Change in the way fast forward works?

agoodm · Post by **agoodm** » Mon Aug 04, 2008 10:00 am

I think the way fast forward works has changed.

I remember previously recording at 1 fps and then asking it to play back at a rate of lets say 10x and you would see each frame as I would expect but at 10fps.

Now when I fast forward at 10x I see every 10th frame meaning that things could have flown past the camera and making fast forward useless?

Post by **zoneminder** » Mon Aug 04, 2008 1:41 pm

Changed from which version to which?

In the DVR mode it should be intelligent enough to schedule frames according to your bandwidht settings. In other words if your bandwidth indicates you can watch 10fps and you are watching a 10fps stream then you will see every frame. If you then increase the rate to 2x you will still be viewing at 10fps and every other frame will be dropped. Otherwise it would just all back up and you would be back to viewing at 1x rate.

agoodm · Post by **agoodm** » Tue Aug 05, 2008 2:39 pm

I have 20 analogue cameras split across 2 servers all recording at 1fps mocord, all is OK.

Normal playback interface: Set bandwidth to high (machines on same lan) Play back on a camera, choose rate at 4x, result is that the actual play speed seems to be 1fps (ie not fast forwarding) but the grey bar moves across at 4x speed.

DVR interface: hit fast forward to get 2x and see every other frame only, effect is worsened with increased speed, ie 10x speed means I see 1 frame for every 10 seconds and miss events I should be seeing.

timcraig · Post by **timcraig** » Tue Aug 05, 2008 5:53 pm

Try tweaking your ZM_WEB_H_VIDEO_MAXFPS under the High B/W tab in ZM's Options window. From my understanding, the lower the number this value is, the more likely zoneminder's streaming process (zms) will skip frames. I would recommend to raise that number if you want to see all the frames of the event. This also means that the fast forwarding will be slower.

From what I see in the code, when streaming events, zms will take the total frames of the event and divide it by the # seconds of the event and then multiply that number by the replay rate. If the resulting number goes over the value in ZM_WEB_H_VIDEO_MAXFPS, zms sets up the streaming to skip frames.

agoodm · Post by **agoodm** » Tue Aug 12, 2008 3:17 pm

Hi,

I checked the setting on both boxes and its set to 25fps on each. Fast forward in normal mode doesnt appear to be working, and the new dvr interface doesnt seem ready for my users just yet. (i understand its beta)

On one of my boxes i start playback and choose 25x rate, the bar at the bottom scrolls across at 25x but the video plays at 1fps and is not skipping frames.

timcraig · Post by **timcraig** » Wed Aug 13, 2008 6:01 am

agoodm,

I poked around with the code and got ZM's 1.23.3 fast forwarding to work much like ZM 1.22.x.
I posted the patch on this thread http://www.zoneminder.com/forums/viewtopic.php?t=12111

I really missed the 1.22.x fast forward performance when I upgraded to 1.23.x. I'm glad I made this modifaction.

agoodm · Post by **agoodm** » Wed Aug 13, 2008 3:03 pm

This has solved the issue which cropped up for me after 1.23 release.

Thank you very much, maybe put this fix into the new release? Or include a toggle for new/old behaviour regarding rewinding.

tanner · Post by **tanner** » Wed Aug 13, 2008 4:17 pm

Thanks for this I will try out the fix. I had the same problem and started looking at the stills because of the problem.

timcraig · Post by **timcraig** » Thu Aug 14, 2008 2:49 am

Your welcome.

There was a bug in the patch, I updated the patch and described how to fix it by hand.