Linux speex音频库-音频数据编解码

2024-09-07 04:32
文章标签 音频 数据 linux 编解码 speex

本文主要是介绍Linux speex音频库-音频数据编解码，希望对大家解决编程问题提供一定的参考价值，需要的开发者们随着小编来一起学习吧！

speex音频数据编解码

  • speex简述
  • speex encoder（编码器）
  • speex decoder（解码器）
  • denoise vad (降噪，语音活性检测)

speex简述

speex官网

Speex: A Free Codec For Free Speech
Overview

Speex is an Open Source/Free Software patent-free audio compression format designed for speech. The Speex Project aims to lower the barrier of entry for voice applications by providing a free alternative to expensive proprietary speech codecs. Moreover, Speex is well-adapted to Internet applications and provides useful features that are not present in most other codecs. Finally, Speex is part of the GNU Project and is available under the revised BSD license.
The Technology

Speex is based on CELP and is designed to compress voice at bitrates ranging from 2 to 44 kbps. Some of Speex’s features include:

Narrowband (8 kHz), wideband (16 kHz), and ultra-wideband (32 kHz) compression in the same bitstream
Intensity stereo encoding
Packet loss concealment
Variable bitrate operation (VBR)
Voice Activity Detection (VAD)
Discontinuous Transmission (DTX)
Fixed-point port
Acoustic echo canceller
Noise suppression
1
2
3
4
5
6
7
8
9
Note that Speex has a number of features that are not present in other codecs, such as intensity stereo encoding, integration of multiple sampling rates in the same bitstream (embedded coding), and a VBR mode; see our comparison page for more.
Getting Involved

One of the simplest things you can do to get involved in Speex is by using it in your application; Speex is well-suited to handle VoIP, internet audio streaming, data archival (like voice mail), and audio books. Currently, LinPhone, Ekiga, and Asterisk are some of the projects currently using Speex. For a list of projects with Speex support, visit our Plugins & Software page.

If you have questions or are interested in contributing to the project, have a look at our roadmap, join our mailing list, or send us money so we can keep working on Speex. You can also contact the Project Lead, Jean-Marc Valin (though the mailing is usually the best place to ask questions).

Patches can be sent to the mailing list, and should apply on the latest master branch.

speex encoder（编码器）

#include <stdio.h>
#include <stdlib.h>
#include <stddef.h>
#include <stdbool.h>
#include <stdint.h>
#include <unistd.h>
#include <getopt.h>#include <speex/speex.h>
#include <speex/speex_header.h>
#include <speex/speex_stereo.h>/*The frame size in hardcoded for this sample code but it doesn’t have to be*/
#define FRAME_SIZE 160
int main(int argc, char **argv)
{char *inFile;FILE *fin;short in[FRAME_SIZE];float input[FRAME_SIZE];char cbits[200];int nbBytes;if (argc < 2){printf("Usge: speexenc in.wav >> out.wav\n");exit(0);}/*Holds the state of the encoder*/void *state;/*Holds bits so they can be read and written to by the Speex routines*/SpeexBits bits;int i, tmp;/*Create a new encoder state in narrowband mode*/state = speex_encoder_init(&speex_nb_mode);/*Set the quality to 8 (15 kbps)*/tmp = 8;speex_encoder_ctl(state, SPEEX_SET_QUALITY, &tmp);inFile = argv[1];fin = fopen(inFile, "r");if(!fin){printf("open file error.\n");}/*Initialization of the structure that holds the bits*/speex_bits_init(&bits);while (1){/*Read a 16 bits/sample audio frame*/fread(in, sizeof(short), FRAME_SIZE, fin);if(feof(fin))break;/*Copy the 16 bits values to float so Speex can work on them*/for (int i=0; i<FRAME_SIZE; i++){input[i] = in[i];}/*Flush all the bits in the struct so we can encode a new frame*/speex_bits_reset(&bits);/*Encode the frame*/speex_encode(state, input, &bits);/*Copy the bits to an array of char that can be written*/nbBytes = speex_bits_write(&bits, cbits, 200);/*Write the size of the frame first. This is what sampledec expects butit’s likely to be different in your own application*/fwrite(&nbBytes, sizeof(int), 1, stdout);/*Write the compressed data*/fwrite(cbits, 1, nbBytes, stdout);}/*Destroy the encoder state*/speex_encoder_destroy(state);/*Destroy the bit-packing struct*/speex_bits_destroy(&bits);fclose(fin);return 0;}

gcc speexenc.c -o speexenc -lspeex
./speexenc in.wav >> out.wav

speex decoder（解码器）

#include <stdio.h>
#include <stdlib.h>
#include <stdbool.h>
#include <stdint.h>
#include <stddef.h>
#include <speex/speex.h>/*The frame size in hardcoded for this sample code but it doesn’t have to be*/
#define FRAME_SIZE 160int main(int argc, char **argv)
{char *outFile;char *inFile;FILE *fout;FILE *fin;/*Holds the audio that will be written to file (16 bits per sample)*/short out[FRAME_SIZE];/*Speex handle samples as float, so we need an array of floats*/float output[FRAME_SIZE];char cbits[200];int nbBytes;/*Holds the state of the decoder*/void *state;/*Holds bits so they can be read and written to by the Speex routines*/SpeexBits bits;int i, tmp;/*Create a new decoder state in narrowband mode*/state = speex_decoder_init(&speex_nb_mode);/*Set the perceptual enhancement on*/   tmp = 1;speex_decoder_ctl(state, SPEEX_SET_ENH, &tmp);outFile = argv[1];fout = fopen(outFile, "w");if (!fout){printf("open out file error\n");}inFile = argv[2];fin = fopen(inFile, "r");if (!fin){printf("open in file error\n");}/*Initialization of the structure that holds the bits*/speex_bits_init(&bits);while (1){/*Read the size encoded by sampleenc, this part will likely be different in your application*/fread(&nbBytes, sizeof(int), 1, fin);fprintf(stderr, "nbBytes: %d\n", nbBytes);if(feof(fin)){break;}/*Read the "packet" encoded by sampleenc*/fread(cbits, 1, nbBytes, fin);/*Copy the data into the bit-stream struct*/speex_bits_read_from(&bits, cbits, nbBytes);/*Decode the data*/speex_decode(state, &bits, output);/*Copy from float to short (16 bits) for output*/for (i=0;i<FRAME_SIZE;i++)out[i]=output[i];/*Write the decoded audio to file*/fwrite(out, sizeof(short), FRAME_SIZE, fout);}/*Destroy the decoder state*/speex_decoder_destroy(state);/*Destroy the bit-stream truct*/speex_bits_destroy(&bits);fclose(fout);return 0;
}

gcc speexdnc.c -o speexdnc -lspeex
./speexdnc new.wav out.wav

denoise vad (降噪，语音活性检测)

VAD:语音活性检测 (Voice activity detection)


#include <speex/speex.h>
#include <speex/speex_preprocess.h>
#include <stdio.h>
#include <ogg/ogg.h>#define FRAME_SIZE 1152
#define FRAME_SAMPLERATE 32000
#define DENOISE_DB (-20)int main(int argn, char* argv[]) 
{char* szInFilename = NULL;char* szOutFilename = NULL;FILE* pInFileHandle = NULL;FILE* pOutFileHandle = NULL;short in[FRAME_SAMPLERATE];int i;SpeexPreprocessState *st;int count=0;float f;printf("starting....\r\n");if(argn != 3){printf("please input 2 parameters\r\n");return -1;}szInFilename = argv[1];szOutFilename = argv[2];pInFileHandle = fopen(szInFilename, "rb");if(!pInFileHandle){printf("open file %s error\r\n", szInFilename);return -2;}pOutFileHandle = fopen(szOutFilename, "wb");if(!pOutFileHandle){printf("open file %s error\r\n", szOutFilename);fclose(pInFileHandle);return -3;}st = speex_preprocess_state_init(FRAME_SIZE, FRAME_SAMPLERATE);int denoise = 1;int noiseSuppress = DENOISE_DB;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_DENOISE, &denoise); //降噪speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_NOISE_SUPPRESS, &noiseSuppress); //设置噪声的dBi=0;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_AGC, &i);i=8000;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_AGC_LEVEL, &i);i=0;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_DEREVERB, &i);f=.0;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_DEREVERB_DECAY, &f);f=.0;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_DEREVERB_LEVEL, &f);int vad = 1;int vadProbStart = 80;int vadProbContinue = 65;speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_VAD, &vad); //静音检测speex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_PROB_START , &vadProbStart); //Set probability required for the VAD to go from silence to voicespeex_preprocess_ctl(st, SPEEX_PREPROCESS_SET_PROB_CONTINUE, &vadProbContinue); //Set probability required for the VAD to stay in the voice state (integer percent)while (1){int vad;int iLen = fread(in, sizeof(short), FRAME_SIZE, pInFileHandle);if(iLen <= 0){break;}if (feof(pInFileHandle))break;vad = speex_preprocess_run(st, in);if(vad != 0){printf("speech.\r\n");fwrite(in, sizeof(short), FRAME_SIZE, pOutFileHandle);}else{printf("slience---------\r\n");fwrite(in, sizeof(short), FRAME_SIZE, pOutFileHandle);}count++;}speex_preprocess_state_destroy(st);fclose(pInFileHandle);fclose(pOutFileHandle);return 0;
}

这篇关于Linux speex音频库-音频数据编解码的文章就介绍到这儿，希望我们推荐的文章对编程师们有所帮助！


http://www.chinasem.cn/article/1144059。

相关文章

一文教你Python如何快速精准抓取网页数据

一文教你Python如何快速精准抓取网页数据

《一文教你Python如何快速精准抓取网页数据》这篇文章主要为大家详细介绍了如何利用Python实现快速精准抓取网页数据,文中的示例代码简洁易懂,具有一定的借鉴价值,有需要的小伙伴可以了解下... 目录1. 准备工作2. 基础爬虫实现3. 高级功能扩展3.1 抓取文章详情3.2 保存数据到文件4. 完整示例
阅读更多...
使用Java将各种数据写入Excel表格的操作示例

使用Java将各种数据写入Excel表格的操作示例

《使用Java将各种数据写入Excel表格的操作示例》在数据处理与管理领域,Excel凭借其强大的功能和广泛的应用,成为了数据存储与展示的重要工具,在Java开发过程中,常常需要将不同类型的数据,本文... 目录前言安装免费Java库1. 写入文本、或数值到 Excel单元格2. 写入数组到 Excel表格
阅读更多...
Linux之systemV共享内存方式

Linux之systemV共享内存方式

《Linux之systemV共享内存方式》：本文主要介绍Linux之systemV共享内存方式,具有很好的参考价值,希望对大家有所帮助,如有错误或未考虑完全的地方,望不吝赐教... 目录一、工作原理二、系统调用接口1、申请共享内存（一）key的获取（二）共享内存的申请2、将共享内存段连接到进程地址空间3、将
阅读更多...
python处理带有时区的日期和时间数据

python处理带有时区的日期和时间数据

《python处理带有时区的日期和时间数据》这篇文章主要为大家详细介绍了如何在Python中使用pytz库处理时区信息,包括获取当前UTC时间,转换为特定时区等,有需要的小伙伴可以参考一下... 目录时区基本信息python datetime使用timezonepandas处理时区数据知识延展时区基本信息
阅读更多...
Qt实现网络数据解析的方法总结

Qt实现网络数据解析的方法总结

《Qt实现网络数据解析的方法总结》在Qt中解析网络数据通常涉及接收原始字节流,并将其转换为有意义的应用层数据,这篇文章为大家介绍了详细步骤和示例,感兴趣的小伙伴可以了解下... 目录1. 网络数据接收2. 缓冲区管理（处理粘包/拆包）3. 常见数据格式解析3.1 jsON解析3.2 XML解析3.3 自定义
阅读更多...
SpringMVC 通过ajax 前后端数据交互的实现方法

SpringMVC 通过ajax 前后端数据交互的实现方法

《SpringMVC通过ajax前后端数据交互的实现方法》：本文主要介绍SpringMVC通过ajax前后端数据交互的实现方法,本文给大家介绍的非常详细,对大家的学习或工作具有一定的参考借鉴价... 在前端的开发过程中，经常在html页面通过AJAX进行前后端数据的交互，SpringMVC的controll
阅读更多...
快速修复一个Panic的Linux内核的技巧

快速修复一个Panic的Linux内核的技巧

《快速修复一个Panic的Linux内核的技巧》Linux系统中运行了不当的mkinitcpio操作导致内核文件不能正常工作，重启的时候，内核启动中止于Panic状态，该怎么解决这个问题呢？下面我们就... 感谢China编程(www.chinasem.cn)网友 鸢一雨音 的投稿写这篇文章是有原因的。为了配置完
阅读更多...
Pandas统计每行数据中的空值的方法示例

Pandas统计每行数据中的空值的方法示例

《Pandas统计每行数据中的空值的方法示例》处理缺失数据（NaN值）是一个非常常见的问题,本文主要介绍了Pandas统计每行数据中的空值的方法示例,具有一定的参考价值,感兴趣的可以了解一下... 目录什么是空值？为什么要统计空值？准备工作创建示例数据统计每行空值数量进一步分析www.chinasem.cn处
阅读更多...
如何使用 Python 读取 Excel 数据

如何使用 Python 读取 Excel 数据

《如何使用Python读取Excel数据》：本文主要介绍使用Python读取Excel数据的详细教程,通过pandas和openpyxl,你可以轻松读取Excel文件,并进行各种数据处理操... 目录使用 python 读取 Excel 数据的详细教程1. 安装必要的依赖2. 读取 Excel 文件3. 读
阅读更多...
Spring 请求之传递 JSON 数据的操作方法

Spring 请求之传递 JSON 数据的操作方法

《Spring请求之传递JSON数据的操作方法》JSON就是一种数据格式,有自己的格式和语法,使用文本表示一个对象或数组的信息,因此JSON本质是字符串,主要负责在不同的语言中数据传递和交换,这... 目录jsON 概念JSON 语法JSON 的语法JSON 的两种结构JSON 字符串和 Java 对象互转
阅读更多...

Copyright China编程 23002807@qq.com

沪ICP备2023033072号-2