[MEncoder-users] Re: using mf:// with stdin

[John Brown]

Morris Beverly <morrisb <at> avpresentations.com> writes:

> 
> 
> RC wrote:
> 
> >On Wed, 18 Apr 2007 16:18:35 -0400
> >Morris Beverly <morrisb <at> avpresentations.com> wrote:
> >
> >  
> >
> >>I've tried a lot of variations like  mf:///dev/stdin, mf://-, 
> >>mf://*.jpg, not using mf:// at all, all with pretty much the same
> >>result:
> >>    
> >>
> >
> >Don't use mf at all.  It's not for streams.
> >
> ...  I 
> wonder if something is not happening with cat going into mencoder 
> properly because of the output  line
> 
> Reading from stdin...
> [file] File size is -1 bytes
> 
[cut]
> success: format: 0  data: 0x0 - 0x0
> MF file format detected.
> ============ Sorry, this file format is not recognized/supported 
> =============
> === If this file is an AVI, ASF or MPEG stream, please contact the 
> author! ===
> Cannot open demuxer.
> 
> Exiting...
> 

For what it's worth, when I run:
'mencoder - -demuxer mf -vc ijpg ... < jpeg-filename', I get the correct
file size (25865 bytes), but when I use cat, I get 17408 bytes. I don't know why
you are getting -1. Are you using the svn version? 

I get the unsupported file format message in either case. Of course, even if it
worked, it would give you only 1 frame.

If you use -v -v, you will see:
STREAM: Comment: based on the code from ??? (probably Arpi)
success: format: 0  data: 0x0 - 0x0
seek to 0xqX
s->pos=0  newpos=0  new_bufpos=0  buflen=0
MF file format detected.
DEMUXER: freeing demuxer at 02506810

Maybe it needs to be able to seek backwards and it cannot because it is stdin.