[Top][All Lists]
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Discuss-gnuradio] hdtv hacking
From: |
Charles Swiger |
Subject: |
Re: [Discuss-gnuradio] hdtv hacking |
Date: |
Mon, 10 Apr 2006 14:06:07 -0400 |
On Fri, 2006-04-07 at 18:20 -0700, Eric Blossom wrote:
> On Fri, Apr 07, 2006 at 06:49:07PM -0400, Charles Swiger wrote:
> >
> > > The most likely reason it doesn't pass, is that there is a 52
> > > segment delay between what you write into the interleaver, and what you
> > > get out of the deinterleaver. To work around the behavior, drop the
> > > first 52 segments of the output and then compare the remainder with
> > > the input.
> > >
> >
> That's great.
> Did you figure out how to compare them without writing to files?
>
Yes, using gr.skiphead(atsc.sizeof_atsc_mpeg_packet_rs_encoded,52)
right after inter/deinterleaving, and also trim 52 * 188 off the
end of expected_result with
expected_result = src_data[0:len(src_data)-(52*188)]
I'm a little cornfused with the data sizes, in light of this:
"An MPEG transport stream packet is 188 bytes long. Internally we use a
packet that is 256 bytes long to help with buffer alignment. This
function adds the appropriate trailing padding to convert each packet
from 188 to 256 bytes."
and these:
>>> atsc.sizeof_atsc_data_segment
1024
>>> atsc.sizeof_atsc_data_segment_pad
188
>>> atsc.sizeof_atsc_mpeg_packet
256
>>> atsc.sizeof_atsc_mpeg_packet_no_sync
256
>>> atsc.sizeof_atsc_mpeg_packet_no_sync_pad
65
>>> atsc.sizeof_atsc_mpeg_packet_pad
68
>>> atsc.sizeof_atsc_mpeg_packet_rs_encoded
256
>>> atsc.sizeof_atsc_mpeg_packet_rs_encoded_pad
45
>>> atsc.sizeof_atsc_soft_data_segment
4096
I would hav expected "atsc_mpeg_packet" to be 188 and
"atsc_mpeg_packet_pad" to be 256 ??
Anyway, seems we should use one of those instead of 188 in
the expected_result trim statement above.
Other than that, make check runs and passes, ready to check
into cvs.
--Chuck
- Re: [Discuss-gnuradio] hdtv hacking, (continued)
- Re: [Discuss-gnuradio] hdtv hacking, Eric Blossom, 2006/04/07
- Re: [Discuss-gnuradio] hdtv hacking, Charles Swiger, 2006/04/07
- Re: [Discuss-gnuradio] hdtv hacking, Michael Dickens, 2006/04/07
- Re: [Discuss-gnuradio] hdtv hacking, Eric Blossom, 2006/04/07
- Re: [Discuss-gnuradio] hdtv hacking, Jens Elsner, 2006/04/08
- Re: [Discuss-gnuradio] hdtv hacking, Martin Dvh, 2006/04/09
- Re: [Discuss-gnuradio] hdtv hacking, Eric Blossom, 2006/04/09
- [Discuss-gnuradio] Re: Viterbi Decoder, Michael Dickens, 2006/04/10
- Re: [Discuss-gnuradio] hdtv hacking, Eric Blossom, 2006/04/07
- Re: [Discuss-gnuradio] hdtv hacking, Charles Swiger, 2006/04/08
- Re: [Discuss-gnuradio] hdtv hacking,
Charles Swiger <=