Managing a file buffer

[David Johnson]

Hi,

I have an application that reads video from a socket and saves it to a file,
which I then play using GStreamer. The major problem with this approach is
that the file keeps getting bigger and bigger until the disk is full ;-)

What I'd like to do is have a buffer, say 5MB in size, which I can point
GStreamer at. So every time I write 60K to the tail of the file, I'd need to
remove 60K from the head of the file.

How can I achieve this in Python? I looked at truncate() but it seems to do
the opposite of what I want.

Thanks in advance,
David.

--
David Johnson
www.david-web.co.uk

[Marc 'BlackJack' Rintsch]

In <ma***************************************@python. org>, David Johnson
wrote:

What I'd like to do is have a buffer, say 5MB in size, which I can point
GStreamer at. So every time I write 60K to the tail of the file, I'd need to
remove 60K from the head of the file.

You can't remove data from the head of a file. At least not without
moving all following data "down", but then the file pointer within
`gstreamer` is wrong. Can't `gstreamer` be fed through a pipe?

Ciao,
Marc 'BlackJack' Rintsch

[Jeremy Sanders]

David Johnson wrote:

I have an application that reads video from a socket and saves it to a
file, which I then play using GStreamer. The major problem with this
approach is that the file keeps getting bigger and bigger until the disk
is full ;-)

What I'd like to do is have a buffer, say 5MB in size, which I can point
GStreamer at. So every time I write 60K to the tail of the file, I'd need
to remove 60K from the head of the file.

A named pipe may be useful to you, depending on your buffering requirements,
and assuming gstreamer can play from one.

e.g. http://www2.linuxjournal.com/article/2156

You can create a named pipe from python.

Jeremy

--
Jeremy Sanders
http://www.jeremysanders.net/