bytedeco/javacv

Using FFmpegFrameFilter with zscale and tonemapping

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#1,389 opened on Mar 21, 2020

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enhancementhelp wanted

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Description

When I attempt to create the following filter:

"zscale=t=linear:npl=100,format=gbrpf32le,zscale=p=bt709,tonemap=tonemap=mobius:desat=0,zscale=t=bt709:m=bt709:r=tv,format=yuv420p,scale=1920:1080"

the filter throws an exception when attempting to start:

org.bytedeco.javacv.FrameFilter$Exception: avfilter_graph_parse_ptr() error -22

The filter in question works fine from ffmpeg command line, but I'm using this filter with frame grabber. Any suggestions?

Contributor guide

Research direction
Examine the filter string for compatibility with FFmpegFrameFilter. Check that all filter options (e.g., zscale, tonemap) are supported and the syntax is correct. Consider alternative approaches such as using a custom FFmpegFrameFilter or constructing the filter graph differently. Also verify that the filtergraph parses correctly with avfilter graph parse ptr.
Tech stack
java
Domain
audio video rtc
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.
Clear
Prerequisites
JavaFFmpeg filter syntax
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
70