WO2015089733A1

WO2015089733A1 - Method for playing audio file in multimedia terminal and multimedia terminal

Info

Publication number: WO2015089733A1
Application number: PCT/CN2013/089678
Authority: WO
Inventors: 易见; 鲁波
Original assignee: 华为终端有限公司
Priority date: 2013-12-17
Filing date: 2013-12-17
Publication date: 2015-06-25

Abstract

Disclosed is an audio file playing method, comprising: pre-decoding at least one frame of an audio file; judging whether left sound-channel signals and right sound-channel signals of all the frames of the audio file are in reverse directions according to a left sound-channel signal and a right sound-channel signal of the at least one frame which is obtained after pre-decoding; if the left sound-channel signals and the right sound-channel signals of all the frames of the audio file are in reverse directions, decoding all the frames of the audio file, and adjusting the left sound-channel signals and the right sound-channel signals of all the frames of the audio file to be in the same direction; and superposing the left sound-channel signals and the right sound-channel signals of all the frames of the audio file that are adjusted to be in the same direction and playing same. Accordingly, also provided is a multimedia terminal. By means of the present invention, an audio file with left and right sound-channel signals being in reverse directions can be un-distortedly played on a multimedia terminal with a single-sound-channel output mechanism, thereby improving user experience.

Description

Method for playing audio file in multimedia terminal and multimedia terminal

The present invention relates to the field of audio and video technologies, and in particular, to a method for playing an audio file in a multimedia terminal and a multimedia terminal. Background technique

With the continuous development of electronic technology, a variety of multimedia terminals have emerged, among which smart terminals capable of playing audio files in formats such as MP3, WAV, WMA and the like are most popular. The channel coding mode of the above format audio file is divided into mono coding and two-channel coding, and most of the audio output devices on the intelligent terminal adopt a mono output mechanism, so it is necessary to play the two-channel audio file. Mixing technology processing.

At present, when a smart terminal based on the Android platform uses a mono output mechanism to play a two-channel audio file, the usual mixing method is to superimpose the two-channel data to achieve the effect of retaining the two-channel information. However, for some special two-channel audio files, such as the left and right channel signals are reversed, the single-stack overlay will distort the signal, resulting in abnormal playback results. Summary of the invention

The embodiment of the invention provides a method for playing an audio file in a multimedia terminal and a multimedia terminal, which can realize the audio file with the left and right channel signals reversed without distortion in the multimedia terminal of the mono output mechanism, and is enhanced. user experience.

A first aspect of the embodiments of the present invention provides a method for playing an audio file, including: decoding, by a multimedia terminal, at least one frame of an audio file, and acquiring a left channel signal and a right channel signal of at least one frame of the audio file. ;

The multimedia terminal superimposes the left channel signal and the right channel signal of at least one frame of the audio file and acquires the superimposed superimposed signal;

The multimedia terminal determines whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, determining a left channel signal and a right channel signal of all frames of the audio file Reverse

If the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal is Decoding all the frames of the audio file, and adjusting the left channel signal and the right channel signal of all frames of the audio file obtained after decoding to the same direction;

The multimedia terminal superimposes and plays the left channel signal and the right channel signal of all frames of the audio file adjusted in the same direction.

In a first possible implementation manner of the first aspect, the multimedia terminal determines whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, determining the The reverse of the left channel signal and the right channel signal of all frames of the audio file includes:

The multimedia terminal determines whether the amplitude of the superimposed signal is zero. If the amplitude of the superimposed signal is zero, it is determined that the left channel signal of all frames of the audio file is opposite to the right channel signal.

With reference to the first aspect, and the first possible implementation manner of the first aspect, in a second possible implementation, the multimedia terminal decodes at least one frame of the audio file, and obtains at least one frame of the audio file The channel signal and the right channel signal also include:

The multimedia terminal acquires a play instruction for the audio file;

Determining, by the multimedia terminal, whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, determining a left channel signal and a right sound of all frames of the audio file After the channel signal is reversed, it also includes:

If it is determined that the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal sets a reverse identifier for the play instruction;

If the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal decodes all frames of the audio file, and decodes all frames of the audio file obtained after decoding. The adjustment of the left channel signal and the right channel signal to the same direction includes:

The multimedia terminal detects whether the reverse identifier is set for the play instruction; if the reverse identifier is detected, the multimedia terminal decodes all frames of the audio file, and the decoded audio is obtained. The left channel signal and the right channel signal of all frames of the file are adjusted in the same direction.

With reference to the second possible implementation manner of the first aspect, in a third possible implementation manner, if the reverse identifier is detected, the multimedia terminal decodes all frames of the audio file, and after decoding After the left channel signal and the right channel signal of all the frames of the obtained audio file are adjusted to be in the same direction, the method further includes: The multimedia terminal clears the reverse identity.

In combination with the first aspect and the first or second or third possible implementation manner of the first aspect, in a fourth possible implementation manner, the multimedia terminal is adjusted to the left of all frames of the audio file in the same direction The superposition and playback of the channel signal and the right channel signal include:

The multimedia terminal adjusts the left channel signal and the right channel signal of all the frames of the audio file in the same direction to reduce the amplitude by a preset ratio, and then superimposes and plays.

In conjunction with the fourth possible implementation of the first aspect, in a fifth possible implementation, the multimedia terminal adjusts the left channel signal and the right channel signal of all frames of the audio file that are adjusted in the same direction. After the scale is reduced, the overlay and play are specifically included:

The multimedia terminal adjusts the left channel signal and the right channel signal of all the frames of the audio file in the same direction to reduce the amplitude by 50%, and superimposes and plays.

In a sixth possible implementation manner of the first aspect, the adjusting the left channel signal and the right channel signal of all frames of the audio file obtained after decoding into the same direction includes:

Keeping the left channel signal of all frames of the audio file unchanged, inverting the right channel signal of all frames of the audio file; or

The right channel signal of all frames of the audio file is kept unchanged, and the left channel signal of all frames of the audio file is inverted.

With reference to the first aspect, and the first, second, or third possible implementation manner of the first aspect, in a seventh possible implementation, the at least one frame of the audio file includes:

The first frame of the audio file or the discrete at least two frames.

A second aspect of the embodiments of the present invention provides a multimedia terminal, including:

An audio decoding module, configured to decode at least one frame of the audio file, and acquire a left channel signal and a right channel signal of at least one frame of the audio file;

a signal superimposing module, configured to superimpose a left channel signal of at least one frame of the audio file and a right channel signal, and obtain a superimposed superimposed signal;

a signal judging module, configured to determine whether a magnitude of the superimposed signal is within a preset range, and if a magnitude of the superimposed signal is within a preset range, determining a left channel signal of all frames of the audio file The right channel signal is reversed;

a signal adjustment module for the left channel signal and the right channel signal of all frames of the audio file In the reverse direction, all the frames of the audio file are decoded, and the left channel signal and the right channel signal of all frames of the audio file obtained after decoding are adjusted to be in the same direction;

And an audio playing module, configured to superimpose and play the left channel signal and the right channel signal of all frames of the audio file adjusted to be in the same direction.

In a first possible implementation manner of the second aspect, the signal determining module is configured to determine whether the amplitude of the superimposed signal is zero, and if the amplitude of the superimposed signal is zero, determine the audio file. The left channel signal of all frames is inverted with the right channel signal.

With reference to the second aspect, and the first possible implementation manner of the second aspect, in the second possible implementation, the multimedia terminal further includes:

a play instruction acquisition module, configured to acquire a play instruction for the audio file to trigger the audio decoding module;

a reverse identifier setting module, configured to: if it is determined that the left channel signal of the entire frame of the audio file is opposite to the right channel signal, set a reverse identifier for the play instruction;

The signal adjustment module includes:

a reverse identifier detecting unit, configured to detect whether the reverse identifier is set for the play instruction before decoding the audio file;

a signal adjustment unit, configured to decode all frames of the audio file if the reverse identifier is detected, and decode the left channel signal and the right channel signal of all frames of the audio file obtained after decoding Adjust to the same direction.

With reference to the second possible implementation of the second aspect, in a third possible implementation, the multimedia terminal further includes:

And a reverse identifier clearing module, configured to clear the reverse identifier after the audio playing module plays the new audio signal.

With reference to the second aspect and the first or second or third possible implementation manner of the second aspect, in a fourth possible implementation, the audio playing module is configured to adjust all of the audio files in the same direction The left channel signal and the right channel signal of the frame are scaled down by a preset ratio, and then superimposed and played.

In conjunction with the fourth possible implementation of the second aspect, in a fifth possible implementation, the audio playback module is configured to adjust a left channel signal and a right channel of all frames of the audio file that are adjusted to be in the same direction The signal is scaled down by 50% and then superimposed and played. In a sixth possible implementation of the second aspect,

The signal adjustment module is used to:

If the left channel signal of all frames of the audio file is opposite to the right channel signal, decoding all frames of the audio file, and keeping the left channel signal of all frames of the audio file unchanged, The right channel signal of all frames of the audio file is inverted; or

If the left channel signal of all frames of the audio file is inverted with the right channel signal, decoding all frames of the audio file, and keeping the right channel signal of all frames of the audio file unchanged, The left channel signal of all frames of the audio file is inverted.

With reference to the second aspect, and the first, second, or third possible implementation manner of the second aspect, in a seventh possible implementation, the at least one frame of the audio file includes:

The first frame of the audio file or the discrete at least two frames.

A third aspect of the embodiments of the present invention provides a multimedia terminal, where the multimedia terminal includes an audio output device, a memory, and a processor, wherein the memory stores a set of player programs, and the processor is configured to call a player program stored in the memory, Used to do the following:

The multimedia terminal decodes at least one frame of the audio file, and acquires a left channel signal and a right channel signal of at least one frame of the audio file;

If the left channel signal of all the frames of the audio file is opposite to the right channel signal, the multimedia terminal decodes all the frames of the audio file, and the left frame of all the frames of the audio file obtained after decoding The channel signal and the right channel signal are adjusted to be in the same direction;

As can be seen from the above, the embodiment of the present invention analyzes the pre-decoded left and right channel signals by pre-decoding a partial frame of the audio file, thereby identifying whether the left and right channel signals of the audio file are reversed, and to the left, The audio file in the reverse direction of the right channel is processed, that is, the left and right channel signals are adjusted to be in the same direction and superimposed. The audio file is played without distortion on the audio output device of the mono output mechanism, thereby improving the user experience. DRAWINGS

In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the embodiments will be briefly described below. Obviously, the drawings in the following description are only some embodiments of the present invention, Those skilled in the art can also obtain other drawings based on these drawings without paying any creative work.

1 is a schematic flowchart of a method for playing an audio file in a multimedia terminal according to an embodiment of the present invention;

2 is a schematic flowchart of another method for playing an audio file in a multimedia terminal according to an embodiment of the present invention;

3 is a schematic flowchart of another method for playing an audio file in a multimedia terminal according to an embodiment of the present invention;

4 is a schematic structural diagram of a multimedia terminal according to an embodiment of the present invention; FIG. 5 is a schematic structural diagram of a signal adjustment module according to an embodiment of the present invention;

6 is a schematic structural diagram of another multimedia terminal according to an embodiment of the present invention;

FIG. 7 is a signal diagram of a PCM decoded audio signal according to an embodiment of the present invention; FIG. 8 is a signal diagram of a partial audio signal PCM decoded according to an embodiment of the present invention; Another partial audio signal PCM decoded signal diagram; FIG. 10 is a superimposed signal diagram provided by an embodiment of the present invention. detailed description

BRIEF DESCRIPTION OF THE DRAWINGS The technical solutions in the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without creative work are within the scope of the present invention.

The audio file proposed in the embodiment of the present invention may include audio files in a common format such as MP3, WAV, WMA, and the like, and may also include audio sub-texts in multimedia files such as videos and movies. Piece or data.

The embodiments of the present invention are mainly implemented on a multimedia terminal using Android as an operating platform, but are not limited to the Android platform. The equivalent implementation process on other operating platforms is still within the scope of the present invention.

FIG. 1 is a schematic flow chart of a method for playing an audio file in a multimedia terminal according to an embodiment of the present invention. The flow of the method for playing an audio file in this embodiment as shown in the figure may include:

5101. The multimedia terminal decodes at least one frame of the audio file, and acquires a left channel signal and a right channel signal of at least one frame of the audio file.

In the embodiment of the present invention, the audio file is mainly for a two-channel audio file, and each audio file may be split into a plurality of consecutive frames according to a certain unit. In addition, the audio file needs to be decoded before being played, in the present invention. In an embodiment, the above decoding may be PCM (Pulse Code Modulation) decoding.

Specifically, before the PCM decoding of the audio file of the audio file, the multimedia terminal first decodes at least one frame of the audio file to obtain the left channel signal and the right channel signal after the frame decoding. It should be noted that at least one frame of the audio file may be one or more frames randomly selected in the entire audio file, for example, a signal diagram of the PCM decoded audio signal shown in FIG. 7, the above decoded object If it is a frame, it can be the first A frame, or the middle G frame, or the last 0 frame. If the above decoded object is a multi-frame, it can be the first frame of A, B, and C. It can also be the middle 0, H, I three frames, or it can be discrete eight, E, H three frames. In addition, in order to avoid decoding to a full "zero amplitude" frame such as an L frame, or M, N three frames, at least one of the above frames is preferably a discrete multiframe, thereby reducing misjudgment of audio files in subsequent processes. Improve the accuracy of playing audio files.

5102. The multimedia terminal superimposes the left channel signal and the right channel signal of at least one frame of the audio file and acquires the superimposed superimposed signal.

The superposition is to sum the two values. Specifically, the multimedia terminal sums the left channel signal and the right channel signal of at least one frame of the audio file, and the summed value is a superimposed signal, and the multimedia terminal acquires the superimposed signal.

5103, the multimedia terminal determines whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, determining a left channel signal and a right sound of all frames of the audio file The channel signal is reversed. There are two main types of two-channel coding technology. One is that two channels are the same direction signals, the other is that the two channels are reverse signals, and the above-mentioned same direction signals are the same signals, for example, two positive signals. Or two negative signals, the reverse signal is a signal with the opposite sign, for example, two positive and negative signals. Specifically, the multimedia terminal determines whether the left channel signal and the right channel signal of all frames of the audio file are reversed according to whether the amplitude of the superimposed signal is within a preset range.

Further, the foregoing determining method may specifically be:

It is judged whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, it is determined that the left channel signal of the audio file is opposite to the right channel signal.

For example, as shown in FIG. 8, a partial audio signal is decoded by a PCM signal. When the left and right channels of the audio signal are reversed, the left channel signals A1, Bl, and CI are respectively associated with the right channel signals A2 and B2. After superimposing C2, the superimposed signals Al+A2, Bl+B2, C1+C2 are obtained. Since IA1I « IA2I, IB1I « IB2I, IC1 « IC2I, then Al+A2 « 0, Bl+B2 « 0, Cl+C2 « 0 . In this case, just set a preset range around "0", such as ± 3, when the superimposed signal satisfies (Al+A2) c [-3,3], (B1+B2) 匚[-3,3], (C1+C2) [ [-3,3], it can be determined that the left and right channel signals of the audio file are reversed.

For another example, as shown in FIG. 9, another partial audio signal is decoded by the PCM signal. When the left and right channels of the audio signal are in the same direction, the left channel signals A1, Bl, and CI are respectively associated with the right channel signal A2. After superimposing B2 and C2, the superimposed signals Al+A2, Bl+B2, and C1+C2 are obtained. If a preset range near "0" is still set, such as ±3, then obviously the superimposed signal is not in this range, that is ( Al+A2) c^ [-3,3] , (B1+B2) (^ [-3,3] , (Cl+C2) c [-3,3] , which in turn determines the left channel of the audio file It is in the same direction as the right channel signal.

Further, since the left and right channel signals generally satisfy IA1I=IA2I, IB1HB2I, IC1HC2I, that is, Al+A2=0, Bl+B2=0, Cl+C2=0. Therefore, the foregoing preset method may directly: determine whether the amplitude of the superimposed signal is zero, and if the amplitude of the superimposed signal is zero, determine that the left channel signal of all frames of the audio file is opposite to the right channel signal. This implementation has the advantages of being simple, practical and highly accurate.

S104. If the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal decodes all frames of the audio file, and decodes all frames of the audio file obtained after decoding. The left channel signal and the right channel signal are adjusted in the same direction.

Specifically, when the multimedia terminal learns that the left channel signal of all frames of the audio file is opposite to the right channel signal, all the frames of the audio file can be decoded and the decoded left and right channel signals are adjusted. The whole signal is in the same direction.

Optionally, the specific adjustment method may be: keeping the left channel signal of all frames of the audio file unchanged, inverting the right channel signal of all frames of the audio file, or maintaining the right channel signal of all frames of the audio file. The same, the left channel signal of all frames of the audio file is inverted. This implementation has the advantages of a single, practical.

S105. The multimedia terminal superimposes and plays the left channel signal and the right channel signal of all frames of the audio file that are adjusted to be in the same direction.

Specifically, in order to simultaneously retain the information of the left channel signal and the right channel signal, the multimedia terminal superimposes the left channel signal and the right channel signal of all the frames of the same audio file to obtain a new signal. The new signal is played simultaneously on the left and right channels of the audio output device. For example, the left channel audio or headphones, right channel audio, or headphones simultaneously output the same music.

It should be pointed out that, as shown in FIG. 10, a superimposed signal diagram, signals obtained by superimposing mono signals of the left and right channels (ie, signals superimposed by two channels in the figure) may appear. In the case of too large a value, the larger the amplitude, the louder the volume, and the excessive volume will reduce the user experience. In addition, if the amplitude of the signal exceeds the channel signal threshold, the signal will be cut off and distortion will occur. The above-mentioned channel signal threshold value refers to the maximum value allowed by the channel signal, for example: The general channel signal is a 16-bit binary code, wherein, after the symbol code is removed, the value ranges from -65535 to +65535, when double-voiced When the code value of the track superimposed signal is greater than +655535 or less than -65535, the signal will be truncated.

Further, in order to avoid the above situation, the multimedia terminal superimposes the left channel signal and the right channel signal of all the frames of the same audio file to be reduced by a preset ratio.

Further optionally, the preset ratio may be 50%. According to the mathematical derivation of the cartridge, the 50% preset ratio not only avoids signal truncation, but also does not significantly change the final volume.

In the embodiment of the present invention, the pre-decoded left and right channel signals are analyzed by pre-decoding a partial frame of the audio file, thereby identifying whether the left and right channel signals of the audio file are reversed, and the left and right channel signals are The reverse audio file is processed, that is, the left and right channel signals are adjusted to be in the same direction and superimposed, and finally the audio file is played without distortion on the audio output device of the mono output mechanism according to the processed signal, thereby improving user experience. 2 is a flow diagram of another method for playing an audio file in a multimedia terminal in an embodiment of the present invention; Schematic diagram. The flow of the method for playing an audio file in this embodiment as shown in the figure may include:

S201. The multimedia terminal acquires a play instruction for the audio file.

Specifically, before the multimedia terminal responds to the operation of the multimedia file, the multimedia terminal acquires a play instruction for the audio file, and performs the following steps S202 to S210 under the play command.

S202. The multimedia terminal decodes at least one frame of the audio file, and acquires a left channel signal and a right channel signal of at least one frame of the audio file.

In the embodiment of the present invention, the audio file is mainly for a two-channel audio file, and each audio file may be split into a plurality of consecutive frames according to a certain unit. In addition, the audio file needs to be decoded before being played, in the present invention. In an embodiment, the above decoding may be PCM decoding.

S203. The multimedia terminal superimposes the left channel signal and the right channel signal of at least one frame of the audio file, and acquires the superimposed superimposed signal.

S204. The multimedia terminal determines whether the amplitude of the superposed signal is within a preset range.

For example, as shown in FIG. 8, a partial audio signal is decoded by a PCM signal. When the left and right channels of the audio signal are reversed, the left channel signals A1, Bl, and CI are respectively associated with the right channel signals A2 and B2. After superimposing C2, the superimposed signals Al+A2, Bl+B2, C1+C2 are obtained. Since IA1I « IA2I, IB1I « IB2I, IC1 « IC2I, then Al+A2 « 0, Bl+B2 « 0, Cl+C2 « 0 . At this point, just set one at "0" The nearby preset range, such as ± 3, when the superimposed signal satisfies (Al+A2) c [-3,3], (B1+B2) 匚[-3,3], (C1+C2) d [-3, 3], it can be determined that the left channel and the right channel signal of the audio file are reversed.

5205. If the amplitude of the superimposed signal is within a preset range, the multimedia terminal determines that the left channel signal of all frames of the audio file is opposite to the right channel signal.

There are two main types of two-channel coding technology. One is that two channels are the same direction signals, the other is that the two channels are reverse signals, and the above-mentioned same direction signals are the same signals, for example, two positive signals. Or two negative signals, the reverse signal is a signal with the opposite sign, for example, two positive and negative signals. Specifically, if the multimedia terminal determines that the amplitude of the superimposed signal is within a preset range, and determines that the left channel signal of the entire frame of the audio file is opposite to the right channel signal, perform the following steps, and vice versa. .

5206. If it is determined that the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal sets a reverse identifier for the play instruction.

Specifically, when the multimedia terminal determines that the left channel signal of all frames of the audio file is opposite to the right channel signal, the reverse identifier is set for later query. For example, when the multimedia terminal is idle, it is determined in advance whether the left and right channel signals of an audio file in the local media library are reversed, and if the reverse direction is set, the reverse identifier is set to immediately know the channel status when the audio file is executed. .

In an optional implementation, the play command is associated with a corresponding parameter variable, and the multimedia terminal can set the value of the parameter variable. In the embodiment of the present invention, if the value of the parameter variable is set to 1, it can be expressed for playing. The instruction setting has a reverse identifier. If it is set to 0, it can indicate that the reverse identifier is not set.

S207. The multimedia terminal detects whether the reverse identifier is set for the play instruction. Specifically, before decoding all the frames of the audio file, the multimedia terminal detects whether a reverse identifier is set for the play instruction.

In an optional implementation manner, the multimedia terminal detects whether the value of the parameter variable in the play command is 1, such as If it is 1, the reverse flag is set for the playback command. If it is 0, it is not.

5208. If the reverse identifier is detected, the multimedia terminal decodes all the frames of the audio file, and adjusts the left channel signal and the right channel signal of all frames of the audio file obtained after decoding to In the same direction.

Specifically, after the multimedia terminal knows that the left channel signal of the audio file is reversed from the right channel signal, the multimedia terminal decodes all the frames of the audio file and adjusts the decoded left and right channel signals to the same direction. signal of.

5209. The multimedia terminal superimposes and plays the left channel signal and the right channel signal of all the frames of the audio file that are adjusted to be in the same direction by a preset ratio.

Specifically, in order to simultaneously retain the information of the left channel signal and the right channel signal, the multimedia terminal adjusts the left channel signal and the right channel signal of all frames of the same audio file to be reduced by a preset ratio and then superimposed. , get a new signal, and play the new signal simultaneously on the left and right channels of the audio output device. For example, the left channel audio or headphones, right channel audio, or headphones simultaneously output the same music.

It should be noted that the reason why the multimedia terminal reduces the left channel signal and the right channel signal of the audio file by a preset ratio and then superimposes is as follows: a superimposed signal diagram as shown in FIG. 10, left and right The signal obtained by superimposing the mono signal of the channel (that is, the signal superimposed by two channels in the picture) may have an excessive amplitude. The larger the amplitude, the louder the volume, and the excessive volume will reduce the user experience. . In addition, if the amplitude of the signal exceeds the channel signal threshold, the signal will be cut off and distortion will occur. The above-mentioned channel signal threshold value refers to the maximum value allowed by the channel signal, for example: The general channel signal is a 16-bit binary code, wherein, after the symbol code is removed, the value ranges from -65535 to +65535, when double-voiced When the code value of the track superimposed signal is greater than +655535 or less than -65535, the signal will be truncated.

5210. The multimedia terminal clears the reverse identifier.

Specifically, the multimedia terminal clears the reverse identifier set by the play instruction, so as to avoid causing mishandling to other subsequent audio files. The embodiment of the present invention sets a play instruction for the audio file, and under the play command, the multimedia terminal analyzes the pre-decoded left and right channel signals, and recognizes the audio files with the left and right channel signals reversed, and plays in the play Set the reverse flag in the command. Before decoding the audio file, the multimedia terminal first detects whether there is a reverse identifier under the play command, and if so, processes the audio file with the left and right channel signals reversed, that is, adjusts the left and right channel signals to In the same direction and superimposed, finally, according to the processed signal, the audio file reversed by the left and right channel signals is played without distortion on the audio output device of the mono output mechanism, thereby improving the user experience. FIG. 3 is a schematic flow chart of another method for playing an audio file in a multimedia terminal according to an embodiment of the present invention. The flow of the method for playing an audio file in this embodiment as shown in the figure may include:

5301. The multimedia terminal acquires a play instruction for the audio file.

Specifically, before the multimedia terminal responds to the operation of the multimedia file, the multimedia terminal acquires a play instruction for the audio file, and performs the following steps S302 to S310 under the play command.

5302. The multimedia terminal decodes a first frame of the audio file, and acquires a left channel signal and a right channel signal of the first frame of the audio file.

In the embodiment of the present invention, the audio file is mainly for a two-channel audio file, and each audio file may be divided into several consecutive frames according to a certain unit. In addition, the audio file needs to be PCM decoded before being played. In an embodiment of the invention, the above decoding may be PCM decoding.

Specifically, before the PCM decoding of an audio file, the multimedia terminal first decodes a frame of the audio file to obtain a left channel signal and a right channel signal of the frame.

It should be noted that the first frame of the above audio file can refer to an A-frame starting from the audio signal PCM decoded signal pattern as shown in FIG.

5303. The multimedia terminal superimposes the left channel signal and the right channel signal of the first frame of the audio file and acquires the superimposed superimposed signal.

The superposition is to sum the two values. Specifically, the multimedia terminal sums the left channel signal and the right channel signal of the first frame of the audio file, and the summed value is a superimposed signal, and the multimedia terminal acquires the superimposed signal.

5304. The multimedia terminal determines whether the amplitude of the superposed signal is within a preset range.

For example, a partial audio signal PCM decoded signal diagram, audio signal as shown in FIG. When the left and right channels are reversed, the left channel signal A1 is superimposed with the right channel signal A2 to obtain a superimposed signal A1+A2. Since IA1I « IA2I, Al+A2 « 0. In this case, just set a preset range near "0", such as ± 3, and when the superimposed signal satisfies (Al+A2) c [-3,3], the left and right sounds of the audio file can be determined. The channel signal is reversed.

For another example, as shown in FIG. 9, another partial audio signal is decoded by the PCM signal. When the left and right channels of the audio signal are in the same direction, the left channel signal A1 is superimposed with the right channel signal A2 to be superimposed. Signal A1+A2, if a preset range around "0", such as ±3, is still set, then obviously the superimposed signal is not in this range, ie (Al+A2) [-3,3], and the audio can be determined The left channel of the file is in the same direction as the right channel signal.

S305. If the amplitude of the superimposed signal is within a preset range, the multimedia terminal determines that the left channel signal of all frames of the audio file is opposite to the right channel signal.

There are two main types of two-channel encoding technology, one is that the two channels are the same direction signals, the other is that the two channels are the reverse signals, and the above-mentioned same direction signals are the same signals, for example, two positive signals. Or two negative signals, the reverse signal is a signal with the opposite sign, for example, two positive and negative signals. Specifically, if the multimedia terminal knows that the amplitude of the superimposed signal is equal to 0, it can be determined that the left channel signal of all frames of the audio file is opposite to the right channel signal, and the following steps are performed, and vice versa.

5306. If it is determined that the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal sets a reverse identifier for the play instruction.

Specifically, when the multimedia terminal determines that the left channel signal of the audio file is opposite to the right channel signal, the reverse identifier is set for later query. For example, when the multimedia terminal is idle, it is determined in advance whether the left and right channel signals of an audio file in the local media library are reversed, and if the reverse direction is set, the reverse identifier is set to immediately know the channel status when the audio file is executed. .

5307. The multimedia terminal detects whether the reverse identifier is set for the play instruction. Specifically, before the multimedia file is formally decoded, the multimedia terminal detects whether a reverse identifier is set for the play instruction. In an optional implementation manner, the multimedia terminal detects whether the value of the parameter variable in the play command is 1, and if it is 1, the reverse flag is set for the play command, and if it is 0, it does not.

5308. If the reverse identifier is detected, the multimedia terminal decodes all frames of the audio file, and keeps the left channel signal of all frames of the audio file unchanged, and all frames of the audio file are Right channel signal.

Specifically, after the multimedia terminal knows that the left channel signal of the audio file is reversed from the right channel signal by the reverse identifier, all the frames of the audio file are decoded and the left channel signal obtained by the decoding is kept unchanged, and the audio file is changed. The right channel signal of all frames is inverted.

5309. The multimedia terminal superimposes and plays the left channel signal and the right channel signal of all the frames of the audio file that are adjusted to be in the same direction by 50%.

Specifically, in order to simultaneously retain the information of the left channel signal and the right channel signal, the multimedia terminal adjusts the left channel signal and the right channel signal of all the frames of the same audio file to be reduced by 50%, and then superimposed. , get a new signal, and play the new signal simultaneously on the left and right channels of the audio output device. For example, the left channel audio or headphones, right channel audio, or headphones simultaneously output the same music.

It should be noted that the reason why the multimedia terminal reduces the left channel signal and the right channel signal of the audio file by 50% and then superimposes is as follows: a superimposed signal diagram as shown in FIG. 10, left and right The signal obtained by superimposing the mono signal of the channel (that is, the signal superimposed by two channels in the picture) may have an excessive amplitude. The larger the amplitude, the louder the volume, and the excessive volume will reduce the user experience. . In addition, if the amplitude of the signal exceeds the channel signal threshold, the signal will be cut off and distortion will occur. The above-mentioned channel signal threshold value refers to the maximum value allowed by the channel signal, for example: The general channel signal is a 16-bit binary code, wherein, after the symbol code is removed, the value ranges from -65535 to +65535, when double-voiced When the code value of the track superimposed signal is greater than +655535 or less than -65535, the signal will be truncated. According to the mathematical derivation of the cartridge, the 50% preset ratio not only avoids signal truncation, but also does not significantly change the final volume.

5310. The multimedia terminal clears the reverse identifier.

Specifically, the multimedia terminal clears the reverse identifier set for the playback instruction, so as to avoid erroneous processing on subsequent audio files.

The embodiment of the invention sets a play instruction for the audio file, and under the play instruction, the multimedia The terminal analyzes the pre-decoded left and right channel signals, recognizes the audio files whose left and right channel signals are reversed, and sets a reverse identifier in the play command. Before decoding the audio file, the multimedia terminal first detects whether there is a reverse identifier under the play command, and if so, keeps the left channel signal of the audio file unchanged, and inverts the right channel signal to implement left and right sounds. The signals are in the same direction, and the backward signals are scaled down by 50%, and finally the left and right channel signals are reversed without distortion on the audio output device of the mono output mechanism according to the processed signals. Audio files to enhance the user experience. FIG. 4 is a schematic structural diagram of a multimedia terminal according to an embodiment of the present invention. The multimedia terminal of the invention comprises smart terminals such as smart phones, PAD, MP3 and MP4. The multimedia terminal in the embodiment of the present invention may include at least an audio decoding module 410, a signal superimposing module 420, a signal judging module 430, a signal adjusting module 440, and an audio playing module 450, where:

The audio decoding module 410 is configured to decode at least one frame of the audio file, and obtain a left channel signal and a right channel signal of at least one frame of the audio file.

Specifically, the audio decoding module 410 decodes at least one frame of the audio file before performing PCM decoding on the audio file to obtain the left channel signal and the right channel signal after the frame decoding. It should be noted that at least one frame of the audio file may be one or more frames randomly selected in the entire audio file, for example, a signal diagram of the PCM decoded audio signal shown in FIG. 7, the above decoded object If it is a frame, it may be the initial A frame, or the middle G frame, or the last 0 frame. If the above decoded object is a multi-frame, it may be the start A, B, C. The frame may also be the intermediate 0, H, and I frames, or may be discrete eight, E, and H frames. Also, to avoid decoding to a similar L frame, or! For all "zero amplitude" frames such as ^, M, and N frames, at least one of the above frames is preferably a discrete multiframe, thereby reducing misjudgment of audio files in subsequent processes and improving the accuracy of playing audio files.

The signal superimposing module 420 is configured to superimpose the left channel signal and the right channel signal of at least one frame of the audio file and obtain the superimposed superimposed signal.

The superposition is to sum the two values. Specifically, the signal overlay module 420 will The left channel signal and the right channel signal of one frame are summed, and the summed value is a superimposed signal, and the multimedia terminal acquires the superimposed signal.

The signal determining module 430 is configured to determine whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, determine a left channel signal of all frames of the audio file. Reversed to the right channel signal.

There are two main types of two-channel coding technology. One is that two channels are the same direction signals, the other is that the two channels are reverse signals, and the above-mentioned same direction signals are the same signals, for example, two positive signals. Or two negative signals, the reverse signal is a signal with the opposite sign, for example, two positive and negative signals. Specifically, the signal determining module 430 determines whether the left channel signal and the right channel signal of all the frames of the audio file are reversed according to whether the amplitude of the superimposed signal is within a preset range.

Further, the foregoing determining method may specifically be:

Further, since the left and right channel signals generally satisfy IA1I=IA2I, IB1HB2I, IC1HC2I, that is, Al+A2=0, Bl+B2=0, Cl+C2=0. Therefore, the foregoing preset method may directly be: determining whether the amplitude of the superimposed signal is zero, and if the amplitude of the superimposed signal is zero, determining that the left channel signal of the audio file is opposite to the right channel signal. This implementation has a single, practical and accurate Advantages.

The signal adjustment module 440 is configured to: if the left channel signal of the entire frame of the audio file is inverted with the right channel signal, decode all the frames of the audio file, and decode the obtained audio file. The left channel signal and the right channel signal of all the frames are adjusted in the same direction.

Specifically, when the signal determining module 430 knows that the left channel signal of all frames of the audio file is opposite to the right channel signal, the signal adjusting module 440 can decode all the frames of the audio file and decode the left and right sounds. The channel signal is adjusted to the same direction signal.

Optionally, the specific adjustment method may be: keeping the left channel signal of the audio file unchanged, inverting the right channel signal of the audio file, or keeping the right channel signal of the audio file unchanged, and the left sound of the audio file The signal is inverted. This implementation has the advantages of a single, practical.

The audio playing module 450 is configured to superimpose and play the left channel signal and the right channel signal of all frames of the audio file adjusted to be in the same direction.

Specifically, in order to simultaneously retain the information of the left channel signal and the right channel signal, the audio playing module 450 superimposes the left channel signal and the right channel signal of all frames adjusted to the same audio file to obtain a new one. Signal and play the new signal simultaneously on the left and right channels of the audio output device. For example, the left channel audio or headphones, right channel audio, or headphones simultaneously output the same music.

Further, in order to avoid the above situation, the audio play module 450 superimposes the left channel signal and the right channel signal of all frames adjusted to the same audio file by a preset ratio and then superimposes the amplitude.

Referring to FIG. 4, the multimedia terminal may further include a play instruction, and the reverse identifier is set. The module 470 and the reverse identity clearing module 480, wherein:

The play instruction acquisition module 460 is configured to acquire a play instruction for the audio file to trigger the audio pre-decoding module.

Specifically, before the operation of the multimedia file is processed, the play instruction acquisition module 460 obtains a play instruction for the audio file, and triggers the audio decoding module under the play command.

The reverse identifier setting module 470 is configured to set a reverse identifier for the play command if it is determined that the left channel signal of all frames of the audio file is opposite to the right channel signal.

Specifically, the reverse identity setting module 470 sets the reverse identity for later query. If the multimedia terminal is idle, it is determined in advance whether the left and right channel signals of an audio file in the local media library are reversed. If the reverse direction, the reverse identifier setting module 470 sets the reverse identifier to enable the audio file to be executed. Immediately know the status of its channel.

In an optional implementation manner, the reverse identifier setting module 470 is provided with a corresponding parameter variable, and the multimedia terminal can set the value of the parameter variable. In the embodiment of the present invention, if the value of the parameter variable is set to 1, It can be said that the reverse indication is set for the play instruction, and if it is set to 0, it can mean that the reverse identifier is not set.

The reverse identifier clearing module 480 is configured to clear the reverse identifier after the audio playing module plays the new audio signal.

Specifically, the reverse identifier clearing module 480 clears the reverse identifier set for the play command to avoid misprocessing of subsequent audio files.

On the basis of this, referring to the structure diagram of a signal adjustment module shown in FIG. 5, the signal adjustment module 440 may further include: a reverse identifier detection unit 441 and a signal adjustment unit 442, where:

The reverse identifier detecting unit 441 is configured to detect whether the reverse identifier is set for the play instruction before decoding the audio file.

Specifically, the reverse identification detecting unit 441 detects whether a reverse identification is set for the playback instruction before the audio file is formally decoded.

In an optional implementation manner, the reverse identifier detecting unit 441 detects whether the value of the parameter variable in the play command is 1 or not. If it is 1, the reverse flag is set for the play command, and if it is 0, it is not.

a signal adjustment unit 442, configured to: if the reverse identifier is detected, the audio file All frames are decoded, and the left channel signal and the right channel signal of all frames of the audio file obtained after decoding are adjusted to be in the same direction.

Specifically, after the signal adjustment unit 442 knows that the left channel signal of the audio file is inverted with the right channel signal, the entire frame of the audio file is decoded and the decoded left and right channel signals are adjusted to The same direction signal.

Optionally, the specific adjustment method may be: keeping the left channel signal of the audio file unchanged, inverting the right channel signal of the audio file, or keeping the right channel signal of the audio file unchanged, and the left sound of the audio file The signal is inverted. This implementation has the advantages of a single, practical. FIG. 6 is a schematic structural diagram of another multimedia terminal according to an embodiment of the present invention. As shown in FIG. 6, the multimedia terminal may include: at least one processor 601, such as a CPU (Central Processing Unit), and a memory 602. At least one communication bus 603, audio output device 604. Among them, the communication bus 603 is used to implement connection communication between these components. Among them, the audio output device 604 is used to convert the channel signal of the audio file into sound. The memory 602 can be a high speed RAM memory or a non-volatile memory such as at least one disk memory. Memory 602 can also be at least one storage device located remotely from processor 602. A set of program codes is stored in the memory 602, and the processor is configured to call program code stored in the memory for performing the following operations:

Decoding at least one frame of the audio file to obtain a left channel signal and a right channel signal of at least one frame of the audio file;

Superimposing a left channel signal of at least one frame of the audio file with a right channel signal and acquiring the superimposed superimposed signal;

Determining whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within a preset range, determining that the left channel signal and the right channel signal of all frames of the audio file are reversed If the left channel signal of all frames of the audio file is inverted with the right channel signal, all frames of the audio file are decoded, and the left channel of all frames of the audio file obtained after decoding is decoded The signal and the right channel signal are adjusted to be in the same direction;

The left channel signal and the right channel signal of all frames of the audio file adjusted to be in the same direction are overlapped and played.

In particular, the processor 601 determines whether the amplitude of the superposed signal is within a preset range. Yes:

It is judged whether the amplitude of the superimposed signal is zero.

Correspondingly, if the amplitude of the superimposed signal is zero, the processor 601 determines that the left channel signal of all frames of the audio file is opposite to the right channel signal.

Optionally, the specific operations performed by the processor 601 may further include:

Obtaining a play instruction for the audio file;

If it is determined that the left channel signal of all frames of the audio file is opposite to the right channel signal, the multimedia terminal sets a reverse flag for the play command.

Correspondingly, the processor 601 can detect whether the left channel signal and the right channel signal of all frames of the audio file are reversed by detecting whether the reverse identifier is set for the play instruction.

Further, if the processor 601 detects the reverse identifier, the entire frame of the audio file is decoded and the left channel signal and the right channel signal are adjusted to be in the same direction.

Further, after the processor 601 superimposes and plays the left channel signal and the right channel signal of all the frames of the audio file adjusted in the same direction, the reverse identifier is cleared.

Optionally, the processor 601 decodes all frames of the audio file and adjusts the left channel signal and the right channel signal to perform the same operation in the same direction:

Optionally, the processor 601 superimposes the left channel signal and the right channel signal of all frames of the audio file that are adjusted to be in the same direction. The specific operation may be:

The left channel signal and the right channel signal of all the frames of the audio file adjusted to be in the same direction are superimposed by a preset ratio reduction amplitude. In particular, the preset ratio can be 50%.

The embodiment of the present invention further provides a computer storage medium, where the computer storage medium stores a program, and the program execution includes an audio file played in a multimedia terminal according to an embodiment of the present invention in combination with FIG. 1 to FIG. Methods. The invention analyzes the pre-decoded left and right channel signals by pre-decoding a partial frame of the audio file, thereby identifying whether the left and right channel signals of the audio file are reversed, and reversing the left and right channel signals. of The audio file is processed, that is, the left and right channel signals are adjusted to be in the same direction and superimposed, and finally the audio file is played without distortion on the audio output device of the mono output mechanism according to the processed signal. Further, the present invention further provides a play instruction for the above process, in which the recognized audio files of the left and right channel signals are reversely identified, which facilitates the multimedia terminal to execute according to the reverse identifier. Processing of audio files. Further, the present invention adjusts the left and right channel signals to the same direction, and then reduces the amplitude by 50% and then superimposes to avoid signal truncation without significantly changing the volume of the volume, thereby improving the user experience.

A person skilled in the art can understand that all or part of the process of implementing the above embodiment method can be completed by a computer program to instruct related hardware, and the program can be stored in a computer readable storage medium, the program When executed, the flow of an embodiment of the methods as described above may be included. The storage medium may be a magnetic disk, an optical disk, a read-only memory (ROM), or a random access memory (RAM).

The above is only the preferred embodiment of the present invention, and the scope of the present invention is not limited thereto, and the equivalent changes made by the claims of the present invention are still within the scope of the present invention.

Claims

Rights request

1. A method for playing audio files in a multimedia terminal, characterized by comprising: the multimedia terminal decoding at least one frame of the audio file, and obtaining the left channel signal and the right channel of at least one frame of the audio file. Signal;

The multimedia terminal superimposes the left channel signal and the right channel signal of at least one frame of the audio file and obtains the superimposed superimposed signal;

The multimedia terminal determines whether the amplitude of the superimposed signal is within the preset range. If the amplitude of the superimposed signal is within the preset range, it determines the left channel signal and the right channel signal of all frames of the audio file. reverse;

If the left channel signal and the right channel signal of all frames of the audio file are reversed, the multimedia terminal decodes all frames of the audio file, and obtains the left channel signal of all frames of the audio file after decoding. channel signal and the right channel signal are adjusted to the same direction;

The multimedia terminal superimposes and plays the left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction.

2. The method of claim 1, wherein the multimedia terminal determines whether the amplitude of the superimposed signal is within a preset range, and if the amplitude of the superimposed signal is within the preset range, then determines The reverse direction of the left channel signal and right channel signal of all frames of the audio file includes:

The multimedia terminal determines whether the amplitude of the superimposed signal is zero. If the amplitude of the superimposed signal is zero, it determines that the left channel signal and the right channel signal of all frames of the audio file are opposite.

3. The method according to any one of claims 1-2, characterized in that the multimedia terminal decodes at least one frame of the audio file and obtains the left channel signal and the right channel signal of at least one frame of the audio file. The channel signal also previously included:

The multimedia terminal obtains a playback instruction for the audio file;

The multimedia terminal determines whether the amplitude of the superimposed signal is within a preset range. If the amplitude of the superimposed signal is within the preset range, it determines the left channel signal and the right channel signal of all frames of the audio file. After the channel signal is reversed, it also includes: If it is determined that the left channel signal and the right channel signal of all frames of the audio file are reversed, the multimedia terminal sets a reverse flag for the playback instruction;

If the left channel signal and the right channel signal of all frames of the audio file are reversed, the multimedia terminal decodes all frames of the audio file and obtains the decoded values of all frames of the audio file. Adjusting the left channel signal and the right channel signal to the same direction includes:

The multimedia terminal detects whether the reverse flag is set for the playback instruction; if the reverse flag is detected, the multimedia terminal decodes all frames of the audio file and obtains the decoded audio The left channel signal and right channel signal of all frames of the file are adjusted to the same direction.

4. The method of claim 3, wherein if the reverse identifier is detected, the multimedia terminal decodes all frames of the audio file, and decodes the audio file obtained after decoding. After the left channel signal and right channel signal of all frames are adjusted to the same direction, it also includes:

The multimedia terminal clears the reverse identifier.

5. The method according to any one of claims 1 to 4, characterized in that the multimedia terminal superimposes and combines the left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction. Playback details include:

The multimedia terminal reduces the amplitude of the left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction according to a preset ratio, then superimposes and plays them.

6. The method of claim 5, wherein the multimedia terminal reduces the amplitude of the left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction according to a preset ratio. Overlaying and playing include:

The multimedia terminal will reduce the amplitude of the left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction by 50%, then superimpose and play them.

7. The method of claim 1, wherein adjusting the left channel signal and the right channel signal of all frames of the decoded audio file to be in the same direction includes: Keep the left channel signal of all frames of the audio file unchanged, and invert the right channel signal of all frames of the audio file; or

8. The method according to any one of claims 1 to 4, characterized in that at least one frame of the audio file includes:

The first first frame or at least two discrete frames of the audio file.

9. A multimedia terminal, characterized in that, the multimedia terminal includes:

An audio decoding module, used to decode at least one frame of the audio file and obtain the left channel signal and the right channel signal of at least one frame of the audio file;

A signal superposition module, used to superimpose the left channel signal and the right channel signal of at least one frame of the audio file and obtain the superimposed superimposed signal;

A signal judgment module, used to judge whether the amplitude of the superimposed signal is within the preset range. If the amplitude of the superimposed signal is within the preset range, then determine the left channel signal of all frames of the audio file and The right channel signal is reversed;

A signal adjustment module, configured to decode all frames of the audio file if the left channel signal and the right channel signal of all frames of the audio file are reversed, and decode all the decoded audio files. The left channel signal and right channel signal of the frame are adjusted to the same direction;

The audio playback module is used to superimpose and play the left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction.

10. The multimedia terminal according to claim 9, characterized in that,

The signal judgment module is used to judge whether the amplitude of the superimposed signal is zero. If the amplitude of the superimposed signal is zero, then it is determined that the left channel signal and the right channel signal of all frames of the audio file are inversely Towards.

11. The multimedia terminal according to any one of claims 9 to 10, characterized in that, the multimedia terminal further includes: A playback instruction acquisition module, used to obtain a playback instruction for the audio file to trigger the audio decoding module;

A reverse flag setting module, configured to set a reverse flag for the playback instruction if it is determined that the left channel signal and the right channel signal of all frames of the audio file are reversed;

The signal adjustment module includes:

A reverse identification detection unit, configured to detect whether the reverse identification is set for the playback instruction before decoding the audio file;

A signal adjustment unit, configured to decode all frames of the audio file if the reverse identifier is detected, and obtain the decoded left channel signal and right channel signal of all frames of the audio file. Adjust to the same direction.

12. The multimedia terminal according to claim 11, characterized in that, the multimedia terminal further includes:

The reverse mark clearing module is used to clear the reverse mark after the audio playback module finishes playing the new audio signal.

13. The multimedia terminal according to any one of claims 9 to 12, wherein the audio playback module is configured to adjust the left channel signal and the right channel signal of all frames of the audio file in the same direction. The signals are reduced in amplitude according to a preset ratio, then superimposed and played.

14. The multimedia terminal according to claim 13, wherein the audio playback module is configured to adjust the left channel signal and the right channel signal of all frames of the audio file in the same direction according to a 50% ratio. Reduce the amplitude and then superimpose and play.

15. The multimedia terminal according to claim 9, characterized in that,

The signal conditioning module is used for:

If the left channel signal and the right channel signal of all frames of the audio file are reversed, decode all frames of the audio file, and keep the left channel signal of all frames of the audio file unchanged, and The right channel signal of all frames of the audio file is inverted; or If the left channel signal and the right channel signal of all frames of the audio file are reversed, decode all frames of the audio file, and keep the right channel signal of all frames of the audio file unchanged, and The left channel signal is inverted for all frames of the audio file.

16. The method according to any one of claims 9-12, characterized in that at least one frame of the audio file includes:

The first first frame or at least two discrete frames of the audio file.

17. A multimedia terminal, characterized in that the multimedia terminal includes an audio output device, a memory and a processor, wherein a set of player programs is stored in the memory, and the processor is used to call the player program stored in the memory, using To do the following:

Decode at least one frame of the audio file and obtain the left channel signal and the right channel signal of at least one frame of the audio file;

Superimpose the left channel signal and the right channel signal of at least one frame of the audio file and obtain the superimposed superimposed signal;

Determine whether the amplitude of the superimposed signal is within the preset range. If the amplitude of the superimposed signal is within the preset range, determine whether the left channel signal and the right channel signal of all frames of the audio file are inversely ; If the left channel signal and the right channel signal of all frames of the audio file are reversed, decode all frames of the audio file, and obtain the left channel of all frames of the audio file after decoding. The signal and the right channel signal are adjusted to the same direction;

The left channel signal and the right channel signal of all frames of the audio file adjusted to the same direction are overlapped and played.