0000853: Project monitor preview: Audio does not match result

View Issue Details [ Jump to Notes ]

[ Issue History ] [ Print ]

Project

Category

View Status

Date Submitted

Last Update

0000853

Kdenlive

User Interface

public

2009-05-24 23:21

2009-06-02 17:19

Reporter

Granjow

Assigned To

ddennedy

Priority

normal

Severity

minor

Reproducibility

sometimes

Status

assigned

Resolution

open

Platform

OS Version

Product Version

Recent git

Target Version

Fixed in Version

Summary

0000853: Project monitor preview: Audio does not match result

Description

I was working with two tracks, an audio (.wav) and a video (.avi, xvid) track. The video clip had audio too. I wanted to match two events exactly and was first relying on the displayed wave form (which finally proved to be correct), but was then upset by the preview (project monitor) where the video's audio came much earlier (about 0.1 or 0.2 seconds) than it should have. So I corrected the position of the video clip until the audio matched.

After rendering the project I found out that it was wrong. So I completely relied on the wave form of both video and audio and rendered a small piece of the video (hey, this feature is really nice!). It was perfectly right. Checking Project Monitor output again -- still a gap of about 0.1 seconds.

Additional Information

Unfortunately I couldn't observe this in a short test project.

Tags

No tags attached.

Build/Install Method

Manual build from SVN

Attached Files

Relationships

Notes
(0002910) Granjow (developer) 2009-05-25 21:38	Seems to be something about the beginning of the video. For another one 0.3 seconds have been cut off, again rendering showed a correct result.

(0002936) ddennedy (developer) 2009-05-27 08:08	Is the audio going through PulseAudio? It is quite difficult to measure and ensure a/v sync as it goes through X11 and ALSA - everyone's system is different, 2 distinct APIs, there is no single clock that drives the output of them.

(0002972) Granjow (developer) 2009-05-29 19:40	PulseAudio? KDE4 shows GStreamer, if that is a PulseAudio equivalent.

(0002975) ddennedy (developer) 2009-05-29 22:57	Kdenlive does not use KDE4 Phonon. So, what you see in System Settings is meaningless. However, some distributions run a sound mixing daemon called PulseAudio and then configure things to go through it by default including the SDL library that MLT uses. Do you have a pavucontrol utility that you can run in konsole? If so, run it while kdenlive is playing and see if there a volume slider widget for the Kdenlive application.

(0003028) Granjow (developer) 2009-06-02 14:36	No, pavucontrol is not installed here.

(0003030) ddennedy (developer) 2009-06-02 17:19	I am seeing the audio behind a couple of hundred milliseconds or so myself now. So, I will see what I can do.

Issue History
Date Modified	Username	Field	Change
2009-05-24 23:21	Granjow	New Issue
2009-05-24 23:21	Granjow	Build/Install Method	=> Manual build from SVN
2009-05-25 21:38	Granjow	Note Added: 0002910
2009-05-27 08:08	ddennedy	Note Added: 0002936
2009-05-27 08:08	ddennedy	Status	new => feedback
2009-05-29 19:40	Granjow	Note Added: 0002972
2009-05-29 22:57	ddennedy	Note Added: 0002975
2009-06-02 14:36	Granjow	Note Added: 0003028
2009-06-02 17:16	ddennedy	Status	feedback => assigned
2009-06-02 17:16	ddennedy	Assigned To	=> ddennedy
2009-06-02 17:19	ddennedy	Note Added: 0003030