bytedeco/javacv

getLengthInVideoFrames's return value is not accurate frame count

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#1,941 opened on Nov 20, 2022

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 (2 comments) (0 reactions) (1 assignee)Java (1,583 forks)batch import
enhancementhelp wanted

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Description

Hi, I'm using FFMpegFrameGrabber to a mp4 file , I use getLengthInvideoFrame after start method, and I get 2108 frames, But when I grab every video frames, totally only 2107 frames, the getLengthInvideoFrame returned is not the real frame count, How can I get the accurately frame count beore grab one by one? Thank you

Contributor guide

Research direction
Investigate why getLengthInVideoFrames() returns 2108 but actual frames are 2107. Check if last frame is being skipped due to keyframe or variable frame rate. Look at FFmpeg's avformat and avcodec for frame count inaccuracies.
Tech stack
java
Domain
backend
Issue type
Bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
Active
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
Mostly clear
Prerequisites
JavaFFmpeg basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60