[Libav-user] NULL pointer using boost asio and many streaming object
Georgi Rosenov Stefanov
georgi.rosenov at gmail.com
Tue Apr 7 14:22:00 CEST 2015
Hi All,
I am trying to create video software which should be able to stream files
over network and to record the streamed data into file.
To realize this I create an object for every stream ( I call it channel)
and another object for recording the stream to file (I call it channel
again :-) )
When I use more than 1 object I got NULL pointer on input context
I know my code has a lot things to be done, but my real problem now is the
NULL pointer
Here is the code
extern "C"
{
#include <libavutil/timestamp.h>
#include <libavformat/avformat.h>
}
#include <iostream>
#include <unistd.h>
#include <boost/asio.hpp>
#include <boost/thread.hpp>
#include <boost/bind.hpp>
#include "applicationlog.hpp"
#include "channel.hpp"
using namespace std;
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void worker(boost::asio::io_service *ios)
{
ios->run();
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
int main(int argc, char **argv)
{
boost::asio::io_service ios;
boost::asio::io_service ios1;
Channel *channels[100];
channels[0] = new Channel(ios, 9078, atoi(argv[1]));
channels[0]->StartTimer(0);
channels[1] = new Channel(ios1, 9079, atoi(argv[1]));
channels[1]->StartTimer(0);
boost::thread t(boost::bind(&worker, &ios));
boost::thread t1(boost::bind(&worker, &ios1));
t.join();
t1.join();
CEVLOG_MSG << "done" << std::endl;
return 0;
}
The Channel class implementation
#include "channel.hpp"
#include "utils.hpp"
#include "boost/lexical_cast.hpp"
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
Channel::Channel(boost::asio::io_service &ioP, int i, bool to_send):
Runnable(ioP),
work( new boost::asio::io_service::work(ioP) ),
ofmt(NULL),
ifmt_ctx(NULL),
ofmt_ctx(NULL)
{
av_register_all();
avformat_network_init();
id = i;
sender = to_send;
if (sender)
{
input.assign("/home/georgi/Downloads/video/IMG_0019.MOV");
output.assign("rtp://10.101.3.60:"); output +=
boost::lexical_cast<std::string>(id);
}
else
{
input.assign("stream"); input +=
boost::lexical_cast<std::string>(id); input += ".sdp";
output.assign("test"); output +=
boost::lexical_cast<std::string>(id); output += ".mp4";
}
video_idx = audio_idx = sub_idx = -1;
if (OpenInput())
{
if (sender)
OpenOutput(eStreamOutput);
else
OpenOutput(eFileOutput);
}
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
Channel::~Channel()
{
av_write_trailer(ofmt_ctx);
avformat_close_input(&ifmt_ctx);
if (ofmt_ctx && !(ofmt->flags & AVFMT_NOFILE))
avio_closep(&ofmt_ctx->pb);
avformat_free_context(ofmt_ctx);
work.reset();
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
bool Channel::OpenInput()
{
CEVLOG_MSG << "opening " << input << std::endl;
int ret;
if ((ret = avformat_open_input(&ifmt_ctx, input.c_str(), 0, 0)) < 0)
{
CEVLOG_ERR << "Could not open input file " << input << std::endl;
return false;
}
CEVLOG_MSG << " " << ifmt_ctx << std::endl;
if ((ret = avformat_find_stream_info(ifmt_ctx, 0)) < 0)
{
CEVLOG_ERR << "Failed to retrieve input stream information" <<
std::endl;
return false;
}
ifmt_ctx->flags |= AVFMT_FLAG_GENPTS;
//read and set timestamps to 0
av_read_frame(ifmt_ctx, &pkt);
pkt.pts = pkt.dts = 0;
return true;
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
bool Channel::OpenOutput(tOutputType WhatToOpen)
{
int SDP_size;
switch (WhatToOpen)
{
case eFileOutput:
avformat_alloc_output_context2(&ofmt_ctx, NULL, NULL,
output.c_str());
break;
case eStreamOutput:
avformat_alloc_output_context2(&ofmt_ctx, NULL, "rtp",
output.c_str());
char SDP[4096];
SDP_size = 4096;
av_sdp_create(&ofmt_ctx, 1, SDP, SDP_size);
CEVLOG_DBG << "SDP=" << SDP << std::endl;
break;
default:
assert(false);
break;
}
if (!ofmt_ctx)
{
CEVLOG_ERR << "Could not create output context" << std::endl;
return false;
}
ofmt = ofmt_ctx->oformat;
video_idx = FindIndex(AVMEDIA_TYPE_VIDEO);
if (!(ofmt->flags & AVFMT_NOFILE))
{
if (avio_open(&ofmt_ctx->pb, output.c_str(), AVIO_FLAG_WRITE) < 0)
{
CEVLOG_ERR << "Could not open output file " << output <<
std::endl;
return false;
}
}
if (avformat_write_header(ofmt_ctx, NULL) < 0)
{
CEVLOG_ERR << "Error occurred when opening output file " << output
<< std::endl;
return false;
}
return true;
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
unsigned int Channel::FindIndex(AVMediaType Type)
{
int idx;
for (idx = 0; idx < ifmt_ctx->nb_streams; idx++)
{
if (ifmt_ctx->streams[idx]->codec->codec_type == Type)
{
AVStream *in_stream = ifmt_ctx->streams[idx];
AVStream *out_stream = avformat_new_stream(ofmt_ctx,
in_stream->codec->codec);
if (!out_stream)
{
CEVLOG_ERR << "Failed allocating output stream" <<
std::endl;
break;
}
if (avcodec_copy_context(out_stream->codec, in_stream->codec) <
0)
{
CEVLOG_ERR << "Failed to copy context from input to output
stream codec context" << std::endl;
break;
}
out_stream->codec->codec_tag = 0;
if (ofmt_ctx->oformat->flags & AVFMT_GLOBALHEADER)
{
out_stream->codec->flags |= CODEC_FLAG_GLOBAL_HEADER;
}
break;
}
}
return idx;
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void Channel::Callback()
{
if (sender)
SendVideo();
else
RecvVideo();
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void Channel::SendVideo()
{
int ret = av_read_frame(ifmt_ctx, &pkt);
int time_ms = 0;
if (ret != 0)
{
av_write_trailer(ofmt_ctx);
work.reset();
return;
}
if (pkt.stream_index == video_idx)
{
AVStream *in_stream = ifmt_ctx->streams[pkt.stream_index];
AVStream *out_stream = ofmt_ctx->streams[pkt.stream_index];
AVRational time_base = ifmt_ctx->streams[video_idx]->time_base;
char timestamp[100];
time_ms = 1000 * 1000 * strtof(timestamp2char(timestamp,
pkt.duration, &time_base), NULL);
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base,
out_stream->time_base, AV_ROUND_NEAR_INF);
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base,
out_stream->time_base, AV_ROUND_NEAR_INF);
pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base,
out_stream->time_base);
pkt.pos = -1;
ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
if (ret < 0)
{
CEVLOG_ERR << "Error muxing packet" << std::endl;
return;
}
}
av_free_packet(&pkt);
StartTimer(time_ms);
}
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
//-----------------------------------------------------------------------------
void Channel::RecvVideo()
{
int ret = av_read_frame(ifmt_ctx, &pkt);
if (ret != 0)
{
//Some error or end of stream is detected. Write file trailer
av_write_trailer(ofmt_ctx);
work.reset();
return;
}
//if is NOT video just continue reading
if (pkt.stream_index == video_idx)
{
AVStream *in_stream = ifmt_ctx->streams[pkt.stream_index];
AVStream *out_stream = ofmt_ctx->streams[pkt.stream_index];
AVRational time_base = ifmt_ctx->streams[video_idx]->time_base;
pkt.pts = av_rescale_q_rnd(pkt.pts, in_stream->time_base,
out_stream->time_base, AV_ROUND_NEAR_INF);
pkt.dts = av_rescale_q_rnd(pkt.dts, in_stream->time_base,
out_stream->time_base, AV_ROUND_NEAR_INF);
pkt.duration = av_rescale_q(pkt.duration, in_stream->time_base,
out_stream->time_base);
pkt.pos = -1;
ret = av_interleaved_write_frame(ofmt_ctx, &pkt);
if (ret < 0)
{
CEVLOG_ERR << "Error muxing packet" << std::endl;
return;
}
}
av_free_packet(&pkt);
StartTimer(0);
}
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <https://ffmpeg.org/pipermail/libav-user/attachments/20150407/beb070e0/attachment.html>
More information about the Libav-user
mailing list