jpegtools.c

linux下开源图片codec

    jpeg_destroy_compress(&th.dst);

    /* replace thumbnail */
    free(ed->data);
    ed->data = th.out;
    ed->size = th.osize;
}

static void do_exif(struct jpeg_decompress_struct *src,
		    JXFORM_CODE *transform, unsigned int flags)
{
    jpeg_saved_marker_ptr mark;
    ExifData *ed = NULL;
    unsigned char *data;
    unsigned int  size;
    
    for (mark = src->marker_list; NULL != mark; mark = mark->next) {
	if (mark->marker != JPEG_APP0 +1)
	    continue;
	ed = exif_data_new_from_data(mark->data,mark->data_length);
	break;
    }
    if (!ed)
	return;

    if (-1 == *transform) {
	/* automagic image transformation */
	int orientation = get_orientation(ed);
	*transform = JXFORM_NONE;
	if (orientation >= 1 && orientation <= 8)
	    *transform = transmagic[orientation];
#if 0
	if (debug)
	    fprintf(stderr,"autotrans: %s\n",transname[*transform]);
#endif
    }

    /* update exif data */
    if (flags & JFLAG_UPDATE_ORIENTATION) {
	update_orientation(ed,EXIF_IFD_0,1);
	update_orientation(ed,EXIF_IFD_1,1);
    }
    if (ed->data && ed->data[0] == 0xff && ed->data[1] == 0xd8 &&
	(flags & JFLAG_TRANSFORM_THUMBNAIL))
	do_thumbnail(ed,*transform);
    update_dimension(ed, (flags & JFLAG_TRANSFORM_IMAGE) ? *transform : JXFORM_NONE,
		     src->image_width, src->image_height);

    /* build new exif data block */
    exif_data_save_data(ed,&data,&size);
    exif_data_unref(ed);

    /* update jpeg APP1 (EXIF) marker */
    mark->data = src->mem->alloc_large((j_common_ptr)src,JPOOL_IMAGE,size);
    mark->original_length = size;
    mark->data_length = size;
    memcpy(mark->data,data,size);
    free(data);
}
#endif

/* ---------------------------------------------------------------------- */

static void do_comment(struct jpeg_decompress_struct *src,
		       unsigned char *comment)
{
    jpeg_saved_marker_ptr mark;
    int size;

    /* find or create comment marker */
    for (mark = src->marker_list;; mark = mark->next) {
	if (mark->marker == JPEG_COM)
	    break;
	if (NULL == mark->next) {
	    mark->next = src->mem->alloc_large((j_common_ptr)src,JPOOL_IMAGE,
					       sizeof(*mark));
	    mark = mark->next;
	    memset(mark,0,sizeof(*mark));
	    mark->marker = JPEG_COM;
	    break;
	}
    }

    /* update comment marker */
    size = strlen(comment) +1;
    mark->data = src->mem->alloc_large((j_common_ptr)src,JPOOL_IMAGE,size);
    mark->original_length = size;
    mark->data_length = size;
    memcpy(mark->data,comment,size);
}

static int do_transform(struct jpeg_decompress_struct *src,
			struct jpeg_compress_struct   *dst,
			JXFORM_CODE transform,
			unsigned char *comment,
			unsigned int flags)
{
    jvirt_barray_ptr * src_coef_arrays;
    jvirt_barray_ptr * dst_coef_arrays;
    jpeg_transform_info transformoption;

    jcopy_markers_setup(src, JCOPYOPT_ALL);
    if (JPEG_HEADER_OK != jpeg_read_header(src, TRUE))
	return -1;

#ifdef HAVE_LIBEXIF
    do_exif(src,&transform,flags);
#endif
    if (-1 == transform)
	transform = JXFORM_NONE;
    if (!(flags & JFLAG_TRANSFORM_IMAGE))
	transform = JXFORM_NONE;
    if ((flags & JFLAG_UPDATE_COMMENT) && NULL != comment)
	do_comment(src,comment);

    memset(&transformoption,0,sizeof(transformoption));
    transformoption.transform = transform;
    transformoption.trim      = FALSE;
    transformoption.force_grayscale = FALSE;

    /* Any space needed by a transform option must be requested before
     * jpeg_read_coefficients so that memory allocation will be done right.
     */
    jtransform_request_workspace(src, &transformoption);
    src_coef_arrays = jpeg_read_coefficients(src);
    jpeg_copy_critical_parameters(src, dst);
    dst_coef_arrays = jtransform_adjust_parameters
	(src, dst, src_coef_arrays, &transformoption);
    
    /* Start compressor (note no image data is actually written here) */
    jpeg_write_coefficients(dst, dst_coef_arrays);
    
    /* Copy to the output file any extra markers that we want to preserve */
    jcopy_markers_execute(src, dst, JCOPYOPT_ALL);
    
    /* Execute image transformation, if any */
    jtransform_execute_transformation(src, dst,
				      src_coef_arrays,
				      &transformoption);
    
    /* Finish compression and release memory */
    jpeg_finish_compress(dst);
    jpeg_finish_decompress(src);

    return 0;
}

/* ---------------------------------------------------------------------- */

int jpeg_transform_fp(FILE *in, FILE *out,
		      JXFORM_CODE transform,
		      unsigned char *comment,
		      unsigned int flags)
{
    struct jpeg_decompress_struct src;
    struct jpeg_compress_struct   dst;
    struct jpeg_error_mgr jdsterr;
    struct longjmp_error_mgr jsrcerr;
    
    /* setup src */
    src.err = jpeg_std_error(&jsrcerr.jpeg);
    jsrcerr.jpeg.error_exit = longjmp_error_exit;
    if (setjmp(jsrcerr.setjmp_buffer))
	/* something went wrong within the jpeg library ... */
	goto oops;
    jpeg_create_decompress(&src);
    jpeg_stdio_src(&src, in);
    
    /* setup dst */
    dst.err = jpeg_std_error(&jdsterr);
    jpeg_create_compress(&dst);
    jpeg_stdio_dest(&dst, out);

    /* transform image */
    do_transform(&src,&dst,transform,comment,flags);

    /* cleanup */
    jpeg_destroy_decompress(&src);
    jpeg_destroy_compress(&dst);
    return 0;

 oops:
    jpeg_destroy_decompress(&src);
    jpeg_destroy_compress(&dst);
    return -1;
}

int jpeg_transform_files(char *infile, char *outfile,
			 JXFORM_CODE transform,
			 unsigned char *comment,
			 unsigned int flags)
{
    int rc;
    FILE *in;
    FILE *out;
    
    /* open infile */
    in = fopen(infile,"r");
    if (NULL == in) {
	fprintf(stderr,"open %s: %s\n",infile,strerror(errno));
	return -1;
    }
    
    /* open outfile */
    out = fopen(outfile,"w");
    if (NULL == out) {
	fprintf(stderr,"open %s: %s\n",outfile,strerror(errno));
	fclose(in);
	return -1;
    }

    /* go! */
    rc = jpeg_transform_fp(in,out,transform,comment,flags);
    fclose(in);
    fclose(out);

    return rc;
}

int jpeg_transform_inplace(char *file,
			   JXFORM_CODE transform,
			   unsigned char *comment,
			   unsigned int flags)
{
    char *tmpfile;
    char *bakfile;
    struct stat st;
    int fd;
    FILE *in  = NULL;
    FILE *out = NULL;

    /* are we allowed to write to the file? */
    if (0 != access(file,W_OK)) {
	fprintf(stderr,"access %s: %s\n",file,strerror(errno));
	return -1;
    }

    /* open infile */
    in = fopen(file,"r");
    if (NULL == in) {
	fprintf(stderr,"open %s: %s\n",file,strerror(errno));
	return -1;
    }
    
    /* open tmpfile */
    tmpfile = malloc(strlen(file)+10);
    sprintf(tmpfile,"%s.XXXXXX",file);
    fd = mkstemp(tmpfile);
    if (-1 == fd) {
	fprintf(stderr,"mkstemp(%s): %s\n",tmpfile,strerror(errno));
	goto oops;
    }
    out = fdopen(fd,"w");

    /* copy owner and permissions */
    if (-1 == fstat(fileno(in),&st)) {
	fprintf(stderr,"fstat(%s): %s\n",file,strerror(errno));
	goto oops;
    }
    if (-1 == fchown(fileno(out),st.st_uid,st.st_gid)) {
	fprintf(stderr,"fchown(%s): %s\n",tmpfile,strerror(errno));
	goto oops;
    }
    if (-1 == fchmod(fileno(out),st.st_mode)) {
	fprintf(stderr,"fchmod(%s): %s\n",tmpfile,strerror(errno));
	goto oops;
    }

    /* transform */
    if (0 != jpeg_transform_fp(in,out,transform,comment,flags))
	goto oops;

    /* worked ok -- commit */
    fclose(in);
    fclose(out);
    if (flags & JFLAG_FILE_BACKUP) {
	bakfile = malloc(strlen(file)+2);
	sprintf(bakfile,"%s~",file);
	rename(file,bakfile);
	free(bakfile);
    }
    rename(tmpfile,file);
    if (flags & JFLAG_FILE_KEEP_TIME) {
	struct utimbuf u;
	u.actime = st.st_atime;
	u.modtime = st.st_mtime;
	utime(file,&u);
    }
        
    /* cleanup & return */
    free(tmpfile);
    return 0;

 oops:
    /* something went wrong -- rollback */
    if (in)
	fclose(in);
    if (out) {
	fclose(out);
	unlink(tmpfile);
    }
    return -1;
}