RE: lingo-l What quicktime compression format?
I have to do a lot of this too. I think of it as enabling random access to movies (the same logic applies to using sliders, etc). With Sorenson you want to stop using the 'natural' key frame setting (which allows the encoder to make all decisions about when key frames are used) and choose to enforce extra key frames at regular intervals. For my material I use every 75 or 150 frames at 25 fps i.e. every 3 or 6 secs. I'm sure you don't need to make every frame a key frame. I've experimented also with the brief pause in playback - the conclusion for me was that it wasn't necessary once I had added regular key frames. I believe Sorenson is unusual in allowing a 'natural' setting which is great for low data rate but not good for random access. For MPEG1 I use a setting called closed GOP, but there is probably less problem with MPEG anyway ... -- Richard Tribe, BBC Interactive dept. -- From: Andreas Gaunitz P11 Reply To: [EMAIL PROTECTED] Sent: Wednesday, March 20, 2002 14:33 PM To: [EMAIL PROTECTED] Subject: Re: lingo-l What quicktime compression format? I'm trying to have 2 video tracks in one movie, and let the user chose which track he wants to see at any moment of the playback. I've done a lot of that. The problem is that the new video track you switch to has to go back to its previous key frame, and build up the current frame, all the time trying to deal with a still playing movie. Ah, so my guessing was quite not too far off then. You can reduce any problems a lot by pausing the movie while you do the switch, giving it some time to get its act together before playing it again, Unfortunatley it's not an option in this case. or/and you could make the key frames more frequent. If you're using Sorenson, you may find that the key frame spacing was set to be quite wide apart, because Sorenson is often used for web video, where infrequent key frames may help to keep the file size down. Try setting the key frames every one or two seconds, and also pause the movie as you switch tracks. Yes, I've been using Sorensson (from Adobe Premiere) until now. I could use any codec but I guess Sorensson is still adequate if I use more frequent keyframes. Thanks for the help! This e-mail (and any attachments) is confidential and may contain personal views which are not the views of the BBC unless specifically stated. If you have received it in error, please delete it from your system, do not use, copy or disclose the information in any way nor act in reliance on it and notify the sender immediately. Please note that the BBC monitors e-mails sent or received. Further communication will signify your consent to this. [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
Re: lingo-l What quicktime compression format?
This is a good reference if you dont already know about it: http://www.siggraph.org/education/materials/HyperGraph/video/codecs/Default.htm Matt Can't open this link?!? I'll try later. -Andreas [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
Re: lingo-l What quicktime compression format?
I'm trying to have 2 video tracks in one movie, and let the user chose which track he wants to see at any moment of the playback. I've done a lot of that. The problem is that the new video track you switch to has to go back to its previous key frame, and build up the current frame, all the time trying to deal with a still playing movie. You can reduce any problems a lot by pausing the movie while you do the switch, giving it some time to get its act together before playing it again, or/and you could make the key frames more frequent. If you're using Sorenson, you may find that the key frame spacing was set to be quite wide apart, because Sorenson is often used for web video, where infrequent key frames may help to keep the file size down. Try setting the key frames every one or two seconds, and also pause the movie as you switch tracks. [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
Re: lingo-l What quicktime compression format?
I'm trying to have 2 video tracks in one movie, and let the user chose which track he wants to see at any moment of the playback. I've done a lot of that. The problem is that the new video track you switch to has to go back to its previous key frame, and build up the current frame, all the time trying to deal with a still playing movie. Ah, so my guessing was quite not too far off then. You can reduce any problems a lot by pausing the movie while you do the switch, giving it some time to get its act together before playing it again, Unfortunatley it's not an option in this case. or/and you could make the key frames more frequent. If you're using Sorenson, you may find that the key frame spacing was set to be quite wide apart, because Sorenson is often used for web video, where infrequent key frames may help to keep the file size down. Try setting the key frames every one or two seconds, and also pause the movie as you switch tracks. Yes, I've been using Sorensson (from Adobe Premiere) until now. I could use any codec but I guess Sorensson is still adequate if I use more frequent keyframes. Thanks for the help! -A. [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
Re: lingo-l What quicktime compression format?
You can reduce any problems a lot by pausing the movie while you do the switch, giving it some time to get its act together before playing it again, Unfortunatley it's not an option in this case. I'm not talking about a huge delay, just enough that the movie doesn't get jerky. Something like this: set the movierate of sprite s to 0 settrackenabled(sprite s,1,false) settrackenabled(sprite s,2,true) updatestage set the movierate of sprite s to 1 -- [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
Re: lingo-l What quicktime compression format?
You can reduce any problems a lot by pausing the movie while you do the switch, giving it some time to get its act together before playing it again, Unfortunatley it's not an option in this case. I'm not talking about a huge delay, just enough that the movie doesn't get jerky. Something like this: set the movierate of sprite s to 0 settrackenabled(sprite s,1,false) settrackenabled(sprite s,2,true) updatestage set the movierate of sprite s to 1 Hm, I'll try it. The movie is one long fly-through, so it's pretty sensitive. I don't expect a perfect result anymore but It'd be nice to reduce jerkyness to a minimum. :-P -A. [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
RE: lingo-l What quicktime compression format?
I may be wrong here but to get the effect of independent images and have compression too,, u can set the keyframes to every video frame I maybe wrong here. Jayp -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED]] On Behalf Of Howdy-Tzi Sent: 19 March 2002 22:05 To: [EMAIL PROTECTED] Subject: Re: lingo-l What quicktime compression format? At 18:56 +0100 03/19/2002, Andreas Gaunitz P11 wrote: What quicktime compression format compresses each frame as an independant image, as opposed to using keyframes and a sort of incremental compression, where every image depends on the previous? I believe that is called raw or no compression. -- Warren Ockrassa | http://www.nightwares.com/ Director help | Free files | Sample chapters | Freelance | Consulting Author | Director 8.5 Shockwave Studio: A Beginner's Guide Published by Osborne/McGraw-Hill http://www.osborne.com/indexes/beginners_guides.shtml [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!] [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
Re: lingo-l What quicktime compression format?
At 18:56 +0100 03/19/2002, Andreas Gaunitz P11 wrote: What quicktime compression format compresses each frame as an independant image, as opposed to using keyframes and a sort of incremental compression, where every image depends on the previous? I believe that is called raw or no compression. -- Warren Ockrassa | http://www.nightwares.com/ Director help | Free files | Sample chapters | Freelance | Consulting Author | Director 8.5 Shockwave Studio: A Beginner's Guide Published by Osborne/McGraw-Hill http://www.osborne.com/indexes/beginners_guides.shtml [To remove yourself from this list, or to change to digest mode, go to http://www.penworks.com/lingo-l.cgi To post messages to the list, email [EMAIL PROTECTED] (Problems, email [EMAIL PROTECTED]). Lingo-L is for learning and helping with programming Lingo. Thanks!]
