root/drivers/media/pci/cx18/cx18-vbi.c

DEFINITIONS

1. copy_vbi_data
2. compress_raw_buf
3. compress_sliced_buf
4. _cx18_process_vbi_data
5. cx18_process_vbi_data

   1 // SPDX-License-Identifier: GPL-2.0-or-later
   2 /*
   3  *  cx18 Vertical Blank Interval support functions
   4  *
   5  *  Derived from ivtv-vbi.c
   6  *
   7  *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
   8  */
   9 
  10 #include "cx18-driver.h"
  11 #include "cx18-vbi.h"
  12 #include "cx18-ioctl.h"
  13 #include "cx18-queue.h"
  14 
  15 /*
  16  * Raster Reference/Protection (RP) bytes, used in Start/End Active
  17  * Video codes emitted from the digitzer in VIP 1.x mode, that flag the start
  18  * of VBI sample or VBI ancillary data regions in the digital ratser line.
  19  *
  20  * Task FieldEven VerticalBlank HorizontalBlank 0 0 0 0
  21  */
  22 static const u8 raw_vbi_sav_rp[2] = { 0x20, 0x60 };    /* __V_, _FV_ */
  23 static const u8 sliced_vbi_eav_rp[2] = { 0xb0, 0xf0 }; /* T_VH, TFVH */
  24 
  25 static void copy_vbi_data(struct cx18 *cx, int lines, u32 pts_stamp)
  26 {
  27         int line = 0;
  28         int i;
  29         u32 linemask[2] = { 0, 0 };
  30         unsigned short size;
  31         static const u8 mpeg_hdr_data[] = {
  32                 /* MPEG-2 Program Pack */
  33                 0x00, 0x00, 0x01, 0xba,             /* Prog Pack start code */
  34                 0x44, 0x00, 0x0c, 0x66, 0x24, 0x01, /* SCR, SCR Ext, markers */
  35                 0x01, 0xd1, 0xd3,                   /* Mux Rate, markers */
  36                 0xfa, 0xff, 0xff,                   /* Res, Suff cnt, Stuff */
  37                 /* MPEG-2 Private Stream 1 PES Packet */
  38                 0x00, 0x00, 0x01, 0xbd,             /* Priv Stream 1 start */
  39                 0x00, 0x1a,                         /* length */
  40                 0x84, 0x80, 0x07,                   /* flags, hdr data len */
  41                 0x21, 0x00, 0x5d, 0x63, 0xa7,       /* PTS, markers */
  42                 0xff, 0xff                          /* stuffing */
  43         };
  44         const int sd = sizeof(mpeg_hdr_data);   /* start of vbi data */
  45         int idx = cx->vbi.frame % CX18_VBI_FRAMES;
  46         u8 *dst = &cx->vbi.sliced_mpeg_data[idx][0];
  47 
  48         for (i = 0; i < lines; i++) {
  49                 struct v4l2_sliced_vbi_data *sdata = cx->vbi.sliced_data + i;
  50                 int f, l;
  51 
  52                 if (sdata->id == 0)
  53                         continue;
  54 
  55                 l = sdata->line - 6;
  56                 f = sdata->field;
  57                 if (f)
  58                         l += 18;
  59                 if (l < 32)
  60                         linemask[0] |= (1 << l);
  61                 else
  62                         linemask[1] |= (1 << (l - 32));
  63                 dst[sd + 12 + line * 43] = cx18_service2vbi(sdata->id);
  64                 memcpy(dst + sd + 12 + line * 43 + 1, sdata->data, 42);
  65                 line++;
  66         }
  67         memcpy(dst, mpeg_hdr_data, sizeof(mpeg_hdr_data));
  68         if (line == 36) {
  69                 /* All lines are used, so there is no space for the linemask
  70                    (the max size of the VBI data is 36 * 43 + 4 bytes).
  71                    So in this case we use the magic number 'ITV0'. */
  72                 memcpy(dst + sd, "ITV0", 4);
  73                 memmove(dst + sd + 4, dst + sd + 12, line * 43);
  74                 size = 4 + ((43 * line + 3) & ~3);
  75         } else {
  76                 memcpy(dst + sd, "itv0", 4);
  77                 cpu_to_le32s(&linemask[0]);
  78                 cpu_to_le32s(&linemask[1]);
  79                 memcpy(dst + sd + 4, &linemask[0], 8);
  80                 size = 12 + ((43 * line + 3) & ~3);
  81         }
  82         dst[4+16] = (size + 10) >> 8;
  83         dst[5+16] = (size + 10) & 0xff;
  84         dst[9+16] = 0x21 | ((pts_stamp >> 29) & 0x6);
  85         dst[10+16] = (pts_stamp >> 22) & 0xff;
  86         dst[11+16] = 1 | ((pts_stamp >> 14) & 0xff);
  87         dst[12+16] = (pts_stamp >> 7) & 0xff;
  88         dst[13+16] = 1 | ((pts_stamp & 0x7f) << 1);
  89         cx->vbi.sliced_mpeg_size[idx] = sd + size;
  90 }
  91 
  92 /* Compress raw VBI format, removes leading SAV codes and surplus space
  93    after the frame.  Returns new compressed size. */
  94 /* FIXME - this function ignores the input size. */
  95 static u32 compress_raw_buf(struct cx18 *cx, u8 *buf, u32 size, u32 hdr_size)
  96 {
  97         u32 line_size = VBI_ACTIVE_SAMPLES;
  98         u32 lines = cx->vbi.count * 2;
  99         u8 *q = buf;
 100         u8 *p;
 101         int i;
 102 
 103         /* Skip the header */
 104         buf += hdr_size;
 105 
 106         for (i = 0; i < lines; i++) {
 107                 p = buf + i * line_size;
 108 
 109                 /* Look for SAV code */
 110                 if (p[0] != 0xff || p[1] || p[2] ||
 111                     (p[3] != raw_vbi_sav_rp[0] &&
 112                      p[3] != raw_vbi_sav_rp[1]))
 113                         break;
 114                 if (i == lines - 1) {
 115                         /* last line is hdr_size bytes short - extrapolate it */
 116                         memcpy(q, p + 4, line_size - 4 - hdr_size);
 117                         q += line_size - 4 - hdr_size;
 118                         p += line_size - hdr_size - 1;
 119                         memset(q, (int) *p, hdr_size);
 120                 } else {
 121                         memcpy(q, p + 4, line_size - 4);
 122                         q += line_size - 4;
 123                 }
 124         }
 125         return lines * (line_size - 4);
 126 }
 127 
 128 static u32 compress_sliced_buf(struct cx18 *cx, u8 *buf, u32 size,
 129                                const u32 hdr_size)
 130 {
 131         struct v4l2_decode_vbi_line vbi;
 132         int i;
 133         u32 line = 0;
 134         u32 line_size = cx->is_60hz ? VBI_HBLANK_SAMPLES_60HZ
 135                                     : VBI_HBLANK_SAMPLES_50HZ;
 136 
 137         /* find the first valid line */
 138         for (i = hdr_size, buf += hdr_size; i < size; i++, buf++) {
 139                 if (buf[0] == 0xff && !buf[1] && !buf[2] &&
 140                     (buf[3] == sliced_vbi_eav_rp[0] ||
 141                      buf[3] == sliced_vbi_eav_rp[1]))
 142                         break;
 143         }
 144 
 145         /*
 146          * The last line is short by hdr_size bytes, but for the remaining
 147          * checks against size, we pretend that it is not, by counting the
 148          * header bytes we knowingly skipped
 149          */
 150         size -= (i - hdr_size);
 151         if (size < line_size)
 152                 return line;
 153 
 154         for (i = 0; i < size / line_size; i++) {
 155                 u8 *p = buf + i * line_size;
 156 
 157                 /* Look for EAV code  */
 158                 if (p[0] != 0xff || p[1] || p[2] ||
 159                     (p[3] != sliced_vbi_eav_rp[0] &&
 160                      p[3] != sliced_vbi_eav_rp[1]))
 161                         continue;
 162                 vbi.p = p + 4;
 163                 v4l2_subdev_call(cx->sd_av, vbi, decode_vbi_line, &vbi);
 164                 if (vbi.type) {
 165                         cx->vbi.sliced_data[line].id = vbi.type;
 166                         cx->vbi.sliced_data[line].field = vbi.is_second_field;
 167                         cx->vbi.sliced_data[line].line = vbi.line;
 168                         memcpy(cx->vbi.sliced_data[line].data, vbi.p, 42);
 169                         line++;
 170                 }
 171         }
 172         return line;
 173 }
 174 
 175 static void _cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf)
 176 {
 177         /*
 178          * The CX23418 provides a 12 byte header in its raw VBI buffers to us:
 179          * 0x3fffffff [4 bytes of something] [4 byte presentation time stamp]
 180          */
 181         struct vbi_data_hdr {
 182                 __be32 magic;
 183                 __be32 unknown;
 184                 __be32 pts;
 185         } *hdr = (struct vbi_data_hdr *) buf->buf;
 186 
 187         u8 *p = (u8 *) buf->buf;
 188         u32 size = buf->bytesused;
 189         u32 pts;
 190         int lines;
 191 
 192         /*
 193          * The CX23418 sends us data that is 32 bit little-endian swapped,
 194          * but we want the raw VBI bytes in the order they were in the raster
 195          * line.  This has a side effect of making the header big endian
 196          */
 197         cx18_buf_swap(buf);
 198 
 199         /* Raw VBI data */
 200         if (cx18_raw_vbi(cx)) {
 201 
 202                 size = buf->bytesused =
 203                      compress_raw_buf(cx, p, size, sizeof(struct vbi_data_hdr));
 204 
 205                 /*
 206                  * Hack needed for compatibility with old VBI software.
 207                  * Write the frame # at the last 4 bytes of the frame
 208                  */
 209                 p += size - 4;
 210                 memcpy(p, &cx->vbi.frame, 4);
 211                 cx->vbi.frame++;
 212                 return;
 213         }
 214 
 215         /* Sliced VBI data with data insertion */
 216 
 217         pts = (be32_to_cpu(hdr->magic) == 0x3fffffff) ? be32_to_cpu(hdr->pts)
 218                                                       : 0;
 219 
 220         lines = compress_sliced_buf(cx, p, size, sizeof(struct vbi_data_hdr));
 221 
 222         /* always return at least one empty line */
 223         if (lines == 0) {
 224                 cx->vbi.sliced_data[0].id = 0;
 225                 cx->vbi.sliced_data[0].line = 0;
 226                 cx->vbi.sliced_data[0].field = 0;
 227                 lines = 1;
 228         }
 229         buf->bytesused = size = lines * sizeof(cx->vbi.sliced_data[0]);
 230         memcpy(p, &cx->vbi.sliced_data[0], size);
 231 
 232         if (cx->vbi.insert_mpeg)
 233                 copy_vbi_data(cx, lines, pts);
 234         cx->vbi.frame++;
 235 }
 236 
 237 void cx18_process_vbi_data(struct cx18 *cx, struct cx18_mdl *mdl,
 238                            int streamtype)
 239 {
 240         struct cx18_buffer *buf;
 241         u32 orig_used;
 242 
 243         if (streamtype != CX18_ENC_STREAM_TYPE_VBI)
 244                 return;
 245 
 246         /*
 247          * Big assumption here:
 248          * Every buffer hooked to the MDL's buf_list is a complete VBI frame
 249          * that ends at the end of the buffer.
 250          *
 251          * To assume anything else would make the code in this file
 252          * more complex, or require extra memcpy()'s to make the
 253          * buffers satisfy the above assumption.  It's just simpler to set
 254          * up the encoder buffer transfers to make the assumption true.
 255          */
 256         list_for_each_entry(buf, &mdl->buf_list, list) {
 257                 orig_used = buf->bytesused;
 258                 if (orig_used == 0)
 259                         break;
 260                 _cx18_process_vbi_data(cx, buf);
 261                 mdl->bytesused -= (orig_used - buf->bytesused);
 262         }
 263 }