i can now read a few portable pixmap, the P6 type

v4l2/grabvidseq.c

@@ -194,6 +194,7 @@ for (i = 0; i < nbre_capt; i++) {
 			    fmt.fmt.pix.width, fmt.fmt.pix.height);
 	fwrite(buffers[buf.index].start, buf.bytesused, 1, fout);
 	fclose(fout);
+
 	if (nbre_capt > 1 && period) {
 		sleep(period);
 		}