summaryrefslogtreecommitdiffstats
path: root/libao2/ao_ivtv.c
blob: 96ea563c9655d93410cba55bac5d6c58cc10b99e (plain)
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
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
/*
 * audio output for WinTV PVR-150/250/350 (a.k.a IVTV) cards
 * through Connexant hardware MPEG decoder
 * See http://ivtvdriver.org/index.php/Main_Page for more details on the
 * cards supported by the ivtv driver.
 *
 * WARNING: You need to force -ac hwmpa for audio output to work.
 *
 * Copyright (C) 2006 Benjamin Zores
 *
 * This file is part of MPlayer.
 *
 * MPlayer 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.
 *
 * MPlayer 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 MPlayer; if not, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

#include <inttypes.h>

#include "config.h"

#include "mp_msg.h"
#include "help_mp.h"

#include "audio_out.h"
#include "audio_out_internal.h"
#include "libaf/af_format.h"
#include "libmpdemux/mpeg_packetizer.h"

#define MPEG_AUDIO_ID 0x1C0

static int freq = 0;

static ao_info_t info = 
{
  "IVTV MPEG Audio Decoder output",
  "ivtv",
  "Benjamin Zores",
  ""
};

LIBAO_EXTERN(ivtv)

/* to set/get/query special features/parameters */
static int
control (int cmd,void *arg)
{
  return CONTROL_UNKNOWN;
}

/* open & setup audio device */
static int
init (int rate, int channels, int format, int flags)
{
  extern int ivtv_fd;

  if (ivtv_fd < 0)
    return 0;

  if (format != AF_FORMAT_MPEG2)
  {
    mp_msg (MSGT_AO, MSGL_FATAL,
            "AO: [ivtv] can only handle MPEG audio streams.\n");
    return 0;
  }
  
  ao_data.outburst = 2048;
  ao_data.samplerate = rate;
  ao_data.channels = channels;
  ao_data.format = AF_FORMAT_MPEG2;
  ao_data.buffersize = 2048;
  ao_data.bps = rate * 2 * 2;
  ao_data.pts = 0;
  freq = rate;

  /* check for supported audio rate */
  if (rate != 32000 || rate != 41000 || rate != 48000)
  {
    mp_msg (MSGT_AO, MSGL_ERR, MSGTR_AO_MPEGPES_UnsupSamplerate, rate);
    rate = 48000;
  }

  return 1;
}

/* close audio device */
static void
uninit (int immed)
{
  /* nothing to do */
}

/* stop playing and empty buffers (for seeking/pause) */
static void
reset (void)
{
  /* nothing to do */
}

/* stop playing, keep buffers (for pause) */
static void
audio_pause (void)
{
  reset ();
}

/* resume playing, after audio_pause() */
static void
audio_resume (void)
{
  /* nothing to do */
}

/* how many bytes can be played without blocking */
static int
get_space (void)
{
  extern int vo_pts;
  float x;
  int y;

  x = (float) (vo_pts - ao_data.pts) / 90000.0;
  if (x <= 0)
    return 0;
  
  y  = freq * 4 * x;
  y /= ao_data.outburst;
  y *= ao_data.outburst;
  
  if (y > 32000)
    y = 32000;

  return y;
}

/* number of bytes played */
static int
play (void *data, int len, int flags)
{
  int ivtv_write (unsigned char *data, int len);
  
  if (ao_data.format != AF_FORMAT_MPEG2)
    return 0;

  send_mpeg_pes_packet (data, len, MPEG_AUDIO_ID, ao_data.pts, 2, ivtv_write);

  return len;
}

/* delay in seconds between first and last sample in buffer */
static float
get_delay (void)
{
  return 0.0;
}