On 2010-10-14 10:09, Jean-Marie Adrien wrote: > Hi chris > Im glad you jumped in. Concerning the topic would the following theory > make sense ? > > it seems that video capture and video tracking do not adress the same > purposes : > > - video capture allows 10 frames of latency to ensure that frame > transfer is correct to the machine for later uses (post production, > montage). This is the major usage now of video, because of DV camescopes > and so on. > > - whereas video tracking requires 1 frame of latency maximum, to produce
which of course is not true at all. it's like saying that audio capture for use with real time processing requires a latency of 1 sample. > real time responses. This is a emergent need, that seems to be covered > by other softwares. 1 frame can be quite long, whereas 10 frames can be way shorter. > > Im trying to crawl to the second point. > For instance, in pidip, it seems that there is a IE1394 object that > processes DV type signals with a long latency, like pix_video does in > GEM, and there is another object pdp_DC1394, that would be quicker, and > could thus interface DC uncompressed industrial cameras without sticking > them into the DVlike process, on Linux at least. > > Does this make sense ? in Gem you don't have different objects for different grabbing APIs. e.g. you would use [pix_video] for grabbing from your dv1394 consumer camera, from your analog capture card and from IDC. > Any DC pix_video object in GEM on MAC with 1 frame of latency ? > DC1394 available on MAC or only on LINUX ? on OSX, Gem uses QuickTime for about everything concerned with image acquisition (thus all the problems with OSX10.6). so on OSX this means: if QuickTime provides support for IIDC, then you get IIDC in Gem; if QuickTime does not support GiG-E, then you don't have GiG-E in Gem on linux there is no grand unified image acquisition API, so there are a number of different backends for the various APIs (thus: Gem has explicit support for GiG-E and IIDC cameras on linux; it only has implicit support (if at all) for those cameras on OSX) and finally: the old rule-of-thumb was, that you get the best latency with analog grabber cards you put into your PCI/express slot. fgmsdr IOhannes
smime.p7s
Description: S/MIME Cryptographic Signature
_______________________________________________ [email protected] mailing list UNSUBSCRIBE and account-management -> http://lists.puredata.info/listinfo/pd-list
