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<TITLE>RE: [vlc-devel] Re: Patch in progress - RTSP scale support</TITLE>
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<P><FONT SIZE=2>Perhaps the question in turn should be - How is fast-forward and rewind implemented in VLC as a client application reading from local sources where the input module sets b_pace_control to true? What can be done to extend this functionality to the RTSP VoD interface? I would note that rate of play of the streaming output can be controlled by way of the VLC rc interface and as such I do not expect this to be a particularly onerous task.<BR>
<BR>
Regards,<BR>
Rob<BR>
<BR>
<BR>
-----Original Message-----<BR>
From: vlc-devel-bounce@videolan.org on behalf of Dermot McGahon<BR>
Sent: Mon 5/15/2006 8:20 PM<BR>
To: vlc-devel@videolan.org<BR>
Subject: [vlc-devel] Re: Patch in progress - RTSP scale support<BR>
<BR>
Rob Casey wrote:<BR>
<BR>
> This conditional is being triggered as a result of the<BR>
> b_out_pace_control being set to a false value as a result of<BR>
> modules/access_output/udp.c setting i_out_pace_nocontrol to true -<BR>
> Modifying this value gives variable results where at times, playback<BR>
> rate is modified, but at others it is not.<BR>
<BR>
When VLC is used a a client this would be correct as it doesn't have<BR>
control over the pace of reading<BR>
the input being streamed from the VOD server. In this case the Scale<BR>
parameter is used as a command<BR>
to the VOD server asking it to only send I-frames for example. The<BR>
commercial VOD servers support<BR>
a limited amount of alternative playback speeds, usually one for<BR>
fast-forward and one for rewind.<BR>
<BR>
Your setup has VLC as a server and if the GOP size is twelve and Scale<BR>
is -12/+12 (for example) then<BR>
it should be possible to send only I-frames to the client but what if<BR>
another value is given? Which parts<BR>
of the should be sent and which omitted? Sending every second P or<BR>
B-frame won't work.<BR>
<BR>
<BR>
Dermot.<BR>
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