Skip site navigation (1)Skip section navigation (2)

FreeBSD Manual Pages


home | help
recmpeg(1)			    recmpeg			    recmpeg(1)

       recmpeg - simple	video encoder

       recmpeg [options] [output_file] [input_file]

       recmpeg is a simple video encoder based on the fame library.

       It  can	encode MPEG-1, MPEG-4 rectangular, and MPEG-4 arbitrary	shaped

       The input sequence must be provided in uncompressed raw YUV 4:2:0  for-
       mat  (also called YV12).	Each frame of the sequence starts from the top
       left corner to the bottom right,	with width*height pixels for the lumi-
       nance  component	 (Y),  and  width/2*height/2  for  the each of the two
       chrominance components (U, V), each packed together, in Y, U, V	order.
       Width  and  height of the sequence are not provided in input file. Thus
       the input sequence has the following structure:

       [ frame 1 Y ][ frame 1 U	][ frame 1 V ][	frame 2	Y ] ...

       output_file and/or input_file can be specified but are not required. If
       no input_file is	specified, standard input will be used instead.	 If no
       ouput_file is specified,	standard output	will be	used instead.

       --help Show usage information.

	      Show information about the progress of the encoding.

	      Select the profile to use. "mpeg1",  "mpeg4"  and	 "mpeg4_shape"
	      are  currently supported.	When this option is not	specified, the
	      default is "mpeg1".

	      Select the motion	estimation algorithm to	use. "none", "pmvfast"
	      and  "fourstep" are currently supported. When this option	is not
	      specified, the default is	"pmvfast".

	      Number of	frames before outputing	a new  sequence	 header.  This
	      option  is useful	for example when broadcasting output to	a net-
	      work to allow users to start decoding in the  middle  of	a  se-
	      quence.  The  default is to generate only	one sequence header at
	      the beginning of the output stream.

       --fps  Number of	frames per second of  the  input  sequence.  When  not
	      specified,  the  default	is  25.	Fractional frame rates are al-

	      Specifies	the search window, in pixel unit, for  motion  estima-
	      tion.  Small  values  give  better result	on slow	motion videos,
	      whereas bigger values work better	with fast motion. The  default
	      is 16 pixels.

	      Quality  of the shape coding in percent. Lower quality will pro-
	      duce smaller bitstream. The default is 100% since	shape data  is
	      often negligible compared	to video data.

	      Size  of the output bitstream buffer. This should	be set accord-
	      ing to the size of the video  being  coded.  Prediction  over  a
	      large  number  of	frames and large frame sizes require a greater
	      output buffer. The default is set	to  1Mbyte,  which  should  be
	      enough  for  nearly  all videos. The unit	is in bytes but	Kbytes
	      and Mbytes can be	specified by appending a K (resp. an M)	to the
	      number (e.g. 4M).

	      Use  fixed  bitrate.  The	unit is	in bits	per second but Kbits/s
	      and Mbits/s can be specified by appending	a K (resp.  an	M)  to
	      the  number  (e.g.  4M).	When this option is used, quality will
	      vary according to	the complexity of  the	scene,	and  thus  the
	      --quality	option becomes irrevelant. The default is to use fixed
	      quality. Note that the actual  bitrate  after  encoding  may  be
	      slightly different from the one specified	here.

	      Quality  of the encoded video in percent.	The lower quality, the
	      smaller encoded bitstream. When using fixed quality, bitrate may
	      vary  depending  on  the complexity of the scene,	thus the --bi-
	      trate option becomes irrevelant. The default  is	to  use	 fixed
	      quality 75%.

	      Specifies	 the  order  and type of frames	to be coded. Currently
	      supported	frame types  are  'I'  for  intra  frames  (completely
	      coded)  and  'P'	for predicted frames (estimated	from preceding
	      'I' or 'P' frame). Other types such as 'B'  (bidirectionnal)  or
	      'S'  (sprite)  are *not* yet supported. The default is "I", i.e.
	      intra frames only. Coding	must always begin  with	 an  I	frame,
	      thus "IP"	is valid whereas "PI" is not.

	      Specifies	 the  picture  size  in	the sequence. It can be	either
	      specified	in widthxheight	format,	or by using names such as  CIF
	      (352x288), SIF (352x240) or QCIF (176x144). The default is CIF.

       recmpeg -v video.mpg video.yuv
	      For encoding a simple MPEG-1 video, and see what's going on.

       recmpeg -q 50 -P	mpeg4 video.cmp	video.yuv
	      For encoding a simple MPEG-4 video at 50%	quality.

       recmpeg -P mpeg4_shape video.cmp	video.yuv video.seg
	      For encoding an MPEG-4 video with	shape coding.

       recmpeg -c IP video.mpg video.yuv
	      For encoding an MPEG-1 video with	motion compensation.

       buffer must be large enough to contain encoded data. There is no	check-
       ing of buffer overflow as this would be too slow.  Encoding of B	 frame
       is not yet supported.

       FAME home page at

       The recmpeg utility and FAME library were written by Vivien Chappelier,
       Thomas Cougnard and Damien Vincent.

recmpeg				 July 29, 2001			    recmpeg(1)


Want to link to this manual page? Use this URL:

home | help