modules/access/v4l2/vbi.c

   1 /*****************************************************************************
   2  * vbi.c : Video4Linux2 VBI input module for vlc
   3  *****************************************************************************
   4  * Copyright (C) 2012 the VideoLAN team
   5  *
   6  * Author: Devin Heitmueller <dheitmueller at kernellabs dot com>
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU Lesser General Public License as published by
  10  * the Free Software Foundation; either version 2.1 of the License, or
  11  * (at your option) any later version.
  12  *
  13  * This program is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  16  * GNU Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public License
  19  * along with this program; if not, write to the Free Software Foundation,
  20  * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  21  *****************************************************************************/
  22
  23 #ifdef HAVE_CONFIG_H
  24 # include "config.h"
  25 #endif
  26
  27 #include <errno.h>
  28 #include <sys/types.h>
  29 #include <fcntl.h>
  30 #include <vlc_common.h>
  31 #include <vlc_block.h>
  32 #include <vlc_fs.h>
  33 #include <vlc_demux.h>
  34
  35 #include "v4l2.h"
  36
  37 #ifdef ZVBI_COMPILED
  38 # include <libzvbi.h>
  39 # define VBI_NUM_CC_STREAMS 4
  40
  41 struct vlc_v4l2_vbi
  42 {
  43     vbi_capture *cap;
  44     es_out_id_t *es[VBI_NUM_CC_STREAMS];
  45 };
  46
  47 vlc_v4l2_vbi_t *OpenVBI (demux_t *demux, const char *psz_device)
  48 {
  49     vlc_v4l2_vbi_t *vbi = malloc (sizeof (*vbi));
  50     if (unlikely(vbi == NULL))
  51         return NULL;
  52
  53     int rawfd = vlc_open (psz_device, O_RDWR);
  54     if (rawfd == -1)
  55     {
  56         msg_Err (demux, "cannot open device '%s': %s", psz_device,
  57                  vlc_strerror_c(errno));
  58         goto err;
  59     }
  60
  61     //Can put more in here. See osd.c in zvbi package.
  62     unsigned int services = VBI_SLICED_CAPTION_525;
  63     char *errstr = NULL;
  64
  65     vbi->cap = vbi_capture_v4l2k_new (psz_device, rawfd,
  66                                       /* buffers */ 5,
  67                                       &services,
  68                                       /* strict */ 1,
  69                                       &errstr,
  70                                       /* verbose */ 1);
  71     if (vbi->cap == NULL)
  72     {
  73         msg_Err (demux, "cannot capture VBI data: %s", errstr);
  74         free (errstr);
  75         vlc_close (rawfd);
  76         goto err;
  77     }
  78
  79     for (unsigned i = 0; i < VBI_NUM_CC_STREAMS; i++)
  80     {
  81         es_format_t fmt;
  82
  83         es_format_Init (&fmt, SPU_ES, VLC_FOURCC('c', 'c', '1' + i, ' '));
  84         if (asprintf (&fmt.psz_description, "Closed captions %d", i + 1) >= 0)
  85         {
  86             msg_Dbg (demux, "new spu es %4.4s", (char *)&fmt.i_codec);
  87             vbi->es[i] = es_out_Add (demux->out, &fmt);
  88         }
  89     }
  90
  91     /* Do a single read and throw away the results so that ZVBI calls
  92        the STREAMON ioctl() */
  93     GrabVBI(demux, vbi);
  94
  95     return vbi;
  96 err:
  97     free (vbi);
  98     return NULL;
  99 }
 100
 101 int GetFdVBI (vlc_v4l2_vbi_t *vbi)
 102 {
 103     return vbi_capture_fd(vbi->cap);
 104 }
 105
 106 void GrabVBI (demux_t *p_demux, vlc_v4l2_vbi_t *vbi)
 107 {
 108     vbi_capture_buffer *sliced_bytes;
 109     struct timeval timeout={0,0}; /* poll */
 110     int canc = vlc_savecancel ();
 111
 112     int r = vbi_capture_pull_sliced (vbi->cap, &sliced_bytes, &timeout);
 113     switch (r) {
 114         case -1:
 115             msg_Err (p_demux, "error reading VBI: %s", vlc_strerror_c(errno));
 116         case  0: /* nothing avail */
 117             break;
 118         case  1: /* got data */
 119         {
 120             int n_lines = sliced_bytes->size / sizeof(vbi_sliced);
 121             if (!n_lines)
 122                 break;
 123
 124             int sliced_size = 2; /* Number of bytes per sliced line */
 125             int size = (sliced_size + 1) * n_lines;
 126             block_t *p_block = block_Alloc (size);
 127             if (unlikely(p_block == NULL))
 128                 break;
 129
 130             uint8_t* data = p_block->p_buffer;
 131             vbi_sliced *sliced_array = sliced_bytes->data;
 132             for (int field = 0; field < n_lines; field++)
 133             {
 134                 *data = field;
 135                 data++;
 136                 memcpy(data, sliced_array[field].data, sliced_size);
 137                 data += sliced_size;
 138             }
 139             p_block->i_pts = vlc_tick_now();
 140
 141             for (unsigned i = 0; i < VBI_NUM_CC_STREAMS; i++)
 142             {
 143                 if (vbi->es[i] == NULL)
 144                     continue;
 145
 146                 block_t *dup = block_Duplicate(p_block);
 147                 if (likely(dup != NULL))
 148                     es_out_Send(p_demux->out, vbi->es[i], dup);
 149             }
 150             block_Release(p_block);
 151         }
 152     }
 153     vlc_restorecancel (canc);
 154 }
 155
 156 void CloseVBI (vlc_v4l2_vbi_t *vbi)
 157 {
 158     vlc_close (vbi_capture_fd (vbi->cap));
 159     vbi_capture_delete (vbi->cap);
 160     free (vbi);
 161 }
 162 #endif