On Mon, Nov 06, 2006 at 03:10:48PM +0100, Marco Masotti wrote: > > ========================== > > Date: Mon, 6 Nov 2006 13:53:27 +0100 > > From: [EMAIL PROTECTED] (Wolfgang Wegner) > > To: Benny Amorsen <[EMAIL PROTECTED]> > > Cc: linux-dvb@linuxtv.org > > Subject: Re: [linux-dvb] Re: hdtv scanning > > ========================== > > > >[...] > > As long as PCs do not have any means to synchronize frame and > > audio rate, > > they are not really suited for MPEG decoding IMHO. > > > > > > I don't question that but, then, how big do you consider the time skew to > have audio and video tolerably in sync? I was assuming that receiving dvb-s > programs, in-software decompressed by a processor in a shared memory > proposition, was deemed common now. Also, it would seem that the whole sense > of this list would be substantially lessen if only intelligent card (those > capable of doing 100% hardware assisted processing - not counting which areas > of code functionalities would be included in such assistance ) were supposed > to correctly work.
My main goal was to say why I do think that special hardware still has its place although actual PC hardware can perform the task of decoding even HDTV yet. Lip-sync is not the real problem, as long as sound is not earlier than video some few milliseconds do not matter. However, when it comes to HDTV, I would prefer to get the quality that is possible with both audio and video and not some interpolated signal (in either time or space) - and that is what you have to do when using standard PC hardware. We can see that this is possible, and results are quite good with current software decoders, but it is not as good as with a dedicated decoder chip which generates its clock from MPEG SC, like every set-top-box does. We (DVB) are broadcast, and not decoder-driven... *dreaming* a graphics card giving the possibility of adjusting the master clock from the TSC and having on-board audio capability, also synchronized from the same clock, would be perfect IMO. Regards, Wolfgang _______________________________________________ linux-dvb mailing list linux-dvb@linuxtv.org http://www.linuxtv.org/cgi-bin/mailman/listinfo/linux-dvb
