Choppy previews and frame rate

Hi all,

I know this has been asked countless times in the past, but I have been spending days reviewing threads, but I am still none the wiser.

I am currently using an older iMac (late 2008) with 8Gb of RAM and an SSD with plenty of space.
DaVinci 14.3.0.014

I am trying to shoot a video using an iPhone (a-ha!!) and I have the variable frame rate issue. I have been using handbrake audit looks as if now I do have a fixed frame rate video, but when I load it it goes out all choppy and the frame rate on the bar at the top goes up and down like a yoyo. Clearly the video encoder is H.264 (shock horror!) and I have tried to change it to MPEG-4, but, again, it has made no difference.

I have tried using a camera which SHOULD have a fixed frame rate, but no joy. The result is the same.

I am not sure where the problem is... is it my older graphics card? The video? The way they are encoded? There are A LOT of solutions around but they all seem to apply to a smaller subset of people.

Apologies for not making any sense... If you need further info, please DO ask and I'll do my best to find the relevant info.

This is what Mediainfo says about my video after it went through handbrake, in case it helps:

General
Complete name : /Users/andrea/Andrea stored/Video Youtube AS/Curve di crescita/Video originali/IMG_0198.mp4
Format : MPEG-4
Format profile : Base Media / Version 2
Codec ID : mp42 (isom/iso2/avc1/mp41)
File size : 238 MiB
Duration : 3 min 50 s
Overall bit rate mode : Variable
Overall bit rate : 8 651 kb/s
Encoded date : UTC 2018-04-21 10:22:32
Tagged date : UTC 2018-04-21 10:22:32
Writing application : HandBrake 1.1.0 2018040700

Video
ID : 1
Format : AVC
Format/Info : Advanced Video Codec
Format profile : High@L4
Format settings : CABAC / 4 Ref Frames
Format settings, CABAC : Yes
Format settings, ReFrames : 4 frames
Codec ID : avc1
Codec ID/Info : Advanced Video Coding
Duration : 3 min 50 s
Bit rate : 8 551 kb/s
Width : 1 920 pixels
Height : 1 080 pixels
Display aspect ratio : 16:9
Frame rate mode : Constant
Frame rate : 29.970 (30000/1001) FPS
Color space : YUV
Chroma subsampling : 4:2:0
Bit depth : 8 bits
Scan type : Progressive
Bits/(Pixel*Frame) : 0.138
Stream size : 235 MiB (99%)
Writing library : x264 core 155 r2893 b00bcaf
Encoding settings : cabac=1 / ref=2 / deblock=1:0:0 / analyse=0x3:0x113 / me=hex / subme=6 / psy=1 / psy_rd=1.00:0.00 / mixed_ref=1 / me_range=16 / chroma_me=1 / trellis=1 / 8x8dct=1 / 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=1 / weightb=1 / open_gop=0 / weightp=1 / keyint=300 / keyint_min=30 / scenecut=40 / intra_refresh=0 / rc_lookahead=30 / rc=crf / mbtree=1 / crf=20.0 / qcomp=0.60 / qpmin=0 / qpmax=69 / qpstep=4 / ip_ratio=1.40 / aq=1:1.00
Encoded date : UTC 2018-04-21 10:22:32
Tagged date : UTC 2018-04-21 10:22:32
Color range : Limited
Color primaries : BT.709
Transfer characteristics : BT.709
Matrix coefficients : BT.709

Audio
ID : 2
Format : AAC
Format/Info : Advanced Audio Codec
Format profile : LC
Codec ID : mp4a-40-2
Duration : 3 min 50 s
Bit rate mode : Variable
Bit rate : 98.3 kb/s
Channel(s) : 2 channels
Channel(s)_Original : 1 channel
Channel positions : Front: C
Sampling rate : 44.1 kHz
Frame rate : 43.066 FPS (1024 SPF)
Compression mode : Lossy
Stream size : 2.70 MiB (1%)
Title : Mono / Mono
Default : Yes
Alternate group : 1
Encoded date : UTC 2018-04-21 10:22:32
Tagged date : UTC 2018-04-21 10:22:32

Thanks

The main problem is your computer. Resolve is hardware hungry. Your core duo processor is slow, you need more ram, and 250mb Vram is totally inadequate. Time for a new computer I think.

More than 8Gb? (that is my limit...)
I wonder if I can upgrade the VRAM.

However if the problem is the computer at least I can put my mind at rest...

What size of VRAM does one need?

You can't upgrade VRAM.

I know, or so I gather now

Your GPU needs to have VRAM in Gigabytes not Megabytes. I get away with 2gb but 4 or more is recommended. I also have an i7 4 core processor which, with hyperthreading, gives me 8 logical cores.

Your computer is definitely not capable nor upgradeable enough. Your footage does have a fixed rate but the system can't handle it so you see the indicator jumping around.

You may get somewhere if you convert all of your footage to ProRes within Resolve using the 'create optimized media' option (find this in the manual). This type of footage requires less power to process when you're working with it so it MIGHT help.

Honestly I think you'll run into crashing or and performance problems later on anyway so it's probably not worth it.

Thanks a lot.

I have to say, I don't have to do a great deal, but I think my best option is to use iMovie (oh dear...), at least it doesn't crash and allows me to do some basic edits. I'll leave the more fancy stuff for a later date.

If you use a current iPhone, you may run into limitations even in iMovie.

iMovie has more limitations (AND bugs) than I can count, BUT... beggars can't be choosers