文章目录
- 1.下载ffmpeg
- 2.交叉编译
- 3.修改cmakelist.txt
- 4.将lib文件复制到install目录下的lib目录
- 5.测试文件
- 6.运行测试样例
- 7.错误
- n.测试文件源码
1.下载ffmpeg
git clone https://git.ffmpeg.org/ffmpeg.git ffmpeg
2.交叉编译
进入下载目录,将ffmpeg编译成arm64平台的版本,编译后的文件存放于./instal_arm64中。
sudo ./configure --prefix=./instal_arm64 --enable-shared --disable-static --enable-cross-compile --arch=arm64 --disable-stripping --target-os=linux --cc=aarch64-linux-gnu-gcc
验证:进入instal_arm64/lib文件夹,使用file命令查看文件格式,若显示为ARM aarch64即成功。
3.修改cmakelist.txt
需要将交叉编译好的lib/include 文件夹导入项目中,修改cmakelist.txt如下图所示。
为方便复制这里将改动内容的文字贴在下面,路径需要改成自己的下载路径。
#ffmpeg
# 设置ffmpeg依赖库及头文件所在目录,并存进指定变量
set(ffmpeg_libs_DIR /home/yi/Downloads/ffmpeg/instal_arm64/lib)
set(ffmpeg_headers_DIR /home/yi/Downloads/ffmpeg/instal_arm64/include)
add_library( avcodec SHARED IMPORTED)
add_library( avfilter SHARED IMPORTED )
add_library( swresample SHARED IMPORTED )
add_library( swscale SHARED IMPORTED )
add_library( avformat SHARED IMPORTED )
add_library( avutil SHARED IMPORTED )
#指定所添加依赖库的导入路径
set_target_properties( avcodec PROPERTIES IMPORTED_LOCATION ${ffmpeg_libs_DIR}/libavcodec.so )
set_target_properties( avfilter PROPERTIES IMPORTED_LOCATION ${ffmpeg_libs_DIR}/libavfilter.so )
set_target_properties( swresample PROPERTIES IMPORTED_LOCATION ${ffmpeg_libs_DIR}/libswresample.so )
set_target_properties( swscale PROPERTIES IMPORTED_LOCATION ${ffmpeg_libs_DIR}/libswscale.so )
set_target_properties( avformat PROPERTIES IMPORTED_LOCATION ${ffmpeg_libs_DIR}/libavformat.so )
set_target_properties( avutil PROPERTIES IMPORTED_LOCATION ${ffmpeg_libs_DIR}/libavutil.so )
# 添加头文件路径到编译器的头文件搜索路径下,多个路径以空格分隔
include_directories(${ffmpeg_headers_DIR})
link_directories(${ffmpeg_libs_DIR})
--------省略若干字。。。。。----------------------
target_link_libraries(rknn_yolov5_demo
${RKNN_RT_LIB}
${RGA_LIB}
${OpenCV_LIBS}
${ffmpeg_libs_DIR}
avcodec avformat avutil swresample swscale swscale avfilter
)
4.将lib文件复制到install目录下的lib目录
这里也许可以只复制项目中需要的lib文件.
sudo cp ~/Downloads/ffmpeg/instal_arm64/lib/* install/rknn_yolov5_demo_Linux/lib/
5.测试文件
这里用一个ffpeg解析rtsp流的案例来测试是否成功。因为源码篇幅过长,放到本文最后。程序大意是:读取rtsp流,将rtsp流解析成帧,并且输入到输出文件,同时统计帧数。
6.运行测试样例
sudo ./build-rk3588…
adb push …
这里省略
最终可得到如图所示的结果,表示编译运行成功。
7.错误
运行时出现了Failed to resolve hostname …无法解析域名的错误。
解决方案:
有两种可能的原因,1.没有配置域名服务器114.114.114.114 。2.开发板没有网络。
- 配置域名服务器
- 连接网络
可以尝试ping www.baidu.com,若没有问题的话,则不是网络问题。
1、安装nmcli
sudo apt-get install nmcli
2、查看网络设备
sudo nmcli dev
3、开启wifi
sudo nmcli r wifi on
4、扫描wifi
sudo nmcli dev wifi
5、连接wifi
sudo nmcli dev wifi connect “wifi名” password “密码”
n.测试文件源码
案例源码:
#ifndef INT64_C
#define INT64_C(c) (c ## LL)
#define UINT64_C(c) (c ## ULL)
#endif
extern "C" {
/*Include ffmpeg header file*/
#include <libavformat/avformat.h>
#include <libavcodec/avcodec.h>
#include <libswscale/swscale.h>
#include <libavutil/imgutils.h>
#include <libavutil/opt.h>
#include <libavutil/mathematics.h>
#include <libavutil/samplefmt.h>
}
#include <iostream>
using namespace std;
int main(void)
{
AVFormatContext* ifmt_ctx = NULL, * ofmt_ctx = NULL;
const char* in_filename, * out_filename;
//in_filename = "rtsp://admin:WY@123456@192.168.0.64/h264/ch1/main/av_stream";
in_filename="rtsp://wowzaec2demo.streamlock.net/vod/mp4:BigBuckBunny_115k.mp4";
out_filename = "output.flv";
avformat_network_init();
AVDictionary* avdic = NULL;
char option_key[] = "rtsp_transport";
char option_value[] = "tcp";
av_dict_set(&avdic, option_key, option_value, 0);
char option_key2[] = "max_delay";
char option_value2[] = "5000000";
av_dict_set(&avdic, option_key2, option_value2, 0);
AVPacket pkt;
AVOutputFormat* ofmt = NULL;
int video_index = -1;
int frame_index = 0;
int i;
//打开输入流
int ret;
if ((ret = avformat_open_input(&ifmt_ctx, in_filename, 0, &avdic)) < 0)
{
cout<<"Could not open input file."<<endl;
goto end;
}
if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0)
{
cout<<"Failed to retrieve input stream information"<<endl;
goto end;
}
//nb_streams代表有几路流
for (i = 0; i < ifmt_ctx->nb_streams; i++)
{
if (ifmt_ctx->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_VIDEO)
{
//视频流
video_index = i;
cout << "get videostream." << endl;
break;
}
}
av_dump_format(ifmt_ctx, 0, in_filename, 0);
//打开输出流
avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL, out_filename);
if (!ofmt_ctx)
{
printf("Could not create output context\n");
ret = AVERROR_UNKNOWN;
goto end;
}
ofmt = ofmt_ctx->oformat;
for (i = 0; i < ifmt_ctx->nb_streams; i++)
{
AVStream* in_stream = ifmt_ctx->streams[i];
AVStream* out_stream = avformat_new_stream(ofmt_ctx, in_stream->codec->codec);
if (!out_stream)
{
printf("Failed allocating output stream.\n");
ret = AVERROR_UNKNOWN;
goto end;
}
//将输出流的编码信息复制到输入流
ret = avcodec_copy_context(out_stream->codec, in_stream->codec);
if (ret < 0)
{
printf("Failed to copy context from input to output stream codec context\n");
goto end;
}
out_stream->codec->codec_tag = 0;
if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
out_stream->codec->flags |= AV_CODEC_FLAG_GLOBAL_HEADER;
}
av_dump_format(ofmt_ctx, 0, out_filename, 1);
if (!(ofmt->flags & AVFMT_NOFILE))
{
ret = avio_open(&ofmt_ctx->pb, out_filename, AVIO_FLAG_WRITE);
if (ret < 0)
{
printf("Could not open output URL '%s'", out_filename);
goto end;
}
}
//写文件头到输出文件
ret = avformat_write_header(ofmt_ctx, NULL);
if (ret < 0)
{
printf("Error occured when opening output URL\n");
goto end;
}
//while循环中持续获取数据包,不管音频视频都存入文件
while (1)
{
AVStream* in_stream, * out_stream;
//从输入流获取一个数据包
ret = av_read_frame(ifmt_ctx, &pkt);
if (ret < 0)
break;
in_stream = ifmt_ctx->streams[pkt.stream_index];
out_stream = ofmt_ctx->streams[pkt.stream_index];
//copy packet
//转换 PTS/DTS 时序
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base, out_stream->time_base, (enum AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base, out_stream->time_base, (enum AVRounding)(AV_ROUND_NEAR_INF | AV_ROUND_PASS_MINMAX));
//printf("pts %d dts %d base %d\n",pkt.pts,pkt.dts, in_stream->time_base);
pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base, out_stream->time_base);
pkt.pos = -1;
//此while循环中并非所有packet都是视频帧,当收到视频帧时记录一下
if (pkt.stream_index == video_index)
{
printf("Receive %8d video frames from input URL\n", frame_index);
frame_index++;
}
//将包数据写入到文件。
ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
if (ret < 0)
{
if (ret == -22) {
continue;
}
else {
printf("Error muxing packet.error code %d\n", ret);
break;
}
}
//av_free_packet(&pkt); //此句在新版本中已deprecated 由av_packet_unref代替
av_packet_unref(&pkt);
}
//写文件尾
av_write_trailer(ofmt_ctx);
end:
av_dict_free(&avdic);
avformat_close_input(&ifmt_ctx);
//Close input
if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
avio_close(ofmt_ctx->pb);
avformat_free_context(ofmt_ctx);
if (ret < 0 && ret != AVERROR_EOF)
{
cout<<"Error occured."<<endl;
return -1;
}
return 0;
}