A Demodulator (short Demod) recovers (demodulates) the original information from the received and downconverted RF signal -- a tuner acquires the RF signal and converts it to an intermediate frequency (IF) which is then passed onto the demodulator for processing. The type of demodulator IC used for this task of information recovery is specific and dependent upon the nature of the signal transmission scheme involved.
In the case of analog TV, the IF inputted into the demodulator contains the composite signal that was originally modulated onto the RF carrier. After recovery, the demodulator outputs a CVSB signal, which will then need to be digitized through sampling techniques performed by a A/V decoder.
In the case of digital TV transmission schemes, the IF inputted into the demodulator contains a MPEG-2 Transport Stream (TS) that was originally modulated onto the RF carrier. In the process of recovering that TS, digital demodulators will perform Forward Error Correction (Convolutional Viterbi- and Block-Reed-Solomon-Decoding). This whole process is sometimes referred to as RF-to-bits, for, unlike the case with analog IF demodulators, the recovered signal outputted from the digital demodulator is already a digital bit stream; specifically a TS. The TS will in turn be sent to a decoder in order to display (and, depending upon what format the underlying video content contained within the TS was encoded with, this could be a MPEG-2 or MPEG-4 decoder ... and either hardware or software based).
Demodulator Chipsets
Analogue IF Demodulators
A Sortable List of Analog IF Demodulators
| Vendor |
Model |
Standards |
Linux Support |
Comments
|
| Philips |
TDA9887 |
NTSC |
Yes |
-
|
| Xceive |
XC3028 |
NTSC, PAL |
er, somewhat |
firmware galore
|
| Xceive |
XC5000 |
NTSC, PAL |
er, somewhat |
firmware galore
|
... and so on ...
Digital Demodulators
A Sortable List of Digital Demodulators
| Vendor |
Model |
Standard |
Linux Support |
Comments
|
| Afatech |
AF9005 |
DVB-T |
yes |
Supports COFDM. A combo USB bridge & demod IC
|
| Afatech |
AF9015 |
DVB-T |
yes |
Supports COFDM. A combo USB bridge & demod IC
|
| ATI/AMD |
Nxt2000 |
ATSC |
? |
Supports 8-VSB, QAM; firmware required
|
| ATI/AMD |
Nxt2002 |
ATSC |
yes |
Supports 8-VSB, QAM; firmware required
|
| ATI/AMD |
Nxt2004 |
ATSC |
yes |
Supports 8-VSB, QAM; firmware required
|
| ATI/AMD |
NXT6000 |
DVB-T |
yes |
Supports COFDM
|
| ATI/AMD |
Theater 31x |
ATSC |
no |
Supports 8-VSB, QAM
|
| Atmel |
AT76C651 |
DVB-C |
? |
supports QAM
|
| Commsonic |
CMS0014 |
DVB-S2 |
? |
QPSK 8PSK, 16APSK and 32APSK
|
| Conexant |
CX24116 |
DVB-S2 |
? |
|
| Conexant |
CX22700 |
DVB-T |
yes |
Supports COFDM
|
| Conexant |
CX24110 |
DVB-S |
yes |
supports QPSK
|
| DiBcom |
DIB3000M |
DVB-T |
yes |
supports COFDM
|
| DiBcom |
DIB3000P |
DVB-T |
yes |
supports ?
|
| DiBcom |
DiB7xxx |
DVB-T |
yes |
supports ?
|
| E3C |
EC168 |
DVB-T |
exp |
|
| Eccincorp |
ECC3100 (SkyPHY) |
DVB-S2 |
? |
|
| Fujitsu |
MB86A16 |
DVB-S |
@mantis source (?) |
supports QPSK
|
| Intel |
|
|
|
there are several intel demods that could be added here
|
| LG |
DT3302 |
ATSC |
yes |
Supports 8-VSB, QAM
|
| LG |
DT3303 |
ATSC |
yes |
Supports 8-VSB, QAM
|
| LSI Logic Corporation |
L64781 |
DVB-T |
yes |
Supports COFDM
|
| LSI Logic Corporation |
L64782 |
DVB-T |
yes |
Supports COFDM
|
| Microtune |
MT8872 |
DVB-T |
? |
COFDM
|
| Oren |
or51211 |
ATSC |
yes |
supports 8-VSB and QAM; firmware required, however, no QAM capable firmware is known
|
| Oren |
or51132 |
ATSC |
yes |
supports 8-VSB and QAM; firmware required
|
| Philips |
TDA10021 |
DVB-C |
yes |
Supports QAM
|
| Philips |
TDA10045 |
DVB-T |
yes |
Supports COFDM
|
| Philips |
TDA10046 |
DVB-T |
yes |
Supports COFDM
|
| Philips |
TDA10048 |
DVB-T |
yes |
Supports COFDM
|
| Philips |
TDA8083 |
DVB-S |
yes |
supports QPSK
|
| Samsung |
s5h1409 |
ATSC |
yes |
Supports 8-VSB, QAM. Also known as the Conexant CX24227
|
| Samsung |
s5h1411 |
ATSC |
yes |
Supports 8-VSB, QAM.
|
| SPaSE |
SP8870 |
DVB-T |
? |
supports COFDM
|
| SPaSE |
SP8872 |
DVB-T |
? |
COFDM
|
| STMicroelectronics |
STV0297 |
DVB-C |
yes |
supports QAM
|
| STMicroelectronics |
STV0299 |
DVB-S |
yes |
supports QPSK
|
| STMicroelectronics |
STB0899 |
DVB-S2 |
yes |
supports 8PSK, QPSK, 16APSK
|
| STMicroelectronics |
STV0900/3 |
DVB-S2 |
? |
supports QPSK
|
| VLSI Technology |
VES1893 |
DVB-S |
yes |
supports QPSK
|
| VLSI Technology |
VES1993 |
DVB-S |
yes |
supports QPSK
|
| VLSI Technology |
VES1820 |
DVB-C |
yes |
supports QAM
|
| Zarlink Semiconductor |
MT312 |
DVB-S/DSS |
yes |
supports QPSK
|
| Zarlink Semiconductor |
MT352 |
DVB-T |
yes |
supports COFDM
|
| Zarlink Semiconductor |
ZL10312 |
DVB-S/DSS |
no |
supports QPSK
|
| Zarlink Semiconductor |
ZL10313 |
DVB-S/DSS |
no |
supports QPSK
|
| Zoran |
Cascade2 (CAS-220) |
ATSC |
? |
Supports 8-VSB, QAM. Formerly Oren
|
...and so on ...
Also see