使用jpeg库将jpeg图像解码为yuv_windows下面jpeg转成yuv422

在做算法的过程中经常终端传来的是jpeg图片，需要将jpeg解码为yuv再进行处理。这里使用jpeg-6b交叉编译，然后进行解码，下面是解码的过程：
1

#include <ctype.h>
#include <errno.h>
#include <unistd.h>
#include <setjmp.h>
#include <sys/stat.h>
#include <stdio.h>
#include <string.h>
#include <time.h>


#include <stdlib.h>
#include <string.h>

 #include "jpeglib.h"
 #include <setjmp.h>

 #include "decode.h"


struct my_error_mgr {
    struct jpeg_error_mgr pub;  /* "public" fields */

    jmp_buf setjmp_buffer;  /* for return to caller */
};

typedef struct my_error_mgr * my_error_ptr;

void my_decompress_error_exit (j_common_ptr cinfo)
{
    /* cinfo->err really points to a my_error_mgr struct, so coerce pointer */
    my_error_ptr myerr = (my_error_ptr) cinfo->err;

    /* Always display the message. */
    /* We could postpone this until after returning, if we chose. */
    (*cinfo->err->output_message) (cinfo);

    /* Return control to the setjmp point */
    longjmp(myerr->setjmp_buffer, 1);
}
int decode_jpeg_file (char *frame,int frame_size,char *decoded_frame,int *decoded_frame_size,int *decoded_width,int *decoded_height,int color_space)
{
			
	struct jpeg_decompress_struct cinfo;
	struct my_error_mgr jerr;
	FILE *infile, *outfile;
	JSAMPARRAY buffer;      /* Output row buffer */
	int row_stride;     /* physical row width in output buffer */

	int finished = 1;
	int chromaWidth, chromaHeight;
	int yMask,xMask;

	int x,y;
	int width,height;

	unsigned char *pixels=NULL,*rgbPixels=NULL, *src=NULL;
	unsigned char *yPixels=NULL, *uPixels=NULL, *vPixels=NULL;
	unsigned char *yPtr=NULL, *uPtr=NULL, *vPtr=NULL;

	cinfo.err = jpeg_std_error(&jerr.pub);
	jerr.pub.error_exit = my_decompress_error_exit;
	if (setjmp(jerr.setjmp_buffer)) 
	{
		jpeg_destroy_decompress(&cinfo);
		//fclose(infile);
		return -1;
	}
	jpeg_create_decompress(&cinfo);
	//jpeg_stdio_src(&cinfo, infile);
	jpeg_stdio_buffer_src(&cinfo,(unsigned char *)(frame),frame_size);
	(void) jpeg_read_header(&cinfo, TRUE);
	/*set parameters for decompression */
	cinfo.out_color_space = JCS_YCbCr;
	(void) jpeg_start_decompress(&cinfo);
	width  = cinfo.output_width;
	height = cinfo.output_height;
	*decoded_width = width;
	*decoded_height = height;

	pixels = (unsigned char *)malloc(width*height*3);
	if(pixels==NULL)
		printf("Malloc pixels failed!!!!\n");
	memset(pixels, 0, width * height * 3);
	
	src = rgbPixels = pixels;
	/* JSAMPLEs per row in output buffer */
	row_stride = cinfo.output_width * cinfo.output_components;
	/* Make a one-row-high sample array that will go away when done with image */
	buffer = (*cinfo.mem->alloc_sarray)((j_common_ptr) &cinfo, JPOOL_IMAGE, row_stride, 1);

	printf("cinfo.output_width:%d\n",cinfo.output_width);
	printf("cinfo.output_height:%d\n",cinfo.output_height);
	printf("cinfo.output_components:%d\n",cinfo.output_components);
	while (cinfo.output_scanline < cinfo.output_height)
	{
		int num_rows = jpeg_read_scanlines(&cinfo, buffer, 1);
	//	printf("cinfo.output_scanline:%d\n",cinfo.output_scanline);
	//	printf("num_rows:%d\n",num_rows);
		
	//	printf("\t\tcinfo.output_components:%d\n",cinfo.output_components);
	//	getchar();

		if (num_rows == 0) 
		{
			finished = 0;
			break;
		}
		if (cinfo.output_components == 1) 
		{        // greyscale
			unsigned int i;
			unsigned char *in = (unsigned char *)(*buffer);
			for (i = 0; i < width * num_rows; ++i)
			{
				*pixels++ = *in; // red   b
				*pixels++ = *in; // green  g
				*pixels++ = *in; // blue  r
				++in;
			}
		} 
		else if (cinfo.output_components == 3) 
		{ // RGB
			memcpy(rgbPixels, (*buffer), num_rows * width * 3);
			rgbPixels += num_rows * width * 3;
			//memcpy(pixels, (*buffer), num_rows * width * 3);
			//pixels += num_rows * width * 3;
		}
	}
	rgbPixels = pixels;
	if(finished)
	{
		printf("jpeg_finish_decompress!\n");
		(void) jpeg_finish_decompress(&cinfo);
	}
	printf("\n");
	jpeg_destroy_decompress(&cinfo);
	printf("jpeg_destroy_decompress finished! \n");
	
//	fwrite(yPixels, 1, width * height, outfile);
//	fwrite(uPixels, 1, chromaWidth*chromaHeight, outfile);
//	fwrite(vPixels, 1, chromaWidth*chromaHeight, outfile);

//	fwrite(rgbPixels, 1, width * height*3, outfile);

	

	//if( NULL !=infile)
	//{
	//	fclose(infile);
	//}
	//if(NULL != outfile)
	//{
	//	fclose(outfile);
	//}

	/*
	if(width!=352||height!=288)
	{
		printf("Decoded img:wid=%d,hgt=%d\tError!!!!!!!not 352*288!!!!\n",width,height);
		return -1;
	}
	else
	*/
	if (color_space == DECODE_COLOR_Y||color_space == DECODE_COLOR_GRAY)
	{
		yPixels = (unsigned char*)malloc(height * width);
		if(yPixels==NULL)printf("Malloc yPixels fail!!!\n");

		yPtr = yPixels;
		for(y = 0; y < height; y++)
		{
			for(x = 0; x < width; x++)
			{	
				*yPtr++ = *rgbPixels++;
				rgbPixels += 2;					
			}
		}
		memcpy(decoded_frame, yPixels, height * width );
		*decoded_frame_size = height * width;
	} 
	else if (color_space == DECODE_COLOR_YUV420)
	{
		chromaWidth = width/2;
		chromaHeight = height/2;
		
		printf("color_space DECODE_COLOR_YUV420! \n");
		
		yMask = xMask = 1;

		yPixels = (unsigned char*)malloc(width * height);
		if(yPixels==NULL)printf("Malloc yPixels fail!!!\n");
		uPixels = (unsigned char*)malloc(chromaWidth*chromaHeight);	
		if(uPixels==NULL)printf("Malloc uPixels fail!!!\n");
		vPixels = (unsigned char*)malloc(chromaWidth*chromaHeight);		
		if(vPixels==NULL)printf("Malloc vPixels fail!!!\n");
		
		yPtr = yPixels;
		uPtr = uPixels;
		vPtr = vPixels;
		for(y = 0; y < height; y++)
		{
			for(x = 0; x < width; x++)
			{	
				*yPtr++ = *rgbPixels++;

				if((y & yMask) == 0 && (x & xMask) == 0)
				{
					*uPtr++ = *rgbPixels++;
					*vPtr++ = *rgbPixels++;	
				}
				else
				{
					rgbPixels += 2;
				}				
			}
		}
		memcpy(decoded_frame, yPixels, height * width );
		memcpy(decoded_frame+height * width, uPixels, chromaHeight * chromaWidth );
		memcpy(decoded_frame+height * width+chromaHeight * chromaWidth, vPixels, chromaHeight * chromaWidth );
		*decoded_frame_size = height * width/2*3;
		printf("decoded_frame:%d\n", *decoded_frame_size);
		rgbPixels=NULL;
		
	}
	else if (color_space == DECODE_COLORYUV444)
	{
		chromaWidth = width;
		chromaHeight = height;

		yPixels = (unsigned char*)malloc(height * width);
		if(yPixels==NULL)printf("Malloc yPixels fail!!!\n");
		uPixels = (unsigned char*)malloc(chromaWidth*chromaHeight);	
		if(uPixels==NULL)printf("Malloc uPixels fail!!!\n");
		vPixels = (unsigned char*)malloc(chromaWidth*chromaHeight);		
		if(vPixels==NULL)printf("Malloc vPixels fail!!!\n");

		yPtr = yPixels;
		uPtr = uPixels;
		vPtr = vPixels;
		for(y = 0; y < height; y++)
		{
			for(x = 0; x < width; x++)
			{	
				*yPtr++ = *rgbPixels++;
				*uPtr++ = *rgbPixels++;
				*vPtr++ = *rgbPixels++;					
			}
		}
		memcpy(decoded_frame, yPixels, height * width );
		memcpy(decoded_frame+height * width, uPixels, height * width );
		memcpy(decoded_frame+2*height * width, vPixels, height * width );
		*decoded_frame_size = height * width*3;

	}
	
	if( NULL !=pixels)
	{
		free(pixels);
		pixels =  NULL;
	}

	if( NULL !=yPixels)
	{
		free(yPixels);
		yPixels = NULL;
	}
	if( NULL !=uPixels)
	{
		free(uPixels);
		uPixels = NULL;
	}
	if( NULL !=vPixels)
	{
		free(vPixels);
		vPixels = NULL;
	}
	if( NULL !=rgbPixels)
	{
		rgbPixels = NULL;
	}
	return 0;
}
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281

需要注意的是，jpeg-6b解码好像只能用gcc编译，用g++会出错，我通常是将其封装成库，用gcc编译，然后在c++中调用。