[libav-api] Resolution Change

Stefan Lederer ledererstefan at gmx.at
Sun Apr 24 15:31:35 CEST 2011


> Hi, could you please use the interleave posting style instead of top
> posting[1]?

Yes, no problem :-)
 
> Segmented streams can be considered either as
> 
> small chunk of uniform bitstream that should be feed to the demuxer
> concatenated (e.g the mpegts case, applehttp protocol in libav) or
> as items in a playlist thus to be considered as unrelated files that
> should be demuxed and decoded independently and whose content has to be
> presented as a continuous stream (thus segment1:frame124 is followed as
> segment2:frame0 as if it were the segment1:frame125)
> 
> Looks like the mp4 segmentation falls in this second case.

No, DASH (dynamic streaming over http) uses the first approach. In my case
I've created an initialization segment and several video segments which are
send to the demuxer like a uniform bitstream. See below.

If you need more information about the mp4 boxes used in DASH you could have
a look at [3]. Unfortunately the standard is not finished yet, so there may
are some unclear parts...

> > I've also provided some of the content which I used for this in [1].
> There
> > are one initialization segment and two video segments in the attached
> > zip-archive.
> 
> Could you please also paste the instructions on how to try that?

I've concatenated the segments in [1] to one mp4 file [2]. This file
consists of one initialization segment, two segments of about 2 sec. at
QCIF, and 2 segments of about 2 sec. of CIF video. 
I've now tested this file using "ffplay foreman_concat.MP4" (which is the
file in [2]) and got the same problems like in VLC with my plugin. 

> I hope we can clarify the issue soon =)
Me too 

Thanks
Stefan

[1] http://www.bitmovin.net/uni-klu/dash/foreman_test.zip
[2] http://www.bitmovin.net/uni-klu/dash/foreman_concat.MP4
[3]
http://www.bitmovin.net/uni-klu/dash/Segment_formats_for_ISO_Base_Media_File
_Format.doc



More information about the libav-api mailing list