[libav-api] Resolution Change

Luca Barbato lu_zero at gentoo.org
Sun Apr 24 14:42:19 CEST 2011


On 4/24/11 2:24 PM, Stefan Lederer wrote:
> Hi Luca,
>
> thanks for your answer!

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

> I'm sorry, my explanation was not very clear. VLC actually does not crash,
> it just does not decode the video correctly after the resolution changed
> during the segmented MP4 and. I've added the libav output during this phase
> after the resolution change to this email.

I will try to run them using ffplay if possible, see below.

> I've created the segmented MP4 with mp4box, which offers some options for
> this. The resolution change happens always at an IDR frame, is there
> anything else I have to consider for this? Do I have to add some additional
> boxes to the MP4 to signal the resolution change?

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.

> 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?

> Thanks you for your help!!

I hope we can clarify the issue soon =)

lu

[1]http://en.wikipedia.org/wiki/Posting_style



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