恼人的刻度与speex [英] Annoying tick with speex
问题描述
我正在做一个应用程序，其中我使用Speex，OpenAL和linsndfile。
I am making an application in which I use Speex, OpenAL and linsndfile.
问题是，当我写一个示例缓冲区的文件16）使用libsndfile一切都是对的。但如果我编码他们，然后使用Spexx解码，我得到了一个'tick'之间的每个样本。
我先说一个样本损失或一些缓冲区太大。但我没有找到任何东西。
起初，代码是在一个带有boost线程的体系结构中，并且分成多个类。即使这个最小的代码，我的问题仍然是。
The problem is that when i write a sample buffer in the file (raw pcm unsigned 16) using libsndfile everything is right.But if i encode them, then decode them using Spexx, I get like a 'tick' between each sample. I first though about a sample loss or some buffer being too big. But i did'nt find anything. At first the code was in an architecture with boost threads and was splitted in multiple classes. Even whith this minimal code, my problem is still.
这是产生问题的完整的最小代码。感谢您的帮助。
Here is the full minimal code which produce the problem. Thanks for you help.
#include <iostream>
#include <stdexcept>
#include <vector>
#include <cstring>
#include <algorithm>
#include <sndfile.h>
#include <AL/al.h>
#include <AL/alc.h>
#include <speex/speex.h>
typedef std::vector<ALshort> Samples;
std::string chooseDevice()
{
std::vector<std::string> ret;
const ALCchar* DeviceList = alcGetString(NULL, ALC_CAPTURE_DEVICE_SPECIFIER);
int i = 0;
if (DeviceList)
while (strlen(DeviceList) > 0) {
std::string tmp = DeviceList;
ret.push_back(tmp);
DeviceList += strlen(DeviceList) + 1;
std::cout << i++ << ": " << tmp << std::endl;
}
std::cout << "Choose a device : " << std::flush;
if (!(std::cin >> i))
throw std::runtime_error("NaN");
return ret[i];
}
SNDFILE* openFile()
{
SNDFILE* file;
SF_INFO fileInfo;
fileInfo.channels = 1;
fileInfo.samplerate = 8000;
fileInfo.format = SF_FORMAT_PCM_16 | SF_FORMAT_WAV;
file = sf_open("capture.wav", SFM_WRITE, &fileInfo);
if (!file)
throw std::runtime_error("SNDFILE error");
return file;
}
enum Mode {DIRECT = 1, ENCODE_AND_DECODE};
void writeToFile(SNDFILE* file, const Samples& samples, const Mode mode)
{
static std::vector<ALshort> buffer;
switch (mode) {
case DIRECT: sf_write_short(file, &samples[0], samples.size()); break; // Ecriture ici
case ENCODE_AND_DECODE: {
std::copy(samples.begin(), samples.end(), std::back_inserter(buffer));
int frameSize;
void* encoderState = speex_encoder_init(&speex_wb_mode);
speex_encoder_ctl(encoderState, SPEEX_GET_FRAME_SIZE, &frameSize);
// AL pourrait donner trop ou pas assez d'échantillons
while (buffer.size() >= frameSize) {
// encodage
void* encoderState = speex_encoder_init(&speex_wb_mode);
SpeexBits bits;
speex_encoder_ctl(encoderState, SPEEX_GET_FRAME_SIZE, &frameSize);
buffer.reserve(2*frameSize);
std::vector<char> output;
output.resize(2*frameSize);
speex_bits_init(&bits);
speex_encode_int(encoderState, &buffer[0], &bits);
int bytes = speex_bits_write(&bits, &output[0], output.size());
speex_bits_destroy(&bits);
speex_encoder_destroy(encoderState);
// décodage
speex_bits_init(&bits);
encoderState = speex_decoder_init(&speex_wb_mode);
speex_encoder_ctl(encoderState, SPEEX_GET_FRAME_SIZE, &frameSize);
speex_bits_read_from(&bits, &output[0], bytes);
std::vector<short> samples(frameSize);
speex_decode_int(encoderState, &bits, &samples[0]);
sf_write_short(file, &samples[0], frameSize); // Ecriture ici
speex_decoder_destroy(encoderState);
speex_bits_destroy(&bits);
buffer.erase(buffer.begin(), buffer.begin()+frameSize);
std::cout << "." << std::flush;
}
}
break;
}
}
void closeFile(SNDFILE* file)
{
sf_close(file);
std::cout << "enregistré dans capture.wav" << std::endl;
}
int main()
{
ALCdevice* device;
ALCdevice* captureDevice;
ALCcontext* context;
device = alcOpenDevice(0);
if (!device)
throw std::runtime_error("Unable to open the AL device");
context = alcCreateContext(device, 0);
if (!context)
throw std::runtime_error("Unable to create AL context");
if (!alcMakeContextCurrent(context))
throw std::runtime_error("Unable to set the context");
if (alcIsExtensionPresent(device, "ALC_EXT_CAPTURE") == AL_FALSE)
throw std::runtime_error("AL Capture extension not available");
captureDevice = alcCaptureOpenDevice(chooseDevice().c_str(), 8000, AL_FORMAT_MONO16, 8000);
if (!captureDevice)
throw std::runtime_error("Unable to open the capture device");
Samples samples;
SNDFILE* file = openFile();
std::cout << "Mode direct (1) ou encodage et décodage ? (2) : " << std::endl;
int i;
std::cin >> i;
Mode mode = Mode(i);
time_t start = time(0);
alcCaptureStart(captureDevice);
while (time(0) - start < 5) {
ALCint availableSamples;
alcGetIntegerv(captureDevice, ALC_CAPTURE_SAMPLES, 1, &availableSamples);
if (availableSamples > 0) {
samples.resize(availableSamples);
alcCaptureSamples(captureDevice, &samples[0], availableSamples);
writeToFile(file, samples, mode);
}
}
alcCaptureStop(captureDevice);
closeFile(file);
alcCaptureCloseDevice(captureDevice);
alcMakeContextCurrent(0);
alcDestroyContext(context);
alcCloseDevice(device);
}
-lspeex -lsndfile -lopenal
推荐答案
好吧，这样说，如果你不需要保持所有帧的相同状态你解码，首先没有状态对象。
Well, put it this way, if you didn't need to keep the same state for all the frames you decode, there would be no state object in the first place.
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