h.264 constant vs variabel
- Thread starter badmannen
- Start date
nayr
IPCT Contributor
well its variable, if your indoors looking at a static scene with low traffic it could save alot of space.. but outdoors it often struggles to cope with the environment.
disk space is cheap, VBR causes more issues than it solves.. for most people I'd say stick with CBR, unless your willing to do alot of experimentation/testing to see if it works for you.
disk space is cheap, VBR causes more issues than it solves.. for most people I'd say stick with CBR, unless your willing to do alot of experimentation/testing to see if it works for you.
Variable bit rate (VBR) is complex. You still set a value in the Bit Rate field, but the camera only treats it as a maximum (e.g. set it to 6 Mbps and the camera will try to never exceed 6 Mbps at any given time). The camera is free to encode below your bit rate setting if it thinks it can achieve your desired quality with a lower bit rate. Like, when nothing is moving it might encode at 2 Mbps, and then if a vehicle drives through your scene it might increase temporarily to 6 Mbps to maintain good image quality. To achieve the same quality with constant bit rate encoding (CBR), the camera would have to encode at 6 Mbps at all times. So with careful tuning, VBR can result in data savings without any noticeable quality loss.
However in my experience, sometimes the VBR logic limits the quality more than you want. With my Dahua 4MP cameras, I can enable VBR at its maximum quality level, with the Bit Rate field maxed out, and it still encodes a cruddy looking image (at a low bit rate like 2 Mbps or less). So with those Dahua cameras, I changed to CBR encoding and got a huge quality boost at the cost of higher data usage. In my testing, Hikvision cameras were better at this, but in the end I chose to use CBR encoding on them too just because storage space is not a concern for me. I have room for years of motion recordings on my server.
However in my experience, sometimes the VBR logic limits the quality more than you want. With my Dahua 4MP cameras, I can enable VBR at its maximum quality level, with the Bit Rate field maxed out, and it still encodes a cruddy looking image (at a low bit rate like 2 Mbps or less). So with those Dahua cameras, I changed to CBR encoding and got a huge quality boost at the cost of higher data usage. In my testing, Hikvision cameras were better at this, but in the end I chose to use CBR encoding on them too just because storage space is not a concern for me. I have room for years of motion recordings on my server.
Ok yea I guessed that. Well disk space is no issue got plenty for what I use it for. It was more to get a decent stream when watching on remote with full resolution. I don't see much difference at all between variable and constant when I put the camera indoors staring at the wall but maybe it depends on noise in the image and things like that so the variable will work better
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nayr
IPCT Contributor
VBR on a substream because you remotely view your cameras often on a slow connection is a good use case for it.. but your main stream I doubt your watching remotely unless you got really good internet uploads.
for recording, Ive found pretty much same as bp2008.. what it thinks is good enough and what I think are good enough are too far apart for me to use it.
for recording, Ive found pretty much same as bp2008.. what it thinks is good enough and what I think are good enough are too far apart for me to use it.
I did not get much of a difference at al with variable at the end . but I tried it out with h.265. ... could not see any difference in the picture ( did not go into much detail I admit ) ... but looked the same as h.264. the nice thing was that it cut the data in half basically . With h.264 I had around 7500 kbps with my 4mp camera doing full resolution with 15fps ... with h.265 ... it dropped down to average less than 3500 kbps =) .... even if data storage is cheap we would only need half =)