Vortex's Viofo A329 Review

Panzer Platform said:
I thought when a camera goes from 30fps to 60fps the Bitrate needs to double to be effective.
Is that not true?
I have a Sony Action Cam (AS200V), and when I switch from 1080p30 to 1080p60 the size of the files double.
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Vortex Radar said:
All things being equal, I believe so, but I think that with compression, you can sometimes get away with less than 2x the file size, though that'll be more true when there's not as much motion around you, aka you're stationary or driving slower and with a clear sky overhead instead of a bunch of trees or something.
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60fps needs more bitrate than 30fps if you are going to keep the same image quality, but you do not need double, generally the codec will only store information on what has moved between the 30 fps frames and the new frames, and that doesn't need much bitrate for a dashcam in a car that is moving at constant speed with no picture vibration, it does not need to store much extra colour information, or spacial detail, your eyes would not pick it up anyway. The general guide is that 60fps should have about 30% more bitrate, but for a dashcam, it should probably be less than that, maybe 20% most of the time. If you have 0% more bitrate then the smoother motion will be at the expense of some other detail, and generally colour detail will get dropped first, then it will become more pixellated and road surface detail gets lost. For normal slow driving, 60Mb/s is enough that the lower image quality of 60fps will be hard to see but the extra smoothness will be obvious, on a sunny day when driving faster under trees, the image quality difference will be more noticeable.

Realistically, 65Mb/s is enough for a dashcam, even at 60fps, until we get above 4K resolution, but it would be nice to have a 100Mb/s 60fps version, even if it is only available for 1 channel use, when you want top quality video. Or if the limit is the microSD card then 100Mb/s only when using an external SSD, as with the iPhone 15 Pro "raw" video recording, Although the iPhone does tend to drop a lot of frames without warning if your external SSD is not fast enough, so that is not a great device to copy!
 
Nigel said:
60fps needs more bitrate than 30fps if you are going to keep the same image quality, but you do not need double, generally the codec will only store information on what has moved between the 30 fps frames and the new frames, and that doesn't need much bitrate for a dashcam in a car that is moving at constant speed with no picture vibration, it does not need to store much extra colour information, or spacial detail, your eyes would not pick it up anyway. The general guide is that 60fps should have about 30% more bitrate, but for a dashcam, it should probably be less than that, maybe 20% most of the time. If you have 0% more bitrate then the smoother motion will be at the expense of some other detail, and generally colour detail will get dropped first, then it will become more pixellated and road surface detail gets lost. For normal slow driving, 60Mb/s is enough that the lower image quality of 60fps will be hard to see but the extra smoothness will be obvious, on a sunny day when driving faster under trees, the image quality difference will be more noticeable.

Realistically, 65Mb/s is enough for a dashcam, even at 60fps, until we get above 4K resolution, but it would be nice to have a 100Mb/s 60fps version, even if it is only available for 1 channel use, when you want top quality video. Or if the limit is the microSD card then 100Mb/s only when using an external SSD, as with the iPhone 15 Pro "raw" video recording, Although the iPhone does tend to drop a lot of frames without warning if your external SSD is not fast enough, so that is not a great device to copy!
Click to expand...
True even my Android phone at 4k60 dropped frames during recording at 60mb/sec bitrate a few weeks ago when I was out of the country - purely because it was 40 degrees Celsius outside and I was recording videos every few minutes. Heat is the enemy lol.
 
Can you have 60 FPS recording and AutoHDR on at the same time? So it records daytime 60 without hdr then night time 30 with HDR? Or does AutoHDR also force 30 fps all the time?
 
alexp999 said:
Can you have 60 FPS recording and AutoHDR on at the same time? So it records daytime 60 without hdr then night time 30 with HDR?
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Yes :)
 
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