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  1. 1. TEST REPORT Professional Satellite Encoder Jiuzhou DVE-4Q 4-Channel MPEG-2 Encoder for Digital TV Headends When we enjoy watching digital tv, That’s where MPEG-2 encod- for installation in 19’ equip- ers come into play. Those are ment racks what is typical we rarely think about how the signal the boxes with one or more for the professional equip- is created. More advanced viewers analog inputs and one digital ment. The front panel looks know that the very initial input signal output carrying a transport unpretentious – no unneces- stream. Converting analog to sary blows and whistles. LCD is quite often in analog form. Such digital signal is not that simple display, power and status analog signal has to be converted to as it might sound. Digital LED’s, and six buttons. But digital format. DVB standard precisely signal processors somewhat after all, MPEG-2 encoder is similar to the microproces- not a device you place in your describes it. This format is called sors we have in our PC must A/V cabinet to impress your MPEG-2 transport stream. Actually, one be used in order to do that guests. It is supposed to be transport stream can carry a number of correctly and in real time. If it installed in the headend sta- is not done correctly, we may tion, programmed and left digitized analog channels. A transport get a lip sync problem (a time unattended. stream is then fed to the modulator shift between video and audio of suitable type: QPSK for DVB-S detectable by human senses) The rear panel reveals what or some digital distortion in DVE-4Q can actually do. It has transmission, QAM for DVB-C or COFDM video (like macroblocks pop- four A/V inputs and although for DVB-T. The same transport stream ping up here and there on the they use BNC connectors, it can be used for digital satellite, cable screen, especially in dynamic is the same type of signal we scenes). have in the satellite receivers or terrestrial tv. But how to create a but with RCA sockets - analog transport stream? Jiuzhou DVE-4Q is designed video and analog stereo audio. 02-03/2010 Jiuzhou DVE- 4Q Excellent MPEG -2 encoder for use in local cable or terrestrial networks 40 TELE-satellite — Global Digital TV Magazine — 02-03/2010 —
  2. 2. — 02-03/2010 — TELE-satellite — Global Digital TV Magazine 41
  3. 3. Instrument specification PAL or NTSC. Next item allows reveals that the input can be you to set the sequence of I, either in PAL or NTSC system B and P frames in the GOP – the encoder will adjust to it (Group of Pictures): IP, IBP automatically. There are two or IBBP. Then, you can adjust ■ Setting the channel bitrate luminance, contrast, satura- output BNC connectors but with exactly the same signal. tion and hue for the input in This is where the transport the next 4 submenus. In this stream is output. So, if nec- way, you can compensate for essary, you can connect two imperfections of the incoming modulators to the encoder analog signal. Those values or a modulator and transport are set either in the range of stream analyzer. 0 to 255 or from 0 to 128 (for hue). Except for the inputs and outputs, there are RS-232 Although it may look dif- and Ethernet interfaces as ficult at the very beginning, well as power socket and changing the numerical switch on the rear panel. values is in fact quite simple Transport stream generated at 720x576 resolution and high bitrate Interesting that there is no and fast. Left/right arrows cooling fan. Quick check in are used o change the digit, the user manual revealed that while up/down to increase/ the device consumed only decrease the digit. However, 30W so the same amount as if the input signal is good and a regular satellite tv receiver. does not require corrections, No wonder a cooling fan was the best idea is to leave the not embedded. The encoder factory defaults. we received for test was dedi- cated for 220 V ±10% mains The further submenus in voltage and ambient temper- the channel settings are more “digital” in nature. These ature 5…40° C. The manufac- are: picture resolution, audio turer recommends assuring sampling rate, audio output Transport stream generated at 352x576 resolution and high bitrate good ventilation for the unit bitrate. The available video and considering air condition- resolutions are: 720x576, ing of the entire room. Indeed, 704x576, 640x576, 544x576, the headend stations are usu- 480x576, 384x576, 352x576 ally chock full of different for PAL and 720x480, 704x480, stuff and taking care of good 640x480, 544x480, 480x480, ventilation is a must. 384x480, 352x480 for NTSC. Audio sampling rates can be Installation set to: 32 kHz, 44.1 kHz or 48 After power up, the instru- kHz and audio output rates: ment initialize itself what 128, 256 or 384 kbps. lasts about 40 seconds, then it shows software and hard- Audio options are the next ware version. You can press menu item. Here you can Transport stream generated at 704x480 resolution and high bitrate now OK button to enter the set it to stereo, joint stereo, main menu. The menu con- dual or mono. The last menu sists of four items: channel items in the channel settings settings, multiplex settings, are the channel output bitrate system settings and check (video+audio together) with the warning information. the setting range from 1 Arrows up/down are used to Mbps to 15 Mbps and PID switch between menu items, settings. PID settings allow OK enters the item. you to set the PID values for video, audio, PCR and PMT of Channel settings menu is a channel. used to set proper param- eters for each A/V input. You When you are finished with Transport stream generated at 720x576 resolution and low bitrate can choose between: Auto, the channel settings, you 42 TELE-satellite — Global Digital TV Magazine — 02-03/2010 —
  4. 4. TELE-satellite World Download this report in other languages from the Internet: can move on to the multiplex ulator. As the input, we used Arabic ‫ﺍﻟﻌﺮﺑﻴﺔ‬ settings. They are not that DVD player and the outputs Indonesian Indonesia Bulgarian Български extended as the channel set- of satellite receivers. The Czech Česky German Deutsch tings. In this menu, you can encoder started to operate English English Spanish Español select which channels are without any problem. Farsi ‫ﻓﺎﺭﺳﻲ‬ French Français to be included in the multi- With the default settings Hebrew ‫עברית‬ plex (transport stream). The the quality of output signal Greek Ελληνικά Croatian Hrvatski next setting of the multiplex was extraordinary good what Italian Italiano Hungarian Magyar is the total output bitrate of you can see in the attached Mandarin 中文 Dutch Nederlands the transport stream. Its set- pictures. CBER better than Polish Polski Portuguese Português ting range is from 1 Mbps 1x10-5 is something you can Romanian Românesc Russian Русский to 54Mbps. Of course, you not see too often. The encoder Swedish Svenska should set the total bitrate Turkish Türkçe created signal in various res- Available online starting from 29 January 2010 larger than the sum of the olutions in accordance to our channel bitrates. setting. The following menu item allows you to choose if the Except for video resolu- SDT table is included in the tion, also the channel bitrate stream or not and the last has enormous impact of the item in the multiplex setting picture quality we see on the is the transport stream ID tv-set. When we decreased it number. below about 1.5 Mbps heavy picture distortion were visible The next menu – system especially during the change settings – is used to set local of a scene. Normally, the area network parameters: IP lower the bitrate the cheaper address, submask and gate- the transmission is. However way. The last item in this you should not decrease it Only in the headend station right at the output of a good modulator, one can see such perfect signal-to-noise performance menu is the reset to factory too much because the view- defaults. ers will notice the distortions. Having an encoder as flexible Finally the last menu “Warn- as DVE-4Q, one can easily set ing Information” is used only the proper settings for him- if the red status LED lights up. self. In this way we can check what the reason of an error was. During the whole test, DVE- 4Q worked flawlessly. It cre- Performance ated transport stream with To check the performance very good quality digital video of the DVE-4Q encoder, we and audio unless our settings connected it to a DVB-T mod- were deliberately low. The constellation diagram reveals that the signal is very “clean” (noiseless) TECHNICAL DATA Expert Opinion Manufacturer SICHUAN JIUZHOU ELECTRONIC TECHNOLOGY CO., Ltd. No. 16, Yuejin Road, Mianyang, Sichuan Province, China + Web DVE-4Q is simple, very flexible and good quality Phone +86-816-2469 300 MPEG-2 encoder which can be successfully used Fax +86-816-2469 411 in digital tv head ends - especially local cable or Model DVE-4Q terrestrial networks. It is suitable for both PAL and Function 4-Channel MPEG-2 Encoder NTSC standard definition signals. Every resolution, Jacek Pawlowski Video input (CVBS) Level 1.0Vp-p, 75ohm, BNC connector TELE-satellite sampling rate or audio output bitrate specified in Test Center Audio input Level 2.0Vp-p, 600ohm, BNC connector DVB standard are supported and the channel and Poland Output standard ASI multiplex bitrates can be set freely. Output level 800mV±10% - Output bitrate 1~100Mbps tunable ( each channel 1~15Mbps tunable) Transport streams used for satellite transmissions usually need Video coding Complying to ISO11172 and ISO13818 (MPEG-2), 4:2:0 MP@ML to have more options set that DVE-4Q can do, for example: channel Audio coding MPEG-1 Lay II, CD audio quality name or event name. So if this encoder is to be used in a full fea- Dimensions 44mmx480mmx320mm tured satellite headend, its output would have to be still processed Temperature 0~+50°C (Operating), -20~+70°C(Storage) digitally before being fed to the QPSK modulator. Power supply 220VAC±10%, 50~60Hz, 30W 44 TELE-satellite — Global Digital TV Magazine — 02-03/2010 —