:ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl is called. Due to
hardware limitations, the last buffer may be empty. In this case
the driver will set the ``bytesused`` field to 0, regardless of
:ref:`VIDIOC_DQBUF <VIDIOC_QBUF>` ioctl is called. Due to
hardware limitations, the last buffer may be empty. In this case
the driver will set the ``bytesused`` field to 0, regardless of