[x264-devel] Configuring by PPS / Inter Keyframe Re-Encodeing

[Jason Garrett-Glaser]

On Fri, May 25, 2012 at 2:14 AM, Evgeny Yakimov <john.yakimov at gmail.com> wrote:
> Hello
>
> I have an encoded h264 live stream coming to my media server in the form of
> RTMP, The stream is encoded by a dedicated encoder with a fixed profile (but
> in theory could come from any h264 encoder). The encode will contain a
> preset keyframe interval (or scene-cut based keyframes), but in any case we
> can consider that the keyframes will be as much as 10 seconds apart in the
> incoming encode.
>
> I wish to allow a user to set a "Start" point by sending a signal to the
> media server which will actually contain a timestamp corresponding to the
> precise frame of where to start (the user will be watching the stream a few
> seconds earlier). This start signal will signal a Capture or Republish Start
> point, To simplify things, lets say that this signal means beginning a
> capture to a file.
>
> The problem is that this start point can come at any time between the 10
> second interval and I do not wish to make the user jump to the last or next
> key frame. I was instead hoping to decode the frames from the Start point
> until the next Key frames, and re-encode them using an x264 instance that
> matches the h264 profile (and as many settings as possible) on the incoming
> stream. As well as the PPS I will have the framerate and bitrate from the
> container header. After this region is re-encoded I wish for the engine to
> switch back to the original encode.
>
> So:
>
> 1) Is it possible to configure x264 to match the settings in the PPS
> container, mainly profile and level?

Sure, just use the same settings that you used for the original stream.

Jason