网络监控摄像头音频编码用aac好还是G.7111音频A好。哪个编码类型的音质好？

来源：蜘蛛抓取(WebSpider) 时间：2016-12-04 09:15 标签： G.7111音频
G.711音频编码方式
G.711是一种由国际电信联盟（ITU-T）制定的音频编码方式，又称为ITU-T
G.711使用64Kbps的带宽，可将14bits转换成8bits。
前G.711有两个编码方式，A-law以及μ-law。2008年3月国际电信联盟正式发布了最新的宽带语音编解码标准G.711.1。
转载自：http://zh.wikipedia.org/wiki/G.711
已投稿到：
以上网友发言只代表其个人观点，不代表新浪网的观点或立场。嵌入式 G711A编码音频转码为AAC过程代码示例
嵌入式 G711A编码音频转码为AAC过程代码示例
分类： 嵌入式
使用开源库faac，该库的编译方法见我的另一个blog：
1、内存泄漏已测试
2、效率也测试通过
Author : kj
Function :joseph aac, g711a changover aac
#include &fcntl.h&
#include &stdio.h&
#include &ctype.h&
#include &errno.h&
#include &stdlib.h&
#include &string.h&
#include &limits.h&
#include &unistd.h&
#include &signal.h&
#include &dirent.h&
#include &pthread.h&
#include &asm/types.h&
#include &arpa/inet.h&
#include &sys/vfs.h&
#include &sys/time.h&
#include &sys/wait.h&
#include &sys/stat.h&
#include &sys/ioctl.h&
#include &sys/types.h&
#include &sys/socket.h&
#include &sys/utsname.h&
#include &netdb.h&
#include &net/if.h&
#include &netinet/in.h&
#include &net/route.h&
#include &net/if_arp.h&
#include &linux/fs.h&
#include &linux/sockios.h&
#include &linux/netlink.h&
#include &linux/rtnetlink.h&
#include &netinet/in.h&
#include &netinet/ip.h&
#include &netinet/ether.h&
#include &netinet/ip_icmp.h&
#include "faac.h"
#define JOSEPH_G711A_FILE
"src.g711a"
#define JOSEPH_AAC_FILE
"dest.aac"
static const int16_t alawtos16[256] =
-22016, -20992, -24064, -23040, -17920, -16896, -19968, -18944,
-30208, -29184, -32256, -31232, -26112, -25088, -28160, -27136,
-11008, -10496, -12032, -11520,
-15104, -14592, -16128, -15616, -13056, -12544, -14080, -13568,
static const int8_t alaw_encode[2049] =
0xD5, 0xD4, 0xD7, 0xD6, 0xD1, 0xD0, 0xD3, 0xD2, 0xDD, 0xDC, 0xDF, 0xDE,
0xD9, 0xD8, 0xDB, 0xDA, 0xC5, 0xC4, 0xC7, 0xC6, 0xC1, 0xC0, 0xC3, 0xC2,
0xCD, 0xCC, 0xCF, 0xCE, 0xC9, 0xC8, 0xCB, 0xCA, 0xF5, 0xF5, 0xF4, 0xF4,
0xF7, 0xF7, 0xF6, 0xF6, 0xF1, 0xF1, 0xF0, 0xF0, 0xF3, 0xF3, 0xF2, 0xF2,
0xFD, 0xFD, 0xFC, 0xFC, 0xFF, 0xFF, 0xFE, 0xFE, 0xF9, 0xF9, 0xF8, 0xF8,
0xFB, 0xFB, 0xFA, 0xFA, 0xE5, 0xE5, 0xE5, 0xE5, 0xE4, 0xE4, 0xE4, 0xE4,
0xE7, 0xE7, 0xE7, 0xE7, 0xE6, 0xE6, 0xE6, 0xE6, 0xE1, 0xE1, 0xE1, 0xE1,
0xE0, 0xE0, 0xE0, 0xE0, 0xE3, 0xE3, 0xE3, 0xE3, 0xE2, 0xE2, 0xE2, 0xE2,
0xED, 0xED, 0xED, 0xED, 0xEC, 0xEC, 0xEC, 0xEC, 0xEF, 0xEF, 0xEF, 0xEF,
0xEE, 0xEE, 0xEE, 0xEE, 0xE9, 0xE9, 0xE9, 0xE9, 0xE8, 0xE8, 0xE8, 0xE8,
0xEB, 0xEB, 0xEB, 0xEB, 0xEA, 0xEA, 0xEA, 0xEA, 0x95, 0x95, 0x95, 0x95,
0x95, 0x95, 0x95, 0x95, 0x94, 0x94, 0x94, 0x94, 0x94, 0x94, 0x94, 0x94,
0x97, 0x97, 0x97, 0x97, 0x97, 0x97, 0x97, 0x97, 0x96, 0x96, 0x96, 0x96,
0x96, 0x96, 0x96, 0x96, 0x91, 0x91, 0x91, 0x91, 0x91, 0x91, 0x91, 0x91,
0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x90, 0x93, 0x93, 0x93, 0x93,
0x93, 0x93, 0x93, 0x93, 0x92, 0x92, 0x92, 0x92, 0x92, 0x92, 0x92, 0x92,
0x9D, 0x9D, 0x9D, 0x9D, 0x9D, 0x9D, 0x9D, 0x9D, 0x9C, 0x9C, 0x9C, 0x9C,
0x9C, 0x9C, 0x9C, 0x9C, 0x9F, 0x9F, 0x9F, 0x9F, 0x9F, 0x9F, 0x9F, 0x9F,
0x9E, 0x9E, 0x9E, 0x9E, 0x9E, 0x9E, 0x9E, 0x9E, 0x99, 0x99, 0x99, 0x99,
0x99, 0x99, 0x99, 0x99, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98, 0x98,
0x9B, 0x9B, 0x9B, 0x9B, 0x9B, 0x9B, 0x9B, 0x9B, 0x9A, 0x9A, 0x9A, 0x9A,
0x9A, 0x9A, 0x9A, 0x9A, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85,
0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x85, 0x84, 0x84, 0x84, 0x84,
0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84, 0x84,
0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87, 0x87,
0x87, 0x87, 0x87, 0x87, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86,
0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x86, 0x81, 0x81, 0x81, 0x81,
0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81, 0x81,
0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x80,
0x80, 0x80, 0x80, 0x80, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83,
0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x83, 0x82, 0x82, 0x82, 0x82,
0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82, 0x82,
0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D, 0x8D,
0x8D, 0x8D, 0x8D, 0x8D, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C,
0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8C, 0x8F, 0x8F, 0x8F, 0x8F,
0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F, 0x8F,
0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E, 0x8E,
0x8E, 0x8E, 0x8E, 0x8E, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89,
0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x89, 0x88, 0x88, 0x88, 0x88,
0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88, 0x88,
0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B, 0x8B,
0x8B, 0x8B, 0x8B, 0x8B, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A,
0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0x8A, 0xB5, 0xB5, 0xB5, 0xB5,
0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5,
0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5, 0xB5,
0xB5, 0xB5, 0xB5, 0xB5, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4,
0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4,
0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4, 0xB4,
0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7,
0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7,
0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB7, 0xB6, 0xB6, 0xB6, 0xB6,
0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6,
0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6, 0xB6,
0xB6, 0xB6, 0xB6, 0xB6, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1,
0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1,
0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1, 0xB1,
0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0,
0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0,
0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB0, 0xB3, 0xB3, 0xB3, 0xB3,
0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3,
0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3, 0xB3,
0xB3, 0xB3, 0xB3, 0xB3, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2,
0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2,
0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2, 0xB2,
0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD,
0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD,
0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBD, 0xBC, 0xBC, 0xBC, 0xBC,
0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC,
0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC, 0xBC,
0xBC, 0xBC, 0xBC, 0xBC, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF,
0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF,
0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF, 0xBF,
0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE,
0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE,
0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xBE, 0xB9, 0xB9, 0xB9, 0xB9,
0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9,
0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9, 0xB9,
0xB9, 0xB9, 0xB9, 0xB9, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8,
0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8,
0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8, 0xB8,
0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB,
0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB,
0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBB, 0xBA, 0xBA, 0xBA, 0xBA,
0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA,
0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA, 0xBA,
0xBA, 0xBA, 0xBA, 0xBA, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5,
0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5,
0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5,
0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5,
0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5,
0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA5, 0xA4, 0xA4, 0xA4, 0xA4,
0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4,
0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4,
0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4,
0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4,
0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4, 0xA4,
0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7,
0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7,
0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7,
0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7,
0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7, 0xA7,
0xA7, 0xA7, 0xA7, 0xA7, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6,
0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA6, 0xA1, 0xA1, 0xA1, 0xA1,
0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1,
0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1,
0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1,
0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1,
0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1, 0xA1,
0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0,
0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0,
0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0,
0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0,
0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0, 0xA0,
0xA0, 0xA0, 0xA0, 0xA0, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3,
0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3,
0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3,
0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3,
0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3,
0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA3, 0xA2, 0xA2, 0xA2, 0xA2,
0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2,
0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2,
0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2,
0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2,
0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2, 0xA2,
0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD,
0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD,
0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD,
0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD,
0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD, 0xAD,
0xAD, 0xAD, 0xAD, 0xAD, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC,
0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC,
0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC,
0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC,
0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC,
0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAC, 0xAF, 0xAF, 0xAF, 0xAF,
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0xAE, 0xAE, 0xAE, 0xAE, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9,
0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9,
0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9,
0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9,
0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9, 0xA9,
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0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8,
0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8,
0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8,
0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8,
0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8, 0xA8,
0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB, 0xAB,
0xAB, 0xAB, 0xAB, 0xAB, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA,
0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0xAA, 0x2A
int g711a_decode(void *pout_buf, int *pout_len, const void *pin_buf, const int
int16_t *dst = (int16_t *)pout_
uint8_t *src = (uint8_t *)pin_
uint32_t i = 0;int Ret = 0;
if ((NULL == pout_buf) || \(NULL == pout_len) || \(NULL == pin_buf)
|| \(0 == in_len) )
return -1;
if ( *pout_len & 2 * in_len )
return -2;
for( i = 0; i & in_ i++ )
*(dst++) = alawtos16[*(src++)];
*pout_len = 2 * in_
Ret = 2 * in_
int g711a_encode(void *pout_buf, int *pout_len, const void *pin_buf, const int in_len)
int8_t *dst = (int8_t *)pout_
int16_t *src = (int16_t *)pin_
uint32_t i = 0;
int Ret = 0;
if ((NULL == pout_buf) || \(NULL == pout_len) || \(NULL == pin_buf)
|| \(0 == in_len) )
return -1;
if ( *pout_len & in_len / 2 )
return -2;
for( i = 0; i & in_len / 2; i++ )
int16_t s = *(src++);
if( s &= 0)
*(dst++) = alaw_encode[s / 16];
*(dst++) = 0x7F & alaw_encode[s / -16];
*pout_len = in_len / 2;
Ret = in_len / 2;
int main(int argc, char *argv[])
{/*pcm file for input*/FILE* fpIn;/*AAC file for output*/FILE* fpOint nRet = 0;int nTmp = 0;int nCount = 0;int nStatus = 0;int nPCMRead = 0;int PCMSize = 320;int gBytesRead = 0;int nBytesRead = 0;int nPCMBufferSize = 0;unsigned char *pPCM = NULL;unsigned char *pbPCMBuffer = NULL;unsigned char *pbAACBuffer = NULL;unsigned char *pbG711ABuffer = NULL;unsigned char *pbPCMTmpBuffer = NULL;
unsigned int objectType = LOW;unsigned int mpegVersion = MPEG2;
static unsigned int useTns = 0;//#define DEFAULT_TNS
0unsigned int nChannels = 1;
unsigned int nPCMBitSize = 16;
unsigned long nInputSamples = 0;unsigned long nSampleRate = 8000; unsigned long nMaxOutputBytes = 0;faacEncHandle hEfaacEncConfigurationPtr pCfpIn = fopen(JOSEPH_G711A_FILE, "rb");if(NULL == fpIn){printf("%s:[%d] open %s file failed\n",__FUNCTION__,__LINE__,JOSEPH_G711A_FILE);return -1;}fpOut = fopen(JOSEPH_AAC_FILE, "wb");if(NULL == fpOut){printf("%s:[%d] open %s file failed\n",__FUNCTION__,__LINE__,JOSEPH_AAC_FILE);return -1;}/*open FAAC engine*/hEncoder = faacEncOpen(nSampleRate, nChannels, &nInputSamples, &nMaxOutputBytes);if(hEncoder == NULL){printf("%s:[%d] failed to call faacEncOpen !\n",__FUNCTION__,__LINE__);return -1;}printf("%s:[%d] nInputSamples == %ld, nMaxOutput == %ld !\n",\__FUNCTION__,__LINE__, nInputSamples, nMaxOutputBytes);nPCMBufferSize = (nInputSamples * (nPCMBitSize/8));pbPCMBuffer = (unsigned char*)malloc(nPCMBufferSize * sizeof(unsigned char));memset(pbPCMBuffer, 0, nPCMBufferSize);pbAACBuffer = (unsigned char*)malloc(nMaxOutputBytes * sizeof(unsigned char));memset(pbAACBuffer,0,nMaxOutputBytes);pbG711ABuffer = (unsigned char *)malloc(164 *sizeof(unsigned char));memset(pbG711ABuffer, 0, 164);pbPCMTmpBuffer = (unsigned char *)malloc(PCMSize *sizeof(unsigned char));memset(pbPCMTmpBuffer, 0, PCMSize);/*get current encoding configuration*/pConfiguration = faacEncGetCurrentConfiguration(hEncoder);pConfiguration-&inputFormat = FAAC_INPUT_16BIT;/*0 - 1 - ADTS*/pConfiguration-&outputFormat = 1;
pConfiguration-&useTns = useT
pConfiguration-&aacObjectType = objectT
pConfiguration-&mpegVersion = mpegV/*set encoding configuretion*/nRet = faacEncSetConfiguration(hEncoder, pConfiguration);while((gBytesRead = fread(pbG711ABuffer, 1, 164, fpIn)) &0){nStatus = 0;/*hisi audio the first 4 bytes is error*/pPCM = pbG711ABuffer + 4;memset(pbPCMTmpBuffer, 0, PCMSize);if((nPCMRead = g711a_decode(pbPCMTmpBuffer, &PCMSize, pPCM, gBytesRead - 4)) & 0){printf("%s:[%d] G711A -& PCM
failed !\n",__FUNCTION__,__LINE__);}if((nPCMBufferSize - nCount) & nPCMRead){nStatus = 1;memset(pbAACBuffer,0,nMaxOutputBytes);memcpy(pbPCMBuffer + nCount, pbPCMTmpBuffer, (nPCMBufferSize - nCount));nInputSamples = (nPCMBufferSize / (nPCMBitSize / 8));nRet = faacEncEncode(hEncoder, (int*)pbPCMBuffer, nInputSamples, pbAACBuffer, nMaxOutputBytes);fwrite(pbAACBuffer, 1, nRet, fpOut);nTmp = nPCMRead - (nPCMBufferSize - nCount);memset(pbPCMBuffer, 0, nPCMBufferSize);memcpy(pbPCMBuffer, pbPCMTmpBuffer + (nPCMBufferSize - nCount),nTmp);nCount = 0;nCount += nT}if( nStatus == 0){memcpy( pbPCMBuffer + nCount, pbPCMTmpBuffer, nPCMRead);nCount += nPCMR}if(nPCMRead & 320){nInputSamples = (nCount / (nPCMBitSize / 8));nRet = faacEncEncode(hEncoder, (int*) pbPCMBuffer, nInputSamples, pbAACBuffer, nMaxOutputBytes);fwrite(pbAACBuffer, 1, nRet, fpOut);}}/*Close FAAC engine*/nRet = faacEncClose(hEncoder);/*free the source of malloc*/free(pbPCMBuffer);pbPCMBuffer = NULL;free(pbAACBuffer);pbAACBuffer = NULL;free(pbG711ABuffer);pbG711ABuffer = NULL;free(pbPCMTmpBuffer);pbPCMTmpBuffer = NULL;/*close file fp*/fclose(fpIn);fclose(fpOut);printf("%s:[%d] The sys changover succeed !\n",__FUNCTION__,__LINE__);return 0;
g711u与g729比较编码格式
WAV格式音频转G.711A
ffmpeg支持G711音频和H.264视频数据同步封装进MP4文件
G711格式音频编解码
h264视频流，aac音频流（g711a转码）推送至rtmp服务器
没有更多推荐了，ffmpeg之G711解析成pcm
ffmpeg在码流转换上面实在是强大，今天实验了一下把G711音频专成PCM的音频，并最终实验成功。
第一步：寻找解码器，若格式不支持，则无法转码
codec = avcodec_find_decoder(AV_CODEC_ID_PCM_ALAW);
if (!codec) {
fprintf(stderr, "Codec not found\n");
提醒：G711A的解码ID为AV_CODEC_ID_PCM_ALAW
第二步：创建解码上下文，主要保持解码相关的信息
c = avcodec_alloc_context3(codec);
fprintf(stderr, "Could not allocate audio codec context\n");
c-&sample_fmt = sample_
c-&sample_rate = sample_
c-&channels =
需要设置3个参数，不然后面打开解码器会失败
sample_fmt：采样格式，标识含义8位，16位等采样
sample_rate：采样频率
channels：采样通道数
第三步：打开解码器
if (avcodec_open2(c, codec, NULL) & 0) {
fprintf(stderr, "Could not open codec\n");
第四步：输入码流
ret = avcodec_send_packet(c, packet);
第五步：输出解码结果
int ret = avcodec_receive_frame(c, frame);
整个过程大约分为这5个步骤。
另外通过研究，有几个重要的关于内存的发现：
由于输入解码的数据格式是AVPacket，而我拿到的数据确是字节流，需要把字节流转换成AVPacket类型。
这里作了如下处理：
packet-&size = iS
packet-&data = (uint8_t *)av_malloc(packet-&size);
memcpy(packet-&data, pData, iSize);
ret = av_packet_from_data(packet, packet-&data, packet-&size);
if (ret &0)
fprintf(stderr, "av_packet_from_data error \n");
av_free(packet-&data);
ret = avcodec_send_packet(c, packet);
av_packet_unref(packet);
通过函数av_packet_from_data生产了AVPacket类型数据，但是需要注意在使用完之后，需要调用av_packet_unref进行释放内存，不然会存在内存泄漏，有人会问上面的内存是通过av_malcoc生成的，我们还需要释放吗？我通过实验发现调用av_packet_unref之后，就不需要再调用av_free来进行释放了，ffmpeg好像自己已经释放了。
另外关于解码出来的音频，需要注意他的存放再uint8_t *data[AV_NUM_DATA_POINTERS];里面的，这是一个数组，每个通道一维。由于pcm保持多通道根据采样率进行顺序保持，所以保持位pcm需要处理一下：
int iCopyPos = 0;
for(int i = 0; i & frame-&nb_ i++)
for (int ch = 0; ch & c-& ch++)
memcpy(m_pOutData + iCopyPos,frame-&data[ch] + data_size * i, data_size);
iCopyPos = iCopyPos + data_
最后，为了便于大家学习和交流，我采用vs2017开发，上传示例如下连接：
G711与PCM互相转换源代码
新版ffmpeg
PCM编码到AAC，swr_convert转换采样精度，稍微修改兼容PCM编码为G711A及MP3，记录下。
G711编解码(G711与PCM类型互转)【转】
Android 录音PCM 转G711U，非常简单，非FFMPEG
G711转AAC代码总结【转】
G711格式音频编解码
嵌入式 G711A编码音频转码为AAC过程代码示例
ffmpeg常用基本命令【转】
G711 编码 PCM （ALAW & ULAW）
Android G711(PCMA/PCMU)、G726、PCM音频转码到AAC
没有更多推荐了，

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