[deb_ffmpeg.git] / ffmpeg / libavcodec / libzvbi-teletextdec.c

/*
 * Teletext decoding for ffmpeg
 * Copyright (c) 2005-2010, 2012 Wolfram Gloger
 * Copyright (c) 2013 Marton Balint
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2 of the License, or (at your option) any later version.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include "avcodec.h"
#include "libavcodec/ass.h"
#include "libavutil/opt.h"
#include "libavutil/bprint.h"
#include "libavutil/intreadwrite.h"
#include "libavutil/log.h"

#include <libzvbi.h>

#define TEXT_MAXSZ    (25 * (56 + 1) * 4 + 2)
#define VBI_NB_COLORS 40
#define RGBA(r,g,b,a) (((a) << 24) | ((r) << 16) | ((g) << 8) | (b))
#define VBI_R(rgba)   (((rgba) >> 0) & 0xFF)
#define VBI_G(rgba)   (((rgba) >> 8) & 0xFF)
#define VBI_B(rgba)   (((rgba) >> 16) & 0xFF)
#define VBI_A(rgba)   (((rgba) >> 24) & 0xFF)
#define MAX_BUFFERED_PAGES 25
#define BITMAP_CHAR_WIDTH  12
#define BITMAP_CHAR_HEIGHT 10
#define MAX_SLICES 64

typedef struct TeletextPage
{
    AVSubtitleRect *sub_rect;
    int pgno;
    int subno;
    int64_t pts;
} TeletextPage;

typedef struct TeletextContext
{
    AVClass        *class;
    char           *pgno;
    int             x_offset;
    int             y_offset;
    int             format_id; /* 0 = bitmap, 1 = text/ass */
    int             chop_top;
    int             sub_duration; /* in msec */
    int             transparent_bg;
    int             chop_spaces;

    int             lines_processed;
    TeletextPage    *pages;
    int             nb_pages;
    int64_t         pts;
    int             handler_ret;

    vbi_decoder *   vbi;
#ifdef DEBUG
    vbi_export *    ex;
#endif
    vbi_sliced      sliced[MAX_SLICES];
} TeletextContext;

static int chop_spaces_utf8(const unsigned char* t, int len)
{
    t += len;
    while (len > 0) {
        if (*--t != ' ' || (len-1 > 0 && *(t-1) & 0x80))
            break;
        --len;
    }
    return len;
}

static void subtitle_rect_free(AVSubtitleRect **sub_rect)
{
    av_freep(&(*sub_rect)->pict.data[0]);
    av_freep(&(*sub_rect)->pict.data[1]);
    av_freep(&(*sub_rect)->ass);
    av_freep(sub_rect);
}

static int create_ass_text(TeletextContext *ctx, const char *text, char **ass)
{
    int ret;
    AVBPrint buf, buf2;
    const int ts_start    = av_rescale_q(ctx->pts,          AV_TIME_BASE_Q,        (AVRational){1, 100});
    const int ts_duration = av_rescale_q(ctx->sub_duration, (AVRational){1, 1000}, (AVRational){1, 100});

    /* First we escape the plain text into buf. */
    av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
    ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);

    if (!av_bprint_is_complete(&buf)) {
        av_bprint_finalize(&buf, NULL);
        return AVERROR(ENOMEM);
    }

    /* Then we create the ass dialog line in buf2 from the escaped text in buf. */
    av_bprint_init(&buf2, 0, AV_BPRINT_SIZE_UNLIMITED);
    ff_ass_bprint_dialog(&buf2, buf.str, ts_start, ts_duration, 0);
    av_bprint_finalize(&buf, NULL);

    if (!av_bprint_is_complete(&buf2)) {
        av_bprint_finalize(&buf2, NULL);
        return AVERROR(ENOMEM);
    }

    if ((ret = av_bprint_finalize(&buf2, ass)) < 0)
        return ret;

    return 0;
}

/* Draw a page as text */
static int gen_sub_text(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
    const char *in;
    AVBPrint buf;
    char *vbi_text = av_malloc(TEXT_MAXSZ);
    int sz;

    if (!vbi_text)
        return AVERROR(ENOMEM);

    sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
                                   /*table mode*/ TRUE, FALSE,
                                   0,             chop_top,
                                   page->columns, page->rows-chop_top);
    if (sz <= 0) {
        av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
        av_free(vbi_text);
        return AVERROR_EXTERNAL;
    }
    vbi_text[sz] = '\0';
    in  = vbi_text;
    av_bprint_init(&buf, 0, TEXT_MAXSZ);

    if (ctx->chop_spaces) {
        for (;;) {
            int nl, sz;

            // skip leading spaces and newlines
            in += strspn(in, " \n");
            // compute end of row
            for (nl = 0; in[nl]; ++nl)
                if (in[nl] == '\n' && (nl==0 || !(in[nl-1] & 0x80)))
                    break;
            if (!in[nl])
                break;
            // skip trailing spaces
            sz = chop_spaces_utf8(in, nl);
            av_bprint_append_data(&buf, in, sz);
            av_bprintf(&buf, "\n");
            in += nl;
        }
    } else {
        av_bprintf(&buf, "%s\n", vbi_text);
    }
    av_free(vbi_text);

    if (!av_bprint_is_complete(&buf)) {
        av_bprint_finalize(&buf, NULL);
        return AVERROR(ENOMEM);
    }

    if (buf.len) {
        int ret;
        sub_rect->type = SUBTITLE_ASS;
        if ((ret = create_ass_text(ctx, buf.str, &sub_rect->ass)) < 0) {
            av_bprint_finalize(&buf, NULL);
            return ret;
        }
        av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
    } else {
        sub_rect->type = SUBTITLE_NONE;
    }
    av_bprint_finalize(&buf, NULL);
    return 0;
}

static void fix_transparency(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page,
                             int chop_top, uint8_t transparent_color, int resx, int resy)
{
    int iy;

    // Hack for transparency, inspired by VLC code...
    for (iy = 0; iy < resy; iy++) {
        uint8_t *pixel = sub_rect->pict.data[0] + iy * sub_rect->pict.linesize[0];
        vbi_char *vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) * page->columns;
        vbi_char *vcnext = vc + page->columns;
        for (; vc < vcnext; vc++) {
            uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
            switch (vc->opacity) {
                case VBI_TRANSPARENT_SPACE:
                    memset(pixel, transparent_color, BITMAP_CHAR_WIDTH);
                    break;
                case VBI_OPAQUE:
                case VBI_SEMI_TRANSPARENT:
                    if (!ctx->transparent_bg)
                        break;
                case VBI_TRANSPARENT_FULL:
                    for(; pixel < pixelnext; pixel++)
                        if (*pixel == vc->background)
                            *pixel = transparent_color;
                    break;
            }
            pixel = pixelnext;
        }
    }
}

/* Draw a page as bitmap */
static int gen_sub_bitmap(TeletextContext *ctx, AVSubtitleRect *sub_rect, vbi_page *page, int chop_top)
{
    int resx = page->columns * BITMAP_CHAR_WIDTH;
    int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
    uint8_t ci, cmax = 0;
    int ret;
    vbi_char *vc = page->text + (chop_top * page->columns);
    vbi_char *vcend = page->text + (page->rows * page->columns);

    for (; vc < vcend; vc++) {
        if (vc->opacity != VBI_TRANSPARENT_SPACE) {
            cmax = VBI_NB_COLORS;
            break;
        }
    }

    if (cmax == 0) {
        av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
        sub_rect->type = SUBTITLE_NONE;
        return 0;
    }

    if ((ret = avpicture_alloc(&sub_rect->pict, AV_PIX_FMT_PAL8, resx, resy)) < 0)
        return ret;
    // Yes, we want to allocate the palette on our own because AVSubtitle works this way
    sub_rect->pict.data[1] = NULL;

    vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
                            sub_rect->pict.data[0], sub_rect->pict.linesize[0],
                            0, chop_top, page->columns, page->rows - chop_top,
                            /*reveal*/ 1, /*flash*/ 1);

    fix_transparency(ctx, sub_rect, page, chop_top, cmax, resx, resy);
    sub_rect->x = ctx->x_offset;
    sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
    sub_rect->w = resx;
    sub_rect->h = resy;
    sub_rect->nb_colors = (int)cmax + 1;
    sub_rect->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
    if (!sub_rect->pict.data[1]) {
        av_freep(&sub_rect->pict.data[0]);
        return AVERROR(ENOMEM);
    }
    for (ci = 0; ci < cmax; ci++) {
        int r, g, b, a;

        r = VBI_R(page->color_map[ci]);
        g = VBI_G(page->color_map[ci]);
        b = VBI_B(page->color_map[ci]);
        a = VBI_A(page->color_map[ci]);
        ((uint32_t *)sub_rect->pict.data[1])[ci] = RGBA(r, g, b, a);
        av_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->pict.data[1])[ci]);
    }
    ((uint32_t *)sub_rect->pict.data[1])[cmax] = RGBA(0, 0, 0, 0);
    sub_rect->type = SUBTITLE_BITMAP;
    return 0;
}

static void handler(vbi_event *ev, void *user_data)
{
    TeletextContext *ctx = user_data;
    TeletextPage *new_pages;
    vbi_page page;
    int res;
    char pgno_str[12];
    vbi_subno subno;
    vbi_page_type vpt;
    int chop_top;
    char *lang;

    snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
    av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
           pgno_str, ev->ev.ttx_page.subno & 0xFF);

    if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
        return;
    if (ctx->handler_ret < 0)
        return;

    res = vbi_fetch_vt_page(ctx->vbi, &page,
                            ev->ev.ttx_page.pgno,
                            ev->ev.ttx_page.subno,
                            VBI_WST_LEVEL_3p5, 25, TRUE);

    if (!res)
        return;

#ifdef DEBUG
    fprintf(stderr, "\nSaving res=%d dy0=%d dy1=%d...\n",
            res, page.dirty.y0, page.dirty.y1);
    fflush(stderr);

    if (!vbi_export_stdio(ctx->ex, stderr, &page))
        fprintf(stderr, "failed: %s\n", vbi_export_errstr(ctx->ex));
#endif

    vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
    chop_top = ctx->chop_top ||
        ((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));

    av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
           page.columns, page.rows, chop_top);

    if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
        if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
            TeletextPage *cur_page = new_pages + ctx->nb_pages;
            ctx->pages = new_pages;
            cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
            cur_page->pts = ctx->pts;
            cur_page->pgno = ev->ev.ttx_page.pgno;
            cur_page->subno = ev->ev.ttx_page.subno;
            if (cur_page->sub_rect) {
                res = (ctx->format_id == 0) ?
                    gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top) :
                    gen_sub_text  (ctx, cur_page->sub_rect, &page, chop_top);
                if (res < 0) {
                    av_freep(&cur_page->sub_rect);
                    ctx->handler_ret = res;
                } else {
                    ctx->pages[ctx->nb_pages++] = *cur_page;
                }
            } else {
                ctx->handler_ret = AVERROR(ENOMEM);
            }
        } else {
            ctx->handler_ret = AVERROR(ENOMEM);
        }
    } else {
        //TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
        av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
        ctx->handler_ret = AVERROR(ENOSYS);
    }

    vbi_unref_page(&page);
}

static inline int data_identifier_is_teletext(int data_identifier) {
    /* See EN 301 775 section 4.4.2. */
    return (data_identifier >= 0x10 && data_identifier <= 0x1F ||
            data_identifier >= 0x99 && data_identifier <= 0x9B);
}

static int slice_to_vbi_lines(TeletextContext *ctx, uint8_t* buf, int size)
{
    int lines = 0;
    while (size >= 2 && lines < MAX_SLICES) {
        int data_unit_id     = buf[0];
        int data_unit_length = buf[1];
        if (data_unit_length + 2 > size)
            return AVERROR_INVALIDDATA;
        if (data_unit_id == 0x02 || data_unit_id == 0x03) {
            if (data_unit_length != 0x2c)
                return AVERROR_INVALIDDATA;
            else {
                int line_offset  = buf[2] & 0x1f;
                int field_parity = buf[2] & 0x20;
                int i;
                ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
                ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
                for (i = 0; i < 42; i++)
                    ctx->sliced[lines].data[i] = vbi_rev8(buf[4 + i]);
                lines++;
            }
        }
        size -= data_unit_length + 2;
        buf += data_unit_length + 2;
    }
    if (size)
        av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
    return lines;
}

static int teletext_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *pkt)
{
    TeletextContext *ctx = avctx->priv_data;
    AVSubtitle      *sub = data;
    int             ret = 0;

    if (!ctx->vbi) {
        if (!(ctx->vbi = vbi_decoder_new()))
            return AVERROR(ENOMEM);
        if (!vbi_event_handler_add(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
            vbi_decoder_delete(ctx->vbi);
            ctx->vbi = NULL;
            return AVERROR(ENOMEM);
        }
    }

    if (avctx->pkt_timebase.den && pkt->pts != AV_NOPTS_VALUE)
        ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);

    if (pkt->size) {
        int lines;
        const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */

        // We allow unreasonably big packets, even if the standard only allows a max size of 1472
        if (full_pes_size < 184 || full_pes_size > 65504 || full_pes_size % 184 != 0)
            return AVERROR_INVALIDDATA;

        ctx->handler_ret = pkt->size;

        if (data_identifier_is_teletext(*pkt->data)) {
            if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
                return lines;
            av_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
                    ctx, pkt->size, lines, (double)pkt->pts/90000.0);
            if (lines > 0) {
#ifdef DEBUG
                int i;
                av_log(avctx, AV_LOG_DEBUG, "line numbers:");
                for(i = 0; i < lines; i++)
                    av_log(avctx, AV_LOG_DEBUG, " %d", ctx->sliced[i].line);
                av_log(avctx, AV_LOG_DEBUG, "\n");
#endif
                vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
                ctx->lines_processed += lines;
            }
        }
        ctx->pts = AV_NOPTS_VALUE;
        ret = ctx->handler_ret;
    }

    if (ret < 0)
        return ret;

    // is there a subtitle to pass?
    if (ctx->nb_pages) {
        int i;
        sub->format = ctx->format_id;
        sub->start_display_time = 0;
        sub->end_display_time = ctx->sub_duration;
        sub->num_rects = 0;
        sub->pts = ctx->pages->pts;

        if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
            sub->rects = av_malloc(sizeof(*sub->rects));
            if (sub->rects) {
                sub->num_rects = 1;
                sub->rects[0] = ctx->pages->sub_rect;
            } else {
                ret = AVERROR(ENOMEM);
            }
        } else {
            av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
            sub->rects = NULL;
        }
        if (!sub->rects) // no rect was passed
            subtitle_rect_free(&ctx->pages->sub_rect);

        for (i = 0; i < ctx->nb_pages - 1; i++)
            ctx->pages[i] = ctx->pages[i + 1];
        ctx->nb_pages--;

        if (ret >= 0)
            *data_size = 1;
    } else
        *data_size = 0;

    return ret;
}

static int teletext_init_decoder(AVCodecContext *avctx)
{
    TeletextContext *ctx = avctx->priv_data;
    unsigned int maj, min, rev;

    vbi_version(&maj, &min, &rev);
    if (!(maj > 0 || min > 2 || min == 2 && rev >= 26)) {
        av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
        return AVERROR_EXTERNAL;
    }

    if (ctx->format_id == 0) {
        avctx->width  = 41 * BITMAP_CHAR_WIDTH;
        avctx->height = 25 * BITMAP_CHAR_HEIGHT;
    }

    ctx->vbi = NULL;
    ctx->pts = AV_NOPTS_VALUE;

#ifdef DEBUG
    {
        char *t;
        ctx->ex = vbi_export_new("text", &t);
    }
#endif
    av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
    return (ctx->format_id == 1) ? ff_ass_subtitle_header_default(avctx) : 0;
}

static int teletext_close_decoder(AVCodecContext *avctx)
{
    TeletextContext *ctx = avctx->priv_data;

    av_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
    while (ctx->nb_pages)
        subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
    av_freep(&ctx->pages);

    vbi_decoder_delete(ctx->vbi);
    ctx->vbi = NULL;
    ctx->pts = AV_NOPTS_VALUE;
    return 0;
}

static void teletext_flush(AVCodecContext *avctx)
{
    teletext_close_decoder(avctx);
}

#define OFFSET(x) offsetof(TeletextContext, x)
#define SD AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM
static const AVOption options[] = {
    {"txt_page",        "list of teletext page numbers to decode, * is all", OFFSET(pgno),           AV_OPT_TYPE_STRING, {.str = "*"},      0, 0,        SD},
    {"txt_chop_top",    "discards the top teletext line",                    OFFSET(chop_top),       AV_OPT_TYPE_INT,    {.i64 = 1},        0, 1,        SD},
    {"txt_format",      "format of the subtitles (bitmap or text)",          OFFSET(format_id),      AV_OPT_TYPE_INT,    {.i64 = 0},        0, 1,        SD,  "txt_format"},
    {"bitmap",          NULL,                                                0,                      AV_OPT_TYPE_CONST,  {.i64 = 0},        0, 0,        SD,  "txt_format"},
    {"text",            NULL,                                                0,                      AV_OPT_TYPE_CONST,  {.i64 = 1},        0, 0,        SD,  "txt_format"},
    {"txt_left",        "x offset of generated bitmaps",                     OFFSET(x_offset),       AV_OPT_TYPE_INT,    {.i64 = 0},        0, 65535,    SD},
    {"txt_top",         "y offset of generated bitmaps",                     OFFSET(y_offset),       AV_OPT_TYPE_INT,    {.i64 = 0},        0, 65535,    SD},
    {"txt_chop_spaces", "chops leading and trailing spaces from text",       OFFSET(chop_spaces),    AV_OPT_TYPE_INT,    {.i64 = 1},        0, 1,        SD},
    {"txt_duration",    "display duration of teletext pages in msecs",       OFFSET(sub_duration),   AV_OPT_TYPE_INT,    {.i64 = 30000},    0, 86400000, SD},
    {"txt_transparent", "force transparent background of the teletext",      OFFSET(transparent_bg), AV_OPT_TYPE_INT,    {.i64 = 0},        0, 1,        SD},
    { NULL },
};

static const AVClass teletext_class = {
    .class_name = "libzvbi_teletextdec",
    .item_name  = av_default_item_name,
    .option     = options,
    .version    = LIBAVUTIL_VERSION_INT,
};

AVCodec ff_libzvbi_teletext_decoder = {
    .name      = "libzvbi_teletextdec",
    .long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
    .type      = AVMEDIA_TYPE_SUBTITLE,
    .id        = AV_CODEC_ID_DVB_TELETEXT,
    .priv_data_size = sizeof(TeletextContext),
    .init      = teletext_init_decoder,
    .close     = teletext_close_decoder,
    .decode    = teletext_decode_frame,
    .capabilities = CODEC_CAP_DELAY,
    .flush     = teletext_flush,
    .priv_class= &teletext_class,
};
Commit	Line	Data
2ba45a60 DM	1	/*
	2	* Teletext decoding for ffmpeg
	3	* Copyright (c) 2005-2010, 2012 Wolfram Gloger
	4	* Copyright (c) 2013 Marton Balint
	5	*
	6	* This library is free software; you can redistribute it and/or
	7	* modify it under the terms of the GNU Lesser General Public
	8	* License as published by the Free Software Foundation; either
	9	* version 2 of the License, or (at your option) any later version.
	10	*
	11	* This library is distributed in the hope that it will be useful,
	12	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	14	* Lesser General Public License for more details.
	15	*
	16	* You should have received a copy of the GNU Lesser General Public
	17	* License along with this library; if not, write to the Free Software
	18	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	19	*/
	20
	21	#include "avcodec.h"
	22	#include "libavcodec/ass.h"
	23	#include "libavutil/opt.h"
	24	#include "libavutil/bprint.h"
	25	#include "libavutil/intreadwrite.h"
	26	#include "libavutil/log.h"
	27
	28	#include <libzvbi.h>
	29
	30	#define TEXT_MAXSZ (25 * (56 + 1) * 4 + 2)
	31	#define VBI_NB_COLORS 40
	32	#define RGBA(r,g,b,a) (((a) << 24) \| ((r) << 16) \| ((g) << 8) \| (b))
	33	#define VBI_R(rgba) (((rgba) >> 0) & 0xFF)
	34	#define VBI_G(rgba) (((rgba) >> 8) & 0xFF)
	35	#define VBI_B(rgba) (((rgba) >> 16) & 0xFF)
	36	#define VBI_A(rgba) (((rgba) >> 24) & 0xFF)
	37	#define MAX_BUFFERED_PAGES 25
	38	#define BITMAP_CHAR_WIDTH 12
	39	#define BITMAP_CHAR_HEIGHT 10
	40	#define MAX_SLICES 64
	41
	42	typedef struct TeletextPage
	43	{
	44	AVSubtitleRect *sub_rect;
	45	int pgno;
	46	int subno;
	47	int64_t pts;
	48	} TeletextPage;
	49
	50	typedef struct TeletextContext
	51	{
	52	AVClass *class;
	53	char *pgno;
	54	int x_offset;
	55	int y_offset;
	56	int format_id; /* 0 = bitmap, 1 = text/ass */
	57	int chop_top;
	58	int sub_duration; /* in msec */
	59	int transparent_bg;
	60	int chop_spaces;
	61
	62	int lines_processed;
	63	TeletextPage *pages;
	64	int nb_pages;
65	int64_t pts;
66	int handler_ret;
67
68	vbi_decoder * vbi;
69	#ifdef DEBUG
70	vbi_export * ex;
71	#endif
72	vbi_sliced sliced[MAX_SLICES];
73	} TeletextContext;
74
75	static int chop_spaces_utf8(const unsigned char* t, int len)
76	{
77	t += len;
78	while (len > 0) {
79	if (--t != ' ' \|\| (len-1 > 0 && (t-1) & 0x80))
80	break;
81	--len;
82	}
83	return len;
84	}
85
86	static void subtitle_rect_free(AVSubtitleRect **sub_rect)
87	{
88	av_freep(&(*sub_rect)->pict.data[0]);
89	av_freep(&(*sub_rect)->pict.data[1]);
90	av_freep(&(*sub_rect)->ass);
91	av_freep(sub_rect);
92	}
93
94	static int create_ass_text(TeletextContext ctx, const char text, char **ass)
95	{
96	int ret;
97	AVBPrint buf, buf2;
98	const int ts_start = av_rescale_q(ctx->pts, AV_TIME_BASE_Q, (AVRational){1, 100});
99	const int ts_duration = av_rescale_q(ctx->sub_duration, (AVRational){1, 1000}, (AVRational){1, 100});
100
101	/* First we escape the plain text into buf. */
102	av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED);
103	ff_ass_bprint_text_event(&buf, text, strlen(text), "", 0);
104
105	if (!av_bprint_is_complete(&buf)) {
106	av_bprint_finalize(&buf, NULL);
107	return AVERROR(ENOMEM);
108	}
109
110	/* Then we create the ass dialog line in buf2 from the escaped text in buf. */
111	av_bprint_init(&buf2, 0, AV_BPRINT_SIZE_UNLIMITED);
112	ff_ass_bprint_dialog(&buf2, buf.str, ts_start, ts_duration, 0);
113	av_bprint_finalize(&buf, NULL);
114
115	if (!av_bprint_is_complete(&buf2)) {
116	av_bprint_finalize(&buf2, NULL);
117	return AVERROR(ENOMEM);
118	}
119
120	if ((ret = av_bprint_finalize(&buf2, ass)) < 0)
121	return ret;
122
123	return 0;
124	}
125
126	/* Draw a page as text */
127	static int gen_sub_text(TeletextContext ctx, AVSubtitleRect sub_rect, vbi_page *page, int chop_top)
128	{
129	const char *in;
130	AVBPrint buf;
131	char *vbi_text = av_malloc(TEXT_MAXSZ);
132	int sz;
133
134	if (!vbi_text)
135	return AVERROR(ENOMEM);
136
137	sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
138	/table mode/ TRUE, FALSE,
139	0, chop_top,
140	page->columns, page->rows-chop_top);
141	if (sz <= 0) {
142	av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
143	av_free(vbi_text);
144	return AVERROR_EXTERNAL;
145	}
146	vbi_text[sz] = '\0';
147	in = vbi_text;
148	av_bprint_init(&buf, 0, TEXT_MAXSZ);
149
150	if (ctx->chop_spaces) {
151	for (;;) {
152	int nl, sz;
153
154	// skip leading spaces and newlines
155	in += strspn(in, " \n");
156	// compute end of row
157	for (nl = 0; in[nl]; ++nl)
158	if (in[nl] == '\n' && (nl==0 \|\| !(in[nl-1] & 0x80)))
159	break;
160	if (!in[nl])
161	break;
162	// skip trailing spaces
163	sz = chop_spaces_utf8(in, nl);
164	av_bprint_append_data(&buf, in, sz);
165	av_bprintf(&buf, "\n");
166	in += nl;
167	}
168	} else {
169	av_bprintf(&buf, "%s\n", vbi_text);
170	}
171	av_free(vbi_text);
172
173	if (!av_bprint_is_complete(&buf)) {
174	av_bprint_finalize(&buf, NULL);
175	return AVERROR(ENOMEM);
176	}
177
178	if (buf.len) {
179	int ret;
180	sub_rect->type = SUBTITLE_ASS;
181	if ((ret = create_ass_text(ctx, buf.str, &sub_rect->ass)) < 0) {
182	av_bprint_finalize(&buf, NULL);
183	return ret;
184	}
185	av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
186	} else {
187	sub_rect->type = SUBTITLE_NONE;
188	}
189	av_bprint_finalize(&buf, NULL);
190	return 0;
191	}
192
193	static void fix_transparency(TeletextContext ctx, AVSubtitleRect sub_rect, vbi_page *page,
194	int chop_top, uint8_t transparent_color, int resx, int resy)
195	{
196	int iy;
197
198	// Hack for transparency, inspired by VLC code...
199	for (iy = 0; iy < resy; iy++) {
200	uint8_t pixel = sub_rect->pict.data[0] + iy sub_rect->pict.linesize[0];
201	vbi_char vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) page->columns;
202	vbi_char *vcnext = vc + page->columns;
203	for (; vc < vcnext; vc++) {
204	uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
205	switch (vc->opacity) {
206	case VBI_TRANSPARENT_SPACE:
207	memset(pixel, transparent_color, BITMAP_CHAR_WIDTH);
208	break;
209	case VBI_OPAQUE:
210	case VBI_SEMI_TRANSPARENT:
211	if (!ctx->transparent_bg)
212	break;
213	case VBI_TRANSPARENT_FULL:
214	for(; pixel < pixelnext; pixel++)
215	if (*pixel == vc->background)
216	*pixel = transparent_color;
217	break;
218	}
219	pixel = pixelnext;
220	}
221	}
222	}
223
224	/* Draw a page as bitmap */
225	static int gen_sub_bitmap(TeletextContext ctx, AVSubtitleRect sub_rect, vbi_page *page, int chop_top)
226	{
227	int resx = page->columns * BITMAP_CHAR_WIDTH;
228	int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
229	uint8_t ci, cmax = 0;
230	int ret;
231	vbi_char vc = page->text + (chop_top page->columns);
232	vbi_char vcend = page->text + (page->rows page->columns);
233
234	for (; vc < vcend; vc++) {
235	if (vc->opacity != VBI_TRANSPARENT_SPACE) {
236	cmax = VBI_NB_COLORS;
237	break;
238	}
239	}
240
241	if (cmax == 0) {
242	av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
243	sub_rect->type = SUBTITLE_NONE;
244	return 0;
245	}
246
247	if ((ret = avpicture_alloc(&sub_rect->pict, AV_PIX_FMT_PAL8, resx, resy)) < 0)
248	return ret;
249	// Yes, we want to allocate the palette on our own because AVSubtitle works this way
250	sub_rect->pict.data[1] = NULL;
251
252	vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
253	sub_rect->pict.data[0], sub_rect->pict.linesize[0],
254	0, chop_top, page->columns, page->rows - chop_top,
255	/reveal/ 1, /flash/ 1);
256
257	fix_transparency(ctx, sub_rect, page, chop_top, cmax, resx, resy);
258	sub_rect->x = ctx->x_offset;
259	sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
260	sub_rect->w = resx;
261	sub_rect->h = resy;
262	sub_rect->nb_colors = (int)cmax + 1;
263	sub_rect->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
264	if (!sub_rect->pict.data[1]) {
265	av_freep(&sub_rect->pict.data[0]);
266	return AVERROR(ENOMEM);
267	}
268	for (ci = 0; ci < cmax; ci++) {
269	int r, g, b, a;
270
271	r = VBI_R(page->color_map[ci]);
272	g = VBI_G(page->color_map[ci]);
273	b = VBI_B(page->color_map[ci]);
274	a = VBI_A(page->color_map[ci]);
275	((uint32_t *)sub_rect->pict.data[1])[ci] = RGBA(r, g, b, a);
276	av_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->pict.data[1])[ci]);
277	}
278	((uint32_t *)sub_rect->pict.data[1])[cmax] = RGBA(0, 0, 0, 0);
279	sub_rect->type = SUBTITLE_BITMAP;
280	return 0;
281	}
282
283	static void handler(vbi_event ev, void user_data)
284	{
285	TeletextContext *ctx = user_data;
286	TeletextPage *new_pages;
287	vbi_page page;
288	int res;
289	char pgno_str[12];
290	vbi_subno subno;
291	vbi_page_type vpt;
292	int chop_top;
293	char *lang;
294
295	snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
296	av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
297	pgno_str, ev->ev.ttx_page.subno & 0xFF);
298
299	if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
300	return;
301	if (ctx->handler_ret < 0)
302	return;
303
304	res = vbi_fetch_vt_page(ctx->vbi, &page,
305	ev->ev.ttx_page.pgno,
306	ev->ev.ttx_page.subno,
307	VBI_WST_LEVEL_3p5, 25, TRUE);
308
309	if (!res)
310	return;
311
312	#ifdef DEBUG
313	fprintf(stderr, "\nSaving res=%d dy0=%d dy1=%d...\n",
314	res, page.dirty.y0, page.dirty.y1);
315	fflush(stderr);
316
317	if (!vbi_export_stdio(ctx->ex, stderr, &page))
318	fprintf(stderr, "failed: %s\n", vbi_export_errstr(ctx->ex));
319	#endif
320
321	vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
322	chop_top = ctx->chop_top \|\|
323	((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));
324
325	av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
326	page.columns, page.rows, chop_top);
327
328	if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
329	if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
330	TeletextPage *cur_page = new_pages + ctx->nb_pages;
331	ctx->pages = new_pages;
332	cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
333	cur_page->pts = ctx->pts;
334	cur_page->pgno = ev->ev.ttx_page.pgno;
335	cur_page->subno = ev->ev.ttx_page.subno;
336	if (cur_page->sub_rect) {
337	res = (ctx->format_id == 0) ?
338	gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top) :
339	gen_sub_text (ctx, cur_page->sub_rect, &page, chop_top);
340	if (res < 0) {
341	av_freep(&cur_page->sub_rect);
342	ctx->handler_ret = res;
343	} else {
344	ctx->pages[ctx->nb_pages++] = *cur_page;
345	}
346	} else {
347	ctx->handler_ret = AVERROR(ENOMEM);
348	}
349	} else {
350	ctx->handler_ret = AVERROR(ENOMEM);
351	}
352	} else {
353	//TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
354	av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
355	ctx->handler_ret = AVERROR(ENOSYS);
356	}
357
358	vbi_unref_page(&page);
359	}
360
361	static inline int data_identifier_is_teletext(int data_identifier) {
362	/* See EN 301 775 section 4.4.2. */
363	return (data_identifier >= 0x10 && data_identifier <= 0x1F \|\|
364	data_identifier >= 0x99 && data_identifier <= 0x9B);
365	}
366
367	static int slice_to_vbi_lines(TeletextContext ctx, uint8_t buf, int size)
368	{
369	int lines = 0;
370	while (size >= 2 && lines < MAX_SLICES) {
371	int data_unit_id = buf[0];
372	int data_unit_length = buf[1];
373	if (data_unit_length + 2 > size)
374	return AVERROR_INVALIDDATA;
375	if (data_unit_id == 0x02 \|\| data_unit_id == 0x03) {
376	if (data_unit_length != 0x2c)
377	return AVERROR_INVALIDDATA;
378	else {
379	int line_offset = buf[2] & 0x1f;
380	int field_parity = buf[2] & 0x20;
381	int i;
382	ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
383	ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
384	for (i = 0; i < 42; i++)
385	ctx->sliced[lines].data[i] = vbi_rev8(buf[4 + i]);
386	lines++;
387	}
388	}
389	size -= data_unit_length + 2;
390	buf += data_unit_length + 2;
391	}
392	if (size)
393	av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
394	return lines;
395	}
396
397	static int teletext_decode_frame(AVCodecContext avctx, void data, int data_size, AVPacket pkt)
398	{
399	TeletextContext *ctx = avctx->priv_data;
400	AVSubtitle *sub = data;
401	int ret = 0;
402
403	if (!ctx->vbi) {
404	if (!(ctx->vbi = vbi_decoder_new()))
405	return AVERROR(ENOMEM);
406	if (!vbi_event_handler_add(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
407	vbi_decoder_delete(ctx->vbi);
408	ctx->vbi = NULL;
409	return AVERROR(ENOMEM);
410	}
411	}
412
413	if (avctx->pkt_timebase.den && pkt->pts != AV_NOPTS_VALUE)
414	ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);
415
416	if (pkt->size) {
417	int lines;
418	const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */
419
420	// We allow unreasonably big packets, even if the standard only allows a max size of 1472
421	if (full_pes_size < 184 \|\| full_pes_size > 65504 \|\| full_pes_size % 184 != 0)
422	return AVERROR_INVALIDDATA;
423
424	ctx->handler_ret = pkt->size;
425
426	if (data_identifier_is_teletext(*pkt->data)) {
427	if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
428	return lines;
429	av_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
430	ctx, pkt->size, lines, (double)pkt->pts/90000.0);
431	if (lines > 0) {
432	#ifdef DEBUG
433	int i;
434	av_log(avctx, AV_LOG_DEBUG, "line numbers:");
435	for(i = 0; i < lines; i++)
436	av_log(avctx, AV_LOG_DEBUG, " %d", ctx->sliced[i].line);
437	av_log(avctx, AV_LOG_DEBUG, "\n");
438	#endif
439	vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
440	ctx->lines_processed += lines;
441	}
442	}
443	ctx->pts = AV_NOPTS_VALUE;
444	ret = ctx->handler_ret;
445	}
446
447	if (ret < 0)
448	return ret;
449
450	// is there a subtitle to pass?
451	if (ctx->nb_pages) {
452	int i;
453	sub->format = ctx->format_id;
454	sub->start_display_time = 0;
455	sub->end_display_time = ctx->sub_duration;
456	sub->num_rects = 0;
457	sub->pts = ctx->pages->pts;
458
459	if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
460	sub->rects = av_malloc(sizeof(*sub->rects));
461	if (sub->rects) {
462	sub->num_rects = 1;
463	sub->rects[0] = ctx->pages->sub_rect;
464	} else {
465	ret = AVERROR(ENOMEM);
466	}
467	} else {
468	av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
469	sub->rects = NULL;
470	}
471	if (!sub->rects) // no rect was passed
472	subtitle_rect_free(&ctx->pages->sub_rect);
473
474	for (i = 0; i < ctx->nb_pages - 1; i++)
475	ctx->pages[i] = ctx->pages[i + 1];
476	ctx->nb_pages--;
477
478	if (ret >= 0)
479	*data_size = 1;
480	} else
481	*data_size = 0;
482
483	return ret;
484	}
485
486	static int teletext_init_decoder(AVCodecContext *avctx)
487	{
488	TeletextContext *ctx = avctx->priv_data;
489	unsigned int maj, min, rev;
490
491	vbi_version(&maj, &min, &rev);
492	if (!(maj > 0 \|\| min > 2 \|\| min == 2 && rev >= 26)) {
493	av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
494	return AVERROR_EXTERNAL;
495	}
496
497	if (ctx->format_id == 0) {
498	avctx->width = 41 * BITMAP_CHAR_WIDTH;
499	avctx->height = 25 * BITMAP_CHAR_HEIGHT;
500	}
501
502	ctx->vbi = NULL;
503	ctx->pts = AV_NOPTS_VALUE;
504
505	#ifdef DEBUG
506	{
507	char *t;
508	ctx->ex = vbi_export_new("text", &t);
509	}
510	#endif
511	av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
512	return (ctx->format_id == 1) ? ff_ass_subtitle_header_default(avctx) : 0;
513	}
514
515	static int teletext_close_decoder(AVCodecContext *avctx)
516	{
517	TeletextContext *ctx = avctx->priv_data;
518
519	av_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
520	while (ctx->nb_pages)
521	subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
522	av_freep(&ctx->pages);
523
524	vbi_decoder_delete(ctx->vbi);
525	ctx->vbi = NULL;
526	ctx->pts = AV_NOPTS_VALUE;
527	return 0;
528	}
529
530	static void teletext_flush(AVCodecContext *avctx)
531	{
532	teletext_close_decoder(avctx);
533	}
534
535	#define OFFSET(x) offsetof(TeletextContext, x)
536	#define SD AV_OPT_FLAG_SUBTITLE_PARAM \| AV_OPT_FLAG_DECODING_PARAM
537	static const AVOption options[] = {
538	{"txt_page", "list of teletext page numbers to decode, * is all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
539	{"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
540	{"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD, "txt_format"},
541	{"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
542	{"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
543	{"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
544	{"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
545	{"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
546	{"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = 30000}, 0, 86400000, SD},
547	{"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
548	{ NULL },
549	};
550
551	static const AVClass teletext_class = {
552	.class_name = "libzvbi_teletextdec",
553	.item_name = av_default_item_name,
554	.option = options,
555	.version = LIBAVUTIL_VERSION_INT,
556	};
557
558	AVCodec ff_libzvbi_teletext_decoder = {
559	.name = "libzvbi_teletextdec",
560	.long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
561	.type = AVMEDIA_TYPE_SUBTITLE,
562	.id = AV_CODEC_ID_DVB_TELETEXT,
563	.priv_data_size = sizeof(TeletextContext),
564	.init = teletext_init_decoder,
565	.close = teletext_close_decoder,
566	.decode = teletext_decode_frame,
567	.capabilities = CODEC_CAP_DELAY,
568	.flush = teletext_flush,
569	.priv_class= &teletext_class,
570	};