Audio and video conversion circuit and live broadcast device

Abstract

An audio and video conversion circuit and a live broadcast device, when a first HDMI multimedia signal is connected through an HDMI conversion circuit, the first HDMI multimedia signal is converted to output an RGB video signal and a first digital audio signal; the RGB conversion circuit converts the RGB video signal to output a digital video signal; the audio synthesis circuit synthesizes the received first analog audio signal and the first digital audio signal to output a second digital audio signal; the USB conversion circuit converts the second digital audio signal and the digital video signal into a USB signal; wherein the first analog audio signal can carry externally input voice information, realizes the synthesis of the first analog audio signal and the first HDMI multimedia signal, and thus realizes the live broadcast of the commentary of the multimedia information carried by the HDMI multimedia signal.

Description

Technical Field

[0001] The present application belongs to the field of multimedia, and in particular to an audio and video conversion circuit and a live broadcast device. Background Art

[0002] At present, the traditional audio and video conversion circuit includes a High Definition Multimedia Interface (HDMI) signal conversion module and a Mobile Industry Processor Interface (MIPI) conversion module; the HDMI signal conversion module converts the HDMI multimedia signal to generate a MIPI video signal and an audio digital signal, and the MIPI conversion module converts the MIPI video signal and the audio digital signal into a Universal Serial Bus (USB) signal. Therefore, the traditional audio and video conversion circuit can only convert the HDMI multimedia signal into a USB signal, and cannot synthesize the analog audio signal and the HDMI multimedia signal, and cannot perform live commentary on the multimedia information carried by the HDMI multimedia signal.

[0003] Since the function of the traditional audio and video conversion circuit is limited to converting the HDMI multimedia signal into a USB signal, it is impossible to perform live commentary on the multimedia information carried by the HDMI multimedia signal. Summary of the invention

[0004] The purpose of the present application is to provide an audio and video conversion circuit and a live broadcast device, aiming to solve the problem that the traditional audio and video conversion circuit cannot interpret and broadcast the multimedia information carried by the HDMI multimedia signal.

[0005] An embodiment of the present application provides an audio-video conversion circuit, including:

[0006] The HDMI conversion circuit is configured to convert the first HDMI multimedia signal to output an RGB video signal and a first digital audio signal when receiving the first HDMI multimedia signal;

[0007] an RGB conversion circuit, connected to the HDMI conversion circuit, configured to convert the RGB video signal to output a digital video signal;

[0008] an audio synthesis circuit, connected to the HDMI conversion circuit, configured to synthesize the received first analog audio signal and the first digital audio signal to output a second digital audio signal;

[0009] The USB conversion circuit is connected to the RGB conversion circuit and the audio synthesis circuit, and is configured to convert the second digital audio signal and the digital video signal into a USB signal.

[0010] In one embodiment, it also includes:

[0011] The HDMI signal regeneration circuit is connected to the HDMI conversion circuit and is configured to synthesize the RGB video signal and the first digital audio signal to output a second HDMI multimedia signal.

[0012] In one embodiment, it also includes:

[0013] The audio output circuit is connected to the HDMI conversion circuit and is configured to output a target analog audio signal according to the first digital audio signal.

[0014] In one embodiment, it also includes:

[0015] The audio collection circuit is connected to the audio synthesis circuit and is used to collect external input sound to generate a first analog audio signal.

[0016] In one embodiment, the audio synthesis circuit includes:

[0017] an audio conversion component, connected to the HDMI conversion circuit, and configured to convert the first digital audio signal into a second analog audio signal;

[0018] The audio synthesis component is connected to the audio conversion component and the USB conversion circuit, and synthesizes the received first analog audio signal and the second analog audio signal to output the second digital audio signal.

[0019] In one embodiment, the audio conversion component includes an audio digital-to-analog converter, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor;

[0020] The serial audio data input terminal of the audio digital-to-analog converter is connected to the first end of the first resistor, the serial clock input terminal of the audio digital-to-analog converter is connected to the first end of the second resistor and the first end of the seventh resistor, the left and right clock input terminals of the audio digital-to-analog converter are connected to the first end of the third resistor, the main clock input terminal of the audio digital-to-analog converter is connected to the first end of the fourth resistor and the second end of the seventh resistor, the second end of the first resistor, the second end of the second resistor, the second end of the third resistor and the second end of the fourth resistor together constitute the first digital audio signal input terminal of the audio conversion component, and the static voltage of the audio digital-to-analog converter The end is connected to the first end of the third capacitor, the positive reference voltage end of the audio digital-to-analog converter is connected to the first end of the fourth capacitor, the right channel analog output end of the audio digital-to-analog converter is connected to the first end of the first capacitor, the left channel analog output end of the audio digital-to-analog converter is connected to the first end of the second capacitor, the second end of the first capacitor, the second end of the second capacitor, the first end of the fifth resistor and the first end of the sixth resistor together constitute the second analog audio signal output end of the audio conversion component, and the second end of the third capacitor, the second end of the fourth capacitor, the second end of the fifth resistor and the second end of the sixth resistor are commonly connected to the power ground.

[0021] In one embodiment, the audio synthesis component includes a stereo encoder, an eighth resistor, a ninth resistor, and a tenth resistor;

[0022] The microphone bias terminal of the stereo encoder, the right channel microphone input terminal of the stereo encoder and the left channel microphone input terminal of the stereo encoder together constitute the first analog audio signal input terminal of the audio synthesis component, the right channel line input terminal of the stereo encoder and the left channel line input terminal of the stereo encoder together constitute the second analog audio signal input terminal of the audio synthesis component, the audio interface bit clock terminal of the stereo encoder is connected to the first end of the eighth resistor, the audio interface left and right clock terminals of the stereo encoder are connected to the first end of the ninth resistor, the digital audio data output terminal of the stereo encoder is connected to the first end of the tenth resistor, and the second end of the eighth resistor, the second end of the ninth resistor and the second end of the tenth resistor together constitute the second digital audio signal output terminal of the audio synthesis component.

[0023] In one embodiment, the HDMI conversion circuit includes an HDMI receiver and 24 current limiting resistors;

[0024] The video master clock terminal of the HDMI receiver, the integrated circuit built-in audio bus (Inter-ICSound, I2 S) word selection terminal, the I 2 S clock terminal and the HDMI receiver's I 2 The S data terminal together constitutes a first digital audio signal output terminal of the HDMI conversion circuit, and the HDMI positive clock terminal of the HDMI receiver, the HDMI negative clock terminal of the HDMI receiver, the HDMI positive first channel terminal of the HDMI receiver, the HDMI negative first channel terminal of the HDMI receiver, the HDMI positive second channel terminal of the HDMI receiver, the HDMI negative second channel terminal of the HDMI receiver, the HDMI positive third channel terminal of the HDMI receiver and the HDMI negative third channel terminal of the HDMI receiver together constitute a first HDMI multimedia signal input terminal of the HDMI conversion circuit;

[0025] The HDMI receiver also includes a group of red video signal output terminals, a group of green video signal output terminals and a group of blue video signal output terminals;

[0026] Among them, a group of the red video signal output terminals, a group of the green video signal output terminals and a group of the blue video signal output terminals all include eight digital video output terminals of the HDMI receiver; each digital video output terminal of the HDMI receiver is respectively connected to the first end of each current limiting resistor in a one-to-one correspondence, and the second end of each current limiting resistor jointly constitutes the RGB video signal output terminal of the HDMI conversion circuit.

[0027] In one of the embodiments, the RGB conversion circuit includes a video processor;

[0028] The video processor comprises a group of red video signal input terminals, a group of green video signal input terminals and a group of blue video signal input terminals; the group of red video signal input terminals, the group of green video signal input terminals and the group of blue video signal input terminals together constitute the RGB video signal input terminals of the RGB conversion circuit;

[0029] Wherein, a group of the red video signal input terminals includes eight red data signal input terminals of the video processor; a group of the green video signal input terminals includes eight green data signal input terminals of the video processor; a group of the blue video signal input terminals includes eight blue data signal input terminals of the video processor;

[0030] The video processor further comprises a group of green video signal output terminals; the group of green video signal output terminals together constitute the digital video signal output terminals of the RGB conversion circuit;

[0031] One group of green video signal output terminals includes eight green digital video signal output terminals of the video processor U4.

[0032] In one embodiment, the USB conversion circuit includes a USB video converter U5;

[0033] The MIPI positive clock terminal of the USB video converter, the MIPI negative clock terminal of the USB video converter, the MIPI positive second channel data terminal of the USB video converter, the MIPI negative second channel data terminal of the USB video converter, the MIPI positive third channel data terminal of the USB video converter, the MIPI negative third channel data terminal of the USB video converter, the MIPI positive fourth channel data terminal of the USB video converter and the MIPI negative fourth channel data terminal of the USB video converter together constitute the digital video signal input terminal of the USB conversion circuit;

[0034] The USB video converter I 2 S clock terminal, the USB video converter I 2 S left and right channel selection terminals and the I 2 The S data terminals together constitute the second digital audio signal input terminal of the USB conversion circuit;

[0035] The USB2.0 positive data terminal of the USB video converter, the USB2.0 negative data terminal of the USB video converter, the USB3.0 positive receiving terminal of the USB video converter, the USB3.0 negative receiving terminal of the USB video converter, the USB3.0 positive sending terminal of the USB video converter and the USB3.0 negative sending terminal of the USB video converter together constitute the USB signal output terminal of the USB conversion circuit.

[0036] The embodiment of the present invention further provides a live broadcast device, the live broadcast device comprising:

[0037] The audio / video conversion circuit as described above; and

[0038] A power supply circuit is configured to supply power to the audio and video conversion circuit.

[0039] Compared with the prior art, the embodiments of the present invention have the following beneficial effects: when a first HDMI multimedia signal is connected through an HDMI conversion circuit, the first HDMI multimedia signal is converted to output an RGB video signal and a first digital audio signal; the RGB conversion circuit converts the RGB video signal to output a digital video signal; the audio synthesis circuit synthesizes the received first analog audio signal and the first digital audio signal to output a second digital audio signal; the USB conversion circuit converts the second digital audio signal and the digital video signal into a USB signal; wherein the first analog audio signal can carry externally input voice information, thereby realizing the synthesis of the first analog audio signal and the first HDMI multimedia signal, thereby realizing the live commentary of the multimedia information carried by the HDMI multimedia signal. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] In order to more clearly illustrate the technical invention in the embodiments of the present invention, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0041] Figure 1 A schematic diagram of the structure of an audio and video conversion circuit provided in one embodiment of the present application;

[0042] Figure 2 Another structural schematic diagram of an audio and video conversion circuit provided in an embodiment of the present application;

[0043] Figure 3 Another structural schematic diagram of an audio and video conversion circuit provided in an embodiment of the present application;

[0044] Figure 4 Another structural schematic diagram of an audio and video conversion circuit provided in an embodiment of the present application;

[0045] Figure 5 A structural schematic diagram of an audio synthesis circuit of an audio-video conversion circuit provided in an embodiment of the present application;

[0046] Figure 6 Another exemplary circuit schematic diagram of an audio and video conversion circuit provided in one embodiment of the present application. DETAILED DESCRIPTION

[0047] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0048] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0049] It should be understood that the orientation or position relationship indicated by terms such as "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0050] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0051] Figure 1 The structure diagram of the audio and video conversion circuit provided by the preferred embodiment of the present application is shown. For the convenience of explanation, only the part related to the present embodiment is shown, which is described in detail as follows:

[0052] The audio and video conversion circuit includes an HDMI conversion circuit 11 , an RGB conversion circuit 12 , an audio synthesis circuit 13 and a USB conversion circuit 14 .

[0053] The HDMI conversion circuit 11 is configured to convert the first HDMI multimedia signal to output an RGB video signal and a first digital audio signal when receiving the first HDMI multimedia signal.

[0054] The RGB conversion circuit 12 is connected to the HDMI conversion circuit 11 and is configured to convert the RGB video signal to output a digital video signal.

[0055] The audio synthesis circuit 13 is connected to the HDMI conversion circuit 11 and is configured to synthesize the received first analog audio signal and the first digital audio signal to output a second digital audio signal.

[0056] The USB conversion circuit 14 is connected to the RGB conversion circuit 12 and the audio synthesis circuit 13, and is configured to convert the second digital audio signal and the digital video signal into a USB signal.

[0057] The first analog audio signal may carry externally input voice information. The digital video signal may be a MIPI signal.

[0058] like Figure 2 As shown, the audio and video conversion circuit also includes an HDMI signal regeneration circuit 15.

[0059] The HDMI signal regeneration circuit 15 is connected to the HDMI conversion circuit 11 and is configured to synthesize the RGB video signal and the first digital audio signal to output a second HDMI multimedia signal.

[0060] The HDMI multimedia signal is regenerated by the HDMI signal regeneration circuit 15, thereby reducing the distortion rate of the multimedia signal and realizing the long-distance transmission of the HDMI multimedia signal.

[0061] like Figure 3 As shown, the audio and video conversion circuit also includes an audio output circuit 16.

[0062] The audio output circuit 16 is connected to the HDMI conversion circuit 11 and is configured to output a target analog audio signal according to the first digital audio signal.

[0063] The audio output circuit 16 outputs the target analog audio signal according to the first digital audio signal, thereby playing the sound information carried by the first HDMI multimedia signal.

[0064] like Figure 4 As shown, the audio and video conversion circuit also includes an audio acquisition circuit 17.

[0065] The audio collection circuit 17 is connected to the audio synthesis circuit 13 and is used to collect external input sound to generate a first analog audio signal.

[0066] The audio capture circuit 17 captures external input sound to generate a first analog audio signal, and through the subsequent synthesis of the first analog audio signal and the first digital audio signal and the synthesis of the second digital audio signal and the digital video signal, live commentary of the multimedia information carried by the HDMI multimedia signal is achieved.

[0067] like Figure 5 As shown, the audio synthesis circuit 13 includes an audio conversion component 131 and an audio synthesis component 132 .

[0068] The audio conversion component 131 is connected to the HDMI conversion circuit 11 and is configured to convert the first digital audio signal into a second analog audio signal.

[0069] The audio synthesis component 132 is connected to the audio conversion component 131 and the USB conversion circuit 14, and synthesizes the received first analog audio signal and the second analog audio signal to output a second digital audio signal.

[0070] The synthesis of the first digital audio signal and the second digital audio signal is achieved through the audio conversion component 131 and the audio synthesis component 132.

[0071] Figure 6 An exemplary circuit structure of an audio and video conversion circuit provided by an embodiment of the present invention is shown. For the sake of convenience, only the part related to the embodiment of the present invention is shown, which is described in detail as follows:

[0072] The audio conversion component 131 includes an audio digital-to-analog converter U1, a first capacitor C1, a second capacitor C2, a third capacitor C3, a fourth capacitor C4, a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6 and a seventh resistor R7.

[0073] The serial audio data input terminal SDIN of the audio digital-to-analog converter U1 is connected to the first end of the first resistor R1, the serial clock input terminal SCLK of the audio digital-to-analog converter U1 is connected to the first end of the second resistor R2 and the first end of the seventh resistor R7, the left and right clock input terminals LRCK of the audio digital-to-analog converter U1 are connected to the first end of the third resistor R3, the main clock input terminal MCLK of the audio digital-to-analog converter U1 is connected to the first end of the fourth resistor R4 and the second end of the seventh resistor R7, the second end of the first resistor R1, the second end of the second resistor R2, the second end of the third resistor R3 and the second end of the fourth resistor R4 together constitute the first digital audio signal input terminal of the audio conversion component 131, and the static voltage of the audio digital-to-analog converter U1 Terminal VQ is connected to the first end of the third capacitor C3, the positive reference voltage terminal FILT+ of the audio digital-to-analog converter U1 is connected to the first end of the fourth capacitor C4, the right channel analog output terminal AOUTR of the audio digital-to-analog converter U1 is connected to the first end of the first capacitor C1, the left channel analog output terminal AOUTL of the audio digital-to-analog converter U1 is connected to the first end of the second capacitor C2, the second end of the first capacitor C1, the second end of the second capacitor C2, the first end of the fifth resistor R5 and the first end of the sixth resistor R6 together constitute the second analog audio signal output terminal of the audio conversion component 131, the second end of the third capacitor C3, the second end of the fourth capacitor C4, the second end of the fifth resistor R5 and the second end of the sixth resistor R6 are commonly connected to the power ground.

[0074] The audio synthesis component 132 includes a stereo encoder U2 , an eighth resistor R8 , a ninth resistor R9 , and a tenth resistor R10 .

[0075] The microphone bias terminal MICBIAS of the stereo encoder U2, the right channel microphone input terminal RINPUT1 of the stereo encoder U2 and the left channel microphone input terminal LINPUT1 of the stereo encoder U2 together constitute the first analog audio signal input terminal of the audio synthesis component 132, the right channel line input terminal RINPUT3 of the stereo encoder U2 and the left channel line input terminal LINPUT3 of the stereo encoder U2 together constitute the second analog audio signal input terminal of the audio synthesis component 132, the audio interface bit clock terminal ADBCLK of the stereo encoder U2 is connected to the first end of the eighth resistor R8, the audio interface left and right clock terminals DACLRC of the stereo encoder U2 are connected to the first end of the ninth resistor R9, the digital audio data output terminal ADCDAT of the stereo encoder U2 is connected to the first end of the tenth resistor R10, the second end of the eighth resistor R8, the second end of the ninth resistor R9 and the second end of the tenth resistor R10 together constitute the second digital audio signal output terminal of the audio synthesis component 132.

[0076] The HDMI conversion circuit 11 includes an HDMI receiver U3 and 24 current limiting resistors.

[0077] The video master clock terminal MUTE_MCLK of the HDMI receiver U3 and the I 2 S-word selection terminal WS_SPDIF, HDMI receiver U3 I 2 S clock terminal SCK_MCLK and HDMI receiver U3's I 2 The S data terminal I2S0 together constitutes the first digital audio signal output terminal of the HDMI conversion circuit 11, and the HDMI positive clock terminal P0_RXCP of the HDMI receiver U3, the HDMI negative clock terminal P0_RXCN of the HDMI receiver U3, the HDMI positive first channel terminal P0_RX0P of the HDMI receiver U3, the HDMI negative first channel terminal P0_RX0N of the HDMI receiver U3, the HDMI positive second channel terminal P0_RX1P of the HDMI receiver U3, the HDMI negative second channel terminal P0_RX1N of the HDMI receiver U3, the HDMI positive third channel terminal P0_RX2P of the HDMI receiver U3 and the HDMI negative third channel terminal P0_RX2N of the HDMI receiver U3 together constitute the first HDMI multimedia signal input terminal of the HDMI conversion circuit 11.

[0078] The HDMI receiver U3 also includes a group of red video signal output terminals, a group of green video signal output terminals, and a group of blue video signal output terminals.

[0079] Among them, a group of red video signal output terminals, a group of green video signal output terminals and a group of blue video signal output terminals all include eight digital video output terminals of the HDMI receiver U3; each digital video output terminal of the HDMI receiver U3 is respectively connected to the first end of each current limiting resistor in a one-to-one correspondence, and the second end of each current limiting resistor jointly constitutes the RGB video signal output terminal of the HDMI conversion circuit 11.

[0080] In a specific implementation, the 24 current limiting resistors may include the eleventh resistor R11 to the thirty-fourth resistor R34. A group of blue video signal output terminals may include the first digital video output terminal QE4 to the eighth digital video output terminal QE11 of the HDMI receiver U3. A group of green video signal output terminals include the ninth digital video output terminal QE16 to the sixteenth digital video output terminal QE23 of the HDMI receiver U3. A group of red video signal output terminals may include the seventeenth digital video output terminal QE28 to the twenty-fourth digital video output terminal QE35 of the HDMI receiver U3.

[0081] The RGB conversion circuit 12 includes a video processor U4.

[0082] The video processor U4 includes a group of red video signal input terminals, a group of green video signal input terminals and a group of blue video signal input terminals; a group of red video signal input terminals, a group of green video signal input terminals and a group of blue video signal input terminals together constitute the RGB video signal input terminals of the RGB conversion circuit 12.

[0083] Among them, a group of red video signal input terminals includes eight red data signal input terminals of the video processor U4; a group of green video signal input terminals includes eight green data signal input terminals of the video processor U4; and a group of blue video signal input terminals includes eight blue data signal input terminals of the video processor U4.

[0084] The video processor U4 also includes a group of green video signal output terminals; the group of green video signal output terminals together constitute the digital video signal output terminals of the RGB conversion circuit 12.

[0085] One group of green video signal output terminals includes eight green digital video signal output terminals of the video processor U4.

[0086] In a specific implementation, a group of red video signal input terminals include the first red data signal input terminal RIN[0] of the video processor U4 to the eighth red data signal input terminal RIN[7] of the video processor U4; a group of green video signal input terminals include the first green data signal input terminal GIN[0] of the video processor U4 to the eighth green data signal input terminal GIN[7] of the video processor U4; a group of blue video signal input terminals include the first blue data signal input terminal BIN[0] of the video processor U4 to the eighth blue data signal input terminal B IN[7] of the video processor U4. A group of green video signal output terminals include the first green digital video signal output terminal GOUT[0] of the video processor U4 to the eighth green digital video signal output terminal GOUT[7] of the video processor U4.

[0087] The USB conversion circuit 14 includes a USB video converter U5.

[0088] The MIPI positive clock terminal Xcinp of the USB video converter U5, the MIPI negative clock terminal Xcinn of the USB video converter U5, the MIPI positive second channel data terminal Xd2inp of the USB video converter U5, the MIPI negative second channel data terminal Xd2inn of the USB video converter U5, the MIPI positive third channel data terminal Xd3inp of the USB video converter U5, the MIPI negative third channel data terminal Xd3inn of the USB video converter U5, the MIPI positive fourth channel data terminal Xd4inp of the USB video converter U5 and the MIPI negative fourth channel data terminal Xd4inn of the USB video converter U5 together constitute the digital video signal input terminal of the USB conversion circuit 14;

[0089] USB Video Converter U5 I 2 S clock end Xiis_adcclk, USB video converter U5 I 2 S left and right channel selection terminal Xiis_adclrc and USB video converter U5 I 2 The S data terminal Xiis_adcdat together constitutes the second digital audio signal input terminal of the USB conversion circuit 14;

[0090] The USB2.0 positive data terminal XDP of the USB video converter U5, the USB2.0 negative data terminal XDM of the USB video converter U5, the USB3.0 positive receiving terminal Xrxp of the USB video converter U5, the USB3.0 negative receiving terminal Xrxm of the USB video converter U5, the USB3.0 positive transmitting terminal Xtxp of the USB video converter U5 and the USB3.0 negative transmitting terminal Xtxm of the USB video converter U5 together constitute the USB signal output terminal of the USB conversion circuit 14.

[0091] The following is a combination of working principles Figure 6 As shown for further explanation:

[0092] The HDMI positive clock terminal P0_RXCP of the HDMI receiver U3, the HDMI negative clock terminal P0_RXCN of the HDMI receiver U3, the HDMI positive first channel terminal P0_RX0P of the HDMI receiver U3, the HDMI negative first channel terminal P0_RX0N of the HDMI receiver U3, the HDMI positive second channel terminal P0_RX1P of the HDMI receiver U3, the HDMI negative second channel terminal P0_RX1N of the HDMI receiver U3, the HDMI positive third channel terminal P0_RX2P of the HDMI receiver U3 and the HDMI negative third channel terminal P0_RX2N of the HDMI receiver U3 are connected to the first HDMI multimedia signal, and the HDMI receiver U3 converts the first HDMI multimedia signal to output an RGB video signal and a first digital audio signal; wherein, the RGB video signal is output from a group of red video signal output terminals (the seventeenth digital video output terminal QE28 to the twenty-fourth digital video output terminal QE35 of the HDMI receiver U3) of the HDMI receiver U3. , a group of green video signal output terminals of the HDMI receiver U3 (the ninth digital video output terminal QE16 to the sixteenth digital video output terminal QE23 of the HDMI receiver U3) and a group of blue video signal output terminals of the HDMI receiver U3 (the first digital video output terminal QE4 to the eighth digital video output terminal QE11 of the HDMI receiver U3) are output, and are sent to a group of red video signal input terminals of the video processor U4 (the first red data signal input terminal RIN[0] of the video processor U4 to the eighth red data signal input terminal RIN[7] of the video processor U4), a group of green video signal input terminals (the first green data signal input terminal GIN[0] of the video processor U4 to the eighth green data signal input terminal GIN[7] of the video processor U4) and a group of blue video signal input terminals (the first blue data signal input terminal BIN[0] of the video processor U4 to the eighth blue data signal input terminal BIN[7] of the video processor U4) via 24 current limiting resistors (the eleventh resistor R11 to the thirty-fourth resistor R34). The first digital audio signal is transmitted from the video main clock terminal MUTE_MCLK of the HDMI receiver U3, the I 2 S-word selection terminal WS_SPDIF, HDMI receiver U3 I 2 S clock terminal SCK_MCLK and HDMI receiver U3's I 2The S data terminal I2S0 is output to the serial audio data input terminal SDIN of the audio digital-to-analog converter U1, the serial clock input terminal SCLK of the audio digital-to-analog converter U1, the left and right clock input terminals LRCK of the audio digital-to-analog converter U1, and the master clock input terminal MCLK of the audio digital-to-analog converter U1.

[0093] The video processor U4 converts the RGB video signal to output a digital video signal; the digital video signal is output from a group of green video signal output terminals of the video processor U4 (the first green digital video signal output terminal GOUT[0] of the video processor U4 to the eighth green digital video signal output terminal GOUT[7] of the video processor U4) to the MIPI positive clock terminal Xcinp of the USB video converter U5, the MIPI negative clock terminal Xcinn of the USB video converter U5, the MIPI positive second channel data terminal Xd2inp of the USB video converter U5, the MIPI negative second channel data terminal Xd2inn of the USB video converter U5, the MIPI positive third channel data terminal Xd3inp of the USB video converter U5, the MIPI negative third channel data terminal Xd3inn of the USB video converter U5, the MIPI positive fourth channel data terminal Xd4inp of the USB video converter U5 and the MIPI negative fourth channel data terminal Xd4inn of the USB video converter U5.

[0094] The audio digital-to-analog converter U1 converts the first digital audio signal into a second analog audio signal, and outputs it from the right channel analog output terminal AOUTR of the audio digital-to-analog converter U1 and the left channel analog output terminal AOUT of the audio digital-to-analog converter U1, and is sent to the right channel line input terminal RINPUT3 of the stereo encoder U2 and the left channel line input terminal LINPUT3 of the stereo encoder U2 via a resistor-capacitor filtering network (a first capacitor C1, a second capacitor C2, a fifth resistor R5 and a sixth resistor R6).

[0095] The audio acquisition circuit 17 acquires external input sound to generate a first analog audio signal and sends it to the microphone bias terminal MICBIAS of the stereo encoder U2, the right channel microphone input terminal RINPUT1 of the stereo encoder U2, and the left channel microphone input terminal LINPUT1 of the stereo encoder U2.

[0096] The stereo encoder U2 synthesizes the received first analog audio signal and the second analog audio signal to output a second digital audio signal, wherein the second digital audio signal is output from the audio interface bit clock terminal ADBCLK of the stereo encoder U2, the audio interface left and right clock terminals DACLRC of the stereo encoder U2, and the digital audio data output terminal ADCDAT of the stereo encoder U2 to the I / O port of the USB video converter U5.2 S clock end Xiis_adcclk, USB video converter U5 I 2 S left and right channel selection terminal Xiis_adclrc and USB video converter U5 I 2 S data terminal Xiis_adcdat.

[0097] The USB video converter U5 synthesizes the received first analog audio signal and the second analog audio signal to output a second digital audio signal, wherein the second digital audio signal is output from the USB2.0 positive data terminal XDP of the USB video converter U5, the USB2.0 negative data terminal XDM of the USB video converter U5, the USB3.0 positive receiving terminal Xrxp of the USB video converter U5, the USB3.0 negative receiving terminal Xrxm of the USB video converter U5, the USB3.0 positive transmitting terminal Xtxp of the USB video converter U5, and the USB3.0 negative transmitting terminal Xtxm of the USB video converter U5.

[0098] The embodiment of the present invention further provides a live broadcast device, the live broadcast device comprising the above-mentioned audio and video conversion circuit; and

[0099] A power supply circuit is configured to supply power to the audio and video conversion circuit.

[0100] The embodiment of the present invention converts the first HDMI multimedia signal to output an RGB video signal and a first digital audio signal through an HDMI conversion circuit when a first HDMI multimedia signal is connected; the RGB conversion circuit converts the RGB video signal to output a digital video signal; the audio synthesis circuit synthesizes the received first analog audio signal and the first digital audio signal to output a second digital audio signal; the USB conversion circuit converts the second digital audio signal and the digital video signal into a USB signal; wherein the first analog audio signal can carry externally input voice information, thereby realizing the synthesis of the first analog audio signal and the first HDMI multimedia signal, thereby realizing the live commentary of the multimedia information carried by the HDMI multimedia signal.

[0101] It should be understood that the size of the serial numbers of the steps in the above embodiments does not mean the order of execution. The execution order of each process should be determined by its function and internal logic, and should not constitute any limitation on the implementation process of the embodiments of the present application.

[0102] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An audio and video conversion circuit, characterized in that: include: The HDMI conversion circuit is configured to convert the first HDMI multimedia signal to output an RGB video signal and a first digital audio signal when receiving the first HDMI multimedia signal; an RGB conversion circuit, connected to the HDMI conversion circuit, configured to convert the RGB video signal to output a digital video signal; an audio synthesis circuit, connected to the HDMI conversion circuit, configured to synthesize the received first analog audio signal and the first digital audio signal to output a second digital audio signal; The USB conversion circuit is connected to the RGB conversion circuit and the audio synthesis circuit, and is configured to convert the second digital audio signal and the digital video signal into a USB signal.

2. The audio-video conversion circuit according to claim 1, characterized in that: Also includes: The HDMI signal regeneration circuit is connected to the HDMI conversion circuit and is configured to synthesize the RGB video signal and the first digital audio signal to output a second HDMI multimedia signal.

3. The audio-video conversion circuit according to claim 1, characterized in that: Also includes: The audio output circuit is connected to the HDMI conversion circuit and is configured to output a target analog audio signal according to the first digital audio signal.

4. The audio-video conversion circuit according to claim 1, characterized in that: Also includes: The audio collection circuit is connected to the audio synthesis circuit and is used to collect external input sound to generate a first analog audio signal.

5. The audio-video conversion circuit according to claim 1, characterized in that: The audio synthesis circuit comprises: an audio conversion component, connected to the HDMI conversion circuit, and configured to convert the first digital audio signal into a second analog audio signal; The audio synthesis component is connected to the audio conversion component and the USB conversion circuit, and synthesizes the received first analog audio signal and the second analog audio signal to output the second digital audio signal.

6. The audio-video conversion circuit according to claim 5, characterized in that: The audio conversion component includes an audio digital-to-analog converter, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, and a seventh resistor; The serial audio data input terminal of the audio digital-to-analog converter is connected to the first end of the first resistor, the serial clock input terminal of the audio digital-to-analog converter is connected to the first end of the second resistor and the first end of the seventh resistor, the left and right clock input terminals of the audio digital-to-analog converter are connected to the first end of the third resistor, the main clock input terminal of the audio digital-to-analog converter is connected to the first end of the fourth resistor and the second end of the seventh resistor, the second end of the first resistor, the second end of the second resistor, the second end of the third resistor and the second end of the fourth resistor together constitute the first digital audio signal input terminal of the audio conversion component, and the static voltage of the audio digital-to-analog converter The end is connected to the first end of the third capacitor, the positive reference voltage end of the audio digital-to-analog converter is connected to the first end of the fourth capacitor, the right channel analog output end of the audio digital-to-analog converter is connected to the first end of the first capacitor, the left channel analog output end of the audio digital-to-analog converter is connected to the first end of the second capacitor, the second end of the first capacitor, the second end of the second capacitor, the first end of the fifth resistor and the first end of the sixth resistor together constitute the second analog audio signal output end of the audio conversion component, and the second end of the third capacitor, the second end of the fourth capacitor, the second end of the fifth resistor and the second end of the sixth resistor are commonly connected to the power ground.

7. The audio-video conversion circuit according to claim 5, characterized in that: The audio synthesis component includes a stereo encoder, an eighth resistor, a ninth resistor and a tenth resistor; The microphone bias terminal of the stereo encoder, the right channel microphone input terminal of the stereo encoder and the left channel microphone input terminal of the stereo encoder together constitute the first analog audio signal input terminal of the audio synthesis component, the right channel line input terminal of the stereo encoder and the left channel line input terminal of the stereo encoder together constitute the second analog audio signal input terminal of the audio synthesis component, the audio interface bit clock terminal of the stereo encoder is connected to the first end of the eighth resistor, the audio interface left and right clock terminals of the stereo encoder are connected to the first end of the ninth resistor, the digital audio data output terminal of the stereo encoder is connected to the first end of the tenth resistor, and the second end of the eighth resistor, the second end of the ninth resistor and the second end of the tenth resistor together constitute the second digital audio signal output terminal of the audio synthesis component.

8. The audio-video conversion circuit according to claim 1, characterized in that: The HDMI conversion circuit includes an HDMI receiver and 24 current limiting resistors; The video master clock terminal of the HDMI receiver, the I 2 S-word selection terminal, the I 2 S clock terminal and the HDMI receiver's I 2 The S data terminal together constitutes a first digital audio signal output terminal of the HDMI conversion circuit, and the HDMI positive clock terminal of the HDMI receiver, the HDMI negative clock terminal of the HDMI receiver, the HDMI positive first channel terminal of the HDMI receiver, the HDMI negative first channel terminal of the HDMI receiver, the HDMI positive second channel terminal of the HDMI receiver, the HDMI negative second channel terminal of the HDMI receiver, the HDMI positive third channel terminal of the HDMI receiver and the HDMI negative third channel terminal of the HDMI receiver together constitute a first HDMI multimedia signal input terminal of the HDMI conversion circuit; The HDMI receiver also includes a group of red video signal output terminals, a group of green video signal output terminals and a group of blue video signal output terminals; Among them, a group of the red video signal output terminals, a group of the green video signal output terminals and a group of the blue video signal output terminals all include eight digital video output terminals of the HDMI receiver; each digital video output terminal of the HDMI receiver is respectively connected to the first end of each current limiting resistor in a one-to-one correspondence, and the second end of each current limiting resistor jointly constitutes the RGB video signal output terminal of the HDMI conversion circuit.

9. The audio-video conversion circuit according to claim 1, characterized in that: The RGB conversion circuit includes a video processor; The video processor comprises a group of red video signal input terminals, a group of green video signal input terminals and a group of blue video signal input terminals; the group of red video signal input terminals, the group of green video signal input terminals and the group of blue video signal input terminals together constitute the RGB video signal input terminals of the RGB conversion circuit; Wherein, a group of the red video signal input terminals includes eight red data signal input terminals of the video processor; a group of the green video signal input terminals includes eight green data signal input terminals of the video processor; a group of the blue video signal input terminals includes eight blue data signal input terminals of the video processor; The video processor further comprises a group of green video signal output terminals; the group of green video signal output terminals together constitute the digital video signal output terminals of the RGB conversion circuit; One group of green video signal output terminals includes eight green digital video signal output terminals of the video processor.

10. The audio-video conversion circuit according to claim 1, characterized in that: The USB conversion circuit includes a USB video converter U5; The MIPI positive clock terminal of the USB video converter, the MIPI negative clock terminal of the USB video converter, the MIPI positive second channel data terminal of the USB video converter, the MIPI negative second channel data terminal of the USB video converter, the MIPI positive third channel data terminal of the USB video converter, the MIPI negative third channel data terminal of the USB video converter, the MIPI positive fourth channel data terminal of the USB video converter and the MIPI negative fourth channel data terminal of the USB video converter together constitute the digital video signal input terminal of the USB conversion circuit; The USB video converter I 2 S clock terminal, the USB video converter I 2 S left and right channel selection terminals and the I 2 The S data terminals together constitute the second digital audio signal input terminal of the USB conversion circuit; The USB2.0 positive data terminal of the USB video converter, the USB2.0 negative data terminal of the USB video converter, the USB3.0 positive receiving terminal of the USB video converter, the USB3.0 negative receiving terminal of the USB video converter, the USB3.0 positive sending terminal of the USB video converter and the USB3.0 negative sending terminal of the USB video converter together constitute the USB signal output terminal of the USB conversion circuit.

11. A live broadcast device, characterized in that: The live broadcast device comprises: The audio-video conversion circuit according to any one of claims 1 to 10; and A power supply circuit is configured to supply power to the audio and video conversion circuit.

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