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9 items tagged "pal"
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transmission [+],
signal [+],
mpeg2 encoder [+],
germany [+],
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christian daniel thomas kleffel [+],
chaos communication congress [+],
video [+],
usa [+],
testing intrusion detection systems [+],
patrick engebretson [+],
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josh pauli [+],
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ids [+],
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bit [+],
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wall [+],
vinod [+],
tvs [+],
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sega master system [+],
programmer [+],
programmable logic [+],
play [+],
papilio [+],
news [+],
microcontrollers [+],
lot [+],
handy gadgets [+],
game system [+],
experimenting [+],
displaying graphics [+],
crystal oscillators [+],
clpd [+],
clock source [+],
clock [+],
ben leperchey [+],
atmega32 [+]
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![Permalink for '[Video] DVB-T - From Pixeldata to COFDM Transmission'](/themes/lilina/web//media/mark_off.gif.pagespeed.ce.FiDKaoEBZK.gif)
21:31
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SecDocs
Authors:
Christian Daniel Thomas Kleffel Tags:
TV Event:
Chaos Communication Congress 23th (23C3) 2006 Abstract: As DVB-T is the key technology for terrestrial broadcasting for the next decades, this lecture tries to explain how it works: It covers the way of raw pixel data over MPEG2 video and audio encoding and via multiplexing of several streams and programs to the actual generation of the COFDM signal used for transmission. As the team has built a DVB-T transmitter, we will give a in-depth insight in how things are really done - including a demonstration of the transmitter. Analog PAL based TV transmission is no more - DVB has taken over in Germany. This should be legitimate reason to take a really deep look into how the new technology works and what needs to be done to get your own transmission into the air. The base for our lecture is a standard FBAS signal coming from a video camera. From there we will go with it through all the necessary stages of encoding, framing, multiplexing and modulating. First step is the A/D conversion of the picture and the sound. The resulting 240MBit/s stream is fed into the MPEG2 encoder where video and audio is encoded using the given parameters resulting in a bitstream of defined datarate. To achieve that, the video is divided into single blocks, movement relative to earlier and later frames is detected, and then the data is transferred into the frequency domain and then encoded. A relatively similar thing is done to audio: It is split into several frequency bands and for every band it is decided if the listener will hear this band or not using a psycho accoustical model. Then the remaining data is encoded into a bitstream as well. After that a program clock reference is generated to enable the receiver to keep video and audio in sync while playing back the stream. During the next stage, all video- and audio-streams are multiplexed into one big transport stream and several data tables are added. These tables define, which programs belong to this transport stream and assign video and audio streams to these programs. Electronic program guide and teletext are added and finally the COFDM modulator has the job to generate a base band signal for transmission. Here data is scrambled and interleaved several times, two types of forward error correction are added and then the bits are distributed to the up to 8000 distinct carriers which compose the final signal. As we have built a complete OFDM modulator we will then demonstrate how all these things work together and finally you will be able to watch our transmission using your own DVB-T stick.
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21:31
»
SecDocs
Authors:
Christian Daniel Thomas Kleffel Tags:
TV Event:
Chaos Communication Congress 23th (23C3) 2006 Abstract: As DVB-T is the key technology for terrestrial broadcasting for the next decades, this lecture tries to explain how it works: It covers the way of raw pixel data over MPEG2 video and audio encoding and via multiplexing of several streams and programs to the actual generation of the COFDM signal used for transmission. As the team has built a DVB-T transmitter, we will give a in-depth insight in how things are really done - including a demonstration of the transmitter. Analog PAL based TV transmission is no more - DVB has taken over in Germany. This should be legitimate reason to take a really deep look into how the new technology works and what needs to be done to get your own transmission into the air. The base for our lecture is a standard FBAS signal coming from a video camera. From there we will go with it through all the necessary stages of encoding, framing, multiplexing and modulating. First step is the A/D conversion of the picture and the sound. The resulting 240MBit/s stream is fed into the MPEG2 encoder where video and audio is encoded using the given parameters resulting in a bitstream of defined datarate. To achieve that, the video is divided into single blocks, movement relative to earlier and later frames is detected, and then the data is transferred into the frequency domain and then encoded. A relatively similar thing is done to audio: It is split into several frequency bands and for every band it is decided if the listener will hear this band or not using a psycho accoustical model. Then the remaining data is encoded into a bitstream as well. After that a program clock reference is generated to enable the receiver to keep video and audio in sync while playing back the stream. During the next stage, all video- and audio-streams are multiplexed into one big transport stream and several data tables are added. These tables define, which programs belong to this transport stream and assign video and audio streams to these programs. Electronic program guide and teletext are added and finally the COFDM modulator has the job to generate a base band signal for transmission. Here data is scrambled and interleaved several times, two types of forward error correction are added and then the bits are distributed to the up to 8000 distinct carriers which compose the final signal. As we have built a complete OFDM modulator we will then demonstrate how all these things work together and finally you will be able to watch our transmission using your own DVB-T stick.
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21:31
»
SecDocs
Authors:
Christian Daniel Thomas Kleffel Tags:
TV Event:
Chaos Communication Congress 23th (23C3) 2006 Abstract: As DVB-T is the key technology for terrestrial broadcasting for the next decades, this lecture tries to explain how it works: It covers the way of raw pixel data over MPEG2 video and audio encoding and via multiplexing of several streams and programs to the actual generation of the COFDM signal used for transmission. As the team has built a DVB-T transmitter, we will give a in-depth insight in how things are really done - including a demonstration of the transmitter. Analog PAL based TV transmission is no more - DVB has taken over in Germany. This should be legitimate reason to take a really deep look into how the new technology works and what needs to be done to get your own transmission into the air. The base for our lecture is a standard FBAS signal coming from a video camera. From there we will go with it through all the necessary stages of encoding, framing, multiplexing and modulating. First step is the A/D conversion of the picture and the sound. The resulting 240MBit/s stream is fed into the MPEG2 encoder where video and audio is encoded using the given parameters resulting in a bitstream of defined datarate. To achieve that, the video is divided into single blocks, movement relative to earlier and later frames is detected, and then the data is transferred into the frequency domain and then encoded. A relatively similar thing is done to audio: It is split into several frequency bands and for every band it is decided if the listener will hear this band or not using a psycho accoustical model. Then the remaining data is encoded into a bitstream as well. After that a program clock reference is generated to enable the receiver to keep video and audio in sync while playing back the stream. During the next stage, all video- and audio-streams are multiplexed into one big transport stream and several data tables are added. These tables define, which programs belong to this transport stream and assign video and audio streams to these programs. Electronic program guide and teletext are added and finally the COFDM modulator has the job to generate a base band signal for transmission. Here data is scrambled and interleaved several times, two types of forward error correction are added and then the bits are distributed to the up to 8000 distinct carriers which compose the final signal. As we have built a complete OFDM modulator we will then demonstrate how all these things work together and finally you will be able to watch our transmission using your own DVB-T stick.
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23:06
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Hack a Day
If you’ve ever wondered why NTSC video is 30 frames and 60 fields a second, it’s because the earliest televisions didn’t have fancy crystal oscillators. The refresh rate of these TVs was controlled by the frequency of the power coming out of the wall. This is the same reason the PAL video standard exists for [...]
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10:02
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Hack a Day
[Vinod] has done a lot of work with microcontrollers, but this is his first try at displaying graphics using composite video. He had a small PAL television on hand, and an ATmega32 which just needs a stable clock source and a few resistors to get things going. There are a lot of other hacks around [...]
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10:23
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SecDocs
Authors:
Josh Pauli Kyle Cronin Patrick Engebretson Tags:
IDS sniffer Event:
Black Hat USA 2010 Abstract: Testing Intrusion Detection Systems (IDS) to ensure the most malicious attacks are detected is a cornerstone of these systems, but there is no standardized method to execute these tests. Running live exploitations is not always a viable option – especially when the rule set isn’t finalized, and clients are often nervous about the use of “hacker tools” on their networks. Furthermore, educators struggle to teach IDS concepts as a standalone principle without teaching attack methodologies at the same time. We are releasing two artifacts to help solve these problems. First we introduce PAL, a PCAP Attack Library full of individual pre-captured attack files that can be easily replayed for IDS testing and education. This library is completely preassembled, clean, and extendable to include further additions of attacks. Our initial library is created from the findings in the Common Attack Pattern Enumeration Classification (CAPEC) from the Department of Homeland Security. Second, we introduce SprayPAL, a software tool that we’ve developed to replay the PCAP attack library files. Users can send attacks to a specific target or broadcast to an entire subnet of machines. Additional features include the ability to select individual or multiple simultaneous attacks as well as provide layer 2 and 3 packet level manipulation. We conclude by presenting a methodology for capturing attacks and adding them to the public library. Both our PCAP attack library and SprayPAL tool will be released at Black Hat 2010 to the general public.
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10:23
»
SecDocs
Authors:
Josh Pauli Kyle Cronin Patrick Engebretson Tags:
IDS sniffer Event:
Black Hat USA 2010 Abstract: Testing Intrusion Detection Systems (IDS) to ensure the most malicious attacks are detected is a cornerstone of these systems, but there is no standardized method to execute these tests. Running live exploitations is not always a viable option – especially when the rule set isn’t finalized, and clients are often nervous about the use of “hacker tools” on their networks. Furthermore, educators struggle to teach IDS concepts as a standalone principle without teaching attack methodologies at the same time. We are releasing two artifacts to help solve these problems. First we introduce PAL, a PCAP Attack Library full of individual pre-captured attack files that can be easily replayed for IDS testing and education. This library is completely preassembled, clean, and extendable to include further additions of attacks. Our initial library is created from the findings in the Common Attack Pattern Enumeration Classification (CAPEC) from the Department of Homeland Security. Second, we introduce SprayPAL, a software tool that we’ve developed to replay the PCAP attack library files. Users can send attacks to a specific target or broadcast to an entire subnet of machines. Additional features include the ability to select individual or multiple simultaneous attacks as well as provide layer 2 and 3 packet level manipulation. We conclude by presenting a methodology for capturing attacks and adding them to the public library. Both our PCAP attack library and SprayPAL tool will be released at Black Hat 2010 to the general public.
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7:06
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Hack a Day
External EPROM burners are pretty handy gadgets to have around. They obviously can read and write EPROMS, but often times they will also handle a pile of PIC’s, some AVR’s, and other programmable logic like PAL/GAL and CLPD’s. While you can often find old models floating around for cheap (or free in my case) there [...]
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16:38
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Hack a Day
[Ben Leperchey] is working on building a Sega Master System clone using the Papilio One FPGA board, and although his ultimate goal has yet to be reached, he’s bringing some great stuff to the table in the meantime. One component that is necessary for any sort of game system clone is NTSC/PAL video output, naturally. [...]
