Abstract:
A video processing device includes a processor, a voltage conversion circuit, and a Syndicat des Constructeurs d&#39;Appareils Radiorécepteurs et Téléviseurs (SCART) chip. The processor is operable to process video signals, and control a GPIO (general purpose input output) pin to output different mode controlling signals according to different video signal formats. The voltage conversion circuit connected to the GPIO pin is operable to receive the mode controlling signals, and output different voltage signals according to the different format controlling signals. The SCART chip connected to the voltage conversion circuit is operable to receive the video signals and the voltage signals, and process the video signals according to the corresponding voltage signals.

Description:
BACKGROUND 
     1. Technical Field 
     The present disclosure relates to multimedia technology, and more particularly to a video processing device. 
     2. Description of Related Art 
     Video devices often output Syndicat des Constructeurs d&#39;Appareils Radiorécepteurs et Téléviseurs (SCART) signals via a multimedia processor, and can process only one format of video signals. Therefore, the video device often requires either additional SCART matrix integrated circuits (IC), or a plurality of general purpose input output (GPIO) pins to process different video signal formats, such as SCART VCR/TV, for example. The additional components often increase device cost and complexity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The details of the disclosure, both as to its structure and operation, can best be understood by referring to the accompanying drawings, in which like reference numbers and designations refer to like elements. 
         FIG. 1  is a circuit diagram of one embodiment of a video processing device; and 
         FIG. 2  is a graph showing one example of a circuit simulation result of the video processing device of  FIG. 1 . 
     
    
    
     DETAILED DESCRIPTION 
       FIG. 1  is a circuit diagram of one embodiment of a video processing device  10 . In one embodiment, the video processing device  10  includes a processor  100 , a voltage conversion circuit  300 , and a SCART chip  500 . 
     In one embodiment, the processor  100 , comprising a general purpose input output (GPIO) pin  200 , is operable to process different video signal formats, and output different mode controlling signals via the GPIO pin  200  according to the different formats of the video signals. In one embodiment, the different video signal formats include a 4:3 video format, and a 16:9 video format. The different mode controlling signals include a high voltage level signal, a low voltage level signal, and a pulse-width modulation (PWM) signal, respectively to direct the SCART chip  500  to assume a standby mode, to output in the 4:3 video format, and to output in the 16:9 video format. 
     In one embodiment, the mode controlling signals output by the GPIO pin  200  of the processor  100  are the low voltage level signals if the video processing device  10  is in the standby mode. In one embodiment, the low voltage signal is 0V, the high voltage signal is 3.3V, the for example. 
     In another embodiment, if the video processing device  10  is in the 4:3 video mode, the mode controlling signals output by the GPIO pin  200  are the high voltage level signals. 
     In a further embodiment, if the video processing device  10  is in the 16:9 video mode the mode controlling signals output by the GPIO pin  200  are the PWM signals. 
     The voltage conversion circuit  300  is connected to the processor  100  via the GPIO pin  200 , and is operable to receive the mode controlling signals and generate and output different voltage signals according to the different mode control signals. The different voltage signals respectively correspond to the different video signal formats. In one embodiment, the voltage conversion circuit  300  outputs a 9.5V-12V voltage signal if the mode controlling signal is the low voltage level signal. 
     In one embodiment, the voltage conversion circuit  300  outputs a 0V-2V voltage signal if the mode controlling signal is the high voltage level signal. 
     In one embodiment, the voltage conversion circuit  300  outputs a 4.5V-7V voltage signal if the mode controlling signal is the PWM signal. 
     In one embodiment, the voltage conversion circuit  300  includes a first current limiting resistor R 1 , a second current limiting resistor R 2 , a first transistor Q 1 , and a second transistor Q 2 . 
     The emitter of the first transistor Q 1  is grounded, the base of the first transistor Q 1  is connected to the GPIO pin  200  through the first current limiting resistor R 1 , and the collector of the first transistor Q 1  is connected to a reference voltage Vcc through the second current limiting resistor R 2 . 
     In one embodiment, the base of the second transistor Q 2  is connected to the collector of the first transistor Q 1 , the collector of the second transistor Q 2  is connected to the reference voltage Vcc, and the emitter of the second transistor Q 2  is connected to the SCART chip  500  to output the different voltage signals to the SCART chip  500 . 
     In one embodiment, the video processing device  10  further comprises a filtering circuit  400 . The filtering circuit  400  is connected between the voltage conversion circuit  300  and the SCART chip  500 , and operable to filter noise from the different voltage signals. 
     In one embodiment, the filtering circuit  400  comprises a third resistor R 3  and a capacitor C 1 . In one embodiment, the third resistor R 3  and the capacitor C 1  are connected in parallel between the emitter of the second transistor Q 2  and the ground. 
     In one embodiment, the value of the first current limiting resistor R 1  is about 1 kΩ. The value of the second current limiting resistor R 2  is about 30 KΩ. The value of the reference voltage Vcc is about 12V. The models of the first transistor Q 1  and the second transistor Q 2  are both Q2N3904. The value of the third resistor R 3  is about 4.7 kΩ, and the value of the capacitor C 1  is about 2.2 uF. In other embodiments, the voltage conversion circuit  300  can employ amplifiers or MOSFETs to control the SCART chip  500  to process different video signals. 
     The SCART chip  500 , connected to the voltage conversion circuit  300  and the processor  100 , is operable to receive the different video signals from the processor  100  and the different voltage signals from the filtering circuit  400 , and process the different video signals according to the corresponding voltage signals. In one embodiment, the processor  100  is connected to the SCART chip  500  through a bus  600 , through which the processor  100  can provide the different video signal formats to the SCART chip  500 . 
     In one embodiment, the SCART chip  500  is in the standby mode and does not process the video signals when the voltage conversion circuit  300  outputs the 0V-2V voltage signal. 
     In another embodiment, the SCART chip  500  processes the video signals according to the 4:3 video format when the voltage conversion circuit  300  outputs the 4.5V-7V voltage signal. 
     In a further embodiment, the SCART chip  500  processes the video signal according to the 16:9 video format when the voltage conversion circuit  300  outputs the 9.5V-12V voltage signal. 
     Referring to  FIG. 2 , a graph showing one example of a circuit simulation result of the video processing device  10  of  FIG. 1  is shown. 
     At time 0-100 ms, the processor  100  processes a 16:9 video format signal. The GPIO pin  200  outputs a PWM mode control signal. Accordingly, the voltage conversion circuit  300  outputs a 5.75V voltage signal, and the SCART chip  500  processes the video signal according to the 16:9 video format. 
     At time 100 ms-200 ms, the processor  100  processes the 4:3 format video signal. The GPIO pin  200  outputs a low voltage level mode control signal. Accordingly the voltage conversion circuit  300  outputs 0V of the voltage signal, and the SCART chip  500  processes the video signal according to the 4:3 video format. 
     At time 200 ms-300 ms, the processor  100  processes no video signal, and the GPIO pin  200  outputs a high voltage level mode control signal. Accordingly, the voltage conversion circuit  300  outputs 10.65V of the voltage signal, and the SCART chip  500  does not processes the video signal. 
     In the present disclosure, the video processing device  10  controls the processor  100  outputs different mode controlling signals via the GPIO pin  200 , and the voltage conversion circuit  300  outputs different voltage signals according to the different mode controlling signals to direct the SCART chip  500  to process the different video signal formats. Therefore, the SCART chip  500  can process different video signal formats without requiring additional SCART matrix integrated circuits (IC) or more than one GPIO pins, and thus the cost of the video processing device  10  is conserved. 
     Although the features and elements of the present disclosure are described in various inventive embodiment in particular combinations, each feature or element can be configured alone or in various within the principles of the present disclosure to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed.