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

FreeBSD Manual Pages


home | help
fame_start_frame(3)	       fame_start_frame		   fame_start_frame(3)

       fame_start_frame	- starts encoding of a frame

       #include	<fame.h>

       void fame_start_frame(fame_context_t *context, fame_yuv_t *yuv, unsigned	char *shape);

       fame_start_frame()  starts  the	encoding of an uncompressed frame from
       yuv to a	binary stream in  buffer, according to initialization  parame-
       ters  and optionnaly previously encoded frames. It should be called be-
       fore starting processing	slices with fame_encode_slice

       Note that in the	case of	video sequences	containing B frames, it	is  up
       to  the	caller	to present frames in the encoder order.	Since B	frames
       require both previous and next reference	frames,	they must be presented
       after  both previous and	next reference frames have been	coded. For ex-
       ample, a	"IBBPBBP" coding sequence must be presented in	"IPBBPBB"  or-
       der.  This  presentation	 order	is  also the order in which the	frames
       should be stored	in a file or sent to a network.

       context is the context handle previously	returned by fame_open

       yuv is a	pointer	to the input frame. Currently, only YV12  planar  for-
       mat,  also  called YUV 4:2:0, is	supported. The YV12 planar format con-
       sists in	three plane, one for the Y (luminance) and two for the Cr  and
       Cb (chrominance)	components, the	chrominance planes being subsampled by
       2x2. These three	planes are mapped linearly in memory:

       yuv ->  +=========+
	       |	 |
	       |    Y	 | height
	       |	 |
	       | Cr | height / 2
	       | Cb | height / 2
	      width / 2

       The process of converting RGB pictures to YUV12 will not	 be  detailled

       shape  represents  the shape in case of video with arbitrary shape.  It
       consists	in a bitmap of width x height bytes, with 255 representing  an
       opaque  pixel  and 0 representing a transparent pixel. Values between 0
       and 255 are not supported yet.  For rectangular video,  this  parameter
       must be set to NULL.

       fame_open(3),	fame_init(3),	fame_close(3),	 fame_encode_slice(3),

libfame			      February 19th, 2002	   fame_start_frame(3)


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

home | help