MPEG/MP3 and url
John M McIntosh
johnmci at smalltalkconsulting.com
Sun Oct 22 17:02:45 UTC 2000
>John M McIntosh wrote:
>> Ok all the file IO I think is located in mpeg3io.c see
>> mpeg3io_read_data for the fread. Basically you do fseeks and freads
>> to get data based on the MPEG model and how you are uncoding the
>> data. This would be replaced by an interface to a positional stream.
>> Of course the trick here is how would you do that?
>Reading a little from the documentation:
>>>Everything you do with
>>>libmpeg3 requires passing the file pointer.
>So the C source would need some alterations to read from a stream instead.
If you create a socket in Squeak and want to read from it from the
MPEG player how would you do that? I guess you could code a cross
plugin call and call the socket support plugin directly, however if
the socket stalls, then here you are in a primitive wanting for data
to arrive, this would appear to lock Squeak up. Other choices like
having a ring buffer you fill in Squeak via reading from a Socket
then feed to the mpeg plugin exist, just a few hours/days of
>How is this handled in other mpeg decoders ?
>This one seams to do it
>It uses the Berkley algoritms for Video I think Tim Rowledge refered to
>as the one they used on the itzy.(?)
>It's under LGPL.
SMPEG is a free MPEG1 video player library with sound support. The
libmpeg3 is MPEG2, which is why I didn't use the SMPEG stuff. However
SMPEG does have code for streaming which could be used to build the
PS the 'other' mpeg stuff I have decodes most/all MPEG2 stream, even
ones that libmpeg3 does not.
John M. McIntosh <johnmci at smalltalkconsulting.com> 1-800-477-2659
Corporate Smalltalk Consulting Ltd. http://www.smalltalkconsulting.com
Custom Macintosh programming & various Smalltalk dialects
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