JPH0272400A - Multipulse speech encoding device - Google Patents

Abstract

PURPOSE:To improve speech quality and to eliminate a waste of pulse retrieval time by positioning significant pulses at intervals wider than a quantization level range by a pulse position determining means for the multipulse train of speech codes. CONSTITUTION:When the final pulse in a necessary pulses is found, a pulse interval which is already found is checked and when the pulse interval is wider than the quantization range, pulses are searched for in the interval. Namely, pulses are searched within the specific pulse search range except one final pulse among necessary pulses. Then intervals of pulses which are already found before the final pulse is searched for and if a pulse interval section A wider than the quantization range is present, the final pulse is searched for in this section A and a pulse (a) is determined. Consequently, dummy pulses are decreased, and effective pulses increase to the contrary to improve the speech quality and eliminate the waste of the pulse search time.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention is applied to a multi-pulse driven linear predictive coding device. In particular, it relates to efficient pulse searching means.

〔overview〕

The present invention improves sound quality and eliminates wasted pulse search time by locating significant pulses at intervals wider than the quantization level range in a pulse position determining means for a multi-pulse train of audio codes. It is something.

[Conventional technology]

The multi-pulse encoding means quantizes and sends the positions and amplitudes of a plurality of pulses generated as sound source information. For pulse positions, the amount of information can be reduced by encoding the pulse interval with a fixed number of bits, but if the pulse interval is wider than the quantum range that can be represented by this number of bits, a dummy pulse with an amplitude value of "O" is sent in between. Ta.

[Problem that the invention seeks to solve]

However, in such conventional methods, dummy pulses are sent out depending on the situation, which reduces the number of effective pulses that can actually be sent, which not only causes deterioration in sound quality, but also wastes pulse search time to find these pulses that are not sent. There are drawbacks to it.

SUMMARY OF THE INVENTION The present invention aims to eliminate such drawbacks and to provide a multipulse speech encoding device that can generate a multipulse train with a large number of effective pulses.

[Means for solving problems]

The present invention provides a pulse searcher that generates a multi-pulse train in which the number of pulses within a pulse search range is a predetermined fixed number, and a means for converting the pulse interval length of the multi-pulse train generated by the pulse searcher into a quantization level. In the multi-pulse speech encoding device, the pulse searcher sets a specific number of pulses among the predetermined number of pulses included in the pulse search range as remaining pulses, and The pulse position is determined within this pulse search range for the number of pulses excluding the pulse, and then this pulse position! If the pulse interval determined based on is wider than the quantization level range of the encoder, the present invention is characterized in that it includes means for searching for the pulse position of the remaining pulse within this pulse interval.

[Effect]

For the first predetermined number of pulses, the pulse is searched within the predetermined pulse search range, and for the remaining pulses, the already determined pulse intervals are checked, and if there is an interval wider than the quantization range, the pulse is searched within it. .

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of this embodiment.

As shown in FIG. 1, this embodiment includes a pulse searcher 1 that determines the amplitude and pulse position of a predetermined number of pulses within a predetermined pulse search range and generates a multi-pulse train, and a pulse searcher 1 that generates a multi-pulse train. and an encoder 2 having means for quantizing the pulse interval of the multi-pulse. That is,
This embodiment includes a pulse searcher 1 that generates a multi-pulse train in which the number of pulses within a pulse search range is a predetermined number, and converts the pulse interval length of the multi-pulse train generated by this pulse searcher 1 into a fostering level. The pulse searcher 1 further includes a specific number of pulses among the predetermined number of pulses included in the pulse search range as remaining pulses, and a number of pulses excluding the remaining pulses. The pulse position is determined within this pulse search range for each pulse, and if the pulse interval determined based on this pulse position is wider than the quantization level range of the quantization means, the pulses of the remaining pulses are determined within this pulse interval. including means for locating the location.

Next, the operation of this embodiment will be explained. FIG. 2 shows a pulse train obtained when the pulse search of this embodiment is executed.

In this embodiment, when determining the last pulse among the required pulses, the already determined pulse interval is checked, and if there is an interval wider than the quantization range, a pulse is searched within that interval.

That is, a pulse search is performed within a predetermined pulse search range except for the last one of the required pulses. Then, before searching for the last pulse, the pulse interval that has already been found is checked, and as a result, if there is a pulse interval section A wider than the quantization range as shown in Figure 2, the last pulse is A pulse search is performed within section A to determine pulse a.

〔Effect of the invention〕

As explained above, in the present invention, the first predetermined pulse is searched in a predetermined pulse search range, and the remaining pulses are searched for by checking the already determined pulse intervals, and if there is an interval wider than the quantization range, the remaining pulses are searched within the predetermined pulse search range. Since the search is performed, the number of dummy pulses is reduced compared to the conventional example, and the number of effective pulses is correspondingly increased, resulting in improved sound quality and the effect of eliminating wasted pulse search time.

[Brief explanation of the drawing]

FIG. 1 is a block configuration diagram showing the configuration of an embodiment of the present invention. FIG. 2 is an explanatory diagram showing the operation of the embodiment of the present invention. 1... Pulse searcher, 2... Encoder.

Claims (1)

[Claims] 1. A pulse searcher that generates a multi-pulse train with a predetermined number of pulses within a pulse search range, and converting the pulse interval length of the multi-pulse train generated by this pulse searcher into a quantization level. In the multi-pulse speech encoding device, the pulse searcher sets a specific number of pulses among the predetermined number of pulses included in the pulse search range as remaining pulses, and The pulse positions are determined within this pulse search range for the number of pulses excluding the remaining pulses, and then, if the pulse interval found based on this pulse position is wider than the quantization level range of the encoder, the pulse interval is determined within this pulse interval. A multi-pulse speech encoding device comprising: means for searching the pulse position of the remaining pulses.