F5OEO-tstools/python/test.txt

Some tests for the Python binding of the TS tools
=================================================

It's difficult to find example data files that are generally available. For
the moment, I'm going to use a file I have locally, and unfortunately others
will have to manage without. This is still better than no testing...

    >>> test_es_file = '/Users/tibs/sw/tstools/data/aladdin.es'

First, check we've got the basics working:

    >>> from tstools import ESFile
    >>> try:
    ...     stream = ESFile(test_es_file)
    ... except:
    ...     test_es_file = '/home/tibs/Videos/aladdin.es'
    ...     stream = ESFile(test_es_file)

The filename is available as a "readonly" value:

    >>> stream.name == test_es_file
    True

We've opened it for read:

    >>> stream.is_readable() == True
    True
    >>> stream.is_writable() == False
    True
    >>> stream.mode
    'r'

We should be able to iterate over its ES units:

    >>> count = 0
    >>> es_unit_list = []
    >>> for unit in stream:
    ...     count += 1
    ...     print unit
    ...     es_unit_list.append(unit)
    ...     if count > 5:
    ...         break
    ES unit: start code 00, len   14: 00 00 01 00 01 1a 01 02
    ES unit: start code 01, len  972: 00 00 01 01 1a 10 73 10
    ES unit: start code 02, len  515: 00 00 01 02 1a 10 b3 05
    ES unit: start code 03, len  372: 00 00 01 03 2a 11 31 41
    ES unit: start code 04, len  347: 00 00 01 04 32 11 75 8f
    ES unit: start code 05, len  335: 00 00 01 05 32 11 70 8b

From hexdump I get (something that can be written out as)::

   00 00 01 00 01 1a 01 02 20 00 00 00 00 00
   00 00 01 01 1a 10 73 10 1e 67 08 53 75 65 bf 1d 00 6d ...

which tends to support those results (applying the rule "split before
00 00 01")..

    Confusingly ('cos it confuses me, who am easily confused), ``esreport -es -v``
    gives me something that translates as::

        ES unit: start code 00, len   12: 00 00 01 00 00 4a 0c 98
        ES unit: start code 01, len 1717: 00 00 01 01 1a 87 e2 40
        ES unit: start code 02, len  988: 00 00 01 02 1b f8 90 69
        ES unit: start code 03, len  865: 00 00 01 03 2a 93 e2 45
        ES unit: start code 04, len  803: 00 00 01 04 2a 93 e2 45
        ES unit: start code 05, len  685: 00 00 01 05 32 93 e2 65

    (which suggests I'm misremembering how that works).

And close it:

    >>> stream.close()
    >>> stream.is_writable() == False
    True
    >>> stream.is_readable() == False
    True
    >>> stream.mode is None
    True

We can ask an ES unit about itself:

    >>> unit = es_unit_list[0]
    >>> unit.start_posn
    (0, 0)
    >>> unit.start_code
    0
    >>> unit.PES_had_PTS
    0
    >>> data = unit.data
    >>> len(data)
    14
    >>> data[0]
    '\x00'
    >>> text = 'data:'
    >>> for ii in range(8):
    ...    text += ' %02x'%ord(data[ii])
    >>> print text
    data: 00 00 01 00 01 1a 01 02
    >>> unit.fred
    Traceback (most recent call last):
    ...
    AttributeError

ES units can be compared for equality (but not order):

    >>> es_unit_list[0] == es_unit_list[0]
    1
    >>> es_unit_list[0] == es_unit_list[1]
    0
    >>> es_unit_list[0] != es_unit_list[1]
    1
    >>> es_unit_list[0] != es_unit_list[0]
    0
    >>> es_unit_list[0] < es_unit_list[1]
    Traceback (most recent call last):
    ...
    TypeError: ESUnit only supports == and != comparisons

We can create an ES unit from a Python 'string':

    >>> from tstools import ESUnit
    >>> print 'old ',repr(es_unit_list[0])
    old  ES unit: start code 00, len   14: 00 00 01 00 01 1a 01 02
    >>> new = ESUnit(es_unit_list[0].data)
    >>> print 'new ',repr(new)
    new  ES unit: start code 00, len   14: 00 00 01 00 01 1a 01 02
    >>> print 'old ',repr(es_unit_list[0])
    old  ES unit: start code 00, len   14: 00 00 01 00 01 1a 01 02
    >>> new == es_unit_list[0]
    True

And write another file...

    >>> import tempfile
    >>> import os
    >>> directory = tempfile.mkdtemp()
    >>> filename = os.path.join(directory,'tstools_test_1.es')
    >>> out = ESFile(filename,'w')
    >>> out.name == filename
    True
    >>> out.is_readable() == False
    True
    >>> out.is_writable() == True
    True
    >>> out.mode
    'w'
    >>> for unit in es_unit_list:
    ...    out.write(unit)
    >>> out.close()

Did that do the right thing? Check that we can read the units back (one by
one, to test the ``read`` method), and that the units we read back are
identical to those we wrote.

    >>> infile = ESFile(filename,'r')
    >>> other_units = []
    >>> for ii in range(0,6):
    ...    other_units.append(infile.read())
    >>>
    >>> for ii in range(0,6):
    ...    if es_unit_list[ii] != other_units[ii]:
    ...        print 'Error: unit %d does not match'%ii
    ...        break




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