On Sat, Jun 15, 2013 at 3:50 PM, Don Moir <[email protected]> wrote:
> 2013/6/14 Matthew Einhorn <[email protected]>: >> >>> Hi, >>> >>> I have a WANSCAM IP camare (AJ-C2WA-C198) which I'm testing in >>> ffplay/ffmpeg. I noticed that playing it through its http address is much >>> slower than when playing it with direct show. I'm linking to logs for >>> both >>> as run in ffplay. >>> >>> ffplay displayed the video through direct http access very slow and >>> choppy >>> using this command :ffplay -report -loglevel debug -i >>> http://user:pwd@IP:99/**videostream.asf -an (see >>> http://paste.ubuntu.com/**5765942/ <http://paste.ubuntu.com/5765942/>). >>> >>> To use direct show, I installed a driver from http://alax.info/blog/1223 >>> which converts a IP cam to direct show and the ffplay speed was faster >>> although still choppy, even with a large realy time buffer. The command >>> line >>> was "ffplay -loglevel debug -report -f dshow -i "video=wanscam" -an >>> -rtbufsize 1000000" (see >>> http://paste.ubuntu.com/**5765952/<http://paste.ubuntu.com/5765952/> >>> ) >>> >>> Finally, viewing the camera directly from Firefox was much faster than >>> either method and it wasn't choppy at all. I am looking for >>> recommendations >>> as to what I can do in ffmpeg to speed it up so that it's as fast as >>> Firefox. In the end I'd be using the API not ffplay. >>> >> > It appears a filter is being used when using ffplay and could be a > problem, but here's a few things I found when connecting to IP cam. > > Some of this might have changed since last time I checked which has been > awhile. > > 1) the probe time may effect the timestamps of the video packets. In other > words, if it takes 5 seconds to do the probe, packet times can be 5 seconds > late. > > 2) audio can effect things quite a bit. For my IP camera its way out of > sync and slowed things and so just did not bother with audio for the time > being. It was way of sync with the installed software as well and not just > ffmpeg. > > 3) When I got down and dirty with the camera IP API things got better. I > still believe that to get the best possible performance you need to 'know' > the camera, meaning some database would be useful. > > 4) I have a special interface for IP and USB cameras and not a generic > interface. This is for a few reasons, but for one it is flagged to ignore > timestamps. The timestamps are way off and I want to see the video in real > time, not 5 to 10 seconds later. > > I have found there is a lot to check for IP cameras and various ways to > interface. Normally there is going to be an optimal interface and you just > need to play with it. > > > Thanks for the replies. I believe I partially figured out how to get a nice fps, at least in vlc, now the question is how to achieve it in ffmpeg. I know very little about network protocols so I'm partially walking in the dark here. But this time I'm using the cam directly without any middleware. Anyway, before,I streamed with http://xxx/videostream.*asf* which resulted in slow speeds, even in VLC. Using http://xxx/videostream.*cgi* instead (which is what firefox uses) with :network-caching=0 resulted in speeds as fast as firefox. The problem is that when trying "ffplay -loglevel debug -analyzeduration 999999999 -probesize 999999999 http://CPL:[email protected]:99/videostream.cgi"; I get Format ingenient probed with size=2048 and score=50q= 0B f=0/0 [ingenient @ 000000000277a2c0] File position before avformat_find_stream_info() is 0 [ingenient @ 000000000277a2c0] Could not find codec parameters for stream 0 (Video: mjpeg): unspecified size Consider increasing the value for the 'analyzeduration' and 'probesize' options [ingenient @ 000000000277a2c0] File position after avformat_find_stream_info() is 4 http://CPL:[email protected]:99/videostream.cgi: could not find codec parameters [AVIOContext @ 0000000002779dc0] Statistics: 27 bytes read, 0 seeks When I tried wgets on the link I get a 27 byte file (attached). I guess something is wrong with the stream, but vlc is able to read it so I'm wondering how I can get ffmpeg to read it as well? increasing probesize and analyzeduration has no effect. Thanks, Matt
videostream
Description: Binary data
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