Video encoder and decoder application solutions

Video decoders and video encoders are commonly used devices in digital signal processing, and they play an important role in data transmission and conversion.

Overview and Application

It is an encoding device that converts analog signals or digital signals into digital signals. It compresses and collects the input audio and video signal sources and converts and encodes them into digital codes that can be recognized by the machine. The encoding is compressed into files or TS stream data that can be transmitted over the network in real time. It is then output through a Gigabit or 100M Ethernet network and transmitted to the next-level device, a remote receiving end or a video server, and is compressed according to different compression algorithms to achieve better compression effects.

Video decoders and video encoders are widely used in digital communications and audio and video compression. Video encoders are the transmitters of video sources. If the receiver is a PC or display device, it needs to be decoded and played by a decoder.

The video decoder restores the compressed signal to the original signal. It only needs to restore the compressed data according to the corresponding standard (such as sound or image, etc.), and then output it through the sound card or display. It is widely used in multimedia players, digital TV set-top boxes and other fields.

Crystal performance requirements

To ensure the high definition and smoothness of audio and video, not only a good network environment and high-performance chips are needed, but also a high-precision crystal oscillator is needed to provide a stable clock signal to avoid frequency deviation or the influence of clutter, which may cause audio mixed with noise, video freeze or no color. As a clock source, the crystal oscillator provides a stable clock signal to the decoder/encoder chip to ensure accurate decoding and synchronization of data, so that each functional module inside the audio and video can work in the correct time sequence, ensuring the normal decoding and display of the video signal.

(Crystal oscillator application block diagram)

The commonly used crystal oscillator frequency for video encoders and video decoders is 27MHz. The following requirements are imposed on the crystal oscillator selection:

① Low phase noise/low jitter: Any jitter or drift of the clock signal may cause decoding errors or incorrect compressed data, while the active oscillator can provide a highly stable clock signal to ensure the normal operation of the video decoder and encoder;

② High precision: Too high or too low clock frequency may cause data sampling distortion or decoding errors. Provide accurate frequency to meet the working requirements of video decoders and encoders;

③ High reliability: The stability and reliability of the crystal oscillator are very important for the long-term operation of the video decoder and encoder, so the crystal oscillator should be resistant to high temperature, high quality and long life.

YXC crystal oscillator recommendation

For video encoder and video decoder applications, it is recommended to use the Yangxing Technology (YXC) active crystal oscillator YSO110TR series, with a frequency range of 1-125MHz, frequency stability of ±30ppm, low jitter of 0.7pS max., wide operating voltage range of 1.8-3.3V, operating temperature of -40~+85°, and package size covering 1612-7050. It has the characteristics of high stability, low jitter, and flexible matching of different package sizes and voltage requirements. The series specifications are as follows: