ffmpeg推流时报错 Unknown encoder 'libx264'
问题
执行以下ffmpeg推流命令时报错
ffmpeg -re -i "/home/lee000/Videos/00001.mp4" -vcodec libx264 -vprofile baseline -acodec aac -ar 44100 -strict -2 -ac 1 -f flv -s 1280x720 -q 10 rtmp://192.168.100.158:1935/rtmplive/test1
[root@localhost Videos]# ffmpeg -re -i "/home/lee000/Videos/00001.mp4" -vcodec libx264 -vprofile baseline -acodec aac -ar 44100 -strict -2 -ac 1 -f flv -s 1280x720 -q 10 rtmp://192.168.100.158:1935/rtmplive/test1
ffmpeg version N-95767-gcda3e8c Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-39)
configuration: --prefix=/usr/softinstall/ffmpeg
libavutil 56. 36.100 / 56. 36.100
libavcodec 58. 62.100 / 58. 62.100
libavformat 58. 35.100 / 58. 35.100
libavdevice 58. 9.100 / 58. 9.100
libavfilter 7. 66.100 / 7. 66.100
libswscale 5. 6.100 / 5. 6.100
libswresample 3. 6.100 / 3. 6.100
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/lee000/Videos/00001.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42isom
creation_time : 2019-10-16T06:58:33.000000Z
Duration: 00:11:12.83, start: 0.000000, bitrate: 1251 kb/s
Stream #0:0(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 1280x720, 791 kb/s, 29.82 fps, 29.92 tbr, 90k tbn, 180k tbc (default)
Stream #0:1(und): Audio: pcm_mulaw (ulaw / 0x77616C75), 8000 Hz, mono, s16, 64 kb/s (default)
Unknown encoder 'libx264'
解决方案
这是在安装ffmpeg时没有安装libx264库导致
安装libx264
1）下载libx264（官网）
git clone https://code.videolan.org/videolan/x264.git
2）切到x264根目录
cd x264
3）生成 Makefile
./configure --prefix=/usr/softinstall/x264/ --includedir=/usr/local/include --libdir=/usr/local/lib --enable-shared
如果不将include和lib安装在/usr/local目录，之后运行ffmpeg推流命令时可能仍然报
ERROR:libx264 not found错误。如果已经安装x264了发现报错，则需要将x264.h这个文件要放在/usr/local/include下，libx264的库文件拷贝到/usr/local/lib下，而不是指定其它目录安装存放。推荐安装时直接运行以上命令。
可能报如下错误：
[root@localhost x264]# ./configure --prefix=/usr/softinstall/x264/ --enable-static --enable-shared
Unknown option --enable-share, ignored Found no assembler Minimum > version is nasm-2.13
If you really want to compile without asm, configure with --disable-asm.
解决方案：
下载更新安装nasm新版本（nasm官网）：
wget https://www.nasm.us/pub/nasm/releasebuilds/2.14/nasm-2.14.tar.gz
4）编译
make
5）安装
sudo make install
重新编译安装ffmpeg（已安装先卸载）
1）生成 Makefile时，加上x264
./configure --prefix=/usr/softinstall/ffmpeg --enable-gpl --enable-shared --enable-libx264
2）清理
make clean
2）编译
make
3）安装
sudo make install
4）配置环境变量（参考：安装linux下tar.gz包）
vim /etc/profile
export FFMPEG_PATH=/usr/softinstall/ffmpeg
export CLASSPATH=$FFMPEG_PATH/lib:$CLASSPATH
PATH=$FFMPEG_PATH/bin:$PATH
source /etc/profile
5）测试
ffmpeg -version
问题一：
重新执行以下ffmpeg推流命令时报错：
[root@localhost ffmpeg]# ffmpeg -re -i "/home/lee000/Videos/00001.mp4" -vcodec libx264 -vprofile baseline -acodec aac -ar 44100 -strict -2 -ac 1 -f flv -s 1280x720 -q 10 rtmp://server:1935/rtmplive/test1
ffmpeg: error while loading shared libraries: libavdevice.so.58: cannot open shared object file: No such file or directory
解决方案：
修改ld.so.conf文件
sudo vim /etc/ld.so.conf
配置文件追加ffmpeg安装目录下的lib文件夹（以下是我本机的）：
/usr/softinstall/ffmpeg/lib
使修改生效：
sudo ldconfig
问题二：
重新执行以下ffmpeg推流命令时报错：
[root@localhost lib]# ffmpeg -re -i "/home/lee000/Videos/00001.mp4" -vcodec libx264 -vprofile baseline -acodec aac -ar 44100 -strict -2 -ac 1 -f flv -s 1280x720 -q 10 rtmp://server:1935/rtmplive/test1
ffmpeg: error while loading shared libraries: libx264.so.158: cannot open shared object file: No such file or directory
解决方案（同问题一）：
修改ld.so.conf文件
sudo vim /etc/ld.so.conf
配置文件追加x264安装目录下的lib文件夹（以下是我本机的）：
/usr/local/lib
使修改生效：
sudo ldconfig
问题三：
[root@localhost lib]# ffmpeg -re -i "/home/lee000/Videos/00001.mp4" -vcodec libx264 -vprofile baseline -acodec aac -ar 44100 -strict -2 -ac 1 -f flv -s 1280x720 -q 10 rtmp://192.168.100.158:1935/rtmplive/test1
ffmpeg version N-95767-gcda3e8c Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 4.8.5 (GCC) 20150623 (Red Hat 4.8.5-39)
configuration: --prefix=/usr/softinstall/ffmpeg --enable-gpl --enable-shared --enable-libx264
libavutil 56. 36.100 / 56. 36.100
libavcodec 58. 62.100 / 58. 62.100
libavformat 58. 35.100 / 58. 35.100
libavdevice 58. 9.100 / 58. 9.100
libavfilter 7. 66.100 / 7. 66.100
libswscale 5. 6.100 / 5. 6.100
libswresample 3. 6.100 / 3. 6.100
libpostproc 55. 6.100 / 55. 6.100
Guessed Channel Layout for Input Stream #0.1 : mono
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/home/lee000/Videos/00001.mp4':
Metadata:
major_brand : mp42
minor_version : 0
compatible_brands: mp42isom
creation_time : 2019-10-16T06:58:33.000000Z
Duration: 00:11:12.83, start: 0.000000, bitrate: 1251 kb/s
Stream #0:0(und): Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p, 1280x720, 791 kb/s, 29.82 fps, 29.92 tbr, 90k tbn, 180k tbc (default)
Stream #0:1(und): Audio: pcm_mulaw (ulaw / 0x77616C75), 8000 Hz, mono, s16, 64 kb/s (default)
[tcp @ 0x1377ec0] Connection to tcp://192.168.100.158:1935 failed: Connection refused
[rtmp @ 0x1409b40] Cannot open connection tcp://192.168.100.158:1935
rtmp://192.168.100.158:1935/rtmplive/test1: Connection refused
解决方案：
配置nginx时，只修改了nginx.conf，但未修改nginx.conf.default默认配置文件，把nginx.conf.default修改和nginx.conf内容一致即可
