1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
|
/*
* lpcm.c: Use the S/P-DIF interface for redirecting PCM stream
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
* Or, point your browser to http://www.gnu.org/copyleft/gpl.html
*
* Copyright (C) 2003,2004 Werner Fink, <werner@suse.de>
*/
#include "types.h"
#include "lpcm.h"
// --- cPCM : Scanning PCM stream simply for forwarding it -----------------------------
cPCM pcm(48000);
cPCM::cPCM(unsigned int rate)
: iec60958(rate, SPDIF_BURST_SIZE, 0)
{
s.pos = s.payload_size = 0;
}
// This function requires two arguments:
// first is the start of the data segment
// second is the tail of the data segment
const frame_t & cPCM::Frame(const uint_8 *&out, const uint_8 *const tail)
{
// We overwrite the none audio magic PCM header (offset is zero)
s.payload_size = SPDIF_BURST_SIZE;
play.burst = (uint_32 *)0;
play.size = 0;
while(s.pos < s.payload_size) {
int rest = tail - out;
if (rest <= 0)
goto done;
if (rest + s.pos > s.payload_size)
rest = s.payload_size - s.pos;
memcpy(¤t[s.pos], out, rest);
s.pos += rest;
out += rest;
}
swab(payload, payload, s.payload_size);
play.burst = (uint_32 *)(¤t[0]);
play.size = s.payload_size;
play.pay = s.payload_size;
Switch();
last.burst = (uint_32 *)(&remember[0]);
last.size = play.size;
last.pay = play.pay;
s.pos = 0;
done:
return play;
}
const bool cPCM::Count(const uint_8 *buf, const uint_8 *const tail)
{
// One sample has two bytes, two channels for stereo
// and 192 samples for a vaild S/P-DIF sequence
return (tail - buf) > 768;
}
|
