MPEG_PLAY(1) MPEG_PLAY(1) NAME mpeg_play - plays mpeg­1 encoded bitstreams using X11 SYNOPSIS mpeg_play [ ­nob ] [ ­nop ] [ ­dither dither_option ] [ ­loop ] [ ­eachstat ] file_name DESCRIPTION mpeg_play decodes and displays mpeg­1 encoded bitstreams on systems running X11. The player will create a new win­ dow, display the bitstream, and exit. Any error messages or notices are sent to stderr. OPTIONS ­nob : causes the player to ignore and not display any B frames. ­nop : causes the player to ignore and not display any P frames. ­dither dither_option : selects from a variety of dither options. The possible values are: ordered ­ ordered dither. This is the default. fs4 ­ Floyd­Steinberg dithering with 4 error values propogated. fs2 ­ Floyd­Steinberg dithering with 2 error values propogated. fs2fast ­ Fast Floyd­Steinberg dithering with 2 error values propogated. hybrid ­ Hybrid dithering, a combination of ordered dithering for the luminance channel and Floyd­Steinberg 2 error dithering for the chrominance channels. Errors are NOT pro­ pogated properly and are dropped all togethor every two pixels in either direc­ tion. hybrid2 ­ Hybrid dithering as above, but with error propogation among pixels. 2x2 ­ A dithering technique using a 2x2 pixel area for each pixel. The image displayed is 4 times larger than the original image encoded. Random error terms are added to each pixel to break up contours and gradi­ ents. gray ­ Grayscale dithering. The image is dithered into 128 grayscales. Chrominance information 30 November 1992 1 MPEG_PLAY(1) MPEG_PLAY(1) is thrown away. color ­ Full color display (only available on 24 bit color displays). none ­ no dithering is done, no image is displayed. Used to time decoding process. mono ­ Floyd­Steinberg dithering for monochrome displays. threshold ­ Floyd­simple dithering for monochrome displays. ­loop : makes the player loop back to the beginning after reaching the end. ­eachstat : causes statistics to be displayed after each frame. Only valid when compiled with ­DANALYSIS. ­shmem_off : turns shared memory off. NOTES The player expects MPEG­1 video streams only. It can not handle multiplexed MPEG streams or video+audio streams. The player uses the paris entropy coding table set (which we believe to be the MPEG­1 standard), but can not handle any bitstreams that use the "berlin" entropy coding table set. Berlin data is relatively rare so there shouldn't be too much to worry about here, but be aware of the differ­ ence when looking for streams to play. Most streams do not end with the proper sequence end code and will probably generate an "Unexpected EOF" error when done playing. This player can play XING data files. Be aware that XING makes no use of temporal redundancy or motion vector information. In other words, they do not use any P or B frames in their streams. Instead, XING data is simply a sequence of I frames. Since I frames take significantly longer to decode, performance of the player using XING data is not representative of the player's ability. AUTHORS Ketan Patel ­ University of California, Berkeley, kpa­ tel@cs.berkeley.edu Brian Smith ­ University of California, Berkeley, bsmith@cs.berkeley.edu Henry Chi­To Ma ­ University of California, Berkeley, cma@cs.berkeley.edu 30 November 1992 2 MPEG_PLAY(1) MPEG_PLAY(1) Kim Man Liu ­ University of California, Berkeley, kliu@cs.berkeley.edu 30 November 1992 3