call avformat_find_stream_info was blocked when open rtsp stream from network. how to deal with it.
------------------ Original ------------------
From: "Taha Ansari"<mtaha.ans...@gmail.com>;
Date: Tue, Jan 22, 2013 03:41 PM
To: "This list is about using libavcodec, libavformat, libavutil,libavdevice and libavfilter."<libav-user@ffmpeg.org>;
Subject: Re: [Libav-user] Detecting bit rate from live stream
1- pFormatCtx = avformat_alloc_context();
2- rv = avformat_open_input(&this->pFormatCtx, this->finalInputName.c_str(), NULL, NULL);
if ( this->pFormatCtx == NULL ||
this->pFormatCtx->iformat == NULL )
{
return -1;
}
3- if(avformat_find_stream_info(this->pFormatCtx, NULL)<0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
av_dump_format(this->pFormatCtx, 0, this->finalInputName.c_str(), 0);
4- this->videoStream = -1;
for(i=0; i<this->pFormatCtx->nb_streams; i++)
{
if(this->pFormatCtx->streams[i]->codec->codec_type==AVMEDIA_TYPE_VIDEO)
{
this->videoStream=i;
break;
}
}
5- if(this->videoStream !=-1)
{
// Get a pointer to the codec context for the video stream
this->pCodecCtxVideo=this->pFormatCtx->streams[this->videoStream]->codec;
// Find the decoder for the video stream
this->pCodecVideo=avcodec_find_decoder(this->pCodecCtxVideo->codec_id);
if(this->pCodecVideo==NULL) {
fprintf(stderr, "Unsupported avido codec!\n");
return -1; // Codec not found
}
// Open codec
AVDictionary *codecDictOptions = NULL;
if(avcodec_open2(this->pCodecCtxVideo, this->pCodecVideo, &codecDictOptions)<0)
return -1; // Could not open codec
...
...
...
So on...
So, in words, this is the sequence:
1- open format context
2- get video stream index
3- get codec context for video 'from' format context's stream
4- open codec using avcodec_open2 function
On Tue, Jan 22, 2013 at 12:34 PM, Taha Ansari <mtaha.ans...@gmail.com> wrote:
Hi kalileo,
Thanks for the reply, yes I just tried this - i.e. looking at following code:
if(avformat_find_stream_info(this->pFormatCtx, NULL)<0)
return -1; // Couldn't find stream information
// Dump information about file onto standard error
av_dump_format(this->pFormatCtx, 0, this->finalInputName.c_str(), 0);
At time of opening up decoder for live udp stream (like: udp://localhost:8765/a.h264) is still giving me bit_rate '0'.
On Tue, Jan 22, 2013 at 10:35 AM, Kalileo <kali...@universalx.net> wrote:
Did you try running avformat_find_stream_info() after opening the codec context and before checking the bitrate fields?
On Jan 22, 2013, at 11:37 , Taha Ansari wrote:
> Hi,
>
> I've been looking deeper into this, unfortunately so far I could not find a way to detect live stream's bit rate, or any way I could some how 'stuff' custom data (which would be bit rate in my case) with the encoder, and extract that on the network decoding end.
>
> Kindly, could anyone guide me how can I achieve this? Also any hints are most welcome...
>
> Thanks for your time...
>
> On Wed, Jan 16, 2013 at 12:48 PM, Taha Ansari <mtaha.ans...@gmail.com> wrote:
> Hi!
>
> I am using h264 encoding to transmit video to destination network address using udp protocol. I also want to detect bit rate of the encoded frame on receiver end. In the pFormatCtx->bit_rate, and pCodecCtx->bit_rate, I see on receiver end, they are all zero. I understand since it is live streaming bit rate isn't stuffed there, but I would like to know if there is any way I could retrieve actual bit rate frame was transmitted on, on client side (i.e. decoder side decoding video over network).
>
> Can anyone kindly provide some guidance or tips on how to do this?
>
> Thanks for your time!
>
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