xref: /openbmc/linux/drivers/media/pci/cx18/cx18-vbi.c (revision be709d48)
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 
19 #include "cx18-driver.h"
20 #include "cx18-vbi.h"
21 #include "cx18-ioctl.h"
22 #include "cx18-queue.h"
23 
24 /*
25  * Raster Reference/Protection (RP) bytes, used in Start/End Active
26  * Video codes emitted from the digitzer in VIP 1.x mode, that flag the start
27  * of VBI sample or VBI ancillary data regions in the digital ratser line.
28  *
29  * Task FieldEven VerticalBlank HorizontalBlank 0 0 0 0
30  */
31 static const u8 raw_vbi_sav_rp[2] = { 0x20, 0x60 };    /* __V_, _FV_ */
32 static const u8 sliced_vbi_eav_rp[2] = { 0xb0, 0xf0 }; /* T_VH, TFVH */
33 
34 static void copy_vbi_data(struct cx18 *cx, int lines, u32 pts_stamp)
35 {
36 	int line = 0;
37 	int i;
38 	u32 linemask[2] = { 0, 0 };
39 	unsigned short size;
40 	static const u8 mpeg_hdr_data[] = {
41 		/* MPEG-2 Program Pack */
42 		0x00, 0x00, 0x01, 0xba,		    /* Prog Pack start code */
43 		0x44, 0x00, 0x0c, 0x66, 0x24, 0x01, /* SCR, SCR Ext, markers */
44 		0x01, 0xd1, 0xd3,		    /* Mux Rate, markers */
45 		0xfa, 0xff, 0xff,		    /* Res, Suff cnt, Stuff */
46 		/* MPEG-2 Private Stream 1 PES Packet */
47 		0x00, 0x00, 0x01, 0xbd,		    /* Priv Stream 1 start */
48 		0x00, 0x1a,			    /* length */
49 		0x84, 0x80, 0x07,		    /* flags, hdr data len */
50 		0x21, 0x00, 0x5d, 0x63, 0xa7,	    /* PTS, markers */
51 		0xff, 0xff			    /* stuffing */
52 	};
53 	const int sd = sizeof(mpeg_hdr_data);	/* start of vbi data */
54 	int idx = cx->vbi.frame % CX18_VBI_FRAMES;
55 	u8 *dst = &cx->vbi.sliced_mpeg_data[idx][0];
56 
57 	for (i = 0; i < lines; i++) {
58 		struct v4l2_sliced_vbi_data *sdata = cx->vbi.sliced_data + i;
59 		int f, l;
60 
61 		if (sdata->id == 0)
62 			continue;
63 
64 		l = sdata->line - 6;
65 		f = sdata->field;
66 		if (f)
67 			l += 18;
68 		if (l < 32)
69 			linemask[0] |= (1 << l);
70 		else
71 			linemask[1] |= (1 << (l - 32));
72 		dst[sd + 12 + line * 43] = cx18_service2vbi(sdata->id);
73 		memcpy(dst + sd + 12 + line * 43 + 1, sdata->data, 42);
74 		line++;
75 	}
76 	memcpy(dst, mpeg_hdr_data, sizeof(mpeg_hdr_data));
77 	if (line == 36) {
78 		/* All lines are used, so there is no space for the linemask
79 		   (the max size of the VBI data is 36 * 43 + 4 bytes).
80 		   So in this case we use the magic number 'ITV0'. */
81 		memcpy(dst + sd, "ITV0", 4);
82 		memmove(dst + sd + 4, dst + sd + 12, line * 43);
83 		size = 4 + ((43 * line + 3) & ~3);
84 	} else {
85 		memcpy(dst + sd, "itv0", 4);
86 		cpu_to_le32s(&linemask[0]);
87 		cpu_to_le32s(&linemask[1]);
88 		memcpy(dst + sd + 4, &linemask[0], 8);
89 		size = 12 + ((43 * line + 3) & ~3);
90 	}
91 	dst[4+16] = (size + 10) >> 8;
92 	dst[5+16] = (size + 10) & 0xff;
93 	dst[9+16] = 0x21 | ((pts_stamp >> 29) & 0x6);
94 	dst[10+16] = (pts_stamp >> 22) & 0xff;
95 	dst[11+16] = 1 | ((pts_stamp >> 14) & 0xff);
96 	dst[12+16] = (pts_stamp >> 7) & 0xff;
97 	dst[13+16] = 1 | ((pts_stamp & 0x7f) << 1);
98 	cx->vbi.sliced_mpeg_size[idx] = sd + size;
99 }
100 
101 /* Compress raw VBI format, removes leading SAV codes and surplus space
102    after the frame.  Returns new compressed size. */
103 /* FIXME - this function ignores the input size. */
104 static u32 compress_raw_buf(struct cx18 *cx, u8 *buf, u32 size, u32 hdr_size)
105 {
106 	u32 line_size = VBI_ACTIVE_SAMPLES;
107 	u32 lines = cx->vbi.count * 2;
108 	u8 *q = buf;
109 	u8 *p;
110 	int i;
111 
112 	/* Skip the header */
113 	buf += hdr_size;
114 
115 	for (i = 0; i < lines; i++) {
116 		p = buf + i * line_size;
117 
118 		/* Look for SAV code */
119 		if (p[0] != 0xff || p[1] || p[2] ||
120 		    (p[3] != raw_vbi_sav_rp[0] &&
121 		     p[3] != raw_vbi_sav_rp[1]))
122 			break;
123 		if (i == lines - 1) {
124 			/* last line is hdr_size bytes short - extrapolate it */
125 			memcpy(q, p + 4, line_size - 4 - hdr_size);
126 			q += line_size - 4 - hdr_size;
127 			p += line_size - hdr_size - 1;
128 			memset(q, (int) *p, hdr_size);
129 		} else {
130 			memcpy(q, p + 4, line_size - 4);
131 			q += line_size - 4;
132 		}
133 	}
134 	return lines * (line_size - 4);
135 }
136 
137 static u32 compress_sliced_buf(struct cx18 *cx, u8 *buf, u32 size,
138 			       const u32 hdr_size)
139 {
140 	struct v4l2_decode_vbi_line vbi;
141 	int i;
142 	u32 line = 0;
143 	u32 line_size = cx->is_60hz ? VBI_HBLANK_SAMPLES_60HZ
144 				    : VBI_HBLANK_SAMPLES_50HZ;
145 
146 	/* find the first valid line */
147 	for (i = hdr_size, buf += hdr_size; i < size; i++, buf++) {
148 		if (buf[0] == 0xff && !buf[1] && !buf[2] &&
149 		    (buf[3] == sliced_vbi_eav_rp[0] ||
150 		     buf[3] == sliced_vbi_eav_rp[1]))
151 			break;
152 	}
153 
154 	/*
155 	 * The last line is short by hdr_size bytes, but for the remaining
156 	 * checks against size, we pretend that it is not, by counting the
157 	 * header bytes we knowingly skipped
158 	 */
159 	size -= (i - hdr_size);
160 	if (size < line_size)
161 		return line;
162 
163 	for (i = 0; i < size / line_size; i++) {
164 		u8 *p = buf + i * line_size;
165 
166 		/* Look for EAV code  */
167 		if (p[0] != 0xff || p[1] || p[2] ||
168 		    (p[3] != sliced_vbi_eav_rp[0] &&
169 		     p[3] != sliced_vbi_eav_rp[1]))
170 			continue;
171 		vbi.p = p + 4;
172 		v4l2_subdev_call(cx->sd_av, vbi, decode_vbi_line, &vbi);
173 		if (vbi.type) {
174 			cx->vbi.sliced_data[line].id = vbi.type;
175 			cx->vbi.sliced_data[line].field = vbi.is_second_field;
176 			cx->vbi.sliced_data[line].line = vbi.line;
177 			memcpy(cx->vbi.sliced_data[line].data, vbi.p, 42);
178 			line++;
179 		}
180 	}
181 	return line;
182 }
183 
184 static void _cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf)
185 {
186 	/*
187 	 * The CX23418 provides a 12 byte header in its raw VBI buffers to us:
188 	 * 0x3fffffff [4 bytes of something] [4 byte presentation time stamp]
189 	 */
190 	struct vbi_data_hdr {
191 		__be32 magic;
192 		__be32 unknown;
193 		__be32 pts;
194 	} *hdr = (struct vbi_data_hdr *) buf->buf;
195 
196 	u8 *p = (u8 *) buf->buf;
197 	u32 size = buf->bytesused;
198 	u32 pts;
199 	int lines;
200 
201 	/*
202 	 * The CX23418 sends us data that is 32 bit little-endian swapped,
203 	 * but we want the raw VBI bytes in the order they were in the raster
204 	 * line.  This has a side effect of making the header big endian
205 	 */
206 	cx18_buf_swap(buf);
207 
208 	/* Raw VBI data */
209 	if (cx18_raw_vbi(cx)) {
210 
211 		size = buf->bytesused =
212 		     compress_raw_buf(cx, p, size, sizeof(struct vbi_data_hdr));
213 
214 		/*
215 		 * Hack needed for compatibility with old VBI software.
216 		 * Write the frame # at the last 4 bytes of the frame
217 		 */
218 		p += size - 4;
219 		memcpy(p, &cx->vbi.frame, 4);
220 		cx->vbi.frame++;
221 		return;
222 	}
223 
224 	/* Sliced VBI data with data insertion */
225 
226 	pts = (be32_to_cpu(hdr->magic) == 0x3fffffff) ? be32_to_cpu(hdr->pts)
227 						      : 0;
228 
229 	lines = compress_sliced_buf(cx, p, size, sizeof(struct vbi_data_hdr));
230 
231 	/* always return at least one empty line */
232 	if (lines == 0) {
233 		cx->vbi.sliced_data[0].id = 0;
234 		cx->vbi.sliced_data[0].line = 0;
235 		cx->vbi.sliced_data[0].field = 0;
236 		lines = 1;
237 	}
238 	buf->bytesused = size = lines * sizeof(cx->vbi.sliced_data[0]);
239 	memcpy(p, &cx->vbi.sliced_data[0], size);
240 
241 	if (cx->vbi.insert_mpeg)
242 		copy_vbi_data(cx, lines, pts);
243 	cx->vbi.frame++;
244 }
245 
246 void cx18_process_vbi_data(struct cx18 *cx, struct cx18_mdl *mdl,
247 			   int streamtype)
248 {
249 	struct cx18_buffer *buf;
250 	u32 orig_used;
251 
252 	if (streamtype != CX18_ENC_STREAM_TYPE_VBI)
253 		return;
254 
255 	/*
256 	 * Big assumption here:
257 	 * Every buffer hooked to the MDL's buf_list is a complete VBI frame
258 	 * that ends at the end of the buffer.
259 	 *
260 	 * To assume anything else would make the code in this file
261 	 * more complex, or require extra memcpy()'s to make the
262 	 * buffers satisfy the above assumption.  It's just simpler to set
263 	 * up the encoder buffer transfers to make the assumption true.
264 	 */
265 	list_for_each_entry(buf, &mdl->buf_list, list) {
266 		orig_used = buf->bytesused;
267 		if (orig_used == 0)
268 			break;
269 		_cx18_process_vbi_data(cx, buf);
270 		mdl->bytesused -= (orig_used - buf->bytesused);
271 	}
272 }
273