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GSMEFR

Encodes audio data streams in the PCM format into the GSMEFR format.

The function calling process is as follows:

  1. Obtain the size of the memory to be applied for encoding (dstBufLen).
  2. Initialize the structure by calling Init.
  3. Call the main function HMPPA_Gsmefr_Encode_16s8u for encoding.
  4. 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_Gsmefr_GetEncodeDstBufLen_16s8u(int32_t len, int32_t *dstBufLen);

  • Initialization:

    HmppResult HMPPA_Gsmefr_EncodeInit_16s8u(HmppaGsmefrEncodePolicy_16s **policy, int32_t dtx);

  • Encoding:

    HmppResult HMPPA_Gsmefr_Encode_16s8u(const int16_t *src, int32_t len, uint8_t *dst, HmppaGsmefrEncodePolicy_16s *policy, int64_t *bytesConsumed, int32_t *bytesEncoded);

  • Release:

    HmppResult HMPPA_Gsmefr_EncodeRelease_16s8u(HmppaGsmefrEncodePolicy_16s *policy);

Parameters

Parameter

Description

Value Range

Input/Output

src

Pointer to the GSMEFR stream to be encoded

Not null

Input

len

Length of the data stream to be encoded (in dual-bytes)

(0, INT_MAX]

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, len]

Output

bytesEncoded

Pointer to the data stream length (in bytes) of the actual encoded output

[0, Theoretical output data stream length after encoding]

Output

dstBufLen

Length (in bytes) required to point to the destination vector

Not null

Output

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);

    HmppaGsmefrEncodePolicy_16s *policy;
    int32_t re = HMPPA_Gsmefr_EncodeInit_16s8u(&policy, 0);

    int dstLen;
    re = HMPPA_Gsmefr_GetEncodeDstBufLen_16s8u(srcLen, &dstLen);
    uint8_t *dst = (uint8_t*)malloc(dstLen * sizeof(uint8_t));

    int64_t bytesConsumed = 0;
    int32_t bytesEncoded = 0;
    re = HMPPA_Gsmefr_Encode_16s8u(src, srcLen, dst, policy, &bytesConsumed, &bytesEncoded);
    printf("HmppResult:%d, bytesConsumed:%d, bytesEncoded:%d\n", re, bytesConsumed, bytesEncoded);

    re = HMPPA_Gsmefr_EncodeRelease_16s8u(policy);
    fwrite(dst, sizeof(uint8_t), dstLen, out);

    fclose(in);
    fclose(out);

    return 0;
}

Output:

HmppResult:0, bytesConsumed:50560, bytesDecoded:4898
Parent topic: Audio Encoding