Where should I begin

On 2011/03/06 13:55, james.fysh wrote:
> Some of you might be aware of the old "teletext" system that was used
> to convey reasonably static "pages" of information to television sets,
> during the Vertical Blanking Interval - a period of time in which the
> electron gun is moving from the bottom corner of the screen back up to
> the top corner to commence drawing the next field of vision - because
> there is no need to transmit visual information at this point, other
> forms of information (such as lines of teletext pages) may be
> transmitted.
>
> Very very briefly, there are approx. 16 video lines per field of
> vision available to carry data.  For PAL-SD video, there are 720
> pixels (or samples) per line.  The EBU-WST specification defines the
> parameters for encoding 45 bytes (360 bits) of data into these 720
> samples (actually, a number of samples at the beginning and end of the
> line are not utilised).  I'm keen to learn how to generate the 720
> samples from the original 45 bytes (and preferably to also work
> backwards from a line of 720 samples to 45 bytes of data).
>
> I guess the questions I have right now are:
> - Am I on the right track, studying DSP (esp. FIR filters) to
> eventually understand how to go from 360 bits to 720 samples?

You might find that a simple digital logic circuit in CMOS might solve 
your problem more easily than the FFT.  It really depends upon the 
particular encoding of the data that you're dealing with.  Most of these 
encoding were designed such that an FFT would not be necessary to decode 
them, so you might be on the wrong track.

Then again, hardware is sometimes more expensive that your time and 
software development, assuming you have access to the full video signal 
including the vertical blanking lines.

Brian Willoughby
Sound Consulting

On 03/07/2011 05:04 AM, Rune Allnor wrote:
> On Mar 6, 10:55 pm, "james.fysh"<james.f...@gmail.com>  wrote:
>
>> I guess the questions I have right now are:
>> - What are the mathematical topics generally required when learning /
>> working with DSP?
>> - Can anyone recommend a good book for re-learning these topics?
>
> Any maths book by Gilbert Strang:
>
> http://www.amazon.com/s/ref=nb_sb_noss?url=search-alias%3Daps&field-keywords=gilbert+strang
>
> Rune

I have his "Linear Algebra", because I somehow missed out on this 
subject in school -- it's my go-to guide, and it is very easy to 
self-learn out of.

-- 

Tim Wescott
Wescott Design Services
http://www.wescottdesign.com

Do you need to implement control loops in software?
"Applied Control Theory for Embedded Systems" was written for you.
See details at http://www.wescottdesign.com/actfes/actfes.html

On Mon, 7 Mar 2011 04:46:50 -0800 (PST), brent
<bulegoge@columbus.rr.com> wrote:


    [Snipped by Lyons]

Hi Brent,
   Weeks ago I sent you a private E-mail asking 
if you'd like a copy of the errata for my 
"Understanding DSP" book.   But I never heard 
back from you.  If you're interested, send me 
an E-mail, OK?

[-Rick-]