Thanks for the response, it works! :) I was thinking to put such a code within a thread. Whenever "avformat_open_input" finds a stream at the given address, then the thread can be terminated. In the meantime, the program can do other stuffs. But do you know how I can make a thread with libavcodec functions?
---------------------------------------- > From: gri...@yandex.ru > To: libav-user@ffmpeg.org > Date: Sun, 12 Jan 2014 22:38:51 +0600 > Subject: Re: [Libav-user] Check an address to see if there is any video > stream on it or not > > > 12.01.2014, 22:23, "Hadi" <hadi.hadiza...@hotmail.com>: >> I want to read a video stream from a UDP address using libavcodec functions. >> To do so, I use the following code: >> >> char *url = "udp://127.0.0.1:1000"; >> AVFormatContext *oc = NULL; >> avformat_open_input(&oc, url, NULL , NULL); >> >> If we run this code, then function "avformat_open_input" starts listening on >> the given UDP address, and it looks like the program is halted if there is >> no video stream at the given UDP address. >> >> Now, I want to write a code to first check the given UDP address quickly to >> see whether there is any data on it or not, if there is no data then the >> program should neglect running "avformat_open_input", otherwise it should >> run this function so that I can avoid the halting situation. >> >> Any idea how I can do this? Thanks! >> _______________________________________________ >> Libav-user mailing list >> Libav-user@ffmpeg.org >> http://ffmpeg.org/mailman/listinfo/libav-user > > use interrupt_callback function to "unblock" avformat_open_input(...); > concept: > > time_t check_timestamp; > > static int interrupt_cb(void* inputdata) > { > time_t current_timestamp; > current_timestamp = time(0) > if (current_timestamp - check_timestamp>= 10) > return true; // interrupt blocked function > else > return false; // NOT interrupt, wait more seconds... > } > ... > oc = avformat_allocate_context(); > oc->interrupt_callbacl = (AVIOInterruptCB){interrupt_cb, NULL}; > checl_timestamp = time(0); > if (avformat_open_input(&oc, url, NULL , NULL) < 0) > { > // error processing > } > > something like that :) if avformat_open_input frezzes more than 10 seconds > (in this example), interrupt_cb will break it execution. > > -- > С уважением, Евгений Гарифуллин. > e-mail: gri...@yandex.ru > jabber: joffad...@jabber.ufanet.ru > ICQ : 387906261 > _______________________________________________ > Libav-user mailing list > Libav-user@ffmpeg.org > http://ffmpeg.org/mailman/listinfo/libav-user > _______________________________________________ Libav-user mailing list Libav-user@ffmpeg.org http://ffmpeg.org/mailman/listinfo/libav-user
