Another FullHD option by air
I will not go into lengthy arguments about the pros and cons of various options for wireless video transmission for various applications, a lot has been written about this. Special branch on RCDesign, which is called - Wireless video transmission in full HD . I will report only on the results.
The tests somehow impromptu turned out, so sorry for the quality of the photo / video.
the noise in the photo is my joint, in the second test it was fixed, but there is no other photo, sorry.
')
Since the transfer of digital video to more or less decent distances is usually accompanied by delays (lags), the analog transmission method remains the fastest. A lot of people use ordinary video transmitters for FPV, to which analog cameras of standard resolution are connected. The video delay is minimal, but I want a higher resolution (not for glasses) and less interference.
In general, the idea was long ago in my head to try to transmit an analog component video signal (YPbPr) using three conventional video transmitters. Many have such an idea in their head, but I have not found a single description of such experiments. Maybe he was looking badly, and maybe no one really checked. In any case, it is interesting to try it yourself.
I have a nuclear briefcase preserved from one design, in which just three receivers at 5.8 GHz are mounted, plus a block of video transmitters at 5.8 GHz. Transmitters of different power, one for 200mW, the other two for 400mW. Temporarily tore off the wiring, soldered the tulips and went to check.
At hand, there is only one component signal source - the Blu-ray Pioneer BDP-320 player. There is also GoPro2, but the component signal in it is only on the rear connector, and I do not have a suitable plug. So I checked the fact of the possibility of video transmission, without checking the delay. But something tells me that the delay will be the same as when transmitting standard definition video. Video output resolution set 1080i (maximum possible). At first, the distance between transmitters and receivers was very small (about a meter), when retested, they smashed them to the maximum possible distance in the apartment (ten meters, diagonally through four walls).
Test result - the video works without problems. When a signal of one of the components deteriorates (or several at once), it gives either a color distortion (in the case of Pb or Pr signals), or a complete disappearance of the picture (in the case of a Y signal). Since the Y signal is the most important here, it is better to connect it to the most powerful transmitter. The sound did not connect, but I think it’s not a problem to send it through one of the three transmitters, as is the case with the usual transmission of standard definition video.
Interference with the first test was quite often, but I remembered that in the suitcase in the immediate vicinity there was a full-fledged comp (motherboard, percent, memory, cooler, everything without a case), so the interference was from him. During the second test, the computer in the suitcase was turned off, so the interferences (bars on the screen) disappeared. In general, watch the videos, everything is visible.
Video of the first test:
The second test:
Do not forget that FPV (First Person View) is used not only for flying devices (airplanes, multikopter), but also for driving, so there is not always a limit on the weight of transmitters.
Of course, it is necessary to check how it will work for long distances, from several hundred meters to kilometers. But here we need more powerful transmitters and antennas better.
But one more variant of wireless video transmission from our Virturilka has been tested . We have a component video output on board (the Y Pb Pr signals on the pins are divorced) 720p / i with the current process, but for full operation you need to add one mikruha, so you have to make a small second floor specifically for this purpose.
In general, I hope the results will be useful to someone and will give impetus to the transition to HD FPV.
If someone knows about similar tests or something new at all about the subject - share in the comments, pliz, do not hold back.
UPD> Removed video with changing permissions
The tests somehow impromptu turned out, so sorry for the quality of the photo / video.
the noise in the photo is my joint, in the second test it was fixed, but there is no other photo, sorry.
')
Since the transfer of digital video to more or less decent distances is usually accompanied by delays (lags), the analog transmission method remains the fastest. A lot of people use ordinary video transmitters for FPV, to which analog cameras of standard resolution are connected. The video delay is minimal, but I want a higher resolution (not for glasses) and less interference.
In general, the idea was long ago in my head to try to transmit an analog component video signal (YPbPr) using three conventional video transmitters. Many have such an idea in their head, but I have not found a single description of such experiments. Maybe he was looking badly, and maybe no one really checked. In any case, it is interesting to try it yourself.
I have a nuclear briefcase preserved from one design, in which just three receivers at 5.8 GHz are mounted, plus a block of video transmitters at 5.8 GHz. Transmitters of different power, one for 200mW, the other two for 400mW. Temporarily tore off the wiring, soldered the tulips and went to check.
At hand, there is only one component signal source - the Blu-ray Pioneer BDP-320 player. There is also GoPro2, but the component signal in it is only on the rear connector, and I do not have a suitable plug. So I checked the fact of the possibility of video transmission, without checking the delay. But something tells me that the delay will be the same as when transmitting standard definition video. Video output resolution set 1080i (maximum possible). At first, the distance between transmitters and receivers was very small (about a meter), when retested, they smashed them to the maximum possible distance in the apartment (ten meters, diagonally through four walls).
Test result - the video works without problems. When a signal of one of the components deteriorates (or several at once), it gives either a color distortion (in the case of Pb or Pr signals), or a complete disappearance of the picture (in the case of a Y signal). Since the Y signal is the most important here, it is better to connect it to the most powerful transmitter. The sound did not connect, but I think it’s not a problem to send it through one of the three transmitters, as is the case with the usual transmission of standard definition video.
Interference with the first test was quite often, but I remembered that in the suitcase in the immediate vicinity there was a full-fledged comp (motherboard, percent, memory, cooler, everything without a case), so the interference was from him. During the second test, the computer in the suitcase was turned off, so the interferences (bars on the screen) disappeared. In general, watch the videos, everything is visible.
Video of the first test:
The second test:
Do not forget that FPV (First Person View) is used not only for flying devices (airplanes, multikopter), but also for driving, so there is not always a limit on the weight of transmitters.
Of course, it is necessary to check how it will work for long distances, from several hundred meters to kilometers. But here we need more powerful transmitters and antennas better.
But one more variant of wireless video transmission from our Virturilka has been tested . We have a component video output on board (the Y Pb Pr signals on the pins are divorced) 720p / i with the current process, but for full operation you need to add one mikruha, so you have to make a small second floor specifically for this purpose.
In general, I hope the results will be useful to someone and will give impetus to the transition to HD FPV.
If someone knows about similar tests or something new at all about the subject - share in the comments, pliz, do not hold back.
UPD> Removed video with changing permissions
Source: https://habr.com/ru/post/197612/
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