[libdv-dev] Converting to library

[James B. <ja...@ex...>]

Morning all,

I'm looking at task 13738, "Feature: Convert to library"
Does anybody have any feelings about how the interface should look?

Why the interest in making libdv a library?  Because then we could make
a regression test that decoded a  frame of pond.dv, then compared them
with "golden" images.  This would make some changes easily verifiable,
for example 13732, 13733, 13737, 13801.

Some changes - like 13731, 13735 - alter the precision of processed
data, so will inevitably make a slightly different final image.  In this
case the comparison would report the largest difference between the
"golden" and actual images.

So how about starting with something like:

dvs *dvs_open(void *(*reader_func)(void*), void *s, enum frame_format)
  Initializes a dv stream, with a given read_func. reader_func(s)
returns a pointer to the next 400 bytes in the stream.  frame_format
would be the target pixel format: 32-bit RGB, 16-bit RGB, raw YCrCb.

dvs_get_frame_dimensions(dvs *s, gint *x, gint *y)
  Returns the frame dimensions of open stream s, either 720x480 or
720x576.

dvs_decode_frame(dvs *s, frame *f)
  Decodes the next frame in the stream s into buffer f.

dvs_close(dvs *)

???

-- 
James Bowman
ja...@ex...