cx18-vbi.c

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/*
 *  cx18 Vertical Blank Interval support functions
 *
 *  Derived from ivtv-vbi.c
 *
 *  Copyright (C) 2007  Hans Verkuil <[email protected]>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
 *  02111-1307  USA
 */

#include "cx18-driver.h"
#include "cx18-vbi.h"
#include "cx18-ioctl.h"
#include "cx18-queue.h"

/*
 * Raster Reference/Protection (RP) bytes, used in Start/End Active
 * Video codes emitted from the digitzer in VIP 1.x mode, that flag the start
 * of VBI sample or VBI ancillary data regions in the digitial ratser line.
 *
 * Task FieldEven VerticalBlank HorizontalBlank 0 0 0 0
 */
static const u8 raw_vbi_sav_rp[2] = { 0x20, 0x60 };    /* __V_, _FV_ */
static const u8 sliced_vbi_eav_rp[2] = { 0xb0, 0xf0 }; /* T_VH, TFVH */

static void copy_vbi_data(struct cx18 *cx, int lines, u32 pts_stamp)
{
    int line = 0;
    int i;
    u32 linemask[2] = { 0, 0 };
    unsigned short size;
    static const u8 mpeg_hdr_data[] = {
        /* MPEG-2 Program Pack */
        0x00, 0x00, 0x01, 0xba,         /* Prog Pack start code */
        0x44, 0x00, 0x0c, 0x66, 0x24, 0x01, /* SCR, SCR Ext, markers */
        0x01, 0xd1, 0xd3,           /* Mux Rate, markers */
        0xfa, 0xff, 0xff,           /* Res, Suff cnt, Stuff */
        /* MPEG-2 Private Stream 1 PES Packet */
        0x00, 0x00, 0x01, 0xbd,         /* Priv Stream 1 start */
        0x00, 0x1a,             /* length */
        0x84, 0x80, 0x07,           /* flags, hdr data len */
        0x21, 0x00, 0x5d, 0x63, 0xa7,       /* PTS, markers */
        0xff, 0xff              /* stuffing */
    };
    const int sd = sizeof(mpeg_hdr_data);   /* start of vbi data */
    int idx = cx->vbi.frame % CX18_VBI_FRAMES;
    u8 *dst = &cx->vbi.sliced_mpeg_data[idx][0];

    for (i = 0; i < lines; i++) {
        struct v4l2_sliced_vbi_data *sdata = cx->vbi.sliced_data + i;
        int f, l;

        if (sdata->id == 0)
            continue;

        l = sdata->line - 6;
        f = sdata->field;
        if (f)
            l += 18;
        if (l < 32)
            linemask[0] |= (1 << l);
        else
            linemask[1] |= (1 << (l - 32));
        dst[sd + 12 + line * 43] = cx18_service2vbi(sdata->id);
        memcpy(dst + sd + 12 + line * 43 + 1, sdata->data, 42);
        line++;
    }
    memcpy(dst, mpeg_hdr_data, sizeof(mpeg_hdr_data));
    if (line == 36) {
        /* All lines are used, so there is no space for the linemask
           (the max size of the VBI data is 36 * 43 + 4 bytes).
           So in this case we use the magic number 'ITV0'. */
        memcpy(dst + sd, "ITV0", 4);
        memcpy(dst + sd + 4, dst + sd + 12, line * 43);
        size = 4 + ((43 * line + 3) & ~3);
    } else {
        memcpy(dst + sd, "itv0", 4);
        cpu_to_le32s(&linemask[0]);
        cpu_to_le32s(&linemask[1]);
        memcpy(dst + sd + 4, &linemask[0], 8);
        size = 12 + ((43 * line + 3) & ~3);
    }
    dst[4+16] = (size + 10) >> 8;
    dst[5+16] = (size + 10) & 0xff;
    dst[9+16] = 0x21 | ((pts_stamp >> 29) & 0x6);
    dst[10+16] = (pts_stamp >> 22) & 0xff;
    dst[11+16] = 1 | ((pts_stamp >> 14) & 0xff);
    dst[12+16] = (pts_stamp >> 7) & 0xff;
    dst[13+16] = 1 | ((pts_stamp & 0x7f) << 1);
    cx->vbi.sliced_mpeg_size[idx] = sd + size;
}

/* Compress raw VBI format, removes leading SAV codes and surplus space
   after the frame.  Returns new compressed size. */
/* FIXME - this function ignores the input size. */
static u32 compress_raw_buf(struct cx18 *cx, u8 *buf, u32 size, u32 hdr_size)
{
    u32 line_size = vbi_active_samples;
    u32 lines = cx->vbi.count * 2;
    u8 *q = buf;
    u8 *p;
    int i;

    /* Skip the header */
    buf += hdr_size;

    for (i = 0; i < lines; i++) {
        p = buf + i * line_size;

        /* Look for SAV code */
        if (p[0] != 0xff || p[1] || p[2] ||
            (p[3] != raw_vbi_sav_rp[0] &&
             p[3] != raw_vbi_sav_rp[1]))
            break;
        if (i == lines - 1) {
            /* last line is hdr_size bytes short - extrapolate it */
            memcpy(q, p + 4, line_size - 4 - hdr_size);
            q += line_size - 4 - hdr_size;
            p += line_size - hdr_size - 1;
            memset(q, (int) *p, hdr_size);
        } else {
            memcpy(q, p + 4, line_size - 4);
            q += line_size - 4;
        }
    }
    return lines * (line_size - 4);
}

static u32 compress_sliced_buf(struct cx18 *cx, u8 *buf, u32 size,
                   const u32 hdr_size)
{
    struct v4l2_decode_vbi_line vbi;
    int i;
    u32 line = 0;
    u32 line_size = cx->is_60hz ? vbi_hblank_samples_60Hz
                    : vbi_hblank_samples_50Hz;

    /* find the first valid line */
    for (i = hdr_size, buf += hdr_size; i < size; i++, buf++) {
        if (buf[0] == 0xff && !buf[1] && !buf[2] &&
            (buf[3] == sliced_vbi_eav_rp[0] ||
             buf[3] == sliced_vbi_eav_rp[1]))
            break;
    }

    /*
     * The last line is short by hdr_size bytes, but for the remaining
     * checks against size, we pretend that it is not, by counting the
     * header bytes we knowingly skipped
     */
    size -= (i - hdr_size);
    if (size < line_size)
        return line;

    for (i = 0; i < size / line_size; i++) {
        u8 *p = buf + i * line_size;

        /* Look for EAV code  */
        if (p[0] != 0xff || p[1] || p[2] ||
            (p[3] != sliced_vbi_eav_rp[0] &&
             p[3] != sliced_vbi_eav_rp[1]))
            continue;
        vbi.p = p + 4;
        v4l2_subdev_call(cx->sd_av, vbi, decode_vbi_line, &vbi);
        if (vbi.type) {
            cx->vbi.sliced_data[line].id = vbi.type;
            cx->vbi.sliced_data[line].field = vbi.is_second_field;
            cx->vbi.sliced_data[line].line = vbi.line;
            memcpy(cx->vbi.sliced_data[line].data, vbi.p, 42);
            line++;
        }
    }
    return line;
}

static void _cx18_process_vbi_data(struct cx18 *cx, struct cx18_buffer *buf)
{
    /*
     * The CX23418 provides a 12 byte header in its raw VBI buffers to us:
     * 0x3fffffff [4 bytes of something] [4 byte presentation time stamp]
     */
    struct vbi_data_hdr {
        __be32 magic;
        __be32 unknown;
        __be32 pts;
    } *hdr = (struct vbi_data_hdr *) buf->buf;

    u8 *p = (u8 *) buf->buf;
    u32 size = buf->bytesused;
    u32 pts;
    int lines;

    /*
     * The CX23418 sends us data that is 32 bit little-endian swapped,
     * but we want the raw VBI bytes in the order they were in the raster
     * line.  This has a side effect of making the header big endian
     */
    cx18_buf_swap(buf);

    /* Raw VBI data */
    if (cx18_raw_vbi(cx)) {

        size = buf->bytesused =
             compress_raw_buf(cx, p, size, sizeof(struct vbi_data_hdr));

        /*
         * Hack needed for compatibility with old VBI software.
         * Write the frame # at the last 4 bytes of the frame
         */
        p += size - 4;
        memcpy(p, &cx->vbi.frame, 4);
        cx->vbi.frame++;
        return;
    }

    /* Sliced VBI data with data insertion */

    pts = (be32_to_cpu(hdr->magic) == 0x3fffffff) ? be32_to_cpu(hdr->pts)
                              : 0;

    lines = compress_sliced_buf(cx, p, size, sizeof(struct vbi_data_hdr));

    /* always return at least one empty line */
    if (lines == 0) {
        cx->vbi.sliced_data[0].id = 0;
        cx->vbi.sliced_data[0].line = 0;
        cx->vbi.sliced_data[0].field = 0;
        lines = 1;
    }
    buf->bytesused = size = lines * sizeof(cx->vbi.sliced_data[0]);
    memcpy(p, &cx->vbi.sliced_data[0], size);

    if (cx->vbi.insert_mpeg)
        copy_vbi_data(cx, lines, pts);
    cx->vbi.frame++;
}

void cx18_process_vbi_data(struct cx18 *cx, struct cx18_mdl *mdl,
               int streamtype)
{
    struct cx18_buffer *buf;
    u32 orig_used;

    if (streamtype != CX18_ENC_STREAM_TYPE_VBI)
        return;

    /*
     * Big assumption here:
     * Every buffer hooked to the MDL's buf_list is a complete VBI frame
     * that ends at the end of the buffer.
     *
     * To assume anything else would make the code in this file
     * more complex, or require extra memcpy()'s to make the
     * buffers satisfy the above assumption.  It's just simpler to set
     * up the encoder buffer transfers to make the assumption true.
     */
    list_for_each_entry(buf, &mdl->buf_list, list) {
        orig_used = buf->bytesused;
        if (orig_used == 0)
            break;
        _cx18_process_vbi_data(cx, buf);
        mdl->bytesused -= (orig_used - buf->bytesused);
    }
}