G726

Decodes G726 audio data streams into the PCM format. Big-endian and little-endian bit stream formats are supported.

The function calling process is as follows:

Obtain the size of the memory to be applied for decoding (dstBufLen).
Initialize the HmppaG726DecodePolicy_16s by calling HMPPA_G726_DecodeInit_8u16s.
Call the main function HMPPA_G726_Decode_8u16s.
Release the memory contained in HmppaG726DecodePolicy_16s by calling HMPPA_G726_DecodeRelease_8u16s.

The function interface declaration is as follows:

Obtaining the size of the memory to be applied for decoding:
HmppResult HMPPA_G726_GetDecodeDstBufLen_8u16s(int32_t len, int32_t *dstBufLen, HmppSpchBitRate rate);

Initialization:
HmppResult HMPPA_G726_DecodeInit_8u16s(HmppSpchBitRate rate, int32_t littleEndian, HmppaG726DecodePolicy_16s **policy);
Decoding:
HmppResult HMPPA_G726_Decode_8u16s(const uint8_t *src, int32_t len, int16_t *dst, HmppaG726DecodePolicy_16s *policy, int32_t *bytesConsumed, int64_t *bytesDecoded);
Release:
HmppResult HMPPA_G726_DecodeRelease_8u16s(HmppaG726DecodePolicy_16s *policy);

Parameters

Parameter	Description	Value Range	Input/Output
rate	Bit rate of the G726 audio stream	HMPP_SPCHBR_16000, HMPP_SPCHBR_24000, HMPP_SPCHBR_32000, or HMPP_SPCHBR_40000	Input
littleEndian	Endian mode of the G726 stream	0: big endian 1: little endian	Input
src	Pointer to the G726 stream to be decoded	The value cannot be NULL.	Input
len	Length of the G726 stream to be decoded, in bytes	(0, INT_MAX]	Input
dst	Pointer to the destination vector	The value cannot be NULL.	Output
policy	Pointer to the special structure	The value cannot be NULL.	Input/Output
bytesConsumed	Pointer to the data stream length (in bytes) actually consumed for decoding	Input: can be left blank or not Output: If the input is left blank, no output is generated. If the input is configured, the output range is [0, len].	Output
bytesDecoded	Pointer to the data stream length (in bytes) of the actual decoded output	Input: can be left blank or not Output: If the input is left blank, no output is generated. If the input is configured, the output range is [0, Theoretical output data stream length after decoding].	Output

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_SIZE_ERR	The value of len is less than or equal to 0.
HMPP_STS_BAD_ARG_ERR	A member of the rate or policy structure is invalid.
HMPP_STS_MALLOC_FAILED	Memory allocation failed.
HMPP_STS_SIZE_WRN	The product of len x 8 is not an integral multiple of the number of bits at each sampling point.

Example

#include <stdio.h>
#include <stdlib.h>
#include "hmpp.h"

#define AUDIO_INBUF_SIZE 20480
#define BIG_ENDIAN_G726 0

int main(int argc, char **argv)
{
    if (argc <= 3) {
        fprintf(stderr, "Usage: %s <bitrates index> <input file> <output file>\n", argv[0]);
        exit(0);
    }
    const char *outFilename, *inFilename;
    int32_t bitrate = atoi(argv[1]);
    inFilename = argv[2];
    outFilename = argv[3];
    uint8_t *data;
    int32_t dataSize;
    int32_t bytesConsumered = 0;
    int64_t bytesDecoded = 0;
	
    FILE *inFile = fopen(inFilename, "rb");
    if(NULL == inFile){
        printf("%s:[%d] open %s file failed\n",__FUNCTION__,__LINE__,inFilename);
        return -1;
    }

    FILE *outFile = fopen(outFilename, "wb");
    if(NULL == outFile){
        printf("%s:[%d] open %s file failed\n",__FUNCTION__,__LINE__,outFilename);
        return -1;
    }

    HmppaG726DecodePolicy_16s *policy;
    HmppResult result = HMPPA_G726_DecodeInit_8u16s((HmppSpchBitRate)bitrate, BIG_ENDIAN_G726, &policy);
    if (result != HMPP_STS_NO_ERR) {
        printf("HMPPA_G729_DecodeInit_8u16s return : %d\n", result);
    }

    fseek(inFile, 0, SEEK_END);
    int32_t srcLen = ftell(inFile);
    fseek(inFile, 0, SEEK_SET);
    int32_t dstLen;
    HMPPA_G726_GetDecodeDstBufLen_8u16s(srcLen, &dstLen, (HmppSpchBitRate)bitrate);

    uint8_t *inBuf = (uint8_t*)malloc(srcLen * sizeof(uint8_t));
    int16_t *outBuf = HMPPS_Malloc_16s(dstLen);
    fread(inBuf, sizeof(uint8_t), srcLen, inFile);
    dataSize = srcLen;

    result = HMPPA_G726_Decode_8u16s(inBuf, dataSize, outBuf, policy, &bytesConsumered, &bytesDecoded);
    fwrite(outBuf, 1, bytesDecoded, outFile);
    printf("HmppResult: %d, bytesConsumed: %d, bytesDecoded: %d\n", result, bytesConsumered, bytesDecoded);

    HMPPA_G726_DecodeRelease_8u16s(policy);
    HMPP_Free(outBuf);
    fclose(inFile);
    fclose(outFile);
	
    return 0;
}

Output:

HmppResult: 0, bytesConsumed: 533504, bytesDecoded: 4268032

Parent topic: Audio Decoding