DragonFly On-Line Manual Pages

fame_start_frame(3)            fame_start_frame            fame_start_frame(3)

NAME
       fame_start_frame - starts encoding of a frame

SYNOPSIS
       #include <fame.h>

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

DESCRIPTION
       fame_start_frame() starts the encoding of an uncompressed frame from
       yuv to a binary stream in  buffer, according to initialization
       parameters and optionnaly previously encoded frames. It should be
       called before 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
       example, a "IBBPBBP" coding sequence must be presented in "IPBBPBB"
       order. 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
       format, also called YUV 4:2:0, is supported. The YV12 planar format
       consists 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:

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

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

       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.

SEE ALSO
       fame_open(3), fame_init(3), fame_close(3), fame_encode_slice(3),
       fame_end_frame(3)

libfame                       February 19th, 2002          fame_start_frame(3)