Re: [Discuss-gnuradio] ATSC real-time application?
> > Will an RFX400 pass a 6MHz wide signal? (AD834X mixer) > > Easily Matt ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
RE: [Discuss-gnuradio] ATSC real-time application?
On Fri, 2006-10-27 at 19:47 -0400, Charles Swiger wrote: > On Fri, 2006-10-27 at 11:11 -0500, Meiners, Jason wrote: > > Has anyone benchmarked the ATSC encode function? Can this be done in > > real time? Decode is always harder to do than encode :) > > > > Actually, an HDTV transmitter function might fulfill a niche that > couldn't be easily implemented otherwise. A pchdtv HD-5500 is > $130, but these can't be cheap: > > http://www.broadcast.harris.com/product_portfolio/product_details.asp?sku=WWWAPEX > > Actually it looks pretty good - the randomizer, Reed-Solomon encoder, interleaver and Trellis Encoder already work in 2.x, all we need to run in 0.9 is Field Sync Mux, Symbol Mapper and Weaver Mod head/tail - drive a basic-TX and suitable analog upconverter and you have a low power hi-def tv station ;) Will an RFX400 pass a 6MHz wide signal? (AD834X mixer) Here's the output of 0.9 atsc_tx re-sending some mpeg captured from a local station (via a disk file, not realtime yet): http://webpages.charter.net/cswiger/photos/atsc_tx_09.jpg ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
RE: [Discuss-gnuradio] ATSC real-time application?
On Fri, 2006-10-27 at 11:11 -0500, Meiners, Jason wrote: > Has anyone benchmarked the ATSC encode function? Can this be done in > real time? Decode is always harder to do than encode :) > Actually, an HDTV transmitter function might fulfill a niche that couldn't be easily implemented otherwise. A pchdtv HD-5500 is $130, but these can't be cheap: http://www.broadcast.harris.com/product_portfolio/product_details.asp?sku=WWWAPEX ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
RE: [Discuss-gnuradio] ATSC real-time application?
Has anyone benchmarked the ATSC encode function? Can this be done in real time? Decode is always harder to do than encode :) -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Charles Swiger Sent: Friday, October 27, 2006 10:56 AM To: Kyle Zhou Cc: discuss-gnuradio@gnu.org Subject: Re: [Discuss-gnuradio] ATSC real-time application? On Sat, 2006-10-28 at 01:19 +1000, Kyle Zhou wrote: > I am quite interested in the ATSC project due to some previous HDTV > R&D experience. > I am not quite sure about the current status of this project. > According to my understanding, ATSC has a very high throughput > requirement with a symbol rate=10.72M / sec > Considering this high symbol rate and the computationally intense > algorithm in RS decoder, Equalizer, Viterbi, etc., I am just wondering > how powerful the computer has to be to process all these in realtime? > What kind of computers have been used in the gr-atsc project to > process realtime HDTV? None that I know of. With a 4-cpu 2Ghz system with the processes spread out so the total utilization is 80%, there's still a maybe (rough guess) 7:1 process-time to real-time ratio. At least I seem to remember taking at least 14 hours to process a 2 hour movie. The bottleneck (cpu running 99%) was still the gnuradio0.9 part from bit-timing-loop to field-sync-demux. Once atsc is completely ported to the 2.x framework more can be done to optimize things. >Recalling that a PC do not have the luxury of parallel computation. For >instance, a 4.0G CPU has to process one symbol in 400 clock durations, >which seems to be not enough. That's the question - is the most intensive atsc function too much for a commonly available cpu to process in realtime? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
Re: [Discuss-gnuradio] ATSC real-time application?
On Sat, 2006-10-28 at 01:19 +1000, Kyle Zhou wrote: > I am quite interested in the ATSC project due to some previous HDTV > R&D experience. > I am not quite sure about the current status of this project. > According to my understanding, ATSC has a very high throughput > requirement with a symbol rate=10.72M / sec > Considering this high symbol rate and the computationally intense > algorithm in RS decoder, Equalizer, Viterbi, etc., I am just wondering > how powerful the computer has to be to process all these in realtime? > What kind of computers have been used in the gr-atsc project to > process realtime HDTV? None that I know of. With a 4-cpu 2Ghz system with the processes spread out so the total utilization is 80%, there's still a maybe (rough guess) 7:1 process-time to real-time ratio. At least I seem to remember taking at least 14 hours to process a 2 hour movie. The bottleneck (cpu running 99%) was still the gnuradio0.9 part from bit-timing-loop to field-sync-demux. Once atsc is completely ported to the 2.x framework more can be done to optimize things. >Recalling that a PC do not have the luxury of parallel computation. For >instance, a 4.0G CPU has to process one symbol in 400 clock durations, >which seems to be not enough. That's the question - is the most intensive atsc function too much for a commonly available cpu to process in realtime? ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
[Discuss-gnuradio] ATSC real-time application?
I am quite interested in the ATSC project due to some previous HDTV R&D experience. I am not quite sure about the current status of this project. According to my understanding, ATSC has a very high throughput requirement with a symbol rate=10.72M / sec Considering this high symbol rate and the computationally intense algorithm in RS decoder, Equalizer, Viterbi, etc., I am just wondering how powerful the computer has to be to process all these in realtime? What kind of computers have been used in the gr-atsc project to process realtime HDTV? Recalling that a PC do not have the luxury of parallel computation. For instance, a 4.0G CPU has to process one symbol in 400 clock durations, which seems to be not enough. Thanks Kyle Zhou ___ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org http://lists.gnu.org/mailman/listinfo/discuss-gnuradio
