Frage von funnyjanni:
Hello!
I am currently writing s.einer work for the university, which is compared with a quality (in terms of time delays, arising employed by the computation of the codec) of 2 video systems.
My question: Can you say flat: "The more frames of a video that must be processed by the codec, the higher the resulting delay to be?"
The best way would it be if you give me an even a source (website, literature, Could you call it), which confirms this conclusion! I've already rumgesucht forever but never found ne real concrete answer.
Thank you for your answers!
January Stanetzki
Antwort von soahC:
I understand that somehow ask garnich ...
delay time?? on what affects them? 2 video systems?
Antwort von prem:
When encoding and decoding streaming of a camera so there will inevitably be delays. I tested these delays at 2 different systems ...
The problem: A system of streams 25 Fields, that other 25 frames. When the system sends the images less, the delay time is greater. To compare both systems would normally run under identical conditions (ie, synonymous), the same amount to send s.Frames, but that is not technically feasible.
My question: The system with 25 Fields is quite slower. Can one lump sum advance the thesis that (it would be able to operate with 25 frames - that is, with dual "picture set") result in the processing of more images would be even higher delay times (because the codec has to do more so) and therefore draw the conclusion that the other video system work more efficiently?
And: Does anyone know a source that shows: "More pictures to be processed leads to higher delay times at the codec"?
Ps: It's not about delays caused due to lack of transfer speed, this is more than enough!
Thank you for your answers,
January
Antwort von b0kaJ:
Neither an opinion about it?
LG,
Jan
Antwort von b0kaJ:
Neither an opinion about it?
LG,
January Since you're asking: I rarely read such a nonsense.
Antwort von b0kaJ:
Hmm ... It is in fact a fairly complex system. So once again an attempt to explain:
In the MPEG standard images are compressed. Through the compression of images, the data rate is lowered, however, the CODEC has more computational work. Through the computation delays incurred in the video system.
Can be a flat rate claims with the encoding of a video takes 25 full frames (frames) per second more than the processing of 25 fields (Fields, representing 12.5 full frames)?
Ne that is really very simple question and I just want to confirm that I really lies with the conclusion, and occur in the defense at work no stupid questions ;-)!
Regards,
January
Antwort von b0kaJ:
Delay = The video is then displayed on a monitor a few milliseconds of the camera when it is taken.
Antwort von soahC:
Sorry, really, but I still do not verstehs. When one sees this delay?
during capture? during play? when compressed??
Antwort von AndyZZ:
Can be a flat rate claims with the encoding of a video takes 25 full frames (frames) per second more than the processing of 25 fields (Fields, representing 12.5 full frames)?
Now I just tell time YES: Is it really logical that the processing of the longer doubling time than the 25 fps of 12.5 full-screen images.
Now the philosophy: That's true only if that's all what you compress. Do you have a film that consists of 1000 blocks à 12,5 pictures and one of the consists of 500 blocks of 25 images, then no difference to be noted.
The question is this: you compare 25 frames with 50 fields? Or, with 25 fields? What Resolutionhaben the fields? Have the half Resolutionwie the frames? Or they have the same, is only every second line blank ...? Questions about questions ...
Antwort von Markus:
Have seldom read such a nonsense. Sorry, really, but I still do not verstehs. I agree s.and wonder where my flaw? If my computer is a video rendering (such as After Effects, where I can arbitrarily vary the frame rate and image size), then the rendering time is obviously in direct relation to the total number of frames, because each picture individually calculated.
Logically, the rendering time synonymous increases when the frame rate (frames per second) is increased, because it synonymous increases the total number of frames. I Set up a faster rendering Calculator, then, logically, the rendering time decreases again. Unless the CPU usage was still not at 100% or the rendering was organized computerintern not effective.
To what extent this can be transferred to DV sources, is probably only theoretical, because DV is always running with 25 fps (= 50 fields per second).
Antwort von Gast1:
I'm sorry, but it is nonsense.
One can not but ask such a question without defining the environment.
I'm assuming the "Video System" is a studio, the encoder is a hardware encoder.
Utilized only as an example: Assume that the capacity of the encoder is 25 fps with only 10% will be synonymous occur at 100 fps, no additional "delay". From any frame rate is to get out of it. Also nix relative, only absolute.
Of course, the picture will appear later on the monitor when it was included in the camera. And before the appearance on the monitor, it must still decoded, etc., are. The speed of light is now finally time. That is why ultimately each production is a major life continuity.
The only possible answer is: Yes, I can get through the irgenwas in MPEG encoding of "delays" when I use inappropriate equipment.
Antwort von mrt:
The "framework" would only further confuse all, believe me ;-)! It is a monitoring system (use in larger projects) as the platform monitoring.
A camera is streaming their images similar to the encoder, which compresses and encodes the data. The data is sent to the decoder via a network and either analog or digital output.
Since we are dealing with an assay system in which only small distances to be bridged and standing Camera & Monitor next to each other, we see the delay directly (current values are around 1 / 2 second). That is, you notice that a motion is displayed on the monitor with delay (eg, when the hand holding the camera).
Since the two "videos" dealing with streams, of course there are no defined end ....
Hope I could make it a little clearer?
Regards,
January
Antwort von AndyZZ:
And now you want to know whether the apparent delay is less when you instead of 25 fps (PAL bsp.-picture) is only 12 fps (so to speak, stroboscopic effect) data transmitted?
Antwort von Markus:
And now you want to know whether the apparent delay is less when you instead of 25 fps (PAL bsp.-picture) is only 12 fps (so to speak, stroboscopic effect) data transmitted? If so: Try it out just yet.
Antwort von Quadruplex:
My question: Can you say flat: "The more frames of a video that must be processed by the codec, the higher the resulting delay to be?" No - at least not necessarily. Check out the (in this forum more often discussed) codec of DV and Digital 8th The latter, called the DCT, only works inside of frames. Ergo: Did you want to process instead of a standard PAL picture via DCT example, HD pictures, you needed a more powerful hardware encoder. If the DCT encoder with toil and Not just the 25 per second PAL creates images, it is a higher-resolution picture is no longer able to encode in real time.
Within certain limits (hardware encoder have but 'ne finite operating frequency) But you could through your DCT encoder well over 25 frames per second with PAL resolution to send - even when DCT coding is only in the image processing time per Picture is therefore only of the compulsive processed image resolution, not of the number of frames per second. (As I said, played a part as long as the hardware in principle.)
The modern, more efficient codecs - MPEG and associates - to achieve its higher coding efficiency significantly by the fact that they average over several images, or only support certain images transmitted completely. (I save me now here is a detailed explanation that you should know or can look).
Is, in principle: Here are the delay time is longer, because you have so caching at least a few pictures and see the differences of one to the other and encode in any form.
Would now mean, as I understand: If such a system, the delay time depends largely on first, if I say, 25 or 250 images was approaching for data reduction. Then make the noticeable tatsählich per second to be transmitted images and the number of pixels per picture.
