- ret = zip_fread(vdev->capfile, buf,
- CHUNKSIZE / vdev->unitsize * vdev->unitsize);
+ /* unitsize is not defined for purely analog session files. */
+ if (vdev->unitsize)
+ ret = zip_fread(vdev->capfile, buf,
+ CHUNKSIZE / vdev->unitsize * vdev->unitsize);
+ else
+ ret = zip_fread(vdev->capfile, buf, CHUNKSIZE);
+