EVS

Encodes audio data streams in the PCM format into the Enhanced Voice Service (EVS) format.

The function calling process is as follows:

Obtain the size of the memory to be applied for encoding (dstBufLen).
Initialize the structure by calling Init.
Call the main function HMPPA_Evs_Encode_16s8u for encoding.
Call Release to release the memory allocated to the structure.

The function interface is declared as follows:

Obtaining the size of the memory to be applied for encoding:
HmppResult HMPPA_Evs_GetEncodeDstBufLen_16s8u(int32_t len, int32_t *dstBufLen, HmppEvsMode mode)
Initialization:
HmppResult HMPPA_Evs_EncodeInit_16s8u(HmppaEvsEncodePolicy_16s **policy, HmppEvsMode mode, int32_t dtx);
Encoding:
HmppResult HMPPA_Evs_Encode_16s8u(const int16_t *src, int32_t len, uint8_t *dst, HmppaEvsEncodePolicy_16s *policy, int64_t *bytesConsumed, int32_t *bytesEncoded);
Release:
HmppResult HMPPA_Evs_EncodeRelease_16s8u(HmppaEvsEncodePolicy_16s *policy);

Parameters

Parameter	Description	Value Range	Input/Output
src	Pointer to the data stream to be encoded	Not null	Input
len	Length of the data stream to be encoded	> 0	Input
dst	Pointer to the destination vector	Not null	Output
policy	Pointer to the special structure	Not null	Input/Output
bytesConsumed	Pointer to the data stream length (in bytes) actually consumed for encoding	≥ 0	Output
bytesEncoded	Pointer to the data stream length (in bytes) of the actual encoded output	≥ 0	Output
dstBufLen	Pointer to the required destination vector length (in bytes)	Not null	Output
mode	Bit rate of the EVS streams to be encoded	Defined by the structure	Input
dtx	Whether to enable the discontinuous transmission (DTX) function	0: disable 1: enable	Input

Return Value

Success: HMPP_STS_NO_ERR
Failure: An error code is returned.

Error Codes

Error Code	Description
HMPP_STS_NULL_PTR_ERR	The value of src, dst, or policy is NULL.
HMPP_STS_MALLOC_FAILED	Memory allocation failed.
HMPP_STS_SIZE_WRN	The input data stream is not completely encoded.

Example

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <string.h>
#include <hmpp.h>

int main(int argc, char *argv[]) 
{
    if (argc < 3) {
        fprintf(stderr, "%s in.amr out.wav\n", argv[0]);
        return 1;
    }

    FILE *in = fopen(argv[1], "r");
    FILE *out = fopen(argv[2], "w+");
    if (!in || !out) {
        printf("Open file failed!\n");
        return 1;
    }

    fseek(in, 0, SEEK_END);
    int32_t srcLen = ftell(in) / 2;
    fseek(in, 0, SEEK_SET);
    int16_t *src = (int16_t*)malloc(srcLen * sizeof(int16_t));
    fread(src, sizeof(int16_t), srcLen, in);

    HmppaAmrnbEncodePolicy_16s *policy;
    int32_t re = HMPPA_Evs_EncodeInit_16s8u(&policy, HMPP_EVS_6600, 0);

    int dstLen;
    re = HMPPA_Evs_GetEncodeDstBufLen_16s8u(srcLen, &dstLen, HMPP_EVS_6600);
    uint8_t *dst = (uint8_t*)malloc(dstLen * sizeof(uint8_t));

    int64_t bytesConsumed = 0;
    int32_t bytesEncoded = 0;
    re = HMPPA_Evs_Encode_16s8u(src, srcLen, dst, policy, &bytesConsumed, &bytesEncoded);
    printf("HmppResult:%d, bytesConsumed:%d, bytesEncoded:%d\n", re, bytesConsumed, bytesEncoded);

    re = HMPPA_Evs_EncodeRelease_16s8u(policy);
    fwrite(dst, sizeof(uint8_t), bytesEncoded, out);

    fclose(in);
    fclose(out);

    return 0;
}

Output:

HmppResult:0, bytesConsumed:50560, bytesDecoded:2054

Parent topic: Audio Encoding