1. PC环境

ubuntu 1804
ffmpeg 3.4.6

2. ffmpeg 下载安装

$ git clone git://source.ffmpeg.org/ffmpeg.git ffmpeg
$ cd ffmpeg
$ ./configure --enable-shared  --prefix=/usr/local/ffmpeg
$ sudo make
$ sudo make install

3. 添加ffmpeg库链接

 $ cd /etc/ld.so.conf.d/
 $ sudo echo " /usr/local/ffmpeg/lib"  >> ffmpeglib.conf

4. 支持pkg-config

$ export PKG_CONFIG_PATH=/usr/local/ffmpeg/lib/pkgconfig:$PKG_CONFIG_PATH

5. 测试

ffmpeg_version.c

#include <stdio.h>
#include <stdlib.h>
#include <libavformat/avformat.h>

int main()
{
    unsigned int ver=0;
    av_register_all();
    ver=avformat_version();
    av_log(NULL,AV_LOG_INFO,"%d\n",ver);
    return 0;
}

编译

gcc

 $ gcc -g -o ffmpeg_version ffmpeg_version.c -I/usr/local/ffmpeg/include -L/usr/local/ffmpeg/lib -lavformat -lavutil

Makefile

FFMPEG=/usr/local/ffmpeg
CC=gcc
CFLAGS=-I$(FFMPEG)/include
LDFLAGS=-L$(FFMPEG)/lib/ -lswscale -lswresample -lavformat -lavdevice -lavcodec -lavutil -lavfilter  -lm 
TARGETS=ffmpeg_version 
$(TARGETS):ffmpeg_version.c
    $(CC) -g -o $@ $^ $(CFLAGS) $(LDFLAGS)
clean:
    rm -rf $(TARGETS)

$ make

pkg-config

$ gcc -g -o ffmpeg_version ffmpeg_version.c `pkg-config --cflags --libs libavformat libavutil`

6. 存在的问题

pkg-config 自动查找路径应该是安装路径，但结果是：

$ pkg-config --cflags --libs libavformat libavutil
-I/usr/include/x86_64-linux-gnu -lavformat -lavutil

7. 学习计划

pkg-config

$ export PKG_CONFIG_PATH=/usr/local/ffmpeg/lib/pkgconfig:$PKG_CONFIG_PATH

$ pkg-config --cflags --libs libavformat
-I/usr/local/ffmpeg/include -L/usr/local/ffmpeg/lib -lavformat -lXv -lX11 -lXext -lSDL2 -lxcb -lxcb-shm -lxcb-xfixes -lxcb-shape -lsndio -lasound -lSDL2 -lm -ldl -llzma -lbz2 -lz -pthread -lavcodec -lXv -lX11 -lXext -lSDL2 -lxcb -lxcb-shm -lxcb-xfixes -lxcb-shape -lsndio -lasound -lSDL2 -lm -ldl -llzma -lbz2 -lz -pthread -lswresample -lm -lavutil -lm

Makefile

# use pkg-config for getting CFLAGS and LDLIBS  
FFMPEG_LIBS=    libavdevice                        \  
                libavformat                        \  
                libavfilter                        \  
                libavcodec                         \  
                libswresample                      \  
                libswscale                         \  
                libavutil                          \  
                sdl \  
  
CFLAGS += -Wall -g  
INCLUDES:=$(shell pkg-config --cflags libavformat libavcodec libswscale libavutil sdl)  
CFLAGS := $(shell pkg-config --cflags $(FFMPEG_LIBS)) $(CFLAGS)  
LDFLAGS:=$(shell pkg-config --libs libavformat libavcodec libswscale libavutil libswresample sdl) -lm   
LDLIBS := $(shell pkg-config --libs $(FFMPEG_LIBS)) $(LDLIBS)  
  
EXE:=  muxing.out  demo.out  
  
#OBJS=$(addsuffix .o,$(EXAMPLES))  
  
# the following examples make explicit use of the math library  
# decoding_encoding: LDLIBS += -lm  
muxing:            LDLIBS += -lm  
  
#.phony: all clean-test clean  
  
#all: $(OBJS) $(EXAMPLES)  
all: dirs $(addprefix bin/, $(EXE)) tags  
  
dirs:  
    mkdir -p obj  
    mkdir -p bin  
  
tags: *.c  
    ctags *.c  
  
bin/%.out: obj/%.o  
    $(CC) $(CFLAGS) $< $(LDFLAGS) -o $@  
  
obj/%.o : %.c  
    $(CC) $(CFLAGS) $< $(INCLUDES) -c -o $@  
  
#clean-test:  
    #$(RM) test*.pgm test.h264 test.mp2 test.sw test.mpg  
  
#clean: clean-test  
    #$(RM) $(EXAMPLES) $(OBJS)  
clean:  
    rm -f obj/*  
    rm -f bin/*  
    rm -f tags