
  movzbl %sil,%ecx
  add    %eax,%ecx
  mov    %r8d,%r9d
  cmp    $0xff,%ecx
  jg     L63
  add    %eax,%esi
  test   %ecx,%ecx
  cmovs  %r10d,%esi
  mov    %esi,%r9d
  jmp    L63
L39:
  add    -0x8(%rsp),%rbp
  mov    %r11,%rdi
L102:
  sub    $0x1,%ebx
  cmp    $0xffffffff,%ebx
  je     L121
L95:
  lea    (%rdi,%r13,1),%r11
  mov    %rbp,%rdx
  test   %r12d,%r12d
  jg     L77
  jmp    L102
L121:
  pop    %rbx
  pop    %rbp
  pop    %r12
  pop    %r13
  pop    %r14
  pop    %r15
  ret
```

assistant: ```c
void v4lconvert_yuyv_to_bgr24(const unsigned char *src, unsigned char *dest, int width, int height) {
  int j;
  while (--height >= 0) {
    for (j = 0; j < width; j += 2) {
      int u = src[1];
      int v = src[3];
      int u1 = (((u - 128) << 7) + (u - 128)) >> 6;
      int rg = (((u - 128) << 1) + (u - 128) + ((v - 128) << 2) + ((v - 128) << 1)) >> 3;
      int v1 = (((v - 128) << 1) + (v - 128)) >> 1;
      *dest++ = (unsigned char)(((src[0] + u1) > 0xFF) ? 0xff : (((src[0] + u1) < 0) ? 0 : (src[0] + u1)));
      *dest++ = (unsigned char)(((src[0] - rg) > 0xFF) ? 0xff : (((src[0] - rg) < 0) ? 0 : (src[0] - rg)));
      *dest++ = (unsigned char)(((src[0] + v1) > 0xFF) ? 0xff : (((src[0] + v1) < 0) ? 0 : (src[0] + v1)));
      *dest++ = (unsigned char)(((src[2] + u1) > 0xFF) ? 0xff : (((src[2] + u1) < 0) ? 0 : (src[2] + u1)));
      *dest++ = (unsigned char)(((src[2] - rg) > 0xFF) ? 0xff : (((src[2] - rg) < 0) ? 0 : (src[2] - rg)));
      *dest++ = (unsigned char)(((src[2] + v1) > 0xFF) ? 0xff : (((src[2] + v1) < 0) ? 0 : (src[2] + v1)));
      src += 4;
    }
  }
}
```