[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);
    av_bprintf(&buf, "\r\n");

    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);
f6fa7814	104	av_bprintf(&buf, "\r\n");
2ba45a60 DM	105
	106	if (!av_bprint_is_complete(&buf)) {
	107	av_bprint_finalize(&buf, NULL);
	108	return AVERROR(ENOMEM);
	109	}
	110
	111	/* Then we create the ass dialog line in buf2 from the escaped text in buf. */
	112	av_bprint_init(&buf2, 0, AV_BPRINT_SIZE_UNLIMITED);
	113	ff_ass_bprint_dialog(&buf2, buf.str, ts_start, ts_duration, 0);
	114	av_bprint_finalize(&buf, NULL);
	115
	116	if (!av_bprint_is_complete(&buf2)) {
	117	av_bprint_finalize(&buf2, NULL);
	118	return AVERROR(ENOMEM);
	119	}
	120
	121	if ((ret = av_bprint_finalize(&buf2, ass)) < 0)
	122	return ret;
	123
	124	return 0;
	125	}
	126
	127	/* Draw a page as text */
	128	static int gen_sub_text(TeletextContext ctx, AVSubtitleRect sub_rect, vbi_page *page, int chop_top)
	129	{
	130	const char *in;
	131	AVBPrint buf;
	132	char *vbi_text = av_malloc(TEXT_MAXSZ);
	133	int sz;
	134
	135	if (!vbi_text)
	136	return AVERROR(ENOMEM);
	137
	138	sz = vbi_print_page_region(page, vbi_text, TEXT_MAXSZ-1, "UTF-8",
	139	/table mode/ TRUE, FALSE,
	140	0, chop_top,
	141	page->columns, page->rows-chop_top);
	142	if (sz <= 0) {
	143	av_log(ctx, AV_LOG_ERROR, "vbi_print error\n");
	144	av_free(vbi_text);
	145	return AVERROR_EXTERNAL;
	146	}
	147	vbi_text[sz] = '\0';
	148	in = vbi_text;
	149	av_bprint_init(&buf, 0, TEXT_MAXSZ);
	150
	151	if (ctx->chop_spaces) {
	152	for (;;) {
	153	int nl, sz;
	154
	155	// skip leading spaces and newlines
	156	in += strspn(in, " \n");
	157	// compute end of row
	158	for (nl = 0; in[nl]; ++nl)
	159	if (in[nl] == '\n' && (nl==0 \|\| !(in[nl-1] & 0x80)))
	160	break;
	161	if (!in[nl])
	162	break;
	163	// skip trailing spaces
	164	sz = chop_spaces_utf8(in, nl);
	165	av_bprint_append_data(&buf, in, sz);
	166	av_bprintf(&buf, "\n");
	167	in += nl;
	168	}
169	} else {
170	av_bprintf(&buf, "%s\n", vbi_text);
171	}
172	av_free(vbi_text);
173
174	if (!av_bprint_is_complete(&buf)) {
175	av_bprint_finalize(&buf, NULL);
176	return AVERROR(ENOMEM);
177	}
178
179	if (buf.len) {
180	int ret;
181	sub_rect->type = SUBTITLE_ASS;
182	if ((ret = create_ass_text(ctx, buf.str, &sub_rect->ass)) < 0) {
183	av_bprint_finalize(&buf, NULL);
184	return ret;
185	}
186	av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", sub_rect->ass);
187	} else {
188	sub_rect->type = SUBTITLE_NONE;
189	}
190	av_bprint_finalize(&buf, NULL);
191	return 0;
192	}
193
194	static void fix_transparency(TeletextContext ctx, AVSubtitleRect sub_rect, vbi_page *page,
195	int chop_top, uint8_t transparent_color, int resx, int resy)
196	{
197	int iy;
198
199	// Hack for transparency, inspired by VLC code...
200	for (iy = 0; iy < resy; iy++) {
201	uint8_t pixel = sub_rect->pict.data[0] + iy sub_rect->pict.linesize[0];
202	vbi_char vc = page->text + (iy / BITMAP_CHAR_HEIGHT + chop_top) page->columns;
203	vbi_char *vcnext = vc + page->columns;
204	for (; vc < vcnext; vc++) {
205	uint8_t *pixelnext = pixel + BITMAP_CHAR_WIDTH;
206	switch (vc->opacity) {
207	case VBI_TRANSPARENT_SPACE:
208	memset(pixel, transparent_color, BITMAP_CHAR_WIDTH);
209	break;
210	case VBI_OPAQUE:
211	case VBI_SEMI_TRANSPARENT:
212	if (!ctx->transparent_bg)
213	break;
214	case VBI_TRANSPARENT_FULL:
215	for(; pixel < pixelnext; pixel++)
216	if (*pixel == vc->background)
217	*pixel = transparent_color;
218	break;
219	}
220	pixel = pixelnext;
221	}
222	}
223	}
224
225	/* Draw a page as bitmap */
226	static int gen_sub_bitmap(TeletextContext ctx, AVSubtitleRect sub_rect, vbi_page *page, int chop_top)
227	{
228	int resx = page->columns * BITMAP_CHAR_WIDTH;
229	int resy = (page->rows - chop_top) * BITMAP_CHAR_HEIGHT;
230	uint8_t ci, cmax = 0;
231	int ret;
232	vbi_char vc = page->text + (chop_top page->columns);
233	vbi_char vcend = page->text + (page->rows page->columns);
234
235	for (; vc < vcend; vc++) {
236	if (vc->opacity != VBI_TRANSPARENT_SPACE) {
237	cmax = VBI_NB_COLORS;
238	break;
239	}
240	}
241
242	if (cmax == 0) {
243	av_log(ctx, AV_LOG_DEBUG, "dropping empty page %3x\n", page->pgno);
244	sub_rect->type = SUBTITLE_NONE;
245	return 0;
246	}
247
248	if ((ret = avpicture_alloc(&sub_rect->pict, AV_PIX_FMT_PAL8, resx, resy)) < 0)
249	return ret;
250	// Yes, we want to allocate the palette on our own because AVSubtitle works this way
251	sub_rect->pict.data[1] = NULL;
252
253	vbi_draw_vt_page_region(page, VBI_PIXFMT_PAL8,
254	sub_rect->pict.data[0], sub_rect->pict.linesize[0],
255	0, chop_top, page->columns, page->rows - chop_top,
256	/reveal/ 1, /flash/ 1);
257
258	fix_transparency(ctx, sub_rect, page, chop_top, cmax, resx, resy);
259	sub_rect->x = ctx->x_offset;
260	sub_rect->y = ctx->y_offset + chop_top * BITMAP_CHAR_HEIGHT;
261	sub_rect->w = resx;
262	sub_rect->h = resy;
263	sub_rect->nb_colors = (int)cmax + 1;
264	sub_rect->pict.data[1] = av_mallocz(AVPALETTE_SIZE);
265	if (!sub_rect->pict.data[1]) {
266	av_freep(&sub_rect->pict.data[0]);
267	return AVERROR(ENOMEM);
268	}
269	for (ci = 0; ci < cmax; ci++) {
270	int r, g, b, a;
271
272	r = VBI_R(page->color_map[ci]);
273	g = VBI_G(page->color_map[ci]);
274	b = VBI_B(page->color_map[ci]);
275	a = VBI_A(page->color_map[ci]);
276	((uint32_t *)sub_rect->pict.data[1])[ci] = RGBA(r, g, b, a);
277	av_dlog(ctx, "palette %0x\n", ((uint32_t *)sub_rect->pict.data[1])[ci]);
278	}
279	((uint32_t *)sub_rect->pict.data[1])[cmax] = RGBA(0, 0, 0, 0);
280	sub_rect->type = SUBTITLE_BITMAP;
281	return 0;
282	}
283
284	static void handler(vbi_event ev, void user_data)
285	{
286	TeletextContext *ctx = user_data;
287	TeletextPage *new_pages;
288	vbi_page page;
289	int res;
290	char pgno_str[12];
291	vbi_subno subno;
292	vbi_page_type vpt;
293	int chop_top;
294	char *lang;
295
296	snprintf(pgno_str, sizeof pgno_str, "%03x", ev->ev.ttx_page.pgno);
297	av_log(ctx, AV_LOG_DEBUG, "decoded page %s.%02x\n",
298	pgno_str, ev->ev.ttx_page.subno & 0xFF);
299
300	if (strcmp(ctx->pgno, "*") && !strstr(ctx->pgno, pgno_str))
301	return;
302	if (ctx->handler_ret < 0)
303	return;
304
305	res = vbi_fetch_vt_page(ctx->vbi, &page,
306	ev->ev.ttx_page.pgno,
307	ev->ev.ttx_page.subno,
308	VBI_WST_LEVEL_3p5, 25, TRUE);
309
310	if (!res)
311	return;
312
313	#ifdef DEBUG
314	fprintf(stderr, "\nSaving res=%d dy0=%d dy1=%d...\n",
315	res, page.dirty.y0, page.dirty.y1);
316	fflush(stderr);
317
318	if (!vbi_export_stdio(ctx->ex, stderr, &page))
319	fprintf(stderr, "failed: %s\n", vbi_export_errstr(ctx->ex));
320	#endif
321
322	vpt = vbi_classify_page(ctx->vbi, ev->ev.ttx_page.pgno, &subno, &lang);
323	chop_top = ctx->chop_top \|\|
324	((page.rows > 1) && (vpt == VBI_SUBTITLE_PAGE));
325
326	av_log(ctx, AV_LOG_DEBUG, "%d x %d page chop:%d\n",
327	page.columns, page.rows, chop_top);
328
329	if (ctx->nb_pages < MAX_BUFFERED_PAGES) {
330	if ((new_pages = av_realloc_array(ctx->pages, ctx->nb_pages + 1, sizeof(TeletextPage)))) {
331	TeletextPage *cur_page = new_pages + ctx->nb_pages;
332	ctx->pages = new_pages;
333	cur_page->sub_rect = av_mallocz(sizeof(*cur_page->sub_rect));
334	cur_page->pts = ctx->pts;
335	cur_page->pgno = ev->ev.ttx_page.pgno;
336	cur_page->subno = ev->ev.ttx_page.subno;
337	if (cur_page->sub_rect) {
338	res = (ctx->format_id == 0) ?
339	gen_sub_bitmap(ctx, cur_page->sub_rect, &page, chop_top) :
340	gen_sub_text (ctx, cur_page->sub_rect, &page, chop_top);
341	if (res < 0) {
342	av_freep(&cur_page->sub_rect);
343	ctx->handler_ret = res;
344	} else {
345	ctx->pages[ctx->nb_pages++] = *cur_page;
346	}
347	} else {
348	ctx->handler_ret = AVERROR(ENOMEM);
349	}
350	} else {
351	ctx->handler_ret = AVERROR(ENOMEM);
352	}
353	} else {
354	//TODO: If multiple packets contain more than one page, pages may got queued up, and this may happen...
355	av_log(ctx, AV_LOG_ERROR, "Buffered too many pages, dropping page %s.\n", pgno_str);
356	ctx->handler_ret = AVERROR(ENOSYS);
357	}
358
359	vbi_unref_page(&page);
360	}
361
362	static inline int data_identifier_is_teletext(int data_identifier) {
363	/* See EN 301 775 section 4.4.2. */
364	return (data_identifier >= 0x10 && data_identifier <= 0x1F \|\|
365	data_identifier >= 0x99 && data_identifier <= 0x9B);
366	}
367
368	static int slice_to_vbi_lines(TeletextContext ctx, uint8_t buf, int size)
369	{
370	int lines = 0;
371	while (size >= 2 && lines < MAX_SLICES) {
372	int data_unit_id = buf[0];
373	int data_unit_length = buf[1];
374	if (data_unit_length + 2 > size)
375	return AVERROR_INVALIDDATA;
376	if (data_unit_id == 0x02 \|\| data_unit_id == 0x03) {
377	if (data_unit_length != 0x2c)
378	return AVERROR_INVALIDDATA;
379	else {
380	int line_offset = buf[2] & 0x1f;
381	int field_parity = buf[2] & 0x20;
382	int i;
383	ctx->sliced[lines].id = VBI_SLICED_TELETEXT_B;
384	ctx->sliced[lines].line = (line_offset > 0 ? (line_offset + (field_parity ? 0 : 313)) : 0);
385	for (i = 0; i < 42; i++)
386	ctx->sliced[lines].data[i] = vbi_rev8(buf[4 + i]);
387	lines++;
388	}
389	}
390	size -= data_unit_length + 2;
391	buf += data_unit_length + 2;
392	}
393	if (size)
394	av_log(ctx, AV_LOG_WARNING, "%d bytes remained after slicing data\n", size);
395	return lines;
396	}
397
398	static int teletext_decode_frame(AVCodecContext avctx, void data, int data_size, AVPacket pkt)
399	{
400	TeletextContext *ctx = avctx->priv_data;
401	AVSubtitle *sub = data;
402	int ret = 0;
403
404	if (!ctx->vbi) {
405	if (!(ctx->vbi = vbi_decoder_new()))
406	return AVERROR(ENOMEM);
407	if (!vbi_event_handler_add(ctx->vbi, VBI_EVENT_TTX_PAGE, handler, ctx)) {
408	vbi_decoder_delete(ctx->vbi);
409	ctx->vbi = NULL;
410	return AVERROR(ENOMEM);
411	}
412	}
413
414	if (avctx->pkt_timebase.den && pkt->pts != AV_NOPTS_VALUE)
415	ctx->pts = av_rescale_q(pkt->pts, avctx->pkt_timebase, AV_TIME_BASE_Q);
416
417	if (pkt->size) {
418	int lines;
419	const int full_pes_size = pkt->size + 45; /* PES header is 45 bytes */
420
421	// We allow unreasonably big packets, even if the standard only allows a max size of 1472
422	if (full_pes_size < 184 \|\| full_pes_size > 65504 \|\| full_pes_size % 184 != 0)
423	return AVERROR_INVALIDDATA;
424
425	ctx->handler_ret = pkt->size;
426
427	if (data_identifier_is_teletext(*pkt->data)) {
428	if ((lines = slice_to_vbi_lines(ctx, pkt->data + 1, pkt->size - 1)) < 0)
429	return lines;
430	av_dlog(avctx, "ctx=%p buf_size=%d lines=%u pkt_pts=%7.3f\n",
431	ctx, pkt->size, lines, (double)pkt->pts/90000.0);
432	if (lines > 0) {
433	#ifdef DEBUG
434	int i;
435	av_log(avctx, AV_LOG_DEBUG, "line numbers:");
436	for(i = 0; i < lines; i++)
437	av_log(avctx, AV_LOG_DEBUG, " %d", ctx->sliced[i].line);
438	av_log(avctx, AV_LOG_DEBUG, "\n");
439	#endif
440	vbi_decode(ctx->vbi, ctx->sliced, lines, 0.0);
441	ctx->lines_processed += lines;
442	}
443	}
444	ctx->pts = AV_NOPTS_VALUE;
445	ret = ctx->handler_ret;
446	}
447
448	if (ret < 0)
449	return ret;
450
451	// is there a subtitle to pass?
452	if (ctx->nb_pages) {
453	int i;
454	sub->format = ctx->format_id;
455	sub->start_display_time = 0;
456	sub->end_display_time = ctx->sub_duration;
457	sub->num_rects = 0;
458	sub->pts = ctx->pages->pts;
459
460	if (ctx->pages->sub_rect->type != SUBTITLE_NONE) {
461	sub->rects = av_malloc(sizeof(*sub->rects));
462	if (sub->rects) {
463	sub->num_rects = 1;
464	sub->rects[0] = ctx->pages->sub_rect;
465	} else {
466	ret = AVERROR(ENOMEM);
467	}
468	} else {
469	av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n");
470	sub->rects = NULL;
471	}
472	if (!sub->rects) // no rect was passed
473	subtitle_rect_free(&ctx->pages->sub_rect);
474
475	for (i = 0; i < ctx->nb_pages - 1; i++)
476	ctx->pages[i] = ctx->pages[i + 1];
477	ctx->nb_pages--;
478
479	if (ret >= 0)
480	*data_size = 1;
481	} else
482	*data_size = 0;
483
484	return ret;
485	}
486
487	static int teletext_init_decoder(AVCodecContext *avctx)
488	{
489	TeletextContext *ctx = avctx->priv_data;
490	unsigned int maj, min, rev;
491
492	vbi_version(&maj, &min, &rev);
493	if (!(maj > 0 \|\| min > 2 \|\| min == 2 && rev >= 26)) {
494	av_log(avctx, AV_LOG_ERROR, "decoder needs zvbi version >= 0.2.26.\n");
495	return AVERROR_EXTERNAL;
496	}
497
498	if (ctx->format_id == 0) {
499	avctx->width = 41 * BITMAP_CHAR_WIDTH;
500	avctx->height = 25 * BITMAP_CHAR_HEIGHT;
501	}
502
503	ctx->vbi = NULL;
504	ctx->pts = AV_NOPTS_VALUE;
505
506	#ifdef DEBUG
507	{
508	char *t;
509	ctx->ex = vbi_export_new("text", &t);
510	}
511	#endif
512	av_log(avctx, AV_LOG_VERBOSE, "page filter: %s\n", ctx->pgno);
513	return (ctx->format_id == 1) ? ff_ass_subtitle_header_default(avctx) : 0;
514	}
515
516	static int teletext_close_decoder(AVCodecContext *avctx)
517	{
518	TeletextContext *ctx = avctx->priv_data;
519
520	av_dlog(avctx, "lines_total=%u\n", ctx->lines_processed);
521	while (ctx->nb_pages)
522	subtitle_rect_free(&ctx->pages[--ctx->nb_pages].sub_rect);
523	av_freep(&ctx->pages);
524
525	vbi_decoder_delete(ctx->vbi);
526	ctx->vbi = NULL;
527	ctx->pts = AV_NOPTS_VALUE;
528	return 0;
529	}
530
531	static void teletext_flush(AVCodecContext *avctx)
532	{
533	teletext_close_decoder(avctx);
534	}
535
536	#define OFFSET(x) offsetof(TeletextContext, x)
537	#define SD AV_OPT_FLAG_SUBTITLE_PARAM \| AV_OPT_FLAG_DECODING_PARAM
538	static const AVOption options[] = {
539	{"txt_page", "list of teletext page numbers to decode, * is all", OFFSET(pgno), AV_OPT_TYPE_STRING, {.str = "*"}, 0, 0, SD},
540	{"txt_chop_top", "discards the top teletext line", OFFSET(chop_top), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
541	{"txt_format", "format of the subtitles (bitmap or text)", OFFSET(format_id), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD, "txt_format"},
542	{"bitmap", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 0}, 0, 0, SD, "txt_format"},
543	{"text", NULL, 0, AV_OPT_TYPE_CONST, {.i64 = 1}, 0, 0, SD, "txt_format"},
544	{"txt_left", "x offset of generated bitmaps", OFFSET(x_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
545	{"txt_top", "y offset of generated bitmaps", OFFSET(y_offset), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 65535, SD},
546	{"txt_chop_spaces", "chops leading and trailing spaces from text", OFFSET(chop_spaces), AV_OPT_TYPE_INT, {.i64 = 1}, 0, 1, SD},
547	{"txt_duration", "display duration of teletext pages in msecs", OFFSET(sub_duration), AV_OPT_TYPE_INT, {.i64 = 30000}, 0, 86400000, SD},
548	{"txt_transparent", "force transparent background of the teletext", OFFSET(transparent_bg), AV_OPT_TYPE_INT, {.i64 = 0}, 0, 1, SD},
549	{ NULL },
550	};
551
552	static const AVClass teletext_class = {
553	.class_name = "libzvbi_teletextdec",
554	.item_name = av_default_item_name,
555	.option = options,
556	.version = LIBAVUTIL_VERSION_INT,
557	};
558
559	AVCodec ff_libzvbi_teletext_decoder = {
560	.name = "libzvbi_teletextdec",
561	.long_name = NULL_IF_CONFIG_SMALL("Libzvbi DVB teletext decoder"),
562	.type = AVMEDIA_TYPE_SUBTITLE,
563	.id = AV_CODEC_ID_DVB_TELETEXT,
564	.priv_data_size = sizeof(TeletextContext),
565	.init = teletext_init_decoder,
566	.close = teletext_close_decoder,
567	.decode = teletext_decode_frame,
568	.capabilities = CODEC_CAP_DELAY,
569	.flush = teletext_flush,
570	.priv_class= &teletext_class,
571	};