EVRC

Decodes enhanced variable rate codec (EVRC) audio data streams into the PCM format.

The function calling process is as follows:

Obtain the size of the memory to be applied for decoding (dstBufLen).
Initialize the HmppaEvrcDecodePolicy_16s structure by calling HMPPA_Evrc_DecodeInit_8u16s.
Call the main function HMPPA_Evrc_Decode_8u16s for decoding.
Call HMPPA_Evrc_DecodeRelease_8u16s to release the memory contained in the HmppaEvrcDecodePolicy_16s structure.

The function interface declaration is as follows:

Obtaining the size of the memory to be applied for decoding:
HmppResult HMPPA_Evrc_GetDecodeDstBufLen_8u16s(int32_t len, int32_t *dstBufLen);
Initialization:
HmppResult HMPPA_Evrc_DecodeInit_8u16s(HmppaEvrcDecodePolicy_16s **policy);
Decoding:
HmppResult HMPPA_Evrc_Decode_8u16s(const uint8_t *src, int32_t len, int16_t *dst, HmppaEvrcDecodePolicy_16s *policy, int32_t *bytesConsumed, int64_t *bytesDecoded);
Release:
HmppResult HMPPA_Evrc_DecodeRelease_8u16s(HmppaEvrcDecodePolicy_16s *policy);

Parameters

Parameter	Description	Value Range	Input/Output
src	Pointer to the EVRC stream to be decoded	The value cannot be NULL.	Input
len	Length of the data 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
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	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_MALLOC_FAILED	Memory allocation failed.
HMPP_STS_SIZE_WRN	The input data stream is not completely decoded.

Example

#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#include "hmppa.h"
int main(int argc, char **argv)
{
    int32_t len;
    FILE *inFile;
    FILE *outFile;
    int32_t bytesConsumed = 0;
    int64_t bytesDecoded = 0;
    struct stat buf;
    uint8_t *src = NULL;
    int16_t *dst = NULL;
    int32_t srcLen = 0;
    int64_t dstLen = 0;
    HmppResult result = 0;
    if (argc < 3)
    {
        printf("Usage: %s <input.pkt> <output.pcm>\n", argv[0]);
        return 0;
    }
    if (stat(argv[1], &buf) != 0)
    {
        printf("stat %s error\n", argv[1]);
        return -1;
    }
    srcLen = buf.st_size;
    result = HMPPA_Evrc_GetDecodeDstBufLen_8u16s(srcLen, &dstLen);
    src = HMPP_Malloc(srcLen);
    if (src == NULL)
    {
        printf("src buffer malloc failed.\n");
        return -1;
    }
    dst = HMPPS_Malloc_16s(dstLen);
    if (dst == NULL)
    {
        HMPP_Free(src);
        printf("dst buffer malloc failed.\n");
        return -1;
    }
    inFile = fopen(argv[1], "rb");
    if (!inFile)
    {
        printf("Open File %s Failed.\n", argv[1]);
        HMPP_Free(src);
        HMPP_Free(dst);
        return -1;
    }
    outFile = fopen(argv[2], "wb");
    if (!outFile)
    {
        printf("Open File %s Failed.\n", argv[2]);
        HMPP_Free(src);
        HMPP_Free(dst);
        fclose(inFile);
        return -1;
    }

    (void)HMPPS_Zero_8u(src, srcLen);
    (void)HMPPS_Zero_16s(dst, dstLen);
    fread(src, sizeof(uint8_t), srcLen, inFile);
    HmppaEvrcDecodePolicy_16s *policy;
    result = HMPPA_Evrc_DecodeInit_8u16s(&policy);
    if (result != HMPP_STS_NO_ERR)
    {
        printf("Evrc decode init failed : %d\n", result);
        HMPP_Free(src);
        HMPP_Free(dst);
        fclose(inFile);
        fclose(outFile);
        return result;
    }
    result = HMPPA_Evrc_Decode_8u16s(src, srcLen, dst, policy, &bytesConsumed, &bytesDecoded);
    if (result == HMPP_STS_NO_ERR)
    {
        fwrite((uint8_t *)dst, sizeof(uint8_t), bytesDecoded, outFile);
        printf("SUCCESS: result = %d, bytesConsumed = %d, bytesDecoded = %ld.\n", result, bytesConsumed,
               bytesDecoded);
    }
    else if (result == HMPP_STS_SIZE_WRN)
    {
        fwrite((uint8_t *)dst, sizeof(uint8_t), bytesDecoded, outFile);
        printf("WARNING: result = %d, bytesConsumed = %d, bytesDecoded = %ld.\n", result,
               bytesConsumed, bytesDecoded);
    }
    else
    {
        printf("ERROR: result = %d\n", result);
    }
    (void)HMPPA_Evrc_DecodeRelease_8u16s(policy);
    HMPP_Free(src);
    HMPP_Free(dst);
    fclose(outFile);
    fclose(inFile);
    return result;
}

Output:

SUCCESS: result = 0, bytesConsumed = 3220872, bytesDecoded = 42944960.

Parent topic: Audio Decoding