xref: /linux/drivers/media/pci/cx18/cx18-vbi.c (revision f3a8b6645dc2e60d11f20c1c23afd964ff4e55ae)
1 /*
2  *  cx18 Vertical Blank Interval support functions
3  *
4  *  Derived from ivtv-vbi.c
5  *
6  *  Copyright (C) 2007  Hans Verkuil <hverkuil@xs4all.nl>
7  *
8  *  This program is free software; you can redistribute it and/or modify
9  *  it under the terms of the GNU General Public License as published by
10  *  the Free Software Foundation; either version 2 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 General Public License for more details.
17  *
18  *  You should have received a copy of the GNU General Public License
19  *  along with this program; if not, write to the Free Software
20  *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
21  *  02111-1307  USA
22  */
23 
24 #include "cx18-driver.h"
25 #include "cx18-vbi.h"
26 #include "cx18-ioctl.h"
27 #include "cx18-queue.h"
28 
29 /*
30  * Raster Reference/Protection (RP) bytes, used in Start/End Active
31  * Video codes emitted from the digitzer in VIP 1.x mode, that flag the start
32  * of VBI sample or VBI ancillary data regions in the digitial ratser line.
33  *
34  * Task FieldEven VerticalBlank HorizontalBlank 0 0 0 0
35  */
36 static const u8 raw_vbi_sav_rp[2] = { 0x20, 0x60 };    /* __V_, _FV_ */
37 static const u8 sliced_vbi_eav_rp[2] = { 0xb0, 0xf0 }; /* T_VH, TFVH */
38 
39 static void copy_vbi_data(struct cx18 *cx, int lines, u32 pts_stamp)
40 {
41 	int line = 0;
42 	int i;
43 	u32 linemask[2] = { 0, 0 };
44 	unsigned short size;
45 	static const u8 mpeg_hdr_data[] = {
46 		/* MPEG-2 Program Pack */
47 		0x00, 0x00, 0x01, 0xba,		    /* Prog Pack start code */
48 		0x44, 0x00, 0x0c, 0x66, 0x24, 0x01, /* SCR, SCR Ext, markers */
49 		0x01, 0xd1, 0xd3,		    /* Mux Rate, markers */
50 		0xfa, 0xff, 0xff,		    /* Res, Suff cnt, Stuff */
51 		/* MPEG-2 Private Stream 1 PES Packet */
52 		0x00, 0x00, 0x01, 0xbd,		    /* Priv Stream 1 start */
53 		0x00, 0x1a,			    /* length */
54 		0x84, 0x80, 0x07,		    /* flags, hdr data len */
55 		0x21, 0x00, 0x5d, 0x63, 0xa7, 	    /* PTS, markers */
56 		0xff, 0xff			    /* stuffing */
57 	};
58 	const int sd = sizeof(mpeg_hdr_data);	/* start of vbi data */
59 	int idx = cx->vbi.frame % CX18_VBI_FRAMES;
60 	u8 *dst = &cx->vbi.sliced_mpeg_data[idx][0];
61 
62 	for (i = 0; i < lines; i++) {
63 		struct v4l2_sliced_vbi_data *sdata = cx->vbi.sliced_data + i;
64 		int f, l;
65 
66 		if (sdata->id == 0)
67 			continue;
68 
69 		l = sdata->line - 6;
70 		f = sdata->field;
71 		if (f)
72 			l += 18;
73 		if (l < 32)
74 			linemask[0] |= (1 << l);
75 		else
76 			linemask[1] |= (1 << (l - 32));
77 		dst[sd + 12 + line * 43] = cx18_service2vbi(sdata->id);
78 		memcpy(dst + sd + 12 + line * 43 + 1, sdata->data, 42);
79 		line++;
80 	}
81 	memcpy(dst, mpeg_hdr_data, sizeof(mpeg_hdr_data));
82 	if (line == 36) {
83 		/* All lines are used, so there is no space for the linemask
84 		   (the max size of the VBI data is 36 * 43 + 4 bytes).
85 		   So in this case we use the magic number 'ITV0'. */
86 		memcpy(dst + sd, "ITV0", 4);
87 		memmove(dst + sd + 4, dst + sd + 12, line * 43);
88 		size = 4 + ((43 * line + 3) & ~3);
89 	} else {
90 		memcpy(dst + sd, "itv0", 4);
91 		cpu_to_le32s(&linemask[0]);
92 		cpu_to_le32s(&linemask[1]);
93 		memcpy(dst + sd + 4, &linemask[0], 8);
94 		size = 12 + ((43 * line + 3) & ~3);
95 	}
96 	dst[4+16] = (size + 10) >> 8;
97 	dst[5+16] = (size + 10) & 0xff;
98 	dst[9+16] = 0x21 | ((pts_stamp >> 29) & 0x6);
99 	dst[10+16] = (pts_stamp >> 22) & 0xff;
100 	dst[11+16] = 1 | ((pts_stamp >> 14) & 0xff);
101 	dst[12+16] = (pts_stamp >> 7) & 0xff;
102 	dst[13+16] = 1 | ((pts_stamp & 0x7f) << 1);
103 	cx->vbi.sliced_mpeg_size[idx] = sd + size;
104 }
105 
106 /* Compress raw VBI format, removes leading SAV codes and surplus space
107    after the frame.  Returns new compressed size. */
108 /* FIXME - this function ignores the input size. */
109 static u32 compress_raw_buf(struct cx18 *cx, u8 *buf, u32 size, u32 hdr_size)
110 {
111 	u32 line_size = VBI_ACTIVE_SAMPLES;
112 	u32 lines = cx->vbi.count * 2;
113 	u8 *q = buf;
114 	u8 *p;
115 	int i;
116 
117 	/* Skip the header */
118 	buf += hdr_size;
119 
120 	for (i = 0; i < lines; i++) {
121 		p = buf + i * line_size;
122 
123 		/* Look for SAV code */
124 		if (p[0] != 0xff || p[1] || p[2] ||
125 		    (p[3] != raw_vbi_sav_rp[0] &&
126 		     p[3] != raw_vbi_sav_rp[1]))
127 			break;
128 		if (i == lines - 1) {
129 			/* last line is hdr_size bytes short - extrapolate it */
130 			memcpy(q, p + 4, line_size - 4 - hdr_size);
131 			q += line_size - 4 - hdr_size;
132 			p += line_size - hdr_size - 1;
133 			memset(q, (int) *p, hdr_size);
134 		} else {
135 			memcpy(q, p + 4, line_size - 4);
136 			q += line_size - 4;
137 		}
138 	}
139 	return lines * (line_size - 4);
140 }
141 
142 static u32 compress_sliced_buf(struct cx18 *cx, u8 *buf, u32 size,
143 			       const u32 hdr_size)
144 {
145 	struct v4l2_decode_vbi_line vbi;
146 	int i;
147 	u32 line = 0;
148 	u32 line_size = cx->is_60hz ? VBI_HBLANK_SAMPLES_60HZ
149 				    : VBI_HBLANK_SAMPLES_50HZ;
150 
151 	/* find the first valid line */
152 	for (i = hdr_size, buf += hdr_size; i < size; i++, buf++) {
153 		if (buf[0] == 0xff && !buf[1] && !buf[2] &&
154 		    (buf[3] == sliced_vbi_eav_rp[0] ||
155 		     buf[3] == sliced_vbi_eav_rp[1]))
156 			break;
157 	}
158 
159 	/*
160 	 * The last line is short by hdr_size bytes, but for the remaining
161 	 * checks against size, we pretend that it is not, by counting the
162 	 * header bytes we knowingly skipped
163 	 */
164 	size -= (i - hdr_size);
165 	if (size < line_size)
166 		return line;
167 
168 	for (i = 0; i < size / line_size; i++) {
169 		u8 *p = buf + i * line_size;
170 
171 		/* Look for EAV code  */
172 		if (p[0] != 0xff || p[1] || p[2] ||
173 		    (p[3] != sliced_vbi_eav_rp[0] &&
174 		     p[3] != sliced_vbi_eav_rp[1]))
175 			continue;
176 		vbi.p = p + 4;
177 		v4l2_subdev_call(cx->sd_av, vbi, decode_vbi_line, &vbi);
178 		if (vbi.type) {
179 			cx->vbi.sliced_data[line].id = vbi.type;
180 			cx->vbi.sliced_data[line].field = vbi.is_second_field;
181 			cx->vbi.sliced_data[line].line = vbi.line;
182 			memcpy(cx->vbi.sliced_data[line].data, vbi.p, 42);
183 			line++;
184 		}
185 	}
186 	return line;
187 }
188 
189 static void _cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf)
190 {
191 	/*
192 	 * The CX23418 provides a 12 byte header in its raw VBI buffers to us:
193 	 * 0x3fffffff [4 bytes of something] [4 byte presentation time stamp]
194 	 */
195 	struct vbi_data_hdr {
196 		__be32 magic;
197 		__be32 unknown;
198 		__be32 pts;
199 	} *hdr = (struct vbi_data_hdr *) buf->buf;
200 
201 	u8 *p = (u8 *) buf->buf;
202 	u32 size = buf->bytesused;
203 	u32 pts;
204 	int lines;
205 
206 	/*
207 	 * The CX23418 sends us data that is 32 bit little-endian swapped,
208 	 * but we want the raw VBI bytes in the order they were in the raster
209 	 * line.  This has a side effect of making the header big endian
210 	 */
211 	cx18_buf_swap(buf);
212 
213 	/* Raw VBI data */
214 	if (cx18_raw_vbi(cx)) {
215 
216 		size = buf->bytesused =
217 		     compress_raw_buf(cx, p, size, sizeof(struct vbi_data_hdr));
218 
219 		/*
220 		 * Hack needed for compatibility with old VBI software.
221 		 * Write the frame # at the last 4 bytes of the frame
222 		 */
223 		p += size - 4;
224 		memcpy(p, &cx->vbi.frame, 4);
225 		cx->vbi.frame++;
226 		return;
227 	}
228 
229 	/* Sliced VBI data with data insertion */
230 
231 	pts = (be32_to_cpu(hdr->magic) == 0x3fffffff) ? be32_to_cpu(hdr->pts)
232 						      : 0;
233 
234 	lines = compress_sliced_buf(cx, p, size, sizeof(struct vbi_data_hdr));
235 
236 	/* always return at least one empty line */
237 	if (lines == 0) {
238 		cx->vbi.sliced_data[0].id = 0;
239 		cx->vbi.sliced_data[0].line = 0;
240 		cx->vbi.sliced_data[0].field = 0;
241 		lines = 1;
242 	}
243 	buf->bytesused = size = lines * sizeof(cx->vbi.sliced_data[0]);
244 	memcpy(p, &cx->vbi.sliced_data[0], size);
245 
246 	if (cx->vbi.insert_mpeg)
247 		copy_vbi_data(cx, lines, pts);
248 	cx->vbi.frame++;
249 }
250 
251 void cx18_process_vbi_data(struct cx18 *cx, struct cx18_mdl *mdl,
252 			   int streamtype)
253 {
254 	struct cx18_buffer *buf;
255 	u32 orig_used;
256 
257 	if (streamtype != CX18_ENC_STREAM_TYPE_VBI)
258 		return;
259 
260 	/*
261 	 * Big assumption here:
262 	 * Every buffer hooked to the MDL's buf_list is a complete VBI frame
263 	 * that ends at the end of the buffer.
264 	 *
265 	 * To assume anything else would make the code in this file
266 	 * more complex, or require extra memcpy()'s to make the
267 	 * buffers satisfy the above assumption.  It's just simpler to set
268 	 * up the encoder buffer transfers to make the assumption true.
269 	 */
270 	list_for_each_entry(buf, &mdl->buf_list, list) {
271 		orig_used = buf->bytesused;
272 		if (orig_used == 0)
273 			break;
274 		_cx18_process_vbi_data(cx, buf);
275 		mdl->bytesused -= (orig_used - buf->bytesused);
276 	}
277 }
278