[FFmpeg-devel] NC4600 camera code

[Michael Niedermayer]

On Sat, Dec 13, 2008 at 09:28:44PM -0500, nicolas martin wrote:
> > On Sat, Dec 13, 2008 at 01:56:09PM -0500, nicolas martin wrote:
> >>> On Sat, Dec 13, 2008 at 12:21:52PM -0500, nicolas martin wrote:
> >>>>>> +int nc4600_ident_packet(unsigned char *p)
> >>>>>> +{
> >>>>>> +    int size=0;
> >>>>>> +    uint32_t *q = (uint32_t*)p;
> >>>>>> +    if (*q==0xA5010000) {
> >>>>>> +        size = p[5] + p[6]*256;
> >>>>>> +    }
> >>>>>> +    return size;
> >>>>>> +}
> >>>>
> >>>> Well I agree on that one, but how am I supposed to get the fifth  
> >>>> and
> >>>> sixth byte of the buffer if I don't know if it really is the good  
> >>>> one
> >>>> (depending on endians ...).
> >>>> Should I take the result of AV_RL32 as granted as it will give the
> >>>> bytes in the order I want them to be ?
> >>>
> >>> I don't understand what you are asking.
> >>> The corrected version of above function would be e.g.
> >>>> if (AV_RL32(p) != 0xA5010000) return 0;
> >>>> return AV_RL16(p + 5);
> >>> _______________________________________________
> >>> ffmpeg-devel mailing list
> >>> ffmpeg-devel at mplayerhq.hu
> >>> https://lists.mplayerhq.hu/mailman/listinfo/ffmpeg-devel
> >>
> >> I made some changes in the comments and functions.
> >>
> >
> > [...]
> >> @@ -914,6 +957,20 @@
> >> };
> >> #endif
> >>
> >> +#ifdef CONFIG_NC4600_DEMUXER
> >> +AVInputFormat nc4600_demuxer = {
> >> +    "nc4600",
> >> +    NULL_IF_CONFIG_SMALL("special raw MPEG-4 video format"),
> >> +    0,
> >
> >> +    nc4600_mpeg4video_probe,
> >> +    video_read_header,
> >> +    nc4600_read_partial_packet,
> >> +    .flags= AVFMT_GENERIC_INDEX,
> >> +    .extensions = "nc4600", //FIXME remove after writing mpeg4_probe
> >
> > at the very least the comment is wrong
> 
> This comment is a copy of the one found in the M4V demuxer ..

thanks, ive just removed it from the m4v demuxer ...


> 
> >
> >
> > also, what does this demuxer has to do with raw? if nothing then it  
> > does not
> > belong in raw.c
> 
> Actually I don't know, I'm not a ffmpeg developper at all ...
> This is just the way I made it work.
> 
> I need one of you that knows exactly the code tree to tell me where I  
> can insert myself ...

pick a file name that is not in use yet in libavformat and that sounds
similar to the format you try to implement, also make sure it ends in .c


> 
> >
> >
> >
> > [...]
> >> Index: libavformat/avio.h
> >> ===================================================================
> >> --- libavformat/avio.h	(revision 16101)
> >> +++ libavformat/avio.h	(working copy)
> > [...]
> >> Index: libavformat/aviobuf.c
> >> ===================================================================
> >> --- libavformat/aviobuf.c	(revision 16101)
> >> +++ libavformat/aviobuf.c	(working copy)
> >
> > all changes to these 2 files are rejected
> > you first should explain why you would ave to change anything in  
> > them at all
> 
> I changed those two files because this is the way I made it work.

> Again, if I could put all my code in a separate file and expect ffmpeg  
> to find it and link proprely I would do it.

http://wiki.multimedia.cx/index.php?title=FFmpeg_demuxer_howto


[...]
-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

In fact, the RIAA has been known to suggest that students drop out
of college or go to community college in order to be able to afford
settlements. -- The RIAA
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