Попов, някои приемници не могат да подкачат толкова висок битрейт и оттам идва проблема.
Приемника ми е забравения вече от към софтуерна поддръжка Strong SRT 7335 CI!Емулатора не отваря Irdeto2...нито AustriaSat!Само ORF отваря и BISS-key!Има проблем с каналите на ZDF Vision HD картината засича и прекъсва!И програми със Symbol rate:под 2000 не излизат!Иначе гледам с един SD Opticum 7100cx!Но проблема е при някои приемници които в началото са скъпи и много бързо забравени от към софтуерна поддръжка!А преди Strong бяха добра марка SRT 7335 загрява и от време на време както си работи изведнъж исписва няма сигнал!и трябва да го рестартираш!Проблема не е във високия Symbol rate!А в стандарта,който някои приемници не поддържат!
Да допълня. Мултистрийм се ползва за ефективно разпространение(голям брой канали само с един транспондер) на DVB-T/T2 канали. Приемникът трябва да е в състояние да обработи всичките стриймове(в случая 4).И при мен се получава пикселизиране на картината.Най-добре с ПС-карта със съответната тех.спецификация както посочи колегата по-горе. Все пак е интересно да видим с кои от по-скъпите приемници сканирането и гледането е възможно.
ПоповП А каква е разликата между ZDF Vision HD и ARD Digital HD?При каналите примерно ARD HD и всички останали освен ZDF Vision HD нямам проблеми при приемането?
Странна работа само на 11,347V/11,362H не ми вървят каналите...картината засича и се накъсва....Нямам обяснение....bit rate-не е в това проблема според мен...незнам?
Ако се съмняваш чети от тук черно на бяло : http://www.infosat.de/Meldungen/?msgID=67607
Цитат на: ivan02121983;176424Странна работа само на 11,347V/11,362H не ми вървят каналите...картината засича и се накъсва....Нямам обяснение....bit rate-не е в това проблема според мен...незнам?
Не съм казал, че бит-рейта е причината, а само дадох инфо в отговор на въпросът ти. Ти сам почти си отговори за причината още в пост #4, а потвъдрих в #11, че трябва определена тех.спецификация - тя включва DVB стандарта
EN 302 307. Ето малко подробности:
ETSI EN 302 307:2006Digital Video Broadcasting (DVB);
Second generation framing structure, channel coding and
modulation systems for Broadcasting, Interactive Services, News Gathering and other
broadband satellite applicationsAdaptive Coding and ModulationTechnology Whitepaper
7 August 2009
1 OF 2 207702 REV - RA 5760
Paradise Datacom LLC Paradise Datacom Ltd.
328 Innovation Blvd. 1 Wheaton Road, Witham
State College, PA 16803 USA Essex CM8 3UJ England
Tel: 1 (814) 238-3450 Tel: +44(0) 1376 515636
Fax: 1 (814) 238-3829 Fax: +44(0) 1376 533764
www.paradisedata.com (http://www.paradisedata.com)
Variable Coding and Modulation (VCM) and Adaptive
Coding and Modulation (ACM) are techniques that are
strongly associated with the
DVB-S2 standard (EN 302
307).
VCM can be used to provide different levels of error
protection to different components within the service. It
does this by allowing different combinations of modulation
and FEC rate to be applied to different parts of the
data stream.
ACM extends VCM by providing a feedback
path from the receiver to the transmitter to allow the level
of error protection to be varied dynamically in accordance
with varying propagation conditions. Claims of performance
improvements exceeding 100% have been made
for ACM in terms of satellite capacity gain.
What is less well known is that the DVB-S2 VCM and
ACM concepts can be applied to traditional Single Channel
Per Carrier (SCPC) types of services and can offer
similar benefits. This whitepaper gives an overview of
how these concepts can be used outside of DVB-S2 satellite
services.
DVB-S2 itself is offered by Paradise in SCPC modems
and can be used in both SCPC and Multiple Channels
Per Carrier (MCPC) modes. However, it is convenient to
use a term that can be used to refer specifically to non-
DVB-S2 SCPC satellite services and the terms 'SCPC'
and 'traditional SCPC' are used in this whitepaper for that
purpose (even although traditional SCPC systems have
themselves evolved to have an MCPC capability).
For the avoidance of doubt, the traditional SCPC services
(i.e. all services offered by Paradise SCPC modems) that
are being referred to include, but are not limited to the
following: IBS and IDR framed satellite services, Closed
Network services, Engineering Service Channel (ESC),
Automatic Uplink Power Control (AUPC), Drop and
Insert, TPC, Viterbi, Reed-Solomon, TCM, LDPC
(including the low-latency variety), all traditional modulations
(including 8QAM and 16QAM), multiplexing of data
from multiple terrestrial interfaces onto a single carrier,
MIL-STD-188-165A/B, etc. – all using a variety of terrestrial
interface types including IP, EIA530, LVDS, G.703
and HSSI.
Background SCPC VCM
VCM can be used to extend traditional SCPC services in
a similar manner to how it is used in DVB-S2.
A quasi-error free quality target is set for each remote
terminal as normal. The choice of modulation and FEC
rate, which determines the strength of the error correction,
will be determined by a number of factors including
the position of the remote terminal within the satellite
footprint.
The DVB-S2 concept of a frame can be applied to SCPC
links along with all of the other DVB-S2 concepts including,
but not limited to, mode adaptation, stream adaptation,
baseband frames, mapping, pilots, dummy frames,
scrambling, bit interleaving, constellation bit mapping,
slots, generic continuous and generic packetized
streams, stream synchronisation, FEC frames and
Physical Layer framing. When applied to traditional
SCPC services, these DVB-S2 concepts perform similar
functions and provide similar benefits to those
documented for DVB-S2.
At its simplest, the user data (whether packetized or
continuous) is put into baseband frames (possibly with
padding), FEC information is added and then a Physical
Layer (PL) header is prefixed prior to transmission to
create the satellite frame for transmission.
The size of the baseband frames is dependent on the
particular FEC scheme being used. For block based
FECs such as LDPC and TPC, the baseband frame size
is related to the block size of the FEC.
Mode adaptation and stream adaptation deal with the
issues of single and multiple stream inputs and merging
and slicing of these streams into a sequence of satellite
frames.
A particular frame, PL header apart (see overleaf), is
always transmitted in a homogeneous manner using a
single modulation and FEC rate.
А за възможностите на процесора виж пост #32 от:http://dtv-bg.com/showthread.php?t=20275&page=3
"ALi second-generation high-definition interactive programs within the integrated two-chip 32-bit computing device to support 2-way TS stream input, can handle multiple streams..."
P.S. 400 MHz ако не греша е и честотата на Extrend 5000 процесора.