In the previous article, we finally talked about a function that directly converts yuv to jpg, but the conversion was not successful. The original function is yuv420 to jpg.
The yuv420 scan sequence is as follows:
YYYY
YYYY
UVUV
The yuv422 line scan sequence is as follows:
YU YV
Modify the function as follows:
static int put_jpeg_yuv420p_memory(unsigned char *dest_image, unsigned char *input_image, int width, int height){ int i, j, jpeg_image_size; JSAMPROW y[16],cb[16],cr[16]; // y[2][5] = color sample of row 2 and pixel column 5; (one plane) JSAMPARRAY data[3]; // t[0][2][5] = color sample 0 of row 2 and column 5 struct jpeg_compress_struct cinfo; struct jpeg_error_mgr jerr; char *pbuf = NULL;int jpglen = 0; data[0] = y; data[1] = cb; data[2] = cr; cinfo.err = jpeg_std_error(&jerr); // errors get written to stderr jpeg_create_compress(&cinfo); cinfo.image_width = width; cinfo.image_height = height; cinfo.input_components = 3; jpeg_set_defaults (&cinfo); jpeg_set_colorspace(&cinfo, JCS_YCbCr); cinfo.raw_data_in = TRUE; // supply downsampled data cinfo.do_fancy_downsampling = FALSE; // fix segfaulst with v7 cinfo.comp_info[0].h_samp_factor = 2; cinfo.comp_info[0].v_samp_factor = 2; cinfo.comp_info[1].h_samp_factor = 1; cinfo.comp_info[1].v_samp_factor = 1; cinfo.comp_info[2].h_samp_factor = 1; cinfo.comp_info[2].v_samp_factor = 1; jpeg_set_quality(&cinfo, 80, TRUE); cinfo.dct_method = JDCT_FASTEST; jpeg_mem_dest(&cinfo, &pbuf, &jpglen); // data written to mem jpeg_start_compress (&cinfo, TRUE); for (j = 0; j < height; j += 16) { for (i = 0; i < 16; i++) { y[i] = input_image + width * (i + j); //cb[i/2] = input_image + width * height + width / 2 * ((i + j) / 2); //cr[i/2] = input_image + width * height + width * height / 4 + width / 2 * ((i + j) / 2); if (i%2 == 0) cb[i/2] = input_image + width * ((i + j) / 2);elsecr[i/2] = input_image + width * ((i + j) / 2); } jpeg_write_raw_data(&cinfo, data, 16); } jpeg_finish_compress(&cinfo); jpeg_destroy_compress(&cinfo); memcpy(dest_image,pbuf,jpglen);if(pbuf)free(pbuf); return jpglen;}
You can directly convert yuv422 to jpg.
The interface function is modified as follows:
JNIEXPORT jint JNICALL Java_com_hclydao_usbcamera_Fimcgzsd_writefile(JNIEnv * env, jclass obj,jbyteArray yuvdata,jbyteArray filename)//jintArray rgbdata{jbyte *ydata = (jbyte*)(*env)->GetByteArrayElements(env, yuvdata, 0);jbyte *filedir = (jbyte*)(*env)->GetByteArrayElements(env, filename, 0);FILE * outfile; if ((outfile = fopen(filedir, "wb")) == NULL) { LOGE("++++++++++++open %s failed\n",filedir); return -1; }unsigned char* dst = malloc(mwidth*mheight*3*sizeof(char));int size = put_jpeg_yuv420p_memory(dst,ydata,mwidth,mheight);fwrite(dst,size,1,outfile);if(dst)free(dst);if(jpgdata)free(jpgdata);fclose(outfile);(*env)->ReleaseByteArrayElements(env, yuvdata, ydata, 0);(*env)->ReleaseByteArrayElements(env, filename, filedir, 0);}
Still need to calm down and study