[vlc-devel] Smooth Streaming, MP4 and H.264

Frederic YHUEL fyhuel at viotech.net
Thu Oct 13 12:14:21 CEST 2011

Hi Chris,

Thank you for your help !

On Wed, Oct 12, 2011 at 6:54 PM, Christopher Mueller
<christopher.mueller at itec.uni-klu.ac.at> wrote:
>> Hi,
>> Unfortunately, I didn't succeed to create a valid avcC box :-(
>> Comparing my avcC box with other genuine avcC boxes I think I didn't
>> do wrong with lengths. Maybe I did wrong with PPS but for now I gave
>> up the endeavor to try and understand MPEG-4 part 10 aka H.264 :-)
>> What I don't understand is that DASH initialization segments (at least
>> those provided by Klagenfurt, for instance see [1]) all have one and
>> only one SPS / PPS.
>> So how could VLC DASH plugin support bitrate switching?
> I do not see the problem? H264 is a codec that supports variable bitrate
> and that is what the decoder sees after the whole demultiplexing process.


> If you switch between different resolutions you have to resend new sps/pps
> do reinit the decoder.

Ok! But how your DASH module do that? Because it doesn't resend the
initialization segment... Are the new SPS/PPS in the moof boxes of
each fragment?

And so what is the point to have the possibility to have an avcC box
with more than one PPS/SPS?

Best Regards,


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