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View Full Version : synch delay in 2nd-audio(external) playback associated with restricted AVI-structure?


Bluedan
2nd February 2002, 14:56
I recently heard the Power-DivX crew working on a new (enhanced ?!) (A)udio(V)ideo(I)nterleaved format. As it obviously will be an appreciated improvement ,so what are so far the limitations of the former AVI ?
From my point of view it's already a quite abusable format with a lot of different audio formats being admitted. How does the AV-interleaving work anyway ?
as follows? :
block 1: {video data | audio data | synch data}
block 2: {video data | audio data | synch data}
block 3: ~ ~ ~
block size ? adjustable ?

The only problems I got is in playback of DivX with AC3, but I think it is due to weak heart failure (CPU @667 MHz combined with choky TNT2 pro graphiccard) - and believe me I consulted a lot of fiendly guides besides Doom9 to fix it... no go...the video pb isn't smooth, but in synch, while pb with mp3-VBR is smooth as grease.
Second restriction - and I think I#m not alone - is damn playback of a 2nd audio stream as an external file source. If played from the beginning of the whole movie (if multi-CD which it is always in my case) it stays synch, but if I try to seek into the movie it lacks behind both in 'forward' and 'chapter jump', for example when using such feature in Micro-DVD-Player.
To come back to my initial question: is the latter issue due to insufficient synch management with audio files originally not intended to be implemented such as VBR-MP3, which I always use for both streams ??
I know it's alot asking at once, but it jammed up in my head.
PLEASE ME ??

ChristianHJW
2nd February 2002, 15:38
TMF/MCS format will have time stamps ( AVI has not ), so it will be possible to mux a number of different streams with perfect sync.

buba king
2nd February 2002, 17:27
Same with OGG Media Stream its a replacement for avi. There is already a working muxer! read: http://www.powerdivx.com/phpbb2/viewtopic.php?t=108

sure it has some bugs but I think it's already better than avi! :)

Bluedan
3rd February 2002, 15:24
Sounds good to me, but how does the synching work in AVI if there is no time stamping ? And where' s the problem of playing back external audio files while there should be every necessary information in the audio file as it has been saved with all the interleaving information (Vitualdub/Nandub)?
And why AVI can handle VBR that's included as Audio stream whereas the Variable Bitstream obviously becomes the spoke in its wheel when it's present as external file ??
What is the problem with VBR anyhow ?

I still have to take care of it as long as there is no reliable and stable replacement for AVI.

I admitt that I didn't understand all that technical talk about Ogg compared to the new PDivX format... I couldn't exactly find out the issue... well ok it was about working or non-working muxer/ demuxer... maybe it's because English is not my mothertongue...

Bluedan
3rd February 2002, 19:26
thank you both, now I have spent the whole afternoon reading about specs, plans and great motivation.

I'm looking forward to it and personally from a point of users who has just enough skills to come along with detailed and complicated utilities to reach his goal- and understand what I'm doing - I give a favour to TMF/MCP.