To support presentation version 2, syntax changes (as highlighted in the following
table) are made to the ac4_dsi_v1.
| Syntax |
Word size (in bits) |
ac4_dsi_v1()
{
ac4_dsi_version;...............................................................3
bitstream_version;.............................................................7
fs_index;......................................................................1
frame_rate_index;..............................................................4
n_presentations;...............................................................9
if (bitstream_version >1)
{b_program_id;................................................................1
if (b_program_id)
{short_program_id;...........................................................16
b_uuid;.....................................................................1
if（b_uuid）
{program_uuid;..............................................................16*8
}
}
}
ac4_bitrate_dsi();
byte_align;....................................................................0-7
for (i = 0; i < n_presentations; i++)
{presentation_version;........................................................8
pres_bytes;..................................................................8
if (pres_bytes == 255)
{add_pres_bytes;............................................................16
pres_bytes += add_pres_bytes;
}
if (presentation_version == 0)
{presentation_bytes = ac4_presentation_v0_dsi();
}
else {
if (presentation_version == 1 || presentation_version == 2)
{presentation_bytes = ac4_presentation_v1_dsi(pres_bytes);}
else
{presentation_bytes = 0;}
}
skip_bytes = pres_bytes - presentation_bytes;
skip_area;..................................................................skip_bytes*8
}
}
|
|
library_booksNote: The number of bits in byte_align pads the number of bits, counted
from the start of
ac4_dsi_v1,
to a multiple of eight.
|