[FFmpeg-devel] [PATCH] Only output necessary NAL units in H.264 extradata in SDP

Loren Merritt lorenm
Sat Apr 4 07:56:38 CEST 2009

On Fri, 3 Apr 2009, Martin Storsj? wrote:

> I found this in RFC 3984:
>    sprop-parameter-sets:
>        This parameter MAY be used to convey
>        any sequence and picture parameter set NAL
>        units (herein referred to as the initial
>        parameter set NAL units) that MUST precede any
>        other NAL units in decoding order.  The
>        parameter MUST NOT be used to indicate codec
>        capability in any capability exchange
>        procedure.
> The way I interpret this, only SPS and PPS are allowed. Am I getting this
> right?

If I interpret it literally, then not even SPS/PPS are allowed. x264's 
versioninfo SEI is a NAL unit, and it can preceded SPS/PPS in decoding 
order. So can any other SEI except for buffering_period.

--Loren Merritt

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