c++ - 如何使用 QByteArray 而不是 SNDFILE
问题描述
我想使用“fvad”库来检测音频静音部分,但我有 QByteArray 而不是 SNDFILE。我怎样才能做到这一点?
sf_read_double(infile, buf0, framelen)
[ https://github.com/dpirch/libfvad/blob/master/examples/fvadwav.c][1]
这是我的代码:/* * 版权所有 (c) 2016 Daniel Pirch * * 此源代码的使用受 BSD 样式许可证 * 的约束,该许可证可在源代码树根目录下的 LICENSE 文件中找到。* 在文件专利中可以找到额外的知识产权授权。所有贡献的项目作者都可以在源代码树根目录的 AUTHORS 文件中找到。*/
#define _POSIX_C_SOURCE 200809L
#include <fvad.h>
#include <stdlib.h>
#include <stdbool.h>
#include <string.h>
#include <errno.h>
#include <unistd.h>
#include <sndfile.h>
static bool process_sf(SNDFILE *infile, Fvad *vad,
size_t framelen, SNDFILE *outfiles[2], FILE *listfile)
{
bool success = false;
double *buf0 = NULL;
int16_t *buf1 = NULL;
int vadres, prev = -1;
long frames[2] = {0, 0};
long segments[2] = {0, 0};
if (framelen > SIZE_MAX / sizeof (double)
|| !(buf0 = malloc(framelen * sizeof *buf0))
|| !(buf1 = malloc(framelen * sizeof *buf1))) {
fprintf(stderr, "failed to allocate buffers\n");
goto end;
}
while (sf_read_double(infile, buf0, framelen) == (sf_count_t)framelen) {
// Convert the read samples to int16
for (size_t i = 0; i < framelen; i++)
buf1[i] = buf0[i] * INT16_MAX;
vadres = fvad_process(vad, buf1, framelen);
if (vadres < 0) {
fprintf(stderr, "VAD processing failed\n");
goto end;
}
if (listfile) {
fprintf(listfile, "%d\n", vadres);
}
vadres = !!vadres; // make sure it is 0 or 1
if (outfiles[vadres]) {
sf_write_double(outfiles[!!vadres], buf0, framelen);
}
frames[vadres]++;
if (prev != vadres) segments[vadres]++;
prev = vadres;
}
printf("voice detected in %ld of %ld frames (%.2f%%)\n",
frames[1], frames[0] + frames[1],
frames[0] + frames[1] ?
100.0 * ((double)frames[1] / (frames[0] + frames[1])) : 0.0);
printf("%ld voice segments, average length %.2f frames\n",
segments[1], segments[1] ? (double)frames[1] / segments[1] : 0.0);
printf("%ld non-voice segments, average length %.2f frames\n",
segments[0], segments[0] ? (double)frames[0] / segments[0] : 0.0);
success = true;
end:
if (buf0) free(buf0);
if (buf1) free(buf1);
return success;
}
static bool parse_int(int *dest, const char *s, int min, int max)
{
char *endp;
long val;
errno = 0;
val = strtol(s, &endp, 10);
if (!errno && !*endp && val >= min && val <= max) {
*dest = val;
return true;
} else {
return false;
}
}
int main(int argc, char *argv[])
{
int retval;
const char *in_fname, *out_fname[2] = {NULL, NULL}, *list_fname = NULL;
SNDFILE *in_sf = NULL, *out_sf[2] = {NULL, NULL};
SF_INFO in_info = {0}, out_info[2];
FILE *list_file = NULL;
int mode, frame_ms = 10;
Fvad *vad = NULL;
/*
* create fvad instance
*/
vad = fvad_new();
if (!vad) {
fprintf(stderr, "out of memory\n");
goto fail;
}
/*
* parse arguments
*/
for (int ch; (ch = getopt(argc, argv, "m:f:o:n:l:h")) != -1;) {
switch (ch) {
case 'm':
if (!parse_int(&mode, optarg, 0, 3) || fvad_set_mode(vad, mode) < 0) {
fprintf(stderr, "invalid mode '%s'\n", optarg);
goto argfail;
}
break;
case 'f':
if (!parse_int(&frame_ms, optarg, 10, 30) || frame_ms % 10 != 0) {
fprintf(stderr, "invalid frame length '%s'\n", optarg);
goto argfail;
}
break;
case 'o':
out_fname[1] = optarg;
break;
case 'n':
out_fname[0] = optarg;
break;
case 'l':
list_fname = optarg;
break;
case 'h':
printf(
"Usage: %s [OPTION]... FILE\n"
"Reads FILE in wav format and performs voice activity detection (VAD).\n"
"Options:\n"
" -m MODE set VAD operating mode (aggressiveness) (0-3, default 0)\n"
" -f DURATION set frame length in ms (10, 20, 30; default 10)\n"
" -o FILE write detected voice frames to FILE in wav format\n"
" -n FILE write detected non-voice frames to FILE in wav format\n"
" -l FILE write list of per-frame detection results to FILE\n"
" -h display this help and exit\n",
argv[0]);
goto success;
default: goto argfail;
}
}
if (optind >= argc) {
fprintf(stderr, "input file expected\n");
goto argfail;
}
in_fname = argv[optind++];
if (optind < argc) {
fprintf(stderr, "unexpected argument '%s'; only one input file expected\n", argv[optind]);
goto argfail;
}
/*
* open and check input file
*/
in_sf = sf_open(in_fname, SFM_READ, &in_info);
if (!in_sf) {
fprintf(stderr, "Cannot open input file '%s': %s\n", in_fname, sf_strerror(NULL));
goto fail;
}
if (in_info.channels != 1) {
fprintf(stderr, "only single-channel wav files supported; input file has %d channels\n", in_info.channels);
goto fail;
}
if (fvad_set_sample_rate(vad, in_info.samplerate) < 0) {
fprintf(stderr, "invalid sample rate: %d Hz\n", in_info.samplerate);
goto fail;
}
/*
* open required output files
*/
for (int i = 0; i < 2; i++) {
if (out_fname[i]) {
out_info[i] = (SF_INFO){
.samplerate = in_info.samplerate,
.channels = 1,
.format = SF_FORMAT_WAV | SF_FORMAT_PCM_16
};
out_sf[i] = sf_open(out_fname[i], SFM_WRITE, &out_info[i]);
if (!out_sf[i]) {
fprintf(stderr, "Cannot open output file '%s': %s\n", out_fname[i], sf_strerror(NULL));
goto fail;
}
}
}
if (list_fname) {
list_file = fopen(list_fname, "w");
if (!list_file) {
fprintf(stderr, "Cannot open output file '%s': %s\n", list_fname, strerror(errno));
goto fail;
}
}
/*
* run main loop
*/
if (!process_sf(in_sf, vad,
(size_t)in_info.samplerate / 1000 * frame_ms, out_sf, list_file))
goto fail;
/*
* cleanup
*/
success:
retval = EXIT_SUCCESS;
goto end;
argfail:
fprintf(stderr, "Try '%s -h' for more information.\n", argv[0]);
fail:
retval = EXIT_FAILURE;
goto end;
end:
if (in_sf) sf_close(in_sf);
for (int i = 0; i < 2; i++)
if (out_sf[i]) sf_close(out_sf[i]);
if (list_file) fclose(list_file);
if (vad) fvad_free(vad);
return retval;
}
解决方案
您应该使用sf_open_virtual而不是sf_open
创建SNDFILE
实例。因此,根据文档,您应该传递SF_VIRTUAL_IO*
给sf_open_virtual。
必须实现该结构的每个成员的定义以反映您的 QBuffer。因此,您需要创建一个辅助类,它接受对 QBuffer 的引用并实现具有相同占用空间的方法,如下所示。
typedef sf_count_t (*sf_vio_get_filelen) (void *user_data) ;
typedef sf_count_t (*sf_vio_seek) (sf_count_t offset, int whence, void *user_data) ;
typedef sf_count_t (*sf_vio_read) (void *ptr, sf_count_t count, void *user_data) ;
typedef sf_count_t (*sf_vio_write) (const void *ptr, sf_count_t count, void *user_data) ;
typedef sf_count_t (*sf_vio_tell) (void *user_data) ;
这是您需要传递给结构的函数的实现:
static sf_count_t
qbuffer_get_filelen (void *user_data)
{ QBuffer *buff = (QBuffer *) user_data ;
return buff->size();
}
static sf_count_t
qbuffer_seek (sf_count_t offset, int whence, void *user_data)
{
QBuffer *buff = (QBuffer *) user_data ;
switch (whence)
{ case SEEK_SET :
buff->seek(offset);
break ;
case SEEK_CUR :
buff->seek(buff->pos()+offset);
break ;
case SEEK_END :
buff->seek(buff->size()+offset);
break ;
default :
break ;
} ;
return buff->pos();
}
static sf_count_t
qbuffer_read (void *ptr, sf_count_t count, void *user_data)
{
QBuffer *buff = (QBuffer *) user_data ;
return buff->read((char*)ptr,count);
}
static sf_count_t
qbuffer_write (const void *ptr, sf_count_t count, void *user_data)
{
QBuffer *buff = (QBuffer *) user_data ;
return buff->write((const char*)ptr,count);
}
static sf_count_t
qbuffer_tell (void *user_data)
{
QBuffer *buff = (QBuffer *) user_data ;
return buff->pos() ;
}
您可以像这样创建结构:
SF_VIRTUAL_IO qbuffer_virtualio ;
qbuffer_virtualio.get_filelen = qbuffer_get_filelen ;
qbuffer_virtualio.seek = qbuffer_seek ;
qbuffer_virtualio.read = qbuffer_read ;
qbuffer_virtualio.write = qbuffer_write ;
qbuffer_virtualio.tell = qbuffer_tell ;
然后当你打电话时sf_open_virtual
QBuffer buffer(&yourArray);
buffer.open(QIODevice::ReadWrite);
sf_open_virtual (&qbuffer_virtualio , mode, sfinfo, (void *)(&buffer));
// doing whatever
// you may want to close the buffer
buffer.close();
你也可以把这些接口函数放在一个类中,QBuffer_SFVIRTUAL_Interface
并像这样引用它们:
qbuffer_virtualio.get_filelen = QBuffer_SFVIRTUAL_Interface::qbuffer_get_filelen ;
qbuffer_virtualio.seek = QBuffer_SFVIRTUAL_Interface::qbuffer_seek ;
qbuffer_virtualio.read = QBuffer_SFVIRTUAL_Interface::qbuffer_read ;
qbuffer_virtualio.write = QBuffer_SFVIRTUAL_Interface::qbuffer_write ;
qbuffer_virtualio.tell = QBuffer_SFVIRTUAL_Interface::qbuffer_tell ;
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