[FFmpeg-devel] [RFC] Questions and suggestions regarding AVSEEK_FORCE?

[Michael Niedermayer]

On Wed, Mar 24, 2010 at 10:05:50AM +0100, Tomas H?rdin wrote:
> Hi
> 
> While poking around with the mov muxer and demuxer the other day I
> noticed a peculiar behavior: ffplay wouldn't play files with
> sufficiently large skip tags inserted before the mdat tag if the file is
> read from a pipe or HTTP stream.
> 
> After some digging I figured out that the recently added AVSEEK_FORCE
> seems to be meant to deal with the situation. I also submitted a patch
> yesterday that fixed a bug in url_fseek() related to that flag. What I'm
> a bit curious about is the reason it's needed at all. I've been digging
> through the archives a bit but so far haven't found a thread related to
> the matter.
> 
> My guess is that it'll be used in the new seek system that is mentioned
> every now and then. That seems fair, but there's a problem: a whole
> bunch of demuxers probably needs that flag as well. As hinted above
> these include the mov demuxer and therefore also the avi demuxer, and
> the dv demuxer (dv_read_seek() will fail) off the top of my head.
> 

> A simpler solution would be to simply have url_fseek() always discard
> data when seeking forward (skipping) in nonseekable media, since it's
> not possible to seek anyway (best effort). I tried that, and it made it
> possible to play and seek forwards in mov and dv files from nonseekable
> HTTP and opening the peculiar mov files mentioned in the first
> paragraph.

iam ok with trying this but this has a high chance of uncovering bugs
(things seeking forward (maybe to the end of the file) and then expecting
  to be able to seek back)


[...]

-- 
Michael     GnuPG fingerprint: 9FF2128B147EF6730BADF133611EC787040B0FAB

Its not that you shouldnt use gotos but rather that you should write
readable code and code with gotos often but not always is less readable
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