[Libav-user] Encoding packetization speed

김희숙 hskim095 at naver.com
Thu Sep 15 04:36:44 CEST 2011

After decoding on another PC(, I can see the delay 2 seconds more. There is no exact calculation.
The decoding module is also ffmpeg library. 
I found out ffmpeg encoder does not return output data even though vfw capture data exist.
After ffmpeg encoder is received more than 40 frames, the encoder returns output data. 
BTW, I added cqp option and then the ffmpeg encoder returns output data promptly.
-----Original Message-----
From: "NEERAJ SHUKLA"<neeraj2009shukla at gmail.com> 
To: "This list is about using libavcodec, libavformat, libavutil, libavdevice and libavfilter."<libav-user at ffmpeg.org>
Sent: 11-09-10(토) 02:14:35
Subject: Re: [Libav-user] Encoding packetization speed
2011/8/31 김희숙 <hskim095 at naver.com>
Hi All,
I'm testing FFMPEG performance with libx264 for H.264 encoding.
I found there may 2 or 3 seconds delay on receiving PC.
The command is as follows:
ffmpeg -r 30 -f vfwcap -s 1280x720 -i 0 -vcodec libx264 -b 2000k -minrate 1000k -coder 0 -flags +loop+cgop -cmp +chroma -partitions -parti8x8+parti4x4+partp8x8-partp4x4-partb8x8 -me_method dia -subq 3 -me_range 24 -g 250 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -b_strategy 1 -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -directpred 1 -flags2 +fastpskip -refs 6 -subq 5 -f rtp rtp://
I also tested cif resolution and I got same result, 2 or 3 seconds delay.
I captured the rtp packets and I found there is no many packets to be sent on receiving side.
In general, how many packets to be sent under 1280x720 at 30fps?
the decoding picture quality was good but there was delay.
I wonder there is missing point on above command or something.
Please advise something to me.
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