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diff --git a/Demo/sgi/video/video.doc b/Demo/sgi/video/video.doc deleted file mode 100755 index 982c008..0000000 --- a/Demo/sgi/video/video.doc +++ /dev/null @@ -1,109 +0,0 @@ - CMIF video tools - -This document gives a quick introduction to some of the tools useful -for recording, editing and playing back video data in CMIF video -format. All the tools mentioned currently live in /ufs/guido/bin/sgi. -A description of the CMIF video file format can be found in -/ufs/jack/cmif-film.ms. - - Recording video - -There are two tools to record video, Vrec and and Vrecb. Vrec does -continuous capture, but can capture at most 15 frames per second. -Vrecb uses burst capture, enabling it to capture all frames. It -captures to main memory, however, so it cannot handle long video -fragments. The following options are common to both programs: - - -r rate Capture one out of 'rate' frames. Default (and - minimum) is 1 for Vrecb, 2 for Vrec. There are some - caveats for recording PAL, see below. - -w width Set initial window width (and height, implicitly). - -g bits Create greyscale film in stead of 8-bit dithered color - film. Allowable values for 'bits' are 2, 4 or 8. - -m Create monochrome dithered film. These look horrible. - -M threshold Create monochrome thresholded film with specified - threshold (in range 0..255). - -G Create 2-bit dithered greyscale film. - -f Capture fields in stead of frames. The film is created - in such a way that the picture will be suitably - enlarged on playback, so aspect ratio, etc. are - maintained. - -d Drop fields if they would cause data from two video - fields to be combined. See the section on PAL for more - details. - -Options for Vrec: - -a Record audio as well. You will have to twiddle audio - and video later if you want lipsync playback. - -q queuesize Set size of the video board circular buffer. A little - experimentation with this may lead to more video being - captured, but not always. - -P frames Preallocate diskspace for 'frames' images. This may - enable you to capture more frames. - -Options for Vrecb: - -n number Capture 'number' frames. Default is 60 (2 seconds). - -Both programs accept a filename to store the video on (default -film.video) and Vrec also accepts an audio file name (default -film.aiff). When you want to record you press the left mouse button. -Vrec stops recording when you release the mouse button and Vrecb stops -after the predetermined number of frames have been recorded. During -recording the picture may look funny, but do not let this worry you, -the film will be ok. - -After recording and saving, Vrec will print the deltas of the field -numbers recorded. A list of '4 4 4 4'... means that all possible -frames (one out of two) have been recorded. Vrecb will tell you how -many duplicate fields have been skipped. See below on PAL useage -again. - - PAL caveats - -The IndigoVideo board converts the incoming video signal to the 60Hz -(59.something, actually) display rate. All further operations, -including capture, are done with respect to display rate. This is -especially bothersome in the case of PAL video, since it means one out -of 5 frames will be duplicated. Together with the fact that, in -continuous capture, you can only capture every second frame this leads -to strange and wondrous effects. The frame numbers returned by the -video board (and displayed by Vrec) are display frame numbers, and so -bear only a very complicated (and probably non-deterministic) relation -to PAL frame numbers. For recording simple videos this is probably no -problem. You can use Vrec and try using -d to see which gives the best -result. On the other hand, if you need every frame and no duplicates -either you have to use Vrecb and supply the -d and -f option. This -will give you exactly the fields as they appeared on the PAL tape. - - Video playback - -The easiest way to play back a video is to use Vplay. Calling it with -an argument of -? will make it list all its options. A few options may -need a bit of explanation: - -M magnify Magnify the images by the given factor. This still - takes any magnification specified in the film (if it - is a field film, for instance) in account. - -w width and - -h height Normally the window will be the correct size for the - film. You can set height and width, though, if you - want the window to be bigger. This is especially - useful if you want to record the film back to - videotape, since you can playback in a window that is - bigger than PAL size with a black background and you - will have no distracting window-manager thingies on - your videotape. - - Video Editing - -Vedit is a (very simple) video editor that allows you to select images -from the input movie and copy them to an output movie. Both input and -output films have a modest buffer that you can move around in. - -Vaddcache takes a movie and adds a frame location cache to it. This -will make some other programs run faster. - -rgb2video converts a set of SGI .rgb files to a movie. - -There are a few programs that can do image format conversion on movies -(i.e. convert an 8-bit dithered RGB movie to a greyscale movie), but -nothing very complete yet. Look at Vcopy.py for more information. |