Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Author: Athanasios Natsiopoulos Institution: Odisee university college Department: Electronics ICT Supervisor: Patrik Debbaut Academic year 2014-2015
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 2. Abstract: This thesis is written to help the future students to understand and get familiar with the digital television techniques and apply their knowledge in specially designed experiments. There was a series of experiments, from previous thesis students, that were tested for their functionality, plenitude and relativity in understanding the digital television.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 3. Preface: There are four parts consisting this thesis. At the first part a correction of the exercises is made and new questions were added. All the corrections that were made are results of: - Malfunctions, such as parts of the experiments that were not working, software that was not updated in the exercises and misleading images in the exercise progress.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 4. A few words about my host university (Odisee): Odisee’s history goes back to 19th century, when some of the consisting institutions were founded. In 1995, 8 of these institutions were merged to form a new unit called KAHO SintLieven. Later on, in 2002 KAHO Sint-Lieven became a member of the K.U. Leuven association. At that point bachelor and master degrees were introduced.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal - Construction and surveying research group Concrete technology Building physics Geomatics – Surveying Laser scanning – 3D modeling Structural mechanics – Dynamics The last but not least is the participation in numerous international programs. Odisee has contacts with universities, companies and associations all around the world.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 5. Table of contents: 1. Title…….…………….…………………………………………………………………………………………..………………………1 2. Abstract….……………………………………………………………………………………………………………………………..2 3. Preface…………………………………………………………………………………………………………………………………..3 4. A few words about my host university…………………………………………………………………………………..4 5. Table of contents…………………………………………………………………………………..………………………………6 6. List of abbreviations…………………………………………………………………………………………..………………….
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 6.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal QEF = Quasi Error Free QPSK = Quadrature Phase Shift Keying RF = Radio Frequency RMS = Root Mean Square SDTV = Standard Definition Television SER = Symbol Error Rate SNR = Signal-to-Noise Ratio SPTS = Single Program Transport Stream TS = Transport Stream TV = Television UHD = Ultra High Definition UHDTV = Ultra High Definition Television UHF = Ultra High Frequency VBER = Viterbi Bit Error Rate
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 7. Glossary: Attenuator: Is an electronic device that reduces the power of a signal without noticeably distorting its waveform. An attenuator is effectively the opposite of an amplifier. While an amplifier provides gain, an attenuator provides loss. Blog: A blog is a discussion or informational site published on the internet and consisting of discrete entries typically displayed in reverse chronological order.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 8. Acknowledgements: At this point I would like to thank: - Both institutes. The T.E.I. of Crete and Odisee university college for all the paperwork needed and for accepting my application even after the deadline. All the people who were involved in this procedure and the support that I had from them. - My supervisor, Prof. Patrik Debbaut for all his help during the whole duration of the thesis.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 9. Document body: In the first part of the document body we will focus on the correction of the exercises. The procedure followed to conduct the experiments was very specific. We had to follow exactly the same procedure as the students are going to do and use the same devices that they will have in their disposal.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.1.1.1: Black & white and colour television waveform. In colour television there are three colours. The red, green and blue (also known as RGB). In order to form an image in black and white there are two states. When electrons are emitted it means that the spot is white and when not, it is black.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal for Phase Alternating Line. It was broadcasting at 625-line and 25 frames per second and used a quadrature amplitude modulated subcarrier, carrying the chrominance information added to the luminance video signal to form a composite video baseband signal. The frequency of this subcarrier is 4.43 MHz.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 9.1.2 Digital video: Digital video is a type of digital recording system that works by using a digital rather than an analog video signal. More specific, digital video is audio/visual in a binary format. Information is represented as a sequence of digital data, rather than in a continuous signal as analog information is.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal A small history of the resolution is presented below: Standard-definition television (SDTV): o 480i (NTSC-compatible) o 576i (PAL-compatible) Enhanced-definition television (EDTV): o 480p (720 × 480 progressive scan) o 576p (720 × 576 progressive scan) High-definition television (HDTV): o 720p (1280 × 720 progressive scan) o 1080i (1920 × 1080 split into two interlaced fields of 540 lines) o 1080p (1920 × 1080 p
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 9.1.3.1 Elementary stream (ES): Elementary stream or ES is the output of an audio or video encoder. Elementary streams contain only one kind of data. The data can be audio or video. The sizes of these data are fixed to 8 bits for the video when it is broadcasted (10 when it is stored in the studio) and 16 bits for the audio either at broadcast or at the studio use.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal optional header. From the PES packets, 184-byte-long pieces are taken and to these another 4byte-long header is added, making up 188-byte-long packets called “transport stream packets” which are then multiplexed. They can be multiplexed directly in transport streams for broadcasting or they can be saved as program streams. Image 9.1.3.2.1: PES (from the presentation of Walter Fischer in Belgium 2008). 9.1.3.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.1.3.3.1: PS structure 9.1.3.4 Transport stream (TS): Transport stream or TS is a container of multiple multiplexed programs including audio and video. To create a transport stream, packets of one program are multiplexed together. All the multiplexed data streams of all the programs are then multiplexed again and combined to form a complete data stream which is called an “MPEG-2 transport stream”.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.1.3.4.1: MPEG PES & TS structure (from the presentation of Walter Fischer in Belgium 2008). 9.1.3.5 The “.mpg” format: The “.mpg” or “.mpeg” (Moving Pictures Expert Group) format is the most widely known and used video storing file. It includes six subcategories.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The MPEG-4 is a graphics and video compressing algorithm that was based in MPEG-1 and MPEG-2 standards. The compression method that uses wavelet based files can create smaller files than jpeg. This allows the transmission of video and images over a narrower bandwidth and can mix video with text, graphics, 2D and 3D animation layers.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.1.3.5.1: MPEG through the years. The MPEG-1 format, is a standard for lossy compression of video and audio. It is designed to compress VHS-quality raw digital video and CD audio down to 1.5 Mbit/s without excessive quality loss, making video CDs, digital cable or satellite TV and digital audio broadcasting possible.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Systems (storage and synchronization of video, audio, and other data together) Video (compressed video content) Audio (compressed audio content) Conformance testing (testing the correctness of implementations of the standard) Reference software (example software showing how to encode and decode according to the standard) Systems: MPEG-1 Systems specifies the logical layout and methods used to store the encoded
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The MPEG-2 format, is also referred some times as H222 or H262. It describes a combination of lossy video compression and lossy audio data compression methods, which permit storage and transmission of movies using currently available storage media and transmission bandwidth.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal high-level communication channel into several low-level logical channels, one for each message signal or data stream to be transferred. A reverse process, known as demultiplexing, can extract the original channels on the receiver side. The device that performs the multiplexing is called multiplexer and the device that performs the reverse process is called demultiplexer.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal channels are. Using the multiplexing technique it is possible to include into one transport stream several programs depending on the sizes and the quality of the image. These programs inside the stream are called channels. Each channel represents one stream and all the streams multiplexed together are called as one, multiplexed transport stream.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.2.1: Visiosat AVT100 amplified indoor antenna. Frequency range: 88-240MHz (VHF-FM) / 470-862MHz (UHF) VHF gain: 18db UHF gain: 18db Noise factor: 4db max. There is no need for software to use this antenna. 9.3 Correction of the exercises: 9.3.1 TS-Reader exercise: In the beginning of this experiment there was a file missing (file: 61.mpg) from the files that had to be used to start it.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal After a couple of openings/closings of the TSReader software I noticed that when we need to access the “input source select” table when opening the program it doesn’t always work with “Ctrl + click”. It needs “Ctrl + Enter” from the keyboard. When you want to open a file at the TSReader you have to be careful to select “all files” from the dropdown box.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Because it is a pay-tv channel and it is blocked. (REMARK: We can understand that it is not possible to playback this channel by the “stream selection” menu where it says in the “other streams” box that it contains private data. It’s not clear that it is a pay-tv.) At question 18 there was only a clarification added to guide the teacher precisely.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal After the change, the directions became: If you are using the Hauppauge WinTV-HVR 900H, you must select as input “HCWDVBTSource.dll (Haupaugge Generic DVB-T)” At question 27 there was just a note added to help the teacher.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal At question 28 there was an extra sub-question added to make the students more familiar with the software. The original questions and answers were: Which is the constellation, Guard Interval and Code Rate of the multiplex? The constellation is 64-QAM, the Guard Interval is ¼ and Code Rate is 1/2.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 9.3.2.1: The spectrum with the receiving frequencies. A couple of steps later, there was a functionality problem with the exercise’s software that worth mentioning. The latest version of RFXpert was installed to the computer (version: 2.6.1). Although, at the part of the exercise that we had to record a transport stream, it couldn’t.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 9.4 Creation of a transport stream out of an analog signal: The concept of this experiment is to use the colour TV pattern generator in order to create a transport stream able to be broadcasted through the laboratory’s TV network. In the beginning the Promax GV-298 TV pattern generator was used to get familiar with devices like this.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.2: Philips 5518-TN colour TV pattern generator. Getting familiar with this device takes a bit more effort. It covers a very wide range of patterns and its features are a lot more, comparing with the previous one.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The pattern generator was firstly connected to an oscilloscope to check the integrity of the produced signals. Later on there was a colour TV connected parallel to the oscilloscope so that the check could be completed -Almost at the end of the thesis progress, some new Samsung TVs were received for the laboratory, so the signals were tested there too. These new TVs were digital smart LED TVs.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.4: Roxio video capture USB.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The final connection has to be like: the pattern generator connected to both the television and the “Roxio video capture USB” using a signal splitter so that we can observe the signal playing on the TV while recording it. Image: 9.4.5: Connection of the television and oscilloscope with the pattern generator.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.6: Installation of “Roxio Easy VHS to DVD 3” software (step 1). At the next window, select the installation language that you prefer. Image: 9.4.7: Installation of “Roxio Easy VHS to DVD 3” software (step 2). Wait a bit till the setup load.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.8: Installation of “Roxio Easy VHS to DVD 3” software (step 3). When the setup load completely you will be able to see the start-up setup wizard for the “Roxio Easy VHS to DVD 3” program. You just have to click “Next”. Image 9.4.9: Installation of “Roxio Easy VHS to DVD 3” software (step 4). Accept the terms in the license agreement indicated and click “Next”.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.10: Installation of “Roxio Easy VHS to DVD 3” software (step 5). At the next step you have to insert the key provided with the package. You can find this key on the back of the CD-case.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.11: Installation of “Roxio Easy VHS to DVD 3” software (step 6). Choose the folder where you want to install the program. It is recommended to leave it as it is indicated on the installation window.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.12: Installation of “Roxio Easy VHS to DVD 3” software (step 7). At the next window, you will just have to click “Install” to let the installation progress start.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.13: Installation of “Roxio Easy VHS to DVD 3” software (step 8). You will have to wait some time, depending on the machine that you use, until the installation is finished.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.14: Installation of “Roxio Easy VHS to DVD 3” software (step 9). At the next window you click finish and right after a pop-up window will appear asking you to restart the computer, click “Yes”.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.15: Installation of “Roxio Easy VHS to DVD 3” software (step 10). When the computer restart the software is fully functioning and you can use all its features. There were videos created for all the patterns and pattern combinations using the above software. The output videos are in “.mpg” format, something that is very convenient for our further processing.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.16: TsMuxer software. At the final stage the transport streams were loaded to the StreamXpress software and using the DTA-115 PCI card on the computer they were broadcasted to the laboratory’s network.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.4.17: Loaded .ts at the StreamXpress program. 9.5 Creation of a multiplexed transport stream: The most challenging part of this thesis is to create a multiplexed transport stream. It can be created by using both software and hardware. We preferred the software way. The path to finally find this software and use it was not an easy path.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal for use. It is called ffmpeg. After a lot of search to different kinds of blogs and forums we concluded that this software can do the job for us. It is easy to find and download it if you know its name but it is not known to a lot of people. This is because it is a DOS software started from linux and expanded to windows and mac. The installation procedure was very confusing and complicated either on linux or on windows.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The next window gives you some information about the program. Click “next”. Image 9.5.2: Elecard Xmuxer installation guide (step 2). After this, you have to accept the license agreement. Tick the box on the bottom of the window and then “next”.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.5.3: Elecard Xmuxer installation guide (step 3). The following window gives you the choice to select the folder where you want to install the program. If you do not have any special preference, keep it like it is. Then click “next”.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.5.4: Elecard Xmuxer installation guide (step 4). At the next window, you can select the group of the program if you want and then click “next”. Image 9.5.5: Elecard Xmuxer installation guide (step 5).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The final window informs you that you are about to begin the installation. To do so, click “next”. Image 9.5.6: Elecard Xmuxer installation guide (step 6). A few moments later the program will be installed and ready for use. There will be a confirmation window. You need to untick the “Run Elecard registration” box and click finish.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.5.7: Elecard Xmuxer installation guide (step 7). At the demo version that we use it is possible to use all types of files as input but, using specific types of files, causes some problems in the output file. After some tests on the file types, the files that are the most suitable for use, as input, are the “.mpg” files. So, before you use this program, if your files are not already in “.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal panel is the input panel. It shows every input that has been added to the program. After this, the program will automatically load the video and give you the information that it contains. Image 9.5.8: How to use Xmuxer (step 1).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal At the next step you click at the double arrow, pointing right, button to load the data of the video to the output panel (the right one). The output panel shows you the structure of the output file that the program will create. Image 9.5.9: How to use Xmuxer (step 2).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The default output destination is the document folder of your computer. If you want to change it you have to click to one of the output files in the output panel and then click output. A popup window will appear and through this you select the place that you want to save your file. Image 9.5.10: How to use Xmuxer (step 3).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal When you have finished with the previous procedure you just have to click the “start” button. Because this is the demo (evaluation) version a pop-up window will appear. You click the “Later” button. Image 9.5.11: How to use Xmuxer (step 4).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The processing procedure will start. Usually it takes only some seconds but it depends on your computer. You can monitor the progress of the processing at the progress bar on the right of the output destination path. When the processing is finished a confirmation window will appear. Image 9.5.12: How to use Xmuxer (step 5). You will find the outputs at the output destination folder that you set.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal button that you have to use and the form that the structure will have after you add in the right panel the first two files (audio and video) for the first program. Image 9.5.13: How to use Xmuxer (step 6).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The structure of the first program is ready. Now we will create the second program. In the right panel right-click the first entry that says “Transport stream” and click the last selection that says “Create program”. Image 9.5.14: How to use Xmuxer (step 7).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal A new program will be created. It is automatically named “Program #2”. Click on the program and then the same way that you added the files in the first program add the files to the second program too. Click on the single arrow pointing right to add the audio and video files of the second video packet. Image 9.5.15: How to use Xmuxer (step 8).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal students can receive the signal in their own plugs on their desks. This way each student can receive the same signal and do their experiments on it. 9.6 Multiplexed transport stream exercise: Multiplexed transport stream exercise This exercise aims to make you familiar with the process of creating a multiplexed transport stream using both analog and digital videos.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal It is very easy to capture a video with Roxio device. In order to do so, open the program and click on the “Record, Edit and Save” button. “Roxio Easy VHS to DVD 3” operation process (picture 1).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal If you have everything connected right the next screen will show up, showing the pattern that you have selected. Make sure that you have connected earphones or speakers or generally a jack 3.5 in the right “speakers” sound port. The program cannot function without a plug connected in the sound port. “Roxio Easy VHS to DVD 3” operation process (picture 2).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal To start recording the pattern motif you just have to press the “rec” button on the bottom right of the program’s window. “Roxio Easy VHS to DVD 3” operation process (picture 3).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The program will start recording and you will be able to see the recording duration too. When you have finished your recording and you want to stop it, press the “stop” button on the bottom right corner. In the same position as the “start” button. “Roxio Easy VHS to DVD 3” operation process (picture 4).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 2nd step: On the next step you will have to create four more videos using the webcam. You will have to ask four different questions to four different classmates. One question for each classmate. Create four videos of about 30 seconds each. In order to record with the webcam, you can do it in three easy steps. Open the Logitech C615 webcam program. On the screen to appear, press the “Quick Capture” button.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal At the next window you will have to select the video option on the left of the screen and then press the record button. If you are experiencing problems with the quality of the video you can change the resolution from the panel on the right of the window. “Logitech C615” operation process (picture 2).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal In order to stop the recording just press the red “stop” button at the bottom middle of the preview panel. “Logitech C615” operation process (picture 3). The video will be saved in “.wmv” format in the “Logitech webcam” folder which is in the “My Videos” folder of the current user that you are logged in. 3rd step: On this step you will have to convert all the videos to transport streams using the TSmuxer software.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal TSmuxer operation process. When the processing is over the new output files are simple transport streams in “.ts” format, ready for use. 4th step: On this step you will have to create multiplexed transport streams using the files that you recorded earlier and the Xmuxer program. You will have to create three different multiplexed transport streams.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal - One multiplexed transport stream using 1 video from the 1st step, 1 video from the 2nd step and one song that you have on your computer (you can also use the sample sound files from windows). Total of 2 videos and 1 audio in 1 multiplexed transport stream. Note: You have to demux the sound file as well before you use it.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal At the next step you click at the double arrow, pointing right, button to load the data of the video to the output panel (the right one). The output panel shows you the structure of the output file that the program will create. How to use Xmuxer (picture 2).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The default output destination is the document folder of your computer. If you want to change it you have to click to one of the output files in the output panel and then click output at the bottom of the right panel. A pop-up window will appear and through this you select the place that you want to save your file. Image 9.5.10: How to use Xmuxer (picture 3).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal When you have finished with the previous procedure you just have to click the “start” button. Because this is the demo (evaluation) version a pop-up window will appear. You click the “Later” button. How to use Xmuxer (picture 4).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The processing procedure will start. Usually it takes only some seconds but it depends on your computer. You can monitor the progress of the processing at the progress bar on the right of the output destination path. When the processing is finished a confirmation window will appear. How to use Xmuxer (picture 5). You will find the outputs at the output destination folder that you set.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal button that you have to use and the form that the structure will have after you add in the right panel the first two files (audio and video) for the first program. How to use Xmuxer (picture 6).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal The structure of the first program is ready. Now we will create the second program. In the right panel right-click the first entry that says “Transport stream” and click the last selection that says “Create program”. How to use Xmuxer (picture 7).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal A new program will be created. It is automatically named “Program #2”. Click on the program and then the same way that you added the files in the first program add the files to the second program too. Click on the single arrow pointing right to add the audio and video files of the second video packet. How to use Xmuxer (picture 8).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal You have to be able now to create your own multiplexed transport streams. You can try to use more programs and more files. Try to create a multiplexed transport stream simulating some television channels and radio stations. E.g.: You can use four 10-minute videos and four 10minute audio files.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 9.7 Conclusion: Concluding this thesis, there is a series of fully corrected experiments that the students will have in their disposal to practice their skills in digital television. Also there are two guides and one exercise. The first guide for the creation of a simple transport stream out of an analog signal can be very useful to understand the differences between the analog and the digital signals on the television.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 10 List of figures: Figure 9.3.2.1: The spectrum with the receiving frequencies……………………………………………………31 11. List of illustrations: Image 9.1.1.1: Black & white and colour television waveform.………………………………..………………12 Image 9.1.1.2: Representation of an RGB image………………………………………………………………………12 Image 9.1.1.3: PAL structure…………………………………………………………………………………………………….13 Image 9.1.2.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Image 9.5.8: How to use Xmuxer (step 1)……………………………………………………………..………………….53 Image 9.5.9: How to use Xmuxer (step 2)……………………………………………………………..………………….54 Image 9.5.10: How to use Xmuxer (step 3).…………………………………………………………..………………...55 Image 9.5.11: How to use Xmuxer (step 4).…………………………………………………………..…………………56 Image 9.5.12: How to use Xmuxer (step 5).…………………………………………………………..…………………57 Image 9.5.13: How to use Xmuxer (step 6).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 12. Bibliography Websites: www.wikipedia.org www.elecard.com www.promax.es www.dektec.com www.rohde-schwarz.com www.ffmpeg.org www.hauppauge.com www.roxio.com www.plextor-digital.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 13. Appendices: 13.1 Full apposition of the corrected exercises 13.1.1 TSReader exercise TS-Reader Exercise The goal of this exercise is to understand how DVB-T works, how it is processed and what is inside a digital TV broadcasting. To do so, we are going to use three different programs: WinTV, TSReader and VLC. 1. Installation First of all, install TSReader, VLC and WinTV on your computer.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Then, select the file “61.mpg” and open it. You are now watching a one minute recording from the main multiplex of TV3 (Catalonia’s public national broadcaster). The TSReader should now look like this: Figure 2.2: TSReader Main Window Let’s see what we can see on the TS reader.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.3: TSReader Main Window A: At part A, we can see all the information broadcasted within the multiplex. We can see the PAT tables, and if we double click on it, the PMT from each service. B: This box is the information box. Here we have the information about the PAT, PMT, CAT, NIT... that we have selected previously on A. C: Here we can see snapshots from the different TV channels.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Now select the Program 801 (PMT PID 0x006e). Question2 Which is the PID of the ES video stream of TV3? What is its resolution? Is it 4:3 or 16:9? What is the format that it is encoded? The PID of the ES video stream of TV3, is PID 111 (0x006f). Its resolution is 720x576i and its aspect ratio is 16:9. It is encoded in MPEG-2 Question3 How many different audios does it has? Write the PID of each audio stream.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal MPEG1 Audio: Bitrate 96 Kbps Sample Rate 48 KHz MPEG1 Audio: Layer II Mode Single Channel Elementary Stream PID 115 (0x0073) Dolby AC3 Audio AC3: Bitrate 192 Kbps Sample Rate 48 KHz AC3: Mode complete main Coding 2/0 L, R Elementary Stream PID 116 (0x0074) MPEG-1 Audio MPEG1 Audio: Bitrate 96 Kbps Sample Rate 48 KHz MPEG1 Audio: Layer II Mode Single Channel Question5 Where can you see if this program has subtitles? Does it
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.4: Stream Selection Window Now, the VLC player should start to run and you should be able to watch the TV program. On the VLC: Go to Audio Audio Track. Figure 2.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question6 How many audio tracks do we have? Are the same audio tracks that we’ve seen on TSReader? Yes, we see 4 audio tracks and they are the same tracks that we have identified on TSReader. Now you can change the audio by selecting a different audio track. Try to listen the Catalan dubbed audio stream (Track 1) or the English original audio stream (Track 2). Try to see the Catalan DVB subtitles.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question8 How many services can we find? We can find 3 different services: One TV (TV3HD) and two radio services (CatalunyaMúsica and iCat.cat). Question9 Now, we see a TV service called “TV3HD”. This is the HD version of TV3. Which video codec does TV3HD use? Is the same codec as the normal (SD) version of TV3? It’s H.264. It is not the same codec as the normal version of TV3 (which uses MPEG2).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question14 Try to watch the channel “AXN”. Why it is not possible? Because it is a pay-tv channel and it is blocked. (REMARK: We can understand that it is not possible to playback this channel by the “stream selection” menu where it says in the “other streams” box that it contains private data. It’s not clear that it is a pay-tv.) Question15 At the TSReader, go to: View Chart Video Bitrate line chart.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.8: Active PIDs chart arranged by weight It is also possible to see that information on the D window (that we have previously introduced). Holding the mouse over one bar will show the streams that it corresponds.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.8.1: Active PIDs main window Restart the TSReader, again, and now select the chart “Active PIDs by PID”. This is useful to see graphically the percentage (%) of usage of the overall MUX bitrate for every service. Question17 Attach a snapshot of the chart. What is the bar on the right side (labeled 0x1ffff)? What are these used for? It corresponds to the null packets.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.9: Active PIDs chart arranged by name Question18 Are the video bitrates fixed or variable? They are variable. We can see it only on the Active PIDs by rate chart. Question19 Which is the overall multiplex bitrate? Around 20Mbps. Now open the file called “39.mpg”.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.10: Mux Usage Chart Question21 Is it better to broadcast with fixed or variable bitrate? Why? It is better to broadcast with variable bitrate because then we allow every TV channel to take the bitrate that it needs. For example, a football match or scenes with a lot of motion, in general, need more bitrate than a static image.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question24 Why are there green blocks on the snapshots? Because we can’t decode whole IPB sequence. MPEG uses three different kinds of images to transmit video: I (Intra), which contains a complete picture, P (Predictive) and B (Bidirectional). Both contain only the difference between pictures and the “I” image. If we are not able to decode the “I” image, we will not be able to see the whole picture.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 3. Recording Live TV with the Hauppauge Receiver and TSReader Close the TSReader. Then, restart the program but keep holding the Ctrl key while you are doing it. TSReader will ask you what kind of source you want to select. If you are using the Hauppauge WinTV-HVR 900H, you must select as input “HCWDVBTSource.dll (Haupaugge Generic DVB-T)” Figure 3.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 3.2: TSReader input select window Now we are going to tune in the VRT multiplex. VRT, broadcasts on channel 22 (482MHz). To do it, configure as follows: Figure 3.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question27 How many different services do you find? Write the names of the programs and their dPMT PIDs: There are 11 programs: PMT PID 4112 (0x1010) - Program 4112 EEN PMT PID 4128 (0x1020) - Program 4128 Canvas PMT PID 4144 (0x1030) - Program 4144 Ketnet op 12 PMT PID 4160 (0x1040) - Program 4160 Radio 1 PMT PID 4176 (0x1050) - Program 4176 Radio 2 PMT PID 4192 (0x1060) - Program 4192 Klara PMT PID 4208 (0x1070) - Progra
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 3.4: PID Usage chart Record “EEN”. To do so, select a channel first, then press Ctrl+R, write an output file name with the complete path (for example “C:\Users\Computer\Desktop\recordings\een.mpg”), and then press start. Press Ctrl+R again to stop the recording. Question31 What do we have recorded? A .PS or a .TS? We have recorded a .PS.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 3.5: VLC Snapshot 13.1.2 DekTec DTU-235 exercise: DekTec DTU-235 Exercise The goal of this exercise is to become familiar with the DekTec DTU-235 USB probe, and help you understand some parameters of the DVB-T broadcastings. We will work with two programs created by DekTec that you need to install on your computer before starting the exercise.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Open the RFXpert and click on connect. The configuration is as follows: Figure 1.1: RFExpert connecting dialogue After clicking on “Connect”, the device is properly connected to the computer, and the tuner should start working without problems if you installed the software according the installation guide. This is the main window that appears.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 1.2: RFExpert System Monitor Question1 What is the EVM? The EVM is the Error Vector Module. It’s calculated from the MER. In fact, it’s the value of the module of the vector that goes from the position of the ideal symbol received (at the I-Q plane) to the position of the real received symbol (which differs from the original position because of the noise).
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal segment (188 bytes) of the digital Transport Stream. The lower it is, the better the signal is. ErrorSEC: it represents the Errored Seconds. An Errored Second is a second that has, at least, one error on the transport stream.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question5 What is the Constellation Diagram? What do we see? The constellation diagram is a representation of the received errors. It shows the way the symbols are being received. We can see the received symbols on the I/Q plane (In phase, Quadrature). Each point is a received symbol. The more symbols received in the same place, the redder is the graph.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 1.4: Spectrum Detail Question10 By seeing the spectrum: how can you determine that it is a digital DVB-T transmission? Because it’s almost flat: we don’t see any peak produced by any analog carrier.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 1.5: Whole Spectrum Detail Question11 By observing the system spectrum: how many DVB-T signals do we receive? Write (approximately) their frequencies: We receive a lot of signals. Because nowadays at the area there is only channel no.22 broadcasting, this is the only DVB-T signal that we receive. Every other signal is noise or interference. The frequency of channel no.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Now try to record a .TS stream and play it with the VLC. To record a file, just press the “Record” button that you can find on the “System Monitor” main window, and write a file name for the recording: Figure 1.6: Record Tab Then, open the file with the VLC player and check if you can watch and listen all the broadcastings of the VRT’s mux: Figure 1.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal 2.StreamXpert Open the Stream Expert and write the correct frequency (482MHz, VRT mux). Make sure that you have the DEMOD (DTU-235) as the selected interface: Figure 2.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.2: StreamXpert main window with channel selection and video decoding On the PID window, you can see all the contents of the .
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.3: StreamXpert PID window Click on the .TS tab: Figure 2.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Question13: How many services do we receive? How many TV and radio services are being broadcasted? We receive a total of 12 services: 3 TV and 9 radios. Expand a TV service information. Question14: Are the video & audio bitrates fixed or variables? All the bitrates are variable. Question15: Is there any channel that broadcasts in 4:3 aspect ratio? No, all the channels are broadcasting in the aspect ratio of 16:9.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.5: Tables of the TS Question18: What can you find at the CAT? At the CAT (Conditional Access Table) we can check if any service is scrambled. No service is scrambled on the VRT mux. Question19: What can you find at the PMT? At the PMT (Program Map Table) we can find the PIDs of the different ES (Elementary Streams) associated with the program.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal event and the following event that is being broadcasted. Question23: What can you find at the TDT? At the TDT (Time and Date Table) we can find the Greenwich Mean Time (UTC). Question24: What can you find at the TOT? At the TOT (Time Offset Table) we can find the local time-offsets (if applicable) depending on the region of broadcast.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.6: PID Grid Question26: What can we see at the grid? At the grid we can see all the used PIDs in a more visual way. On the X axis we have the units, and on the Y axis we have the hundreds. Every different kind of PID has its own color.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.7: PCR tab Question27: What do we see at the PCR tab? What is the PCR? The PCR is every copy from the SCT (System Time Clock). It has to be transmitted at least every 40ms in order to let the decoder to lock on the transmission. If it doesn’t happen, we have a “PCR error”. As we can see on PCR Interval, all the PCR are under 40ns.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2.8: Error Table TR 101 290 13.1.3 DTA-115 exercise: DTA-115 EXERCISE The goal of this exercise is to understand how the different features that compose a video signal work and what are the consequences of changing them.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 1: Antenna attenuator Connect the attenuator to the TVexplorer and then connect the main output of the DTA-115 to the attenuator. Double click on the StreamXpress icon and open the “DTU_recordedTS”. The StreamXpress should look like this: NOTE: The default file extension is .TS and .TRP for MPEG-2 Transport Streams. If the file extension is not .TS or .TRP, it may not show up in the list of available files.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Figure 2: StreamXpert Main Window Let’s see what we can find on StreamXpress.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal A: Part A represents the Transport Stream Info. It will display the following information if it’s available in the stream: - Transport Stream ID. Each program detected into the stream. Program name and total bitrate of the program. B: This window represents the PID info. It will display the following information if it is available in the stream: - Each PID and its association with a program number.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Create a loop to start the exercises. Just click on the “Edit” button and press the “Sub Loop…” option: Figure 3. Sub Loop option The next window will appear. Select the “Sub loop” option and then write the length of the loop. Figure 3.2. Sub Loop option parameters Click on play button. Now you will be able to see the loop on the TV EXPLORER.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal If you don’t see anything press the magnifying glass button and check that the blue LEDs “T” and “D” are switched on. Figure 4. Promax’s Satellite/Terrestrial and Analog Digital buttons. Also you will have to check the tuning frequency, it has to be the same at the StreamXpress and at the TV EXPLORER. NOTE: Only CBR Transport Streams are supported Exercise1 Explain the differences between DVB-H, DVB-C and DVB-T.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Exercise4 What happen if you change the guard interval, the frequency or the 8k value? The image doesn’t appear in all of them. Changing the frequency to 7MHz the spectrum is smaller and we can not receive right the constellation, there are too many scattered symbols. With all of these features, we can’t see the video signal, because is not possible to decode correctly. Now we are going to inject some errors.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal Exercise5 Play a little introducing different values of lost packets. What’s happening? Doesn’t seem to be any changes at the constellation diagram, but there are some problems in the image. There are some parts of the image missing. That’s due to these lost packets, there is some information lost in them, so we can not see some frames of the sequence.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal While the video is playing, tick the “Spectral Inversion” box. Exercise 8 What happens if we check the spectral inversion? Why does this happen? The video stops playing. This happens because we inverted the spectrum without any additional process. The new data of the inversed spectrum are not readable from the TV Explorer because they cannot form a proper signal.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal On the main screen click the “more” box on the right side of the program: 126 | P a g e
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal On the next pop-up window on the first row at the dropdown box it shows “0”. Change it to “1” and see what happens. Exercise 9 Why does the transmission stops? The transmission stops because the signal is not processable anymore so, the TV explorer cannot read and play it. This happens because we added an inner artificial interpolation. This interpolation is different than the normal ones caused by neighboring channels.
Generation of a transport stream for DVB and realisation of a HF-modulated DVB-signal On the main screen again, untick the RMX box: Exercise 10 What happens if we untick the RMX box? Why does this happen? When we untick the RMX box the out rate and the transport stream rate become the same. This is something that causes malfunction to the signal, resulting the playback device to play some parts and not the whole transport stream.
