我使用RTSP在LAN流视频上有一个IPCamera。我已经能够使用ffplay命令成功捕获并显示它:
ffplay rtsp://admin:123456@192.168.2.50:7070
(带身份验证)
所以我想使用ffmpeg
库在C / C ++中使用编程实现相同的功能。我想这一定是可能的。
所以让我说两个简单的问题:
如何使用FFMPEG库在C / C ++程序中接收流? (只是提供一些URL /教程,因为谷歌没有帮助)
如何显示收到的视频? (在这里,一些很好的URL指导我)。
答案 0 :(得分:30)
对于rtsp流,以下内容适用于我(在接收帧后,我将结果保存为ppm文件):
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <fstream>
#include <sstream>
extern "C"
{
#include <avcodec.h>
#include <avformat.h>
#include <avio.h>
#include <swscale.h>
}
void log_callback(void *ptr, int level, const char *fmt, va_list vargs)
{
static char message[8192];
const char *module = NULL;
if (ptr)
{
AVClass *avc = *(AVClass**) ptr;
module = avc->item_name(ptr);
}
vsnprintf_s(message, sizeof(message), fmt, vargs);
std::cout << "LOG: " << message << std::endl;
}
int main(int argc, char** argv) {
SwsContext *img_convert_ctx;
AVFormatContext* context = avformat_alloc_context();
AVCodecContext* ccontext = avcodec_alloc_context();
int video_stream_index;
av_register_all();
avformat_network_init();
//av_log_set_callback(&log_callback);
//open rtsp
if(avformat_open_input(&context, "rtsp://134.169.178.187:8554/h264.3gp",NULL,NULL) != 0){
return EXIT_FAILURE;
}
if(avformat_find_stream_info(context,NULL) < 0){
return EXIT_FAILURE;
}
//search video stream
for(int i =0;i<context->nb_streams;i++){
if(context->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
video_stream_index = i;
}
AVPacket packet;
av_init_packet(&packet);
//open output file
//AVOutputFormat* fmt = av_guess_format(NULL,"test2.mp4",NULL);
AVFormatContext* oc = avformat_alloc_context();
//oc->oformat = fmt;
//avio_open2(&oc->pb, "test.mp4", AVIO_FLAG_WRITE,NULL,NULL);
AVStream* stream=NULL;
int cnt = 0;
//start reading packets from stream and write them to file
av_read_play(context);//play RTSP
AVCodec *codec = NULL;
codec = avcodec_find_decoder(CODEC_ID_H264);
if (!codec) exit(1);
avcodec_get_context_defaults3(ccontext, codec);
avcodec_copy_context(ccontext,context->streams[video_stream_index]->codec);
std::ofstream myfile;
if (avcodec_open(ccontext, codec) < 0) exit(1);
img_convert_ctx = sws_getContext(ccontext->width, ccontext->height, ccontext->pix_fmt, ccontext->width, ccontext->height,
PIX_FMT_RGB24, SWS_BICUBIC, NULL, NULL, NULL);
int size = avpicture_get_size(PIX_FMT_YUV420P, ccontext->width, ccontext->height);
uint8_t* picture_buf = (uint8_t*)(av_malloc(size));
AVFrame* pic = avcodec_alloc_frame();
AVFrame* picrgb = avcodec_alloc_frame();
int size2 = avpicture_get_size(PIX_FMT_RGB24, ccontext->width, ccontext->height);
uint8_t* picture_buf2 = (uint8_t*)(av_malloc(size2));
avpicture_fill((AVPicture *) pic, picture_buf, PIX_FMT_YUV420P, ccontext->width, ccontext->height);
avpicture_fill((AVPicture *) picrgb, picture_buf2, PIX_FMT_RGB24, ccontext->width, ccontext->height);
while(av_read_frame(context,&packet)>=0 && cnt <1000)
{//read 100 frames
std::cout << "1 Frame: " << cnt << std::endl;
if(packet.stream_index == video_stream_index){//packet is video
std::cout << "2 Is Video" << std::endl;
if(stream == NULL)
{//create stream in file
std::cout << "3 create stream" << std::endl;
stream = avformat_new_stream(oc,context->streams[video_stream_index]->codec->codec);
avcodec_copy_context(stream->codec,context->streams[video_stream_index]->codec);
stream->sample_aspect_ratio = context->streams[video_stream_index]->codec->sample_aspect_ratio;
}
int check = 0;
packet.stream_index = stream->id;
std::cout << "4 decoding" << std::endl;
int result = avcodec_decode_video2(ccontext, pic, &check, &packet);
std::cout << "Bytes decoded " << result << " check " << check << std::endl;
if(cnt > 100)//cnt < 0)
{
sws_scale(img_convert_ctx, pic->data, pic->linesize, 0, ccontext->height, picrgb->data, picrgb->linesize);
std::stringstream name;
name << "test" << cnt << ".ppm";
myfile.open(name.str());
myfile << "P3 " << ccontext->width << " " << ccontext->height << " 255\n";
for(int y = 0; y < ccontext->height; y++)
{
for(int x = 0; x < ccontext->width * 3; x++)
myfile << (int)(picrgb->data[0] + y * picrgb->linesize[0])[x] << " ";
}
myfile.close();
}
cnt++;
}
av_free_packet(&packet);
av_init_packet(&packet);
}
av_free(pic);
av_free(picrgb);
av_free(picture_buf);
av_free(picture_buf2);
av_read_pause(context);
avio_close(oc->pb);
avformat_free_context(oc);
return (EXIT_SUCCESS);
}
答案 1 :(得分:11)
FWIW,我更新了@technique提供的代码,以便使用我从FFMPEG 3.2.2获得的库。希望这有助于谷歌搜索这个。对于那些绊倒这个答案的人来说,有一些微小的变化可能会令人困惑。
#include <stdio.h>
#include <stdlib.h>
#include <iostream>
#include <fstream>
#include <sstream>
extern "C" {
#include <libavcodec/avcodec.h>
#include <libavformat/avformat.h>
#include <libavformat/avio.h>
#include <libswscale/swscale.h>
}
int main(int argc, char** argv) {
// Open the initial context variables that are needed
SwsContext *img_convert_ctx;
AVFormatContext* format_ctx = avformat_alloc_context();
AVCodecContext* codec_ctx = NULL;
int video_stream_index;
// Register everything
av_register_all();
avformat_network_init();
//open RTSP
if (avformat_open_input(&format_ctx, "rtsp://134.169.178.187:8554/h264.3gp",
NULL, NULL) != 0) {
return EXIT_FAILURE;
}
if (avformat_find_stream_info(format_ctx, NULL) < 0) {
return EXIT_FAILURE;
}
//search video stream
for (int i = 0; i < format_ctx->nb_streams; i++) {
if (format_ctx->streams[i]->codec->codec_type == AVMEDIA_TYPE_VIDEO)
video_stream_index = i;
}
AVPacket packet;
av_init_packet(&packet);
//open output file
AVFormatContext* output_ctx = avformat_alloc_context();
AVStream* stream = NULL;
int cnt = 0;
//start reading packets from stream and write them to file
av_read_play(format_ctx); //play RTSP
// Get the codec
AVCodec *codec = NULL;
codec = avcodec_find_decoder(AV_CODEC_ID_H264);
if (!codec) {
exit(1);
}
// Add this to allocate the context by codec
codec_ctx = avcodec_alloc_context3(codec);
avcodec_get_context_defaults3(codec_ctx, codec);
avcodec_copy_context(codec_ctx, format_ctx->streams[video_stream_index]->codec);
std::ofstream output_file;
if (avcodec_open2(codec_ctx, codec, NULL) < 0)
exit(1);
img_convert_ctx = sws_getContext(codec_ctx->width, codec_ctx->height,
codec_ctx->pix_fmt, codec_ctx->width, codec_ctx->height, AV_PIX_FMT_RGB24,
SWS_BICUBIC, NULL, NULL, NULL);
int size = avpicture_get_size(AV_PIX_FMT_YUV420P, codec_ctx->width,
codec_ctx->height);
uint8_t* picture_buffer = (uint8_t*) (av_malloc(size));
AVFrame* picture = av_frame_alloc();
AVFrame* picture_rgb = av_frame_alloc();
int size2 = avpicture_get_size(AV_PIX_FMT_RGB24, codec_ctx->width,
codec_ctx->height);
uint8_t* picture_buffer_2 = (uint8_t*) (av_malloc(size2));
avpicture_fill((AVPicture *) picture, picture_buffer, AV_PIX_FMT_YUV420P,
codec_ctx->width, codec_ctx->height);
avpicture_fill((AVPicture *) picture_rgb, picture_buffer_2, AV_PIX_FMT_RGB24,
codec_ctx->width, codec_ctx->height);
while (av_read_frame(format_ctx, &packet) >= 0 && cnt < 1000) { //read ~ 1000 frames
std::cout << "1 Frame: " << cnt << std::endl;
if (packet.stream_index == video_stream_index) { //packet is video
std::cout << "2 Is Video" << std::endl;
if (stream == NULL) { //create stream in file
std::cout << "3 create stream" << std::endl;
stream = avformat_new_stream(output_ctx,
format_ctx->streams[video_stream_index]->codec->codec);
avcodec_copy_context(stream->codec,
format_ctx->streams[video_stream_index]->codec);
stream->sample_aspect_ratio =
format_ctx->streams[video_stream_index]->codec->sample_aspect_ratio;
}
int check = 0;
packet.stream_index = stream->id;
std::cout << "4 decoding" << std::endl;
int result = avcodec_decode_video2(codec_ctx, picture, &check, &packet);
std::cout << "Bytes decoded " << result << " check " << check
<< std::endl;
if (cnt > 100) //cnt < 0)
{
sws_scale(img_convert_ctx, picture->data, picture->linesize, 0,
codec_ctx->height, picture_rgb->data, picture_rgb->linesize);
std::stringstream file_name;
file_name << "test" << cnt << ".ppm";
output_file.open(file_name.str().c_str());
output_file << "P3 " << codec_ctx->width << " " << codec_ctx->height
<< " 255\n";
for (int y = 0; y < codec_ctx->height; y++) {
for (int x = 0; x < codec_ctx->width * 3; x++)
output_file
<< (int) (picture_rgb->data[0]
+ y * picture_rgb->linesize[0])[x] << " ";
}
output_file.close();
}
cnt++;
}
av_free_packet(&packet);
av_init_packet(&packet);
}
av_free(picture);
av_free(picture_rgb);
av_free(picture_buffer);
av_free(picture_buffer_2);
av_read_pause(format_ctx);
avio_close(output_ctx->pb);
avformat_free_context(output_ctx);
return (EXIT_SUCCESS);
}
它可以通过以下方式编译:
g++ -w my_streamer.cpp -o my_streamer $(pkg-config --cflags --libs libavformat libswscale)
我包含-w
,因为库中的这些函数有很多弃用警告。您需要安装pkg-config以及安装的libavformat和libswscale库。
答案 2 :(得分:4)
FFmpeg可以直接打开rtsp流,就像打开本地视频文件一样。 Here是一个教程代码,使用最新版本的FFmpeg进行更新。
答案 3 :(得分:1)
检查./configure文件。可能是armlinux
的编译而不是x86
。这就是为什么你得到'avcodec_register_all'
以下是解决方案: -
$ cd ffmpeg
$export LD_RUN_PATH=/usr/local/lib:/usr/lib:/lib
$ ./configure
$ make && make install
然后编译你的申请。