libao2/ao_ivtv.c

   1 /*
   2  * audio output for WinTV PVR-150/250/350 (a.k.a IVTV) cards
   3  * through Connexant hardware MPEG decoder
   4  * See http://ivtvdriver.org/index.php/Main_Page for more details on the
   5  * cards supported by the ivtv driver.
   6  *
   7  * WARNING: You need to force -ac hwmpa for audio output to work.
   8  *
   9  * Copyright (C) 2006 Benjamin Zores
  10  *
  11  * This file is part of MPlayer.
  12  *
  13  * MPlayer is free software; you can redistribute it and/or modify
  14  * it under the terms of the GNU General Public License as published by
  15  * the Free Software Foundation; either version 2 of the License, or
  16  * (at your option) any later version.
  17  *
  18  * MPlayer is distributed in the hope that it will be useful,
  19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21  * GNU General Public License for more details.
  22  *
  23  * You should have received a copy of the GNU General Public License along
  24  * with MPlayer; if not, write to the Free Software Foundation, Inc.,
  25  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  26  */
  27
  28 #include <inttypes.h>
  29
  30 #include "config.h"
  31
  32 #include "mp_msg.h"
  33
  34 #include "audio_out.h"
  35 #include "audio_out_internal.h"
  36 #include "libaf/af_format.h"
  37 #include "libmpdemux/mpeg_packetizer.h"
  38
  39 #define MPEG_AUDIO_ID 0x1C0
  40
  41 static int freq = 0;
  42
  43 static const ao_info_t info =
  44 {
  45   "IVTV MPEG Audio Decoder output",
  46   "ivtv",
  47   "Benjamin Zores",
  48   ""
  49 };
  50
  51 LIBAO_EXTERN(ivtv)
  52
  53 /* to set/get/query special features/parameters */
  54 static int
  55 control (int cmd,void *arg)
  56 {
  57   return CONTROL_UNKNOWN;
  58 }
  59
  60 /* open & setup audio device */
  61 static int
  62 init (int rate, int channels, int format, int flags)
  63 {
  64   extern int ivtv_fd;
  65
  66   if (ivtv_fd < 0)
  67     return 0;
  68
  69   if (format != AF_FORMAT_MPEG2)
  70   {
  71     mp_msg (MSGT_AO, MSGL_FATAL,
  72             "AO: [ivtv] can only handle MPEG audio streams.\n");
  73     return 0;
  74   }
  75
  76   ao_data.outburst = 2048;
  77   ao_data.samplerate = rate;
  78   ao_data.channels = channels;
  79   ao_data.format = AF_FORMAT_MPEG2;
  80   ao_data.buffersize = 2048;
  81   ao_data.bps = rate * 2 * 2;
  82   ao_data.pts = 0;
  83   freq = rate;
  84
  85   /* check for supported audio rate */
  86   if (rate != 32000 || rate != 41000 || rate != 48000)
  87   {
  88     mp_tmsg (MSGT_AO, MSGL_ERR, "[AO MPEGPES] %d Hz not supported, try to resample.\n", rate);
  89     rate = 48000;
  90   }
  91
  92   return 1;
  93 }
  94
  95 /* close audio device */
  96 static void
  97 uninit (int immed)
  98 {
  99   /* nothing to do */
 100 }
 101
 102 /* stop playing and empty buffers (for seeking/pause) */
 103 static void
 104 reset (void)
 105 {
 106   /* nothing to do */
 107 }
 108
 109 /* stop playing, keep buffers (for pause) */
 110 static void
 111 audio_pause (void)
 112 {
 113   reset ();
 114 }
 115
 116 /* resume playing, after audio_pause() */
 117 static void
 118 audio_resume (void)
 119 {
 120   /* nothing to do */
 121 }
 122
 123 /* how many bytes can be played without blocking */
 124 static int
 125 get_space (void)
 126 {
 127   extern int vo_pts;
 128   float x;
 129   int y;
 130
 131   x = (float) (vo_pts - ao_data.pts) / 90000.0;
 132   if (x <= 0)
 133     return 0;
 134
 135   y  = freq * 4 * x;
 136   y /= ao_data.outburst;
 137   y *= ao_data.outburst;
 138
 139   if (y > 32000)
 140     y = 32000;
 141
 142   return y;
 143 }
 144
 145 /* number of bytes played */
 146 static int
 147 play (void *data, int len, int flags)
 148 {
 149   int ivtv_write (const unsigned char *data, int len);
 150
 151   if (ao_data.format != AF_FORMAT_MPEG2)
 152     return 0;
 153
 154   send_mpeg_pes_packet (data, len, MPEG_AUDIO_ID, ao_data.pts, 2, ivtv_write);
 155
 156   return len;
 157 }
 158
 159 /* delay in seconds between first and last sample in buffer */
 160 static float
 161 get_delay (void)
 162 {
 163   return 0.0;
 164 }