CN100380446C - Sound fast-forward playing method and device thereof - Google Patents

Abstract

A fast-forward playing method and device for audio data includes a sound data distinguishing program, a playing data converting program and a gain processing program. A sound data discrimination program for discriminating a sound data inputted from the outside into at least one first play data and at least one omission data; a play data conversion program for multiplying the first play data by a window function to convert the first play data into a second play data; the gain processing program multiplies the first playing data by a first gain value to obtain first gain playing data, multiplies the second playing data by a second gain value to obtain second gain playing data, and sums the first gain playing data and the second gain playing data to obtain fast forward playing data.

Description

Sound fast-forward playback method and device thereof

technical field

The invention relates to a sound fast-forward playing method, in particular to a sound fast-forward playing method and a device thereof for an audio decoding system.

Background technique

The purpose of fast-forwarding at double speed or high speed is to make it convenient for the user to find the paragraph or content of the track he wants to listen to. Two-channel (CDDA, MP3, MPEG) or multi-channel (AC3, DTS, MPEG MultiCH, MLP) audio decoding system generally adopts the following four when playing at double speed or high speed fast forward (Fast-Forward, FF) Method: The first method is to increase the sampling frequency to fully decode and play. At this time, the setting of the digital/analog converter (DAC) should also be increased accordingly, but after the setting of the digital/analog converter is increased, the pitch will be made (Key) rises, which makes people feel unpleasant; the second way is to increase the sampling frequency to fully decode and play, and then use Down Sampling (Down Sampling) technology for down-pitch playback, so users will not have pitch-up The third way is to read in the data stream (Skip Data) to play, and the setting of the digital/analog converter remains unchanged at this time; the fourth way is to switch to the mute (Mute) state.

For the first two methods mentioned above, because the digital signal processor (CPU or DSP) has a limited computing speed, it may not be able to fully cooperate with the improvement of the sound sampling frequency for continuous fast-forward playback, and will cause a huge hardware performance loss. Hardware performance is a very valuable resource in a two-channel or multi-channel audio decoding system. For example, the hardware performance required by DTS 5.1 Surround Decoding is 50MIPS (million instructions/second), and MLP Decoding is even more than 65MIPS, at double speed. Or when high-speed fast-forward playback, the number of MIPS required is doubled. If the calculation speed of the digital signal processor cannot match the increase in the sound sampling frequency to continuously fast-forward playback, the general digital audio-visual player will be in this situation. Cut to silence or choose to respond by skipping into the data stream. However, when the digital audio-visual player chooses to fast-forward playback by jumping into the data, because the reading of part of the data is omitted, the phenomenon of broken noise (Broken Noise) will occur when the discontinuous points of the sound (Discontinuous Point) are connected. , which will affect the user's judgment of the content, and also make people feel unpleasant.

Therefore, how to provide a fast-forward playback method that does not need to consume huge hardware performance and can increase the continuity of the sound to avoid the phenomenon of popping is really one of the subjects of the current audio decoding system.

Contents of the invention

In view of the above problems, the present invention provides a sound fast-forward playback method and its device that can increase the continuity of the sound without consuming huge hardware performance and avoid the popping phenomenon.

The sound fast-forward playing method of the present invention includes a sound data distinguishing program, a playing data conversion program and a gain processing program. Among them, the sound data distinguishing program is to distinguish an externally input sound data into at least one first play data and at least one omitted data; the play data conversion program is to multiply the first play data by a window function to convert into a first play data Two playback data; the gain processing program is to multiply the first playback data by a first gain value to obtain a first gain playback data, and multiply the second playback data by a second gain value to obtain a second gain playback data, and sum the first gain play data and the second gain play data to obtain a fast-forward play data.

In addition, the present invention also discloses a sound fast-forward playback device, which includes a sound data differentiation module, a playback data conversion module and a gain processing module. The sound data distinguishing module divides an externally input sound data into at least one first playing data and at least one omitted data; the playing data conversion module multiplies the first playing data by a window function to convert into a second playing data; gain The processing module multiplies the first playback data by a first gain value to obtain a first gain playback data, and multiplies the second playback data by a second gain value to obtain a second gain playback data, and the first gain The playback data is summed with the second gain playback data to obtain a fast-forward playback data.

The present invention also discloses a digital laser video disc playback system that eliminates fast-forward popping sound, including a sound data division module, a playback data conversion module, a gain processing module and a user operation interface. The sound data distinguishing module is to distinguish a sound data into at least one first play data and at least one omitted data during fast-forward playback, wherein the sound data is two-channel sound data and multi-channel sound data; play data conversion The module is to multiply the first playback data by a window function to convert into a second playback data; the gain processing module is to multiply the first playback data by a first gain value to obtain a first gain playback data, and the second The two play data is multiplied by a second gain value to obtain a second gain play data, and the first gain play data and the second gain play data are summed to obtain a fast-forward play data; the user operation interface is used for The user provides the option to fast-forward the playback function.

As mentioned above, because the audio fast-forward playback method according to the present invention utilizes the combination of the playback data and the window function, and utilizes gain processing to modify the required playback data, so that the digital signal processor does not need to decode with all its strength, so it does not need to consume a huge amount of time. Improve the hardware performance, and increase the continuity of the sound to avoid the phenomenon of popping sound.

Description of drawings

Fig. 1 is the flowchart showing the sound fast-forward playback method according to a preferred embodiment of the present invention;

2A to 2D are schematic diagrams showing the audio data flow of the audio fast-forward playback method according to a preferred embodiment of the present invention;

3A to 3C are schematic diagrams showing sound data;

Figure 4 is a schematic diagram showing a sound fast-forward playback device according to a preferred embodiment of the present invention; and

FIG. 5 is a schematic diagram showing a digital laser disc playback system that eliminates popping sound during fast-forward playback.

Description of component symbols:

P1 Voice Data Differentiation Program

P2 play data conversion program

P3 buff handler

21 Sound data input from outside

211 The first play data

212 omit data

Wf(x) window function

211’ second playback data

g1 first gain value

g2 second gain value

213 The first gain play data

213’ second gain playback data

22 Fast forward and play data

31 Sound data distinguishing module

32 Play data conversion module

33 gain processing module

40 User Operation Interface

5 Digital Laser Video Disc Playback System

Detailed ways

The audio fast-forward playback method according to a preferred embodiment of the present invention will be described below with reference to the relevant drawings, wherein the same components will be described with the same reference symbols.

Please refer to FIG. 1 , the audio fast-forward playback method according to the preferred embodiment of the present invention includes an audio data distinguishing program P1 , a playback data conversion program P2 and a gain processing program P3 . In the voice data distinguishing program P1, an externally input voice data 21 is divided into at least one first playing data 211 and at least one omitted data 212 (as shown in FIG. 2A ). Wherein, the sound data input from the outside can be two-channel sound data and multi-channel sound data. Wherein, as shown in Figure 2A, the two-channel sound data (taking CDDA two-channel sound data as an example), is divided into the first play data 211 and the omitted data 212 through the sound data distinguishing program P1. Here, the first play sound The data 211 and the omitted data 212 are a plurality of pulse code modulation sampling data (PCM Samples), and if the first playback data 211 is too small when the sound is fast-forwarded, it will produce the feeling of raising the pitch. In this embodiment, the first A playback sound data 211 includes 8192 PCM sample data.

In addition, as shown in FIG. 2B, the multi-channel sound data is divided into the first play data 211 and the omitted data 212 through the sound data distinguishing program P1. Here, the first played sound data 211 and the omitted data 212 are a plurality of frames (Frame ), in this embodiment, the first playing sound data 211 includes 4 frames.

In the playback data converting procedure P2, the first playback data 211 is multiplied by a window function Wf(x) to be converted into a second playback data 211' (as shown in FIG. 2C ). Wherein, the window function can be a Hanning window function, a Hamming window function or a Blackman window function, and the equation of the Hanning window function is Wf(x)=cos ² ( ^πx / ₂ ) , the equation of the Hamming window function is Wf(x)=0.54-0.46cos(πx) and the equation of the Blackman window function is Wf(x)=0.42-0.5cos(πx)+0.08cos(2πx). Wherein, the variable χ in the equation is the first playing data 211 . In this embodiment, the window function Wf(x) is a Hanning window function. In the gain processing program P3, the first playback data 211 is multiplied by a first gain value g1 to obtain a first gain playback data 213, and the second playback data 211' is multiplied by a second gain value g2 to obtain a second gain play data 213', and sum the first gain play data 213 and the second gain play data 213' to obtain a fast forward play data 22 (as shown in FIG. 2D). Wherein, the first gain value g1 is a value smaller than the second gain value g2, and the sum of the first gain value g1 and the second gain value g2 is less than or equal to 1.

In this embodiment, if only the sound data distinguishing program P1 is passed, the result is as shown in FIG. Since the data 211 is output, it is difficult for the user to distinguish the content of the voice, which makes people feel unpleasant. After the playback data conversion program P2, the result is as shown in Figure 3B. After the first playback data 211 is converted by the window function Wf(x), the user can distinguish the sound content more clearly, but due to the window function Wf( The characteristics of x) may cause silence at the junction of sound data. Finally, after the gain processing program P3, the result is shown in Figure 3C. Using the gain correction, the junction of the sound data is modified to be smoother, so that the user can clearly distinguish the sound content without causing unpleasantness Figure 3C shows the processing result when the first gain value g1 is 0.2 and the second gain value g2 is 0.8.

FIG. 4 is a sound fast-forward playback device according to a preferred embodiment of the present invention, including a sound data differentiation module 31 , a playback data conversion module 32 and a gain processing module 33 . In this embodiment, the sound data distinguishing module 31 is to distinguish a sound data 21 input from the outside into at least one first play data 211 and at least one omitted data 212, wherein the sound data 21 input from the outside can be two channel audio data, and multi-channel audio data (as shown in FIG. 2A and FIG. 2B ).

The playback data conversion module 32 multiplies the first playback data 211 by a window function Wf(x) to convert it into a second playback data 211' (as shown in FIG. 2C ). Among them, the window function can be a Hanning window function, a Hamming window function or a Blackman window function, and the equation of the Hanning window function is Wf(x)=cos ² ( ^πx / ₂ ), and the equation of the Hamming window function is Wf (x)=0.54-0.46cos(πx) and the equation of the Blackman window function is Wf(x)=0.42-0.5cos(πx)+0.08cos(2πx). Wherein, the variable x in the equation is the first play data 211 . In this embodiment, the window function Wf(x) is a Hanning window function.

The gain processing module 33 multiplies the first playback data 211 by a first gain value g1 to obtain a first gain playback data 213, and multiplies the second playback data 211' by a second gain value g2 to obtain a first gain processing module 33. Two gain playback data 213 ′, and sum the first gain playback data 213 and the second gain playback data 213 ′ to obtain a fast forward playback data 22 (as shown in FIG. 2D ). Wherein, the first gain value g1 is a value smaller than the second gain value g2, and the sum of the first gain value g1 and the second gain value g2 is less than or equal to 1. In this embodiment, the first gain value g1 is 0.2, and the second gain value g2 is 0.8.

Fig. 5 is a schematic diagram of a digital laser video disc playback system that eliminates fast-forward popping sound. In the present embodiment, the digital laser disc playback system 5 (such as a DVD player with fast forward playback function) includes a user operation interface 40, a voice data distinguishing module 31, a playback data conversion module 32 and A gain processing module 33 .

The user operation interface 40 is used to provide the user with a fast-forward playback function when the digital laser disc system is played; when the fast-forward playback is performed, the sound data distinguishing module 31 distinguishes a sound data into at least one first play data and at least one One omits data, and sound data can be two-channel sound data, and multi-channel sound data; Play data conversion module 32 is to multiply the first play data by a window function and convert into a second play data, and window function can be is a Hanning window function, a Hamming window function or a Blackman window function, wherein the equation of the Hanning window function is Wf(x)=cos ² ( ^πx / ₂ ), and the equation of the Hamming window function is Wf(x)=0.54 The equation of -0.46cos(πx) and Blackman window function is Wf(x)=0.42-0.5cos(πx)+0.08cos(2πx), and the variable x in the equation is the first playback data, and Wf(x) It is the second playback data; the gain processing module 33 multiplies the first playback data by a first gain value to obtain a first gain playback data, and multiplies the second playback data by a second gain value to obtain a first playback data playing the data with two gains, and summing the playing data of the first gain and the playing data of the second gain to obtain a fast-forward playing data. Wherein, the first gain value is a value smaller than the second gain, and in addition, the sum of the first gain value and the second gain value is less than or equal to 1.

In summary, because the sound fast-forward playback method and its device of the present invention utilize the combination of playback data and window functions, and use gain processing to modify the required playback data, the digital signal processor does not need to fully decode, so there is no need to It consumes a huge amount of hardware performance, and can increase the continuity of the sound to avoid the phenomenon of popping.

The above descriptions are illustrative only, not restrictive. Any equivalent modification or change without departing from the spirit and scope of the present invention shall be included in the scope of the appended claims.

Claims (8)

1. sound fast-forward play method comprises:

One voice data is distinguished program, is to divide at least one first played data and at least one omitted data with one from the voice data of outside input;

One played data converse routine is that this first played data be multiply by a window function to convert one second played data to; And

One gain process program, be that this first played data be multiply by one first yield value to obtain one first gain played data, and this second played data be multiply by one second yield value obtaining one second gain played data, and this first gain played data and this second gain played data are sued for peace to obtain fast-forward play data;

Wherein this first yield value is the numerical value littler than this second yield value, and this first yield value and this second yield value sum are smaller or equal to 1.

2. sound fast-forward play method as claimed in claim 1 wherein should comprise two track voice datas from the voice data of outside input, and the multi-channel sound data.

3. sound fast-forward play method as claimed in claim 1, wherein this window function is the Hanning window function.

4. sound fast-forward play method as claimed in claim 1, wherein this window function is a Hamming window function.

5. sound fast-forward play method as claimed in claim 1, wherein this window function is the Blacknam window function.

6. sound fast-forward play device comprises:

One voice data discriminating module is to divide at least one first played data and at least one omitted data with one from the voice data of outside input;

One played data modular converter, it multiply by a window function with this first played data, to convert one second played data to; And

One gain process module, it multiply by one first yield value to obtain one first gain played data with this first played data, and this second played data be multiply by one second yield value obtaining one second gain played data, and this first gain played data and this second gain played data are sued for peace to obtain fast-forward play data;

Wherein this first yield value is the numerical value littler than this second yield value, and this first yield value and this second yield value sum are smaller or equal to 1.

7. sound fast-forward play device as claimed in claim 6 should be two track voice datas from the voice data of outside input wherein, and the multi-channel sound data.

8. Video CD Play System of eliminating the fast-forward play sonic boom comprises:

One voice data discriminating module is when fast-forward play, and a voice data is divided at least one first played data and at least one omitted data, and wherein this voice data is one or two track voice data, and multi-channel sound data;

One played data modular converter, it multiply by this first played data one window function and converts one second played data to;

One gain process module, it multiply by one first yield value to obtain one first gain played data with this first played data, and this second played data be multiply by one second yield value obtaining one second gain played data, and this first gain played data and this second gain played data are sued for peace to obtain fast-forward play data; And

One user's operation interface is selected the fast-forward play function in order to the user to be provided;

Wherein this first yield value is the numerical value littler than this second yield value, and this first yield value and this second yield value sum are smaller or equal to 1.

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