try repeated save to a buffer

try207.c

/* compile with
 *
 * gcc -g -Wall try207.c `pkg-config vips --cflags --libs`
 */

#include <stdio.h>

#include <vips/vips.h>

int
main( int argc, char **argv )
{       
        VipsImage *im;
        int i;

        if( !(im = vips_image_new_from_file( argv[1] )) )
                vips_error_exit( "can't open" ); 

        for( i = 0; i < 10; i++ ) {
                void *buf;
                size_t len;

                if( vips_jpegsave_buffer( im, &buf, &len, NULL ) )
                        vips_error_exit( "save #1 failed" );

                printf( "saved %zd bytes to %p\n", len, buf );

                g_free( buf );
        }

        g_object_unref( im ); 

        return( 0 );
}