1

I have a small HP server (ProLiant MicroServer Gen8) and I use it to make surveillance camera recordings. The on-board graphics were quite weak, so I added a GeForce GT730 and installed the latest nVidia drivers for it. I did not change any settings in iSpy, but the resulting video files are now roughly 10x in size.

The quality looks the same, the frame rate and the resolution is also the same. What can be the reason of this? I included the file info I obtained using MPC-HC (old, new), I also copy the differing fields here:

                                 old file                     new file
File size                      : 19.6 MiB                     185 MiB
Duration                       : 15 min 1 s                   14 min 44 s
Overall bit rate               : 183 kb/s                     1 758 kb/s
Writing application            : Lavf57.56.100                Lavf57.83.100

Format settings, GOP           :    (no data)                 N=1
Duration                       : 15 min 1 s                   14 min 44 s
Bit rate                       : 182 kb/s                     1 757 kb/s
Frame rate                     : 4.358 FPS                    4.565 FPS
Bits/(Pixel*Frame)             : 0.136                        1.253
Stream size                    : 19.5 MiB (100%)              185 MiB (100%)
Writing library                : x264 core 148 r2721 72d53ab  x264 core 152 r2851 ba24899
Encoding settings :
old: cabac=1 / ref=5 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=8 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=2 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=-2 / threads=3 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=3 / weightb=1 / open_gop=0 / weightp=2 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=50 / rc=crf / mbtree=1 / crf=23.0 / qcomp=0.60 / qpmin=16 / qpmax=26 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
new: cabac=1 / ref=1 / deblock=1:0:0 / analyse=0x1:0x111 / me=hex / subme=2 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=0 / me_range=16 / chroma_me=1 / trellis=0 / 8x8dct=0 / cqm=0 / deadzone=21,11 / fast_pskip=1 / chroma_qp_offset=0 / threads=3 / lookahead_threads=1 / sliced_threads=0 / nr=0 / decimate=1 / interlaced=0 / bluray_compat=0 / constrained_intra=0 / bframes=3 / b_pyramid=2 / b_adapt=1 / b_bias=0 / direct=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=250 / keyint_min=25 / scenecut=40 / intra_refresh=0 / rc_lookahead=10 / rc=crf / mbtree=1 / crf=23.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
2
  • Lock your bitrate at a max of 200 kb/s
    – Narzard
    Dec 26, 2017 at 20:26
  • Consider checking the latest version of the iSpy software too and looking at the release notes of newer versions and such. You did change hardware so perhaps there's a bug with that hardware and those drivers and the version of iSpy you are running whereas perhaps the release notes will tell if any applicable bugs have since been patched. Never hurts to upgrade if you can after your typical backups and such. I still like the GPU offload explanation answered earlier as well too. Dec 27, 2017 at 4:55

1 Answer 1

1

From iSpy User Guide You can also set a maximum CPU target value in settings. By default this is set to 90%. This means that when your CPU usage goes over 90% iSpy will start reducing the framerates of your cameras to help protect against a crash.

Basically what was happening is your prior setup had the integrated graphics which put the stress on your CPU. Your CPU must have always been around or above 90% utilization.

Now that you have a dedicated GPU, all of that graphics work has been offloaded from your CPU and put onto your GPU. Now it is no longer reducing the frame rates of your cameras, since your CPU is not as stressed, which would cause larger file sizes without having changed any settings.

4
  • I'd say that's a rather good explanation of why this could happen. Dec 27, 2017 at 4:53
  • @ITSnuggles prior to posting an answer, I was unsure exactly what is going on because the FPS is nearly the same. The only thing that is very different is the bit rate. I assumed iSpy was capping this bit rate, and acting in the same manner as the CPU reference. It could have also been a high CPU utilization and lowered the bit rate, due to the already low FPS. The higher bit rate indicates a better quality image, which is a correlation to the stated integrated graphics being "quite weak," compared a dedicated graphics card. High bit rate + low fps = a lot of data per frame.
    – DrZoo
    Dec 27, 2017 at 5:12
  • And any iSpy gurus should chime in. I've never used the software before. I'm just taking a best guess in hopes of helping Rolf discover a solution.
    – DrZoo
    Dec 27, 2017 at 5:13
  • I did some experimenting. @Narzard unfortunately iSpy does not have a bitrate option. Tried lowering the 'quality' option but strangely had no effect on the video. If I limit the CPU, the files start getting a bit smaller (~20%) but having worse framerates (~3fps). (Similar behaviour would be desired, though: same fps, lower bitrate [kbps].) I think the only option I have is the 'profile' option in iSpy which is basically the codec, it has MP4 native H264 and Mobile, and also various AVI options. Is there a way I can change the default options for the H264 codec directly, outside of iSpy?
    – Rolf
    Feb 6, 2018 at 14:31

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .