我只需要使用 LibJpeg 将 yuv 422 图像中的 Y 压缩为 jpeg 图像
Y only 是灰度图像
这是我的代码:
y = (char*) malloc(640*480);
for (i = 0, j = 0; j < n; i++, j += 2)
y[i] = raw[j];
Image *dst;
dst = CreateImage(sz, 8, 1);
dst->imageData = y;
//frame is the dst image
bool ipl2jpeg(Image *frame, unsigned char **outbuffer, long unsigned int *outlen) {
unsigned char *outdata = (uchar *) frame->imageData;
struct jpeg_compress_struct cinfo ;
struct jpeg_error_mgr jerr;
JSAMPROW row_ptr[1];
int row_stride;
*outbuffer = NULL;
*outlen = 0;
cinfo.err = jpeg_std_error(&jerr);
jpeg_create_compress(&cinfo);
jpeg_mem_dest(&cinfo, outbuffer, outlen);
cinfo.image_width = frame->width;
cinfo.image_height = frame->height;
cinfo.input_components = frame->nChannels;
cinfo.in_color_space = JCS_GRAYSCALE;
jpeg_set_defaults(&cinfo);
jpeg_set_quality (&cinfo, 50, true);
jpeg_start_compress(&cinfo, TRUE);
row_stride = frame->width * frame->nChannels;
while (cinfo.next_scanline < cinfo.image_height) {
row_ptr[0] = &outdata[cinfo.next_scanline * row_stride];
jpeg_write_scanlines(&cinfo, row_ptr, 1); // Iam getting segm. fault here
}
jpeg_finish_compress(&cinfo);
jpeg_destroy_compress(&cinfo);
return true;
}
我在 jpeg_write_scanlines 中遇到分段错误我不确定我做对了。这是将灰度图像转换为 jpeg 的正确方法吗?