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 
copy_vbi_data(struct cx18 * cx,int lines,u32 pts_stamp)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. */
compress_raw_buf(struct cx18 * cx,u8 * buf,u32 size,u32 hdr_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 
compress_sliced_buf(struct cx18 * cx,u8 * buf,u32 size,const u32 hdr_size)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 
_cx18_process_vbi_data(struct cx18 * cx,struct cx18_buffer * buf)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 
cx18_process_vbi_data(struct cx18 * cx,struct cx18_mdl * mdl,int streamtype)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 }
264