Questions tagged [video]
22 questions
10
votes
4 answers
How does a computer play a video while doing something else?
How is video playback done on a computer? It's obviously not relying purely on the CPU, since video playback continues when a user performs another activity, such as typing into a YouTube comment field. This task seems further complicated in the…
Ellen Spertus
- 1,592
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5
votes
1 answer
Why are blocking artifacts serious when there is fast motion in MPEG?
Why are blocking artifacts serious when there is fast motion in MPEG?
Here is the guess I made:
In MPEG, each block in an encoding frame is matched with a block in the reference frame.
If the difference of two blocks is small, only the difference is…
Bear
- 153
- 3
4
votes
1 answer
Why does a color video compress better than a black and white video?
It was asked in an exam why a color video compress better than a black and white (grayscale) video using MPEG but can't find anything explaining it.
In other words, we would apparently get a better compression ratio when compressing color videos…
Stéphane Bruckert
- 159
- 1
- 8
3
votes
0 answers
Lossless Video Compression Pipeline
The only paper I can find about an implementation of a lossless video codec is an article by Michael Niedermayer which explains the FF1V compression pipeline.
I'm wondering if anyone else has found any articles similar to this. I've looked on IEEE…
ninjaneer
- 131
- 1
3
votes
1 answer
Why Is Inverse Quantization and Inverse Transform Taken Before Motion Estimation in H.264?
Here is the block diagram of the pipeline for the H.264 encoder (Fundamentals of Multimedia by Ze-Nian Li, Mark S. Drew and Jiangchuan Liu).
The feedback loop is used for motion estimation, but why is it taken after the transform and quantization…
Xosrov
- 131
- 1
2
votes
2 answers
How to label a video for supervised learning?
I have just started discovering the machine learning world! I found many tutorials showing how to deal with different types of data. I walked through some tensorFlow tutorials and I think they have very good way for showing how the (x, y) pair for…
Sumo
- 21
- 1
2
votes
2 answers
Why does a software video encoder create higher quality output than a hardware video encoder
It is said commonly that a software video encoder has creates higher quality output than hardware encoder. Higher quality here means higher picture quality at a given bit rate.
Hardware encoders are commonly for realtime usage and some are for…
jw_
- 171
- 5
2
votes
2 answers
identify abrupt frame changes in a video
The frames of live streams or videos, in general, do not flow smoothly. A sports game would have multiple cameras recording the game and hence, there will be camera switches in the stream. I am detecting objects and tracking them as long as…
Yashas
- 275
- 1
- 10
1
vote
2 answers
How does RAMDAC get notified about framebuffer write?
I'm learning computer graphics, and I read this course lecture in order to understand how graphics I/O works under the hood. But the following explanation was not very clear to me:
The values in the framebuffer are converted from a digital (1s and…
user6039980
- 431
- 9
- 21
1
vote
1 answer
Algorithm for weighted elliptic curve fit
Background:
I was trying to detect a face solely on the bases of features and the confidence of the features found.
I am using a method to identify the features along with the response (confidence). Stronger features have higher responses.
I was…
Akshay Rathod
- 13
- 4
1
vote
1 answer
How to feed videos to a neural network
I have been coding and testing Neural Networks for a while but as of now I have only used IMAGE datasets. (i.e. I have M training images and N testing images).
Some datasets are video datasets. The UCSD Peds dataset for example has the following…
user83728
1
vote
0 answers
Convergent cameras stitching
I am currently working on a computer vision problem that involve 8 convergent cameras.
I am trying to recreate a 2D image (I actually don't care of the shape of the image) that is the representation of my scene seen from the 8 convergent cameras…
Axel
- 11
- 2
1
vote
0 answers
Compare 2 video files (could be in different formats and quality) by content
I'm interested - is it possible to implement algorithm which could compare 2 video files and answer, are they the same with some level of precision.
Is currently exist some methods which allow to solve that problem effectively?
The same - means like…
Ph0en1x
- 141
- 5
1
vote
1 answer
How is a video file read frame by frame without loading the entire video file in memory?
As I understand that a video file is a binary file, the frames are not really present in a contiguous manner in a video file, so reading the video file by doing a seek and reading it frame by frame wouldn't work until you have loaded the entire…
Himanshuman
- 115
- 6
0
votes
1 answer
Sample K representative frames within a video
I have an image-based processing module that takes photos for some computer vision processing. I have many videos, but I need to sample representative frames as its inputs, preferably those frames with higher attention.
What are some good and…
Tina J
- 131
- 3