Dear, Marcus

Here's my codes

include/rll.h: https://gist.github.com/gsongsong/07e28c797bb65572982b
lib/rll_impl.h: https://gist.github.com/gsongsong/615649f628262c44c8cf
lib/rll_impl.cc: https://gist.github.com/gsongsong/14e7bdab27216bbe7a17

Please excuses some typos and syntax violation if any.

Regards,
Jeon.

2015-03-27 16:30 GMT+09:00 Marcus Müller <[email protected]>:

>  Hi Jeon,
>
> could you paste the whole C++ file to the gist?
> Basically, what I suspect is that you're not checking whether
> get_tags_in_range() produced a tag at all, or/and might have an error in
> your state machine that stores the "current" coder.
>
> Greetings,
> Marcus
>
>
> On 03/27/2015 06:23 AM, Jeon wrote:
>
>  After thinking about it for a couple of days, I've decided not to use
> two separated RLL blocks.
> Instead, I made a block as below:
>
>  In work() function:
>
> get_tags_in_range(tags, 0, nitems_read(0),
>         nitems_read(0) + ninput_items[0],
>         pmt::mp("rll_coding"));
> RLL_CODE rll_code = (RLL_CODE)pmt::to_long(tags[0].value);
>
> // ... omitted trivial things
>
> switch (rll_code) {
>     case RLLMANCHESTER:
>         for(int i = 0; i < ninput_items[0]; i++) {
>             out[2 * i]     = !!in[i];
>             out[2 * i + 1] =  !in[i];
>         }
>         break;
>     case RLL4B6B:
>         for(int i = 0; i < ninput_items[0] / 4; i += 4) {
>             int rll4B = 0;
>             for (int j = 0; j < 4; j++) {
>                 // make four bits into one bytes
>                 rll4B |= (in[i + j] & 1) << j;
>             }
>             for (int j = 0; j < 6; j++) {
>                 // put six bits corresponding to rll4B
>                 out[6 * i + j] = !!(rll4B6B[rll4B] & (1 << j));
>             }
>         }
>     break;
> }
>
> // mapping definition
>
> const char rll4B6B[16] = {
>     0b011100,    0b101100,    0b110010,    0b011010,
>     0b101010,    0b110001,    0b011001,    0b101001,
>     0b100110,    0b010110,    0b001110,    0b100011,
>     0b010011,    0b100101,    0b010101,    0b001101
> };
>
>  If the code are not formatted well and hard to read, please refer:
> https://gist.github.com/gsongsong/f3e34991a55f29dac5d2
> There might be some syntax violation and variable definitions missing, I
> apologize for that.
>  And please note that each in[i] is either 0b00000000 or 0b00000001.
>
>  By using a tag, RLL coding scheme are not changing during the stream.
>  Currently, I haven't built it and tested yet.
>
>  What do you think of it?
>
>  I will make some notes after build and test the entire system.
>
>  Regrads,
>  Jeon.
>
> 2015-03-26 23:17 GMT+09:00 Kevin Reid <[email protected]>:
>
>> On Mar 25, 2015, at 2:15, Marcus Müller <[email protected]> wrote:
>>
>> > source -+--> custom_block0 ---> encoder0 ---> add -->
>> >         +--> custom_block1 ---> encoder1 ------^
>> >
>> > you'd need to implement custom_block in python or C++, that would either
>> > pass through items, just like the block does that comes out of
>> > gr_modtool add -l python -t sync
>> > or set the output items to 0. You'd toggle that behavior exactly at the
>> > sample that you get a tag.
>>
>> Note that if you don't actually need the switch to happen at a specific
>> point in the stream, but you still want the switch to be atomic (guaranteed
>> not to drop or repeat any items), the existing multiply_matrix block can do
>> the switching in this flowgraph: it would be configured with one input and
>> two outputs, and setting the matrix to either [[0, 1]] or [[1, 0]].
>>
>> (Of course, the disadvantage of either of these strategies is that you're
>> paying the CPU cost of both encoders all of the time.)
>>
>> --
>> Kevin Reid                                  <http://switchb.org/kpreid/>
>>
>>
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>
>
>
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