examples/rawout.c

Raw VBI output example.

/*
 *  libzvbi raw VBI output example.
 *
 *  Copyright (C) 2006 Michael H. Schimek
 *
 *  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., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

/* $Id: rawout.c,v 1.5 2006/10/27 04:52:08 mschimek Exp $ */

/* This example shows how to convert VBI data in a DVB PES stream
   to raw VBI data.

   gcc -o rawout rawout.c `pkg-config zvbi-0.2 --cflags --libs`

   ./rawout <pes | mplayer - -rawvideo on:w=720:h=34:format=0x32595559 */

#undef NDEBUG
#include <assert.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include <libzvbi.h>

static vbi_dvb_demux *          dvb;
static uint8_t                  pes_buffer[2048];
static vbi_sampling_par         sp;
static uint8_t *                image;
static unsigned int             image_size;
static unsigned int             pixel_mask;
static int64_t                  last_pts;
static vbi_raw_decoder          rd;

static void
raw_test                        (const vbi_sliced *     expect_sliced,
                                 unsigned int           expect_n_lines)
{
        vbi_sliced sliced[50];
        unsigned int n_lines;
        unsigned int i;

        n_lines = vbi_raw_decode (&rd, image, sliced);
        assert (n_lines == expect_n_lines);

        for (i = 0; i < n_lines; ++i) {
                unsigned int payload;

                assert (sliced[i].id == expect_sliced[i].id);
                assert (sliced[i].line == expect_sliced[i].line);

                payload = (vbi_sliced_payload_bits (sliced[i].id) + 7) / 8;
                assert (0 == memcmp (sliced[i].data,
                                     expect_sliced[i].data,
                                     payload));
        }
}

static vbi_bool
convert                         (vbi_dvb_demux *        dx,
                                 void *                 user_data,
                                 const vbi_sliced *     sliced,
                                 unsigned int           n_lines,
                                 int64_t                pts)
{
        vbi_bool success;
        ssize_t actual;

        dx = dx; /* unused */
        user_data = user_data;

        pts &= ((int64_t) 1 << 33) - 1;

        /* Handle PTS wrap-around. */
        if (0 == last_pts) {
                last_pts = pts;
        } else if (pts < last_pts) {
                last_pts -= (int64_t) 1 << 33;
        }

        while (pts - last_pts > 90000 / 25 * 3 / 2) {
                /* No data for this frame. */

                success = vbi_raw_video_image (image, image_size, &sp,
                                               0, 0, 0, pixel_mask, FALSE,
                                               NULL, /* n_lines */ 0);
                assert (success);

                raw_test (NULL, 0);

                actual = write (STDOUT_FILENO, image, image_size);
                assert (actual == (ssize_t) image_size);

                last_pts += 90000 / 25;
        }

        success = vbi_raw_video_image (image, image_size, &sp,
                                       /* blank_level: default */ 0,
                                       /* black_level: default */ 0,
                                       /* white_level: default */ 0,
                                       pixel_mask,
                                       /* swap_fields */ FALSE,
                                       sliced, n_lines);
        assert (success);

        raw_test (sliced, n_lines);

        actual = write (STDOUT_FILENO, image, image_size);
        assert (actual == (ssize_t) image_size);

        last_pts = pts;

        return TRUE; /* success */
}

static void
mainloop                        (void)
{
        while (1 == fread (pes_buffer, sizeof (pes_buffer), 1, stdin)) {
                vbi_bool success;

                success = vbi_dvb_demux_feed (dvb,
                                              pes_buffer,
                                              sizeof (pes_buffer));
                assert (success);
        }

        fprintf (stderr, "End of stream.\n");
}

int
main                            (void)
{
        if (isatty (STDIN_FILENO)) {
                fprintf (stderr, "No DVB PES on standard input.\n");
                exit (EXIT_FAILURE);
        }

        if (isatty (STDOUT_FILENO)) {
                fprintf (stderr, "Output is binary image data. Pipe to "
                         "another tool or redirect to a file.\n");
                exit (EXIT_FAILURE);
        }

        /* Helps debugging. */
        vbi_set_log_fn ((VBI_LOG_NOTICE |
                         VBI_LOG_WARNING |
                         VBI_LOG_ERROR),
                        vbi_log_on_stderr,
                        /* user_data */ NULL);

        dvb = vbi_dvb_pes_demux_new (convert, /* user_data */ NULL);
        assert (NULL != dvb);

        memset (&sp, 0, sizeof (sp));

#if 1
        /* ITU BT.601 YUYV. */

        sp.scanning             = 625; /* PAL/SECAM */
        sp.sampling_format      = VBI_PIXFMT_YUYV;
        sp.sampling_rate        = 13.5e6;
        sp.bytes_per_line       = 720 * 2; /* 2 bpp */
        sp.offset               = 9.5e-6 * 13.5e6;
        sp.start[0]             = 6;
        sp.count[0]             = 17;
        sp.start[1]             = 319;
        sp.count[1]             = 17;
        sp.interlaced           = TRUE;
        sp.synchronous          = TRUE;

        /* Other bytes are left unmodified. */
        pixel_mask              = 0x000000FF; /* 0xAAVVUUYY */
#else
        /* PAL square pixels BGRA32. */

        sp.scanning             = 625; /* PAL/SECAM */
        sp.sampling_format      = VBI_PIXFMT_BGRA32_LE;
        sp.sampling_rate        = 14.75e6;
        sp.bytes_per_line       = 768 * 4; /* 4 bpp */
        sp.offset               = 10.2e-6 * 14.75e6;
        sp.start[0]             = 6;
        sp.count[0]             = 17;
        sp.start[1]             = 319;
        sp.count[1]             = 17;
        sp.interlaced           = TRUE;
        sp.synchronous          = TRUE;

        pixel_mask              = 0x0000FF00; /* 0xAABBGGRR */
#endif

        image_size = (sp.count[0] + sp.count[1]) * sp.bytes_per_line;
        image = malloc (image_size);
        assert (NULL != image);

        if (VBI_PIXFMT_YUYV == sp.sampling_format) {
                /* Reset Cb/Cr bytes. */
                memset (image, 0x80, image_size);
        } else {
                memset (image, 0x00, image_size);
        }

        /* To verify the generated raw VBI data we feed it back
           into a decoder and compare the sliced VBI data. */

        vbi_raw_decoder_init (&rd);

        rd.scanning             = sp.scanning;
        rd.sampling_format      = sp.sampling_format;
        rd.sampling_rate        = sp.sampling_rate;
        rd.bytes_per_line       = sp.bytes_per_line;
        rd.offset               = sp.offset;
        rd.start[0]             = sp.start[0];
        rd.start[1]             = sp.start[1];
        rd.count[0]             = sp.count[0];
        rd.count[1]             = sp.count[1];
        rd.interlaced           = sp.interlaced;
        rd.synchronous          = sp.synchronous;

        /* Strict 0 because the function would consider the
           square pixel timing too tight to reliably decode
           Teletext. */
        vbi_raw_decoder_add_services (&rd,
                                      (VBI_SLICED_TELETEXT_B |
                                       VBI_SLICED_VPS |
                                       VBI_SLICED_CAPTION_625),
                                      /* strict */ 0);

        mainloop ();

        vbi_dvb_demux_delete (dvb);

        exit (EXIT_SUCCESS);

        return 0;
}

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