Converting 29.97 fps to 25 fps

[jagabo]

It allows decreasing frame rate but only to 2/3 the source or higher (50 -> 33.3). So one would want:

Yadif(mode=0) # 25i to 25p
FrameRateConverter(30000, 1001)

Or use some other frame rate converter.

[Cornucopia]

2 things of note:

Depending on model, and which app you use, you may very well be able to force your phone into recording at 25fps instead of 29.97.

Which leads us to....

Regardless of whatever phone you have, or whatever app you have, if your phone doesn't have plentiful amount of light, it will record using VARIABLE framerate (which can often go from ~1fps through 60fps, etc). Some will do it anyway, regardless of plentiful light. Has to do with compromises with phone sensor computing power vs. time vs. minimum exposure expectations for consumer video.
As such, it will ALWAYS have sync issues when converting to any standard Constant framerate, such as 25, or 29.97. Also does NOT matter which method, though optical flow/motion-compensated methods ought to be the smartest, and thus hopefully most accurate guesses.

Scott

[marius2du]

Or use some other frame rate converter.

I was using this:

AssumeTFF()
AssumeFPS(25)
QTGMC(preset="fast")
sRestore(frate=29.97)

and this:

ConvertFPS(29.97)

So far, FrameRateConverter() gives the best result.

[marius2du]

2 things of note:

Depending on model, and which app you use, you may very well be able to force your phone into recording at 25fps instead of 29.97.

Hi Scott,
I have no option to change fps' on the smartphone. Recording goes at ~29.97 fps, when I match the timeline in Vegas with the recorded file, or with MediaInfo,it will show sometimes 30.007

[Cornucopia]

You don't THINK you have an option to change framerate, but you may still have that option regardless.

Example: I have a Samsung Android phone (personal) and an iPhone6 (work). The iPhone's stock camera app, if you look in [Settings | Camera | Record Video] gives you the option for 720p30, 1080p30 and 1080p60. The Android phone's STOCK camera app does NOT give you any option like that.
However, you can get "OpenCamera" free app for Android, or a free/paid "FV-5" camera for Android, or the similar, but paid "ProCam" for iPhone, both of which give you many resolution & framerate options. Though again, ALL are dependent on light level.
The OpenCamera app has settings for:

• Default
• 15
• 24
• 25
• 30 (which is probably actually 29.97)
• 60
• 96
• 100
• 120

BTW, MediaInfo is giving a best guess based on the fact that it should know it is VFR and is trying to average it for you. And, also, because of the way that MP4 and MKV count their timebase, it is not always possible to give an exact, "standard" framerate in those formats.

Scott

[marius2du]

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