kopia lustrzana https://github.com/F5OEO/tstools
Python bindings: Re-reading the Pyrex documentation, it is obvious (!) that
Python methods in extension types *can* call cdef methods, so make the cdef functions I was using, because I hadn't figured this out, be cdef methods instead. This (a) makes the code simpler/nicer, and (b) will make it easier to accumulate PAT (and later PMT) over repeated calls of the (now a) method that reads the next TS packet. --HG-- extra : convert_revision : svn%3Aeff31bef-be4a-0410-a8fe-e47997df2690/trunk%4097issue20
tibs
rodzic
f16d7ed982
commit
9a493c00b0
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@ -1,8 +1,10 @@
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"""tstools.pyx -- Pyrex bindings for the TS tools
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This is being developed on a Mac, running OS X. I expect that it will also
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build on a Linux machine. I do not expect it to build (as it stands) on
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Windows, as it is making assumptions that may not follow thereon.
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This is being developed on a Mac, running OS X, and also tested on my Ubuntu
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system at work.
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I do not expect it to build (as it stands) on Windows, as it is making
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assumptions that may not follow thereon.
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It is my intent to worry about Windows after it works on the platforms that
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I can test most easily!
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@ -182,16 +184,6 @@ cdef extern from 'es_fns.h':
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class TSToolsException(Exception):
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pass
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cdef same_ES_unit(ES_unit_p this, ES_unit_p that):
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"""Two ES units do not need to be at the same place to be the same.
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"""
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if this.data_len != that.data_len:
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return False
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for 0 <= ii < this.data_len:
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if this.data[ii] != that.data[ii]:
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return False
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return True
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cdef class ESOffset:
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"""An offset within an ES file.
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@ -249,6 +241,16 @@ cdef class ESOffset:
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else:
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return 0
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cdef same_ES_unit(ES_unit_p this, ES_unit_p that):
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"""Two ES units do not need to be at the same place to be the same.
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"""
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if this.data_len != that.data_len:
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return False
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for 0 <= ii < this.data_len:
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if this.data[ii] != that.data[ii]:
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return False
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return True
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cdef class ESUnit # Forward declaration
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cdef object compare_ESUnits(ESUnit this, ESUnit that, int op):
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"""op is 2 for ==, 3 for !=, other values not allowed.
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@ -336,40 +338,6 @@ cdef class ESUnit:
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else:
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raise AttributeError
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# Is this the simplest way? Since it appears that a class method
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# doesn't want to take a non-Python item as an argument...
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cdef _next_ESUnit(ES_p stream, filename):
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cdef ES_unit_p unit
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# The C function assumes it has a valid ES stream passed to it
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# = I don't think we're always called with such
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if stream == NULL:
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raise TSToolsException,'No ES stream to read'
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retval = find_and_build_next_ES_unit(stream, &unit)
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if retval == EOF:
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raise StopIteration
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elif retval != 0:
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raise TSToolsException,'Error getting next ES unit from file %s'%filename
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# I'd like to be able to do:
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# return ESUnit(unit=unit)
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# but it's not possible to pass anything other than a Python object
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# to methods, and an ES_unit_p is not (which is the point of what we're
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# doing!). I could take the innards of the ES unit, and pass them as
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# individual arguments, appropriately mangled, but that seems a bit like
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# overkill when the (rather inelegant but at least hidden in this factory
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# method) approach below actually works.
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# Maybe I'll figure out something better as I learn more about Pyrex.
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# From http://www.philhassey.com/blog/2007/12/05/pyrex-from-confusion-to-enlightenment/
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# Pyrex doesn't do type inference, so it doesn't detect that 'u' is allowed
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# to hold an ES_unit_p. It's up to us to *tell* it, specifically, what type
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# 'u' is going to be.
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cdef ESUnit u
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u = ESUnit()
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u.unit = unit
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return u
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cdef class ESFile:
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"""A Python class representing an ES stream.
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@ -444,12 +412,34 @@ cdef class ESFile:
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"""
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return self.mode == 'w' and self.file_stream != NULL
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cdef _next_ESUnit(self):
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cdef ES_unit_p unit
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# The C function assumes it has a valid ES stream passed to it
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# = I don't think we're always called with such
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if self.stream == NULL:
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raise TSToolsException,'No ES stream to read'
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retval = find_and_build_next_ES_unit(self.stream, &unit)
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if retval == EOF:
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raise StopIteration
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elif retval != 0:
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raise TSToolsException,'Error getting next ES unit from file %s'%self.name
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# From http://www.philhassey.com/blog/2007/12/05/pyrex-from-confusion-to-enlightenment/
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# Pyrex doesn't do type inference, so it doesn't detect that 'u' is allowed
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# to hold an ES_unit_p. It's up to us to *tell* it, specifically, what type
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# 'u' is going to be.
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cdef ESUnit u
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u = ESUnit()
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u.unit = unit
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return u
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# For Pyrex classes, we define a __next__ instead of a next method
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# in order to form our iterator
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def __next__(self):
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"""Our iterator interface retrieves the ES units from the stream.
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"""
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return _next_ESUnit(self.stream,self.name)
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return self._next_ESUnit()
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def seek(self,*args):
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"""Seek to the given 'offset', which should be the start of an ES unit.
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@ -484,7 +474,7 @@ cdef class ESFile:
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"""Read the next ES unit from this stream.
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"""
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try:
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return _next_ESUnit(self.stream,self.name)
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return self._next_ESUnit()
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except StopIteration:
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raise EOFError
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@ -802,36 +792,6 @@ cdef class TSPacket:
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else:
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raise AttributeError
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# Not a method, honest
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# (__dealloc__ is not allowed to call Python methods, just in case,
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# and Python methods don't seem to be allowed to call __dealloc__,
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# since I assume it's not a "real" method)
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cdef _TSFile_close_for_read(TS_reader_p *tsreader):
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if tsreader != NULL:
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retval = close_TS_reader(tsreader)
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if retval != 0:
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raise TSToolsException,"Error closing file '%s':"\
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" %s"%(self.name,strerror(errno))
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cdef TSPacket _next_TSPacket(TS_reader_p tsreader, filename):
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cdef byte *buffer
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if tsreader == NULL:
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raise TSToolsException,'No TS stream to read'
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retval = read_next_TS_packet(tsreader, &buffer)
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if retval == EOF:
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raise StopIteration
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elif retval == 1:
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raise TSToolsException,'Error getting next TS packet from file %s'%filename
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# Remember the buffer we get handed a pointer to is transient
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# so we need to take a copy of it (which we might as well keep in
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# a Python object...)
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buffer_str = PyString_FromStringAndSize(<char *>buffer, TS_PACKET_LEN)
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try:
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return TSPacket(buffer_str)
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except TSToolsException, what:
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raise TSToolsException,\
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'Error getting next TS packet from file %s (%s)'%(filename,what)
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cdef class TSFile:
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"""A Python class representing a TS file.
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@ -877,8 +837,18 @@ cdef class TSFile:
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self.name = filename
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self.mode = mode
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# (__dealloc__ is apparently not allowed to call Python methods,
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# and Python methods don't seem to be allowed to call __dealloc__,
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# so let's have an intermediary)
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cdef _close_for_read(self):
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if self.tsreader != NULL:
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retval = close_TS_reader(&self.tsreader)
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if retval != 0:
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raise TSToolsException,"Error closing file '%s':"\
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" %s"%(self.name,strerror(errno))
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def __dealloc__(self):
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_TSFile_close_for_read(&self.tsreader)
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self._close_for_read()
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#if self.tsreader != NULL:
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# retval = close_TS_reader(&self.tsreader)
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# if retval != 0:
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@ -910,12 +880,40 @@ cdef class TSFile:
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#return self.mode == 'w' and self.file_stream != NULL
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pass
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cdef TSPacket _next_TSPacket(self):
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"""Read the next TS packet and return an equivalent TSPacket instance.
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``filename`` is given for use in exception messages - it should be the
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name of the file we're reading from (using ``tsreader``). Perhaps the
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tstools C mechanisms should be enhanced to allow that to be recovered
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*from* ``tsreader``.
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"""
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# XXX Should we update self.PAT if the packet has PID 0?
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# XXX See tsreport.c::report_ts for how to do this
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cdef byte *buffer
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if self.tsreader == NULL:
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raise TSToolsException,'No TS stream to read'
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retval = read_next_TS_packet(self.tsreader, &buffer)
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if retval == EOF:
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raise StopIteration
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elif retval == 1:
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raise TSToolsException,'Error getting next TS packet from file %s'%self.name
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# Remember the buffer we get handed a pointer to is transient
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# so we need to take a copy of it (which we might as well keep in
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# a Python object...)
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buffer_str = PyString_FromStringAndSize(<char *>buffer, TS_PACKET_LEN)
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try:
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return TSPacket(buffer_str)
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except TSToolsException, what:
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raise TSToolsException,\
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'Error getting next TS packet from file %s (%s)'%(self.name,what)
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# For Pyrex classes, we define a __next__ instead of a next method
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# in order to form our iterator
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def __next__(self):
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"""Our iterator interface retrieves the TS packets from the stream.
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"""
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return _next_TSPacket(self.tsreader,self.name)
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return self._next_TSPacket()
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def seek(self,offset):
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"""Seek to the given offset, which should be a multiple of 188.
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@ -929,10 +927,8 @@ cdef class TSFile:
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def read(self):
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"""Read the next TS packet from this stream.
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"""
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# XXX Should we update self.PAT if the packet has PID 0?
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# XXX See tsreport.c::report_ts for how to do this
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try:
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return _next_TSPacket(self.tsreader,self.name)
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return self._next_TSPacket()
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except StopIteration:
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raise EOFError
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@ -984,7 +980,7 @@ cdef class TSFile:
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# if retval != 0:
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# raise TSToolsException,"Error closing file '%s':"\
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# " %s"%(self.name,strerror(errno))
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_TSFile_close_for_read(&self.tsreader)
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self._close_for_read()
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self.name = None
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self.mode = None
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