Extracting PID from MPEG Transport Stream. VHDL code

Fractional-N · Feb 2, 2014

Hi,
I want to extract the PID from a TS
this is the code that I'm proposed to use

Code VHDL - [expand]
1
2
3
4
5
6
...
    ID(7 downto 0)  <= DATA_IN;
    ID(15 downto 8) <= ID(7 downto 0);
    DATA_OUT        <= ID(15 downto 8);
...
PID <= ID(12 downto 0);

this is the TS header:

I think if I use this VHDL code, by reading 12 downto 0 bits of "ID" I won't get the PID because I will have:
[(5 bits of PID, 3 flag bits),(8 bits of PID)]
so reading 13 lower bits from that I will get:
[(2 bits of PID, 3 flag bits, 8 bits of PID)]

am I right?

I've tested this code myself and as I said above I couldn't get the correct PID, BUT, since I saw the above code in a somehow "reliable" source I'm thinking maybe I've done something wrong. I'm suspicious maybe I'm reading the bytes in wrong order. so can you help me?

this is a sample of TS packet I've used. I read this file using hread and other functions of "textio".

Code:

47100014C4A0055EBEA2ED2A016F2BA6EB4108F93FD042744FE60499B2D0A02E76B43EBF982D66C4FC8349262B243960B9D510F911E049A42D05BCE49BBF102745D66001CB3F8EA6634B2BEBA352C06DEA645EB220EE1385A7399D7FEB9AFACE74B9FE38F38DB2FB8824EAE68C9391C23CACF4AD9B3DC206F4FA4F2898AB88E44AD725DF98C3A6FE910DA69E8D1561A08D549DB071A883768E24B16A9AC78C7B93F9EC26772E2EDA2814C1AAE61613B65735069CD455F34228C9F19C

aruipksni · Feb 3, 2014

you need to store information to do that.
the easy way is to use 8 bit registers.

Code:

Data(7..0)=>[R0(7..0)]=>[R1(7..0)]=>[R2(7..0)]=>[R3(7..0)]
DataV      => [4 Counter] => read_register

pid = R3..0(20 downto 8) when read_register = '1' and R3..0(31..24)= x47

Extracting PID from MPEG Transport Stream. VHDL code

Fractional-N

Full Member level 1

aruipksni

Full Member level 6

Similar threads

Code VHDL - [expand]
1 2 3 4 5 6	... ID(7 downto 0) <= DATA_IN; ID(15 downto 8) <= ID(7 downto 0); DATA_OUT <= ID(15 downto 8); ... PID <= ID(12 downto 0);

Extracting PID from MPEG Transport Stream. VHDL code

Fractional-N

Full Member level 1

aruipksni

Full Member level 6

Similar threads

Privacy & Transparency

Privacy & Transparency