Trimmed .mov showing some deleted frames when converted
Posted: Sun May 13, 2018 7:36 am
Description of problem or question:
I have a number of screen recordings made using Quicktime where I have already used QT to trim them. You can't control QT's screen recording bit rate so the files are big - so I want to convert them to mp4 files with the same frame rate but lower bit rate. That's all fine. Trouble is when I do it some frames appear in the mp4 at the start which have apparently been removed in the QT edit. I presume that's because QT can only cut at a key frame so the mov container simply instructs the QT player to ignore the first X frames. I have validated that theory by playing the mov files in VLC, which upon opening start at the correct point but you can scroll back to see the unwanted frames. However, when reencoding Handbrake doesn't appear to take any notice of the 'don't play these frames' instruction and encodes them. Is there any way to force it to take notice of the container instruction so it doesn't encode the unwanted frames? Or failing that, any way to find out how many frames to manually tell it to skip? I can't see any way in QT or MediaInfo to find out how many frames the player is being instructed to skip.
Steps to reproduce the problem (If Applicable):
HandBrake version (e.g., 1.0.0):
1.1.0
Operating system and version (e.g., Ubuntu 16.04 LTS, macOS 10.13 High Sierra, Windows 10 Creators Update):
MacOS 10.13.4
HandBrake Activity Log ***required*** (see How-to get an activity log)
I have a number of screen recordings made using Quicktime where I have already used QT to trim them. You can't control QT's screen recording bit rate so the files are big - so I want to convert them to mp4 files with the same frame rate but lower bit rate. That's all fine. Trouble is when I do it some frames appear in the mp4 at the start which have apparently been removed in the QT edit. I presume that's because QT can only cut at a key frame so the mov container simply instructs the QT player to ignore the first X frames. I have validated that theory by playing the mov files in VLC, which upon opening start at the correct point but you can scroll back to see the unwanted frames. However, when reencoding Handbrake doesn't appear to take any notice of the 'don't play these frames' instruction and encodes them. Is there any way to force it to take notice of the container instruction so it doesn't encode the unwanted frames? Or failing that, any way to find out how many frames to manually tell it to skip? I can't see any way in QT or MediaInfo to find out how many frames the player is being instructed to skip.
Steps to reproduce the problem (If Applicable):
HandBrake version (e.g., 1.0.0):
1.1.0
Operating system and version (e.g., Ubuntu 16.04 LTS, macOS 10.13 High Sierra, Windows 10 Creators Update):
MacOS 10.13.4
HandBrake Activity Log ***required*** (see How-to get an activity log)
Code: Select all
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