Top Document: SGI movie Frequently Asked Questions (FAQ) Previous Document: -31- How do I write a program to read and write compressed data to a movie file? Next Document: -33- I want to write a program which can create a JPEG- compressed movie file compatible with the Cosmo Compress See reader questions & answers on this topic! - Help others by sharing your knowledge compression quality. How do I do this with the Movie Library? Date: Fri May 3 11:05:05 PDT 1996 As of IRIX 6.2, there are additional parameters that you can pass in to mvAddTrack to control the compression quality: DM_IMAGE_QUALITY_SPATIAL, DM_IMAGE_QUALITY_TEMPORAL, DM_IMAGE_BITRATE. Note that not all codecs support all of these parameters. JPEG in particular, supports only the SPATIAL setting. (Certain Apple codecs support both TEMPORAL and SPATIAL quality settings; CinePak also supports the BITRATE setting.) Additionally, you can do the compression yourself (as could be done prior to IRIX 6.2): create a movie file with all the appropriate image track parameters (see above), But instead of simply writing frames to the movie and letting the Movie Library automatically compress the frames for you, you handle the compression yourself. To do the compression yourself, you open a Compression Library JPEG compressor, set the quality factor, and use it to compress each frame. Then you write the *compressed* data to the movie file (see above for instructions on how to do this). The tools (dmconvert/makemovie/movieconvert) support these settings in Digital Media Tools 5.5 (see the first question in this FAQ) and IRIX 6.2. User Contributions:Top Document: SGI movie Frequently Asked Questions (FAQ) Previous Document: -31- How do I write a program to read and write compressed data to a movie file? Next Document: -33- I want to write a program which can create a JPEG- compressed movie file compatible with the Cosmo Compress Single Page [ Usenet FAQs | Web FAQs | Documents | RFC Index ] Send corrections/additions to the FAQ Maintainer: sgi-faq@viz.tamu.edu (The SGI FAQ group)
Last Update March 27 2014 @ 02:12 PM
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