[FFmpeg-user] Copying streams from partial FLVs?

[Chris Pennello]

On Mar 20, 2014, at 1:24 AM, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:

> Chris Pennello <chris <at> redux.com> writes:
> 
>> Note, though, that Flash can't play this without 
>> already having loaded up the non-"pseudo-streaming"
>> resource.
> 
> Meaning the global header which is needed for h264 
> decoding is missing from the file. I don't think 
> there is anything you can do.

Yeah, that's what I somewhat suspected.  Neither Flash nor FFmpeg would play the file where I stitched together the global header with the partial FLV.  It's too bad--it seems like it should be somehow possible given that Flash can play them after seeking ahead.

In any case, the solution I ended up going with was to pull only the global header, read the keyframes, and then use the time indexes with fast seeking: -ss *preceding* the URL of the resource passed with -i. So I used FFmpeg to quickly pull the partial FLV in a way it could then parse instead of doing the partial fetch with Range headers, or by using the "pseudo-streaming" features of the web server.