0001551: Audio desynchronizes when "Crop From Start" is used

View Issue Details [ Jump to Notes ]

[ Issue History ] [ Print ]

Project

Category

View Status

Date Submitted

Last Update

0001551

Kdenlive

MLT

public

2010-04-11 08:39

2010-05-04 17:24

Reporter

foobar123

Assigned To

Priority

normal

Severity

major

Reproducibility

always

Status

acknowledged

Resolution

open

Platform

32 bit intel and alike

Kubuntu Linux

OS Version

9.10

Product Version

Recent git

Target Version

Fixed in Version

Summary

0001551: Audio desynchronizes when "Crop From Start" is used

Description

- Generated an OGV file with Kdenlive's screen capture feature
- Added the clip to a track
- Cropped away the first few seconds

When the project is played back, at first the audio is out of sync - it is as if only the video had been cropped, but not the audio, so the audio is "late". Also, audio pops and crackles, and is played back too fast. Some time later, audio syncs again.

The broken audio is exported also to rendered files, so it is not a playback problem of the Project Monitor.

Cropping clips of other file formats seems to work fine, so the first thing I tried was transcoding the clip to another format - which led me to bug 0001549 "Crash when loading Lossless Matroska clip"... (Which I reported first because a crash is probably more severe than an audio de-sync problem.)

I've uploaded example files here because the upload function doesn't let me upload files.
http://tumbetoene.tuxfamily.org/temp/kdenlive/kdenlive-ogv-audio-desync.tar.bz2 [^]

Tags

No tags attached.

Build/Install Method

Distribution package

Attached Files

Relationships

related to	0000618	closed	ddennedy	When rendering one clip does not become visible until 5 seonds after clip starts
related to	0000619	closed	LeHomard	after adjusting the video boundary, audio 'shifts' with the boundary so the same audio is played in different part of timeline

Notes
(0005013) foobar123 (reporter) 2010-04-11 08:42 edited on: 2010-04-11 08:44	Sorry for reporting the same bug twice - there was an error message so I assumed it hadn't been posted. You can delete #0001550.

(0005043) LeHomard (developer) 2010-04-18 18:59	Acknowledged on latest svn, using the provided files : the sound starts slightly late and is sped up (wich also distorts it) for a few seconds before getting back into sync with the right speed. First time I've comme across the problem, probably only happens for Theora/Vorbis files (maybe only a problem with Vorbis ?)

(0005086) ddennedy (developer) 2010-05-01 07:30	Seeking on Theora is known to be problematic in FFmpeg. There is nothing we can do unless it is fixed there or someone creates some other provider in MLT.

Issue History
Date Modified	Username	Field	Change
2010-04-11 08:39	foobar123	New Issue
2010-04-11 08:42	foobar123	Note Added: 0005013
2010-04-11 08:43	foobar123	Note Edited: 0005013	View Revisions
2010-04-11 08:44	foobar123	Note Edited: 0005013	View Revisions
2010-04-18 18:59	LeHomard	Note Added: 0005043
2010-04-18 18:59	LeHomard	Status	new => acknowledged
2010-04-18 19:01	LeHomard	Relationship added	related to 0000619
2010-05-01 07:30	ddennedy	Note Added: 0005086
2010-05-04 17:24	ddennedy	Relationship added	related to 0000618