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video formats

PostPosted: Wed Nov 21, 2018 3:38 pm
by satanete666
I am doing some test in a not powerfull machine (windows 10 64 pro, i7 3770k , 16gbram, 512 ssd sata,gtx680) to use mp4 files and i see that the sound don´t follow audio, i put the video in timeline and put at the end jump cue to beginning and i see that sometimes has more desync between audio and video , i read that pandoras box can play any kind of videos and the audio always follow video but in my case is not true (1920x1080,25p 8mbits bit rate) also if i put more than one time the video i see that the system canot play video smooth , but if i put outside the pandoras box 4 times the same video in play the system is under 30% of cpu and in pandoras box the same video 4 times it take 70% of the cpu , there is something that i need setup to improve the performance in pandoras box?

Kind regards

Re: video formats

PostPosted: Wed Nov 21, 2018 11:40 pm
by Daniel Kaminski

please read this section in the help file: ... ormats.htm
This might clarify a lot of things.

MP4 is a very bad format for realtime playback. It was developed to transport Video over the Internet. So it is optimized to be very small but the format has a lot of weaknesses when used in mediaservers. On of them is called VBR. Varibale Bit rate.

I do not know what the exact problem with your video is, but I recommand you start by using MPEG2 videos with CBR (Constant Bit Rate) or videos that use an imageSeq like DDS, HAP or HAPQ. In case of Image Seq make sure you use seperate Audio and Video and play back the audio on ASIO Tracks.


Re: video formats

PostPosted: Thu Nov 22, 2018 8:14 am
by satanete666
Hi Daniel,

I understand that mp4 is not optimal file format for pandora and if you want to have multiple machines in sync for a blending etc is not recomended , but i can´t understand that is a file format in the list of suported and i cant playback the file in only one computer in sync with the audio.

I think is better to remove from the list because it causing confusion.


Re: video formats

PostPosted: Fri Nov 23, 2018 2:32 pm
by Christian Hinxlage

I'm afraid, we're mixing up two things.
First is, that we do not recommend mp4 and mov files as long as the mov files don't contain image sequences like hap for example.
This is because they are not played back natively and need the quicktime plugin for playback and you never know exactly what's inside the container. This may also lead to a higher performance.
Nevertheless PB can playback them and it's still an option.

Second is, that I assume, you're playing back the mp4 file with embedded audio on a video layer. Synchronized audio is only guaranteed on an audio layer that uses an ASIO device. So once you split the audio from the video, play it back on a tracklayer and you will get synchronized audio to the video

Hope that helps,

Best regards,


Re: video formats

PostPosted: Sat Nov 24, 2018 12:54 am
by satanete666
Hi Christian,

If I am not wrong there is some post writes by coolux stag that mention That video files that include audio embedded keep in sync only this sound and video but not with the system and if the mp4 is supported I think you must post the exact encode options for optimal playback with synchronization a/v and if is not possible you must warning that will not work well.

Pandoras Box and Audio
Postby Dennis Kuypers » Fri Dec 23, 2016 11:55 pm

If you have a single machine that plays one video with embedded audio then you can use the Video layers without restrictions. If you plan to use multiple machines or if you have multiple clips that require sync use an ASIO device.

There are two ways to play back audio using Pandoras Box. DirectSound (video layer) or ASIO (audio track) where the latter should be the preferred way to go.

played back using a video layer
file formats: mp3, any video format with embedded audio (except HAP/HAPQ)
uses the default Windows audio device (configure routing in Windows)
can play mono, stereo and even 5.1 or 7.1 if the audio routing is correct and supports it
the files played back through DirectSound are not synced with any other media
video-audio sync is given within a single file, but not against other files playing

ASIO (preferred way)
uses audio tracks
requires a ASIO capable sound card (please do not use ASIO4ALL in production environments!)
you have to enable use audio clock as master in the ASIO configuration in Pandoras Box to get synced playback
only one machine can be the clock master
can not be mixed with an incoming SMPTE sync
plays back PCM WAVE files (.wav), mono and stereo
Dennis Kuypers
Product Developer, Software

Online Manual

Re: video formats

PostPosted: Wed Nov 28, 2018 1:39 pm
by Christian Hinxlage
Hi ....

yes you're right. It should be synchronized with itself, but not with other files.

If it's not, I would recommend to convert it, split it and use ASIO Tracklayer for the audio.