GSMHR

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

The function calling process is as follows:

Obtain the size of the memory to be applied for encoding (dstBufLen).
Initialize the HmppaGsmhrEncodePolicy_16s structure by calling HMPPA_Gsmhr_EncodeInit_16s8u.
Call the main function HMPPA_Gsmhr_Encode_16s8u for decoding.
Call HMPPA_Gsmhr_EncodeRelease_16s8u to release the memory allocated to the HmppaGsmhrEncodePolicy_16s structure.

The function interface declaration is as follows:

Obtaining the size of the memory to be applied for encoding:
HmppResult HMPPA_Gsmhr_GetEncodeDstBufLen_16s8u(int32_t len, int32_t *dstBufLen);
Initialization:
HmppResult HMPPA_Gsmhr_EncodeInit_16s8u(HmppaGsmhrEncodePolicy_16s **policy);
Encoding:
HmppResult HMPPA_Gsmhr_Encode_16s8u(const int16_t *src, int32_t len, int32_t dtx, uint8_t *dst, HmppaGsmhrEncodePolicy_16s *policy, int64_t *bytesConsumed, int32_t *bytesEncoded);
Release:
HmppResult HMPPA_Gsmhr_EncodeRelease_16s8u(HmppaGsmhrEncodePolicy_16s *policy);

Parameters

Parameter	Description	Value Range	Input/Output
src	Pointer to the PCM stream to be encoded	The value cannot be NULL.	Input
len	Length of the PCM stream to be encoded, in bytes	(0, INT_MAX]	Input
dtx	Whether to enable the discontinuous transmission (DTX) function	0: disable 1: enable	Input
dst	Pointer to the destination vector	The value cannot be NULL.	Output
policy	Pointer to the GSMHR structure	The value cannot be 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 duel-bytes) required to point to the destination vector	The value cannot be NULL.	Output

Return Value

Success: HMPP_STS_NO_ERR
Failure: An error code is returned.

Error Codes

Error Code	Description
HMPP_STS_NULL_PTR_ERR	Any of the input pointers is NULL.
HMPP_STS_SIZE_ERR	The value of len is not a positive number.
HMPP_STS_SIZE_WRN	The src is not completely encoded.

Example

#include<stdlib.h>
#include<stdio.h>
#include"hmppa.h"
#define ONE_FRAME_GSM 14
#define ONE_FRAME_PCM 160
int main(int argc, char* argv[])
{
    if (argc <3) {
        printf("%s in.pcm out.gsmhr\n", argv[0]);
        return 0;
    }
    FILE *file =fopen(argv[1], "rb");
    if (file ==NULL) {
        printf("Open File %s Failed\n", argv[1]);
        return 0;
    }
    fseek(file, 0, SEEK_END);
    int32_t srcLen =ftell(file) / 2;
    int32_t dstLen;
    HMPPA_Gsmhr_GetEncodeDstBufLen_16s8u(srcLen, &dstLen);
    fseek(file, 0, SEEK_SET);
    short src[srcLen];
    unsigned char rb[dstLen];
    HmppaGsmhrEncodePolicy_16s *policy;
    HMPPA_Gsmhr_EncodeInit_16s8u(&policy);
    FILE *out = fopen(argv[2], "wb");

    fread(src, sizeof(short), srcLen, file);
    long int bytesConsumed;
    int bytesEncoded;
    int dtx = 1;
    int res = HMPPA_Gsmhr_Encode_16s8u(src, srcLen, dtx, rb, policy, &bytesConsumed, &bytesEncoded);
    HMPPA_Gsmhr_EncodeRelease_16s8u(policy);
    printf("bytesConsumed = %d, bytesDecoded = %d, res = %d\n", bytesConsumed, bytesEncoded, res);
    fwrite(rb, sizeof(unsigned char), bytesEncoded, out);
}

Output:

bytesConsumed = 50560, bytesDecoded = 2212, res = 0

Parent topic: Audio Encoding