我编写了一个使用portaudio和sndfile播放声音文件的函数。不幸的是,音质很糟糕。声音更像是嘶嘶声。以下是我正在使用的函数的源代码。
#define _GLIBCXX_USE_C99_MATH 1
#include "PlaySound_config.h"
#include <boost/predef.h>
#if !defined(USE_PORTAUDIO) // {
# define USE_PORTAUDIO 0
# if (! BOOST_OS_CYGWIN && ! BOOST_OS_WINDOWS) // {
# undef USE_PORTAUDIO
# define USE_PORTAUDIO 1
# endif // }
#endif // }
#if (PLAY_SOUND_HAVE_PORTAUDIO_H && PLAY_SOUND_HAVE_SNDFILE_H && PLAY_SOUND_HAVE_SNDFILE_HH && USE_PORTAUDIO) // {
#if (PLAY_SOUND_HAVE_UNISTD_H)
# include <unistd.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <portaudio.h>
#include <sndfile.hh>
#include <cmath>
#include <fstream>
#include <iostream>
#include <vector>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/format.hpp>
#include "PlaySound.h"
#include "PlaySoundStrings.h"
void SoundWarning(const std::string& message)
{
std::cerr << message << std::endl;
}
bool PlaySoundFile(const std::string& soundFile, unsigned long /* volume */)
{
const int MAX_CHANNELS = 1;
const double SAMPLE_RATE = 11025.0;
const unsigned long FRAMES_PER_BUFFER = 1024;
const size_t BUFFER_LEN = 1024;
using boost::format;
using boost::io::group;
std::string message;
if (soundFile.empty())
{
errno = EINVAL;
message = playSoundStrings[error_invalid_argument];
SoundWarning(message);
return false;
}
boost::filesystem::path soundFilePath(soundFile);
if (! boost::filesystem::exists(soundFilePath))
{
errno = EINVAL;
message = str(format(playSoundStrings[error_file_does_not_exist]) % soundFile.c_str());
SoundWarning(message);
return false;
}
PaError paError = Pa_Initialize();
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_initialize_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
return false;
}
SNDFILE* sndFile;
SF_INFO sfInfo;
sndFile = sf_open(soundFile.c_str(), SFM_READ, &sfInfo);
if (! sndFile)
{
message = str(format(playSoundStrings[error_sf_open_failed]) % soundFile.c_str() % sf_strerror(nullptr));
SoundWarning(message);
Pa_Terminate();
return false;
}
if (sfInfo.channels > MAX_CHANNELS)
{
message = str(format(playSoundStrings[error_too_many_channels]) % sfInfo.channels % MAX_CHANNELS);
SoundWarning(message);
Pa_Terminate();
return false;
}
PaStream* stream = nullptr;
PaStreamParameters paStreamParameters;
paStreamParameters.device = Pa_GetDefaultOutputDevice();
paStreamParameters.channelCount = sfInfo.channels;
paStreamParameters.sampleFormat = paInt16;
paStreamParameters.suggestedLatency = Pa_GetDeviceInfo(paStreamParameters.device)->defaultLowOutputLatency;
paStreamParameters.hostApiSpecificStreamInfo = nullptr;
paError = Pa_OpenStream(
&stream, nullptr, &paStreamParameters,
SAMPLE_RATE, FRAMES_PER_BUFFER, paClipOff,
nullptr, nullptr);
if (paError != paNoError || ! stream)
{
message = str(format(playSoundStrings[error_pa_open_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
Pa_Terminate();
return false;
}
paError = Pa_StartStream(stream);
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_start_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
Pa_Terminate();
return false;
}
sf_count_t readCount = 0;
double data[BUFFER_LEN];
while ((readCount = sf_read_double(sndFile, data, BUFFER_LEN)))
{
paError = Pa_WriteStream(stream, data, BUFFER_LEN);
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_write_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
break;
}
}
paError = Pa_CloseStream(stream);
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_close_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
Pa_Terminate();
return false;
}
Pa_Terminate();
return true;
}
我在文章What is a lightweight cross platform WAV playing library?中看到了一些示例代码,但示例不完整。它似乎只播放文件的前五秒。我想播放整个文件。
知道我做错了吗?
此代码是我PlaySound项目的一部分。
答案 0 :(得分:2)
我在原始版本的代码中犯了几个错误。第一个是在我初始化PaStreamParameters结构的sampleFormat成员的行中。
在我的原始代码中,我按如下方式初始化了该成员。
paStreamParameters.sampleFormat = paInt16;
我应该按如下方式对其进行初始化。
paStreamParameters.sampleFormat = paInt32;
我的下一个错误是对Pa_OpenStream函数的调用。我将sampleRate参数设置为硬编码常量,在本例中为11025.0。我应该将它设置为SF_INFO结构的samplerate成员的值。
我的第三个错误是使用sf_read_double函数从声音文件中读取。在最终找到的几个工作示例中,包括sndfile-play应用程序,使用了sf_read_float函数。
我的第四个错误是我在将声音文件传递给Pa_WriteStream函数之前没有缩放从声音文件中读取的数据。我找到了在sndfile-play应用程序的源代码中扩展数据的代码。
对于任何感兴趣的人,我的源代码的最终版本如下。
#define _GLIBCXX_USE_C99_MATH 1
#include "PlaySound_config.h"
#include <boost/predef.h>
#if !defined(USE_PORTAUDIO) // {
# define USE_PORTAUDIO 0
# if (! BOOST_OS_CYGWIN && ! BOOST_OS_WINDOWS) // {
# undef USE_PORTAUDIO
# define USE_PORTAUDIO 1
# endif // }
#endif // }
#if (PLAY_SOUND_HAVE_PORTAUDIO_H && PLAY_SOUND_HAVE_SNDFILE_H && PLAY_SOUND_HAVE_SNDFILE_HH && USE_PORTAUDIO) // {
#if (PLAY_SOUND_HAVE_UNISTD_H)
# include <unistd.h>
#endif
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <portaudio.h>
#include <sndfile.hh>
#include <cmath>
#include <fstream>
#include <iostream>
#include <vector>
#include <boost/filesystem/operations.hpp>
#include <boost/filesystem/path.hpp>
#include <boost/format.hpp>
#include "PlaySound.h"
#include "PlaySoundStrings.h"
void SoundWarning(const std::string& message)
{
std::cerr << message << std::endl;
}
bool PlaySoundFile(const std::string& soundFile, unsigned long /* volume */)
{
const int MAX_CHANNELS = 1;
const size_t BUFFER_LEN = 1024;
using boost::format;
using boost::io::group;
std::string message;
if (soundFile.empty())
{
errno = EINVAL;
message = playSoundStrings[error_invalid_argument];
SoundWarning(message);
return false;
}
boost::filesystem::path soundFilePath(soundFile);
if (! boost::filesystem::exists(soundFilePath))
{
errno = EINVAL;
message = str(format(playSoundStrings[error_file_does_not_exist]) % soundFile.c_str());
SoundWarning(message);
return false;
}
PaError paError = Pa_Initialize();
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_initialize_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
return false;
}
SNDFILE* sndFile = nullptr;
SF_INFO sfInfo;
::memset(&sfInfo, 0, sizeof(sfInfo));
sndFile = sf_open(soundFile.c_str(), SFM_READ, &sfInfo);
if (! sndFile)
{
message = str(format(playSoundStrings[error_sf_open_failed]) % soundFile.c_str() % sf_strerror(nullptr));
SoundWarning(message);
Pa_Terminate();
return false;
}
if (sfInfo.channels > MAX_CHANNELS)
{
message = str(format(playSoundStrings[error_too_many_channels]) % sfInfo.channels % MAX_CHANNELS);
SoundWarning(message);
Pa_Terminate();
return false;
}
PaStream* stream = nullptr;
PaStreamParameters paStreamParameters;
paStreamParameters.device = Pa_GetDefaultOutputDevice();
paStreamParameters.channelCount = sfInfo.channels;
paStreamParameters.sampleFormat = paInt32;
paStreamParameters.suggestedLatency = Pa_GetDeviceInfo(paStreamParameters.device)->defaultLowOutputLatency;
paStreamParameters.hostApiSpecificStreamInfo = nullptr;
paError = Pa_OpenStream(
&stream, nullptr, &paStreamParameters,
sfInfo.samplerate, paFramesPerBufferUnspecified, paClipOff,
nullptr, nullptr);
if (paError != paNoError || ! stream)
{
message = str(format(playSoundStrings[error_pa_open_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
Pa_Terminate();
return false;
}
paError = Pa_StartStream(stream);
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_start_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
Pa_Terminate();
return false;
}
int subFormat = sfInfo.format & SF_FORMAT_SUBMASK;
double scale = 1.0;
if (subFormat == SF_FORMAT_FLOAT || subFormat == SF_FORMAT_DOUBLE)
{
sf_command(sndFile, SFC_CALC_SIGNAL_MAX, &scale, sizeof(scale));
if (scale < 1e-10)
{
scale = 1.0;
}
else
{
scale = 32700.0 / scale;
}
}
sf_count_t readCount = 0;
float data[BUFFER_LEN];
::memset(data, 0, sizeof(data));
while ((readCount = sf_read_float(sndFile, data, BUFFER_LEN)))
{
if (subFormat == SF_FORMAT_FLOAT || subFormat == SF_FORMAT_DOUBLE)
{
int m = 0;
for (m = 0 ; m < readCount ; ++m)
{
data[m] *= scale;
}
}
paError = Pa_WriteStream(stream, data, BUFFER_LEN);
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_write_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
break;
}
::memset(data, 0, sizeof(data));
}
paError = Pa_CloseStream(stream);
if (paError != paNoError)
{
message = str(format(playSoundStrings[error_pa_close_stream_failed]) % Pa_GetErrorText(paError));
SoundWarning(message);
Pa_Terminate();
return false;
}
Pa_Terminate();
return true;
}