Charles.Forsyth20060303-partialeea662d19 years agoHistory
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.TH MPEG 3.SH NAMEmpeg \- Boffin mpeg decoder.SH SYNOPSIS.Bbind -b #E /dev.PP.B /dev/mpeg.br.B /dev/mpegctl.SH DESCRIPTIONThe.I mpegdevice serves two files giving access to a Boffin MPEG-1 decoder..PPThe control file.B mpegctlwhen read returns lines of text giving the device's properties.Each line starts.B videoor.B audiofollowed by a list of capabilities.The current device returns a fixed set:.IP.EXvideo mpeg1,sif.braudio musicam,I musicam,II.EE.PPThe control file accepts the following commands:.TF pause.PD.TP.B initReinitialise the device's video and audio subsystems;cancel the effect of.B stopor.B pause.TP.B stopStop the display immediately..TP.B pauseSuspend display..TP.B video iso11172 mpeg1,sifSet the output video mode and formats; only this precise setting is valid..TP.BI audio " format rate"There are two choices for.IR format :.B musicam,I(MPEG audio layer 1),with.I ratefrom 64000 to 448000 Hz,and.B musicam,II(MPEG audio layer 2)with.I ratefrom 48000 to 384000..TP.BI window " minx miny maxx maxy"Sets the overlay window on the screen, in screen coordinates.If the window size exceeds 320x240, the image is scaled accordingly,separately in each dimension..PPThe data file.B mpegis an exclusive-use device.Once the device has been initialised and an output windowset using the.B initand.B windowcommands to the control file,and an audio format selected by the.B audiocommand,MPEG data can be written in the agreed format to the.B mpegfile,for display in the output window.The driver buffers the data written and implements flow control between applicationand the hardware.When closed, the device waits for the last block of data to displaybefore returning to the application..SH SOURCE.B /os/pc/devmpeg.c.SH CONFIGURATION.B "mpeg0=port=0x1e0 irq=15 dma=6.SH SEE ALSO.IR mpeg (2),.I streamin.IR sys-read (2).SH DIAGNOSTICSAn error results on a write to the device once stopped.