Re: [Discuss-gnuradio] hdtv hacking

[Eric Blossom]

On Fri, Apr 07, 2006 at 05:05:24PM -0400, Charles Swiger wrote:
> On Fri, 2006-04-07 at 15:28 -0400, Charles Swiger wrote:
> > Well, (this is a boy trying a grown-ups job ;) I managed to get
> > two new modules to compile in gr-atsc,   atsc_interleaver and
> > atsc_deinterleaver, just by copying atsc_rs_encoder and atsc_rd_decoder
> 
> > Anyway, after putting in another python test_loopback_002(self):
> > with the two stages interleaver/deinterleaver it will fail
> > make check , printing out a bunch of numbers.
> > 
> 
> Ah, I need a clue how to do this:
> 
> >When you loop the deinterleaver back, you'll need to account for the
> >52 segment delay through it.  Using gr.skiphead is probably the
> >easiest solution (thanks Martin!).
> 
> 
> As this sure didn't help:
> 
>         src = vector_source_ts(self.fg, src_data)
>         rand = atsc.randomizer()
>         rs_enc = atsc.rs_encoder()
>         inter = atsc.interleaver()
> =?=>    skip = gr.skiphead(atsc.sizeof_atsc_mpeg_packet_rs_encoded,52)
>         deinter = atsc.deinterleaver()
>         rs_dec = atsc.rs_decoder()
>         derand = atsc.derandomizer()
>         dst = vector_sink_ts(self.fg)
>         self.fg.connect(src, rand, rs_enc, inter, skip, deinter, rs_dec,
> derand, dst)
> 
> 
> apologies if the above is laughably inept ;)


I think you're close.

>         src = vector_source_ts(self.fg, src_data)
>         rand = atsc.randomizer()
>         rs_enc = atsc.rs_encoder()
>         inter = atsc.interleaver()
>         deinter = atsc.deinterleaver()
>         rs_dec = atsc.rs_decoder()
>         derand = atsc.derandomizer()
> =?=>    skip = gr.skiphead(atsc.sizeof_atsc_mpeg_packet,52)
>         dst = vector_sink_ts(self.fg)
>         self.fg.connect(src, rand, rs_enc, inter, skip, deinter, rs_dec,
> derand, dst)

Then you'll still need to drop the last 52 segments of the source
before comparing.

Eric