Pulse encoding and decoding method and pulse codec

• US 9,508,348 B2
• Filed: 11/19/2014
• Issued: 11/29/2016
• Est. Priority Date: 06/24/2010
• Status: Active Grant

• Current Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Original Assignee: Huawei Technologies Co., Ltd. (Huawei Investment & Holding Co., Ltd.)
• Inventors: Ma, Fuwei, Zhang, Dejun
• Primary Examiner(s): BAKER, MATTHEW H
• Application Number:
  US14/547,860
• Publication Number:
  US 20150081284A1
• Time in Patent Office: 741 Days
• US Class Current: 1/1
• CPC Class Codes: G10L 19/00 Speech or audio signals analysis-synthesis techniques for redundancy reduction, e.g. in vocoders; Coding or decoding of speech or audio signals, using source filter models or psychoacoustic analysis in musical instruments G10H
• CPC Class Codes: G10L 19/002 Dynamic bit allocation for perceptual audio coders G10L19/032
• CPC Class Codes: G10L 19/008 Multichannel audio signal coding or decoding using interchannel correlation to reduce redundancy, e.g. joint-stereo, intensity-coding or matrixing
• CPC Class Codes: G10L 19/107 Sparse pulse excitation, e.g. by using algebraic codebook
• CPC Class Codes: G10L 19/12 the excitation function being a code excitation, e.g. in code excited linear prediction [CELP] vocoders
• CPC Class Codes: G10L 19/24 Variable rate codecs, e.g. for generating different qualities using a scalable representation such as hierarchical encoding or layered encoding

Abstract

In a pulse encoding and decoding method and a pulse codec, more than two tracks are jointly encoded, so that free codebook space in the situation of single track encoding can be combined during joint encoding to become code bits that may be saved. Furthermore, a pulse that is on each track and required to be encoded is combined according to positions, and the number of positions having pulses, distribution of the positions that have pulses on the track, and the number of pulses on each position that has a pulse are encoded separately, so as to avoid separate encoding performed on multiple pulses of a same position, thereby further saving code bits.

Claims

1. A pulse encoding method comprising:

determining, by a speech pulse encoder, pulses that are on T tracks and required to be encoded, wherein T is an integer greater than or equal to 2;

separately collecting, by the speech pulse encoder, according to positions, statistics about a pulse that is on each track and required to be encoded, to obtain the number N_t of positions that have pulses on each track, distribution of the positions that have pulses on the track, and the number of pulses on each position that has a pulse, wherein the subscript t represents a t^th track, and tε

[0, T−

1];

according to the number of positions that have pulses and are on each track, determining, by the speech pulse encoder, a first index I1_t of each track, wherein the first index I1_t corresponds to all possible distribution situations of positions that have pulses and are on each track under the number of the positions having pulses, wherein the number of the positions having pulses is represented it;

determining, by the speech pulse encoder, a second index I2_t of each track separately according to distribution of positions that have pulses and are on each track, wherein the second index indicates, among all possible distribution situations corresponding to the first index, a distribution situation which corresponds to distribution of current positions having pulses and is on the track;

determining, by the speech pulse encoder, a third index I3_t of each track separately according to the number of pulses on each position that has the pulse and is on each track;

wherein the step of determining a third index I3_t of each track separately according to the number of pulses on each position that has the pulses and is on each track comprises;

for the t^th track, situations that N_t positions having pulses have pulses are mapped to situations that N_t positions have −

N_t pulses, wherein represents the total number of pulses required to be encoded on the t^th track; and

according to set order, all possible distribution situations of −

N_t pulses on N_t positions are arrayed, and an arrayed serial number is used as the third index I3_t indicating the number of pulses on a position that has a pulse; and

generating, by the speech pulse encoder, a code index hid, wherein the code index comprises information of the first, second, and third indexes of each track; and

encoding and transmitting the code index hid to a decoding device.

2. The method according to claim 1, wherein a calculation formula of the third index I3_t of each track is:

3. The method according to claim 1, wherein a calculation formula of the second index I2_t of each track is:

4. The method according to claim 1, wherein:

during the separately collecting, by the speech pulse encoder, according to the positions, the statistics about the pulse that is on each track of a speech signal and required to be encoded, according to a positive or negative feature of a pulse symbol of each position that has the pulse and is on each track, pulse symbol information of each position that has the pulse and is on each track is obtained; and

the code index further comprises information of a symbol index which corresponds to each position that has the pulse and is on each track, and the symbol index indicates pulse symbol information which is of a position that has a pulse and corresponds to the code index.

5. A non-transitory computer readable storage medium in a speech pulse encoder, wherein the computer readable storage medium stores computer executable instructions which when executed causes a processor in the speech pulse encoder to:

determine pulses that are on T tracks of a speech signal and required to be encoded, wherein T is an integer greater than or equal to 2;

separately collect, according to positions, statistics about a pulse that is on each track and required to be encoded, to obtain the number N_t of positions that have pulses on each track, distribution of the positions that have pulses on the track, and the number of pulses on each position that has a pulse, wherein the subscript t represents a t^th track, and tε

[0, T−

1];

according to the number of positions that have pulses and are on each track, determine a first index I1_t of each track, wherein the first index I1_t corresponds to all possible distribution situations of positions that have pulses and are on each track under the number of the positions having pulses, wherein the number of the positions having pulses is represented it;

determine a second index I2_t of each track separately according to distribution of positions that have pulses and are on each track, wherein the second index indicates, among all possible distribution situations corresponding to the first index, a distribution situation which corresponds to distribution of current positions having pulses and is on the track;

determine a third index I3_t of each track separately according to the number of pulses on each position that has the pulse and is on each track;

wherein the step of determining a third index I3_t of each track separately according to the number of pulses on each position that has the pulses and is on each track comprises;

for the t^th track, situations that N_t positions having pulses have pulses are mapped to situations that N_t positions have −

N_t pulses, wherein represents the total number of pulses required to be encoded on the t^th track; and

according to set order, all possible distribution situations of −

N_t pulses on N_t positions are arrayed, and an arrayed serial number is used as the third index I3_t indicating the number of pulses on a position that has a pulse;

generate a code index hid, wherein the code index comprises information of the first, second, and third indexes of each track; and

encoding and transmitting the code index hid to a decoding device.

6. The non-transitory computer readable storage medium according to claim 5, wherein a calculation formula of the third index I3_t of each track is:

7. The non-transitory computer readable storage medium according to claim 5, wherein a calculation formula of the second index I2_t of each track is:

8. The non-transitory computer readable storage medium according to claim 5, wherein:

during the separately collecting, according to the positions, the statistics about the pulse that is on each track of a speech signal and required to be encoded, according to a positive or negative feature of a pulse symbol of each position that has the pulse and is on each track, pulse symbol information of each position that has the pulse and is on each track is obtained; and

the code index further comprises information of a symbol index which corresponds to each position that has the pulse and is on each track, and the symbol index indicates pulse symbol information which is of a position that has a pulse and corresponds to the code index.

9. A non-transitory computer-readable storage medium in a speech pulse encoder, storing computer executable instructions, where the computer executable instructions execute the computer executable instructions to:

determine pulses that are on T tracks and required to be encoded, wherein T is an integer greater than or equal to 2;

separately collect, according to positions, statistics about at least one pulse that are on each track and required to be encoded, to obtain (a) the number of positions that have at least one pulse on each track, (b) distribution of the positions that have at least one pulses on each track, and (c) the number of pulses on each position that has at least one pulse, wherein the subscript t represents a t^th track, and tε

[0, T−

1];

determine a first index I1_t of each track according to the number of positions that have at least one pulse and are on each track;

determine a second index I2_t of each track according to the distribution of positions that have at least one pulse and are on each track;

determine a third index I3_t of each track according to the number of pulses on each position that has at least one pulse and is on each track; and

determine a code index hid according to the first indexes of each track, the second indexes of each track and third indexes of each track;

wherein the third index I3_t of each track is determined according to the following;

10. The non-transitory computer-readable storage medium according to claim 9, wherein the second index I2_t of each track is determined according to the following: