Embedded masters, embedded masters, please enter software hardware

Generally, embedded is to learn arm9 + linux

Linux at least has no problem with use, not with a mouse, but with a keyboard, open files, copy files, unzip, package, **source software, are very simple. Knowledge of Linux architecture. I don't say anything about the degree, the more familiar the better, especially the Linux composition.

There is C to be familiar with, if C is a master, then there is no problem, the best is to learn a single-chip microcomputer, mainly depends on whether you learn the embedded software layer or the hardware layer, I will kill the software and hardware.

1.People who are proficient in hardware and have low-level programming experience are more likely to be able to afford it (e.g., driver writing).

2.Hardware can be studied electronic information majors, electrical (this is a little crooked, but the general school is about the same), of course, computer majors can also be, university Xidian, Southeast, North Post are very good, it is recommended to choose the provincial capital city when picking a university. If you are admitted to graduate school, you will have an advantage in taking the entrance examination of this school.

3.It's good to learn the basic courses well in the freshman year (to expand your horizons, you should often go to some embedded BBS).

At the beginning of the sophomore year, you will be able to open digital electricity and modular electricity, and it is best to quickly learn by yourself, and then win the single-chip microcomputer course (this is more important for learning embedded).

In the junior year, when others are learning microcontrollers, you can learn high-end embedded processors (32-bit computers), s3c2410a, and the senior year is to do things...

4.Tell me if you know.

Shenzhen's Libang, Huawei, ZTE, too much, undergraduates are generally 5000-5500, and graduate students are at least about 6000 (provided that you have real talent and real learning) There are more communication companies in foreign companies, such as UT Starcom...

VAD Translation – Programming Term.

VAD is a technical term in programming.

Definition of programming term VAD.

VAD is an abbreviation for Virtual Address Descriptor, which is the Virtual Address Descriptor. A VAD holds a piece of information about the address space that is allocated, and all VADs form a binary sort tree to describe the user's address space. Each process has its own user address space, so each process also has its own VAD binary sort tree.

VAD – Voice Activity Detection.

vad，voice activation detection。

Silent suppression paraphrasing.

Silent suppression, also known as voice activity detection. The purpose of mute suppression is to identify and eliminate long quiet periods from the sound signal flow, so as to save voice resources without reducing service quality, which is an important part of IP** applications. Silent suppression can save valuable bandwidth resources and can help reduce the end-to-end latency perceived by users.

Silent suppression applications.

When a user calls **, he or she does not always occupy the call channel. According to the statistics of traditional services, the actual time occupied by a user on the call channel will not exceed 40% of the entire call time. This mainly includes the following reasons:

One is listening to the other person; the second is a pause between a passage caused by thinking, taking a break, etc.; The third is the pause in the middle of speech, such as hesitation, breathing, stuttering, etc. In the first case, the pause gap is long and the frequency is low; In the third case, the pause gap is short and the frequency is high; The second situation is boundary.

1. Between the three situations. This characteristic of the voice source is called the on-off feature, and it is sometimes called the voice silence feature. When the user is not speaking, there is no voice packet transmission, which can further reduce the voice bitrate.

When the user's voice signal energy falls below a certain threshold, it is considered to be in a silent state, and no voice packets are sent. A voice signal is generated and transmitted when a burst of active sound is detected. With this technology, more than 50% of the bandwidth can be obtained.

Mute suppression attention problems.

There are two issues that need to be paid attention to when performing mute detection: one is the background noise problem, that is, how to detect mute in large background noise; The second is the shear problem of front and back edges. The so-called front and back edge clipping is that when the speech is restored, because there is a certain judgment threshold and delay between the beginning of the actual speech and the detection of the voice, sometimes the beginning and end parts of the voice waveform will be discarded as mute, and the restored voice will change, so it is necessary to add a voice grouping in front of or behind the burst voice packet for smoothing to solve this problem.

In practice, if there is a long period of silence, it will feel very unnatural for the user. As a result, the receiver often sends packets during muted periods, resulting in background noise that makes the user feel more comfortable, the so-called comfort noise.

I think it's strong enough. I'm embedded, but I don't really know what you're talking about.