How to insert appropriate timecode in 120 or 300 fps footage?

[Heliooos]

Hi,
I already tried to solve this some years ago but finally had to use manual subtitles.
I have videos shot using 300fps and 120fps setting but the resulting video has standard framerate.

MediaInfo output for raw footage is following:

300fps video

General
Format                                   : MPEG-4
Format profile                           : QuickTime
Codec ID                                 : qt   2001.03 (qt  /caqv)
File size                                : 855 MiB
Duration                                 : 1h 53mn
Overall bit rate mode                    : Variable
Overall bit rate                         : 1 049 Kbps
Writing application                      : Casio Digital Camera

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 1 frame
Format settings, GOP                     : M=1, N=30
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 1h 53mn
Bit rate mode                            : Variable
Bit rate                                 : 1 047 Kbps
Maximum bit rate                         : 22.4 Mbps
Width                                    : 512 pixels
Height                                   : 384 pixels
Display aspect ratio                     : 4:3
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)                       : 0.178
Stream size                              : 854 MiB (100%)
Language                                 : English

and

120fps video:

General
Format                                   : MPEG-4
Format profile                           : Sony PSP
Codec ID                                 : MSNV (MSNV/mp42/isom)
File size                                : 1.23 GiB
Duration                                 : 28mn 49s
Overall bit rate mode                    : Variable
Overall bit rate                         : 6 122 Kbps

Video
ID                                       : 1
Format                                   : AVC
Format/Info                              : Advanced Video Codec
Format profile                           : Main@L4
Format settings, CABAC                   : Yes
Format settings, ReFrames                : 2 frames
Codec ID                                 : avc1
Codec ID/Info                            : Advanced Video Coding
Duration                                 : 28mn 49s
Source duration                          : 28mn 49s
Bit rate mode                            : Variable
Bit rate                                 : 5 991 Kbps
Maximum bit rate                         : 16.0 Mbps
Width                                    : 1 280 pixels
Height                                   : 720 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)                       : 0.217
Stream size                              : 1.21 GiB (98%)
Source stream size                       : 1.21 GiB (98%)

Audio
ID                                       : 2
Format                                   : AAC
Format/Info                              : Advanced Audio Codec
Format profile                           : LC
Codec ID                                 : 40
Duration                                 : 28mn 49s
Bit rate mode                            : Constant
Bit rate                                 : 128 Kbps
Channel(s)                               : 2 channels
Channel positions                        : Front: L R
Sampling rate                            : 48.0 KHz
Frame rate                               : 46.875 fps (1024 spf)
Compression mode                         : Lossy
Stream size                              : 26.4 MiB (2%)

I am using KDEnlive and the "Dynamic text" feature. Unfortunately, same as Avisynth "ShowFrameNumber" it uses the video framerate and it is not possible to change it.

Is there any solution for this? Maybe I could somehow generate SRT/SUB subtitles with timecode as text and then manually change it. But it would need a lot of time...

advice would be helpful

thanks

[sneaker]

AssumeFPS() #slow/fast
ShowFrameNumber()
AssumeFPS() #fast/slow

?

[Heliooos]

OK,
I will dive a little bit more in this. Thought AssumeFPS is used to speed up/slow down a video while I only want to keep the current speed (eg. slow-motion) - so keep the current framerate 29.970 fps but show time for the 300 or 120 fps.

[sneaker]

AssumeFPS() doesn't drop, insert or blend frames in any way. It will basically only change the internal fps flag used by AviSynth. So you change the flag to the value you need for ShowFrameNumber() and afterwards set it back to 30000/1001 again.

[Heliooos]

OK, thanks. I will check it tomorrow on the Windows machine.

[jagabo]

Using this script on a 29.97 fps video:

original_fps = framerate
AssumeFPS(120)
ShowTime()
AssumeFPS(original_fps)

you get:


[Attachment 41614 - Click to enlarge]

You can see that the timestamp in the video at frame #60 is 00.5 seconds (what you expect of a 120 fps video), and the frame time indicated by VirtualDub is 2.002 seconds (what you expect from a 29.97 fps video). So the video will play at 29.97 fps, but the printed timestamps will be at 120 fps intervals.