| /* |
| * 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA |
| */ |
| |
| #include "avcodec.h" |
| #include "libavutil/opt.h" |
| #include "libavutil/intreadwrite.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) |
| |
| /* main data structure */ |
| typedef struct TeletextContext |
| { |
| AVClass *class; |
| char *pgno; |
| int x_offset; |
| int y_offset; |
| char *format; |
| int format_id; /* 0 = bitmap, 1 = text */ |
| int chop_top; |
| int sub_duration; /* in msec */ |
| int transparent_bg; |
| int chop_spaces; |
| |
| int lines_processed; |
| AVSubtitleRect *sub_rect; |
| |
| vbi_decoder * vbi; |
| vbi_dvb_demux * dx; |
| #ifdef DEBUG |
| vbi_export * ex; |
| #endif |
| /* Don't even _think_ about making sliced stack-local! */ |
| vbi_sliced sliced[64]; |
| } 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; |
| } |
| |
| // draw a page as text |
| static int |
| gen_sub_text(TeletextContext *ctx, vbi_page *page, int chop_top) |
| { |
| AVSubtitleRect *sub_rect = ctx->sub_rect; |
| char *text; |
| const char *in; |
| char *out; |
| 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; |
| out = text = av_malloc(TEXT_MAXSZ); |
| if (!text) { |
| av_free(vbi_text); |
| return AVERROR(ENOMEM); |
| } |
| 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); |
| memcpy(out, in, sz); |
| out += sz; |
| *out++ = '\n'; |
| in += nl; |
| } |
| } else { |
| strcpy(text, vbi_text); |
| out += sz; |
| *out++ = '\n'; |
| } |
| av_free(vbi_text); |
| *out = '\0'; |
| if (out > text) { |
| sub_rect->type = SUBTITLE_TEXT; |
| sub_rect->text = text; |
| av_log(ctx, AV_LOG_DEBUG, "subtext:%s:txetbus\n", text); |
| } else { |
| sub_rect->type = SUBTITLE_NONE; |
| av_free(text); |
| } |
| return 0; |
| } |
| |
| static void |
| fix_transparency(TeletextContext *ctx, vbi_page *page, int chop_top, uint8_t transparent_color, int resx, int resy) |
| { |
| AVSubtitleRect *sub_rect = ctx->sub_rect; |
| 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 / 10 + chop_top) * page->columns; |
| vbi_char *vcnext = vc + page->columns; |
| for (; vc < vcnext; vc++) { |
| uint8_t *pixelnext = pixel + 12; |
| switch (vc->opacity) { |
| case VBI_TRANSPARENT_SPACE: |
| memset(pixel, transparent_color, 12); |
| 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, vbi_page *page, int chop_top) |
| { |
| AVSubtitleRect *sub_rect = ctx->sub_rect; |
| int resx = page->columns * 12; |
| int resy = (page->rows - chop_top) * 10; |
| 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, page, chop_top, cmax, resx, resy); |
| sub_rect->x = ctx->x_offset; |
| sub_rect->y = ctx->y_offset; |
| 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); |
| #ifdef DEBUG |
| av_log(ctx, AV_LOG_DEBUG, "palette %0x\n", |
| ((uint32_t *)sub_rect->pict.data[1])[ci]); |
| #endif |
| } |
| ((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; |
| 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; |
| |
| /* Fetch the page. */ |
| 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->sub_rect) { |
| ctx->sub_rect = av_mallocz(sizeof(*ctx->sub_rect)); |
| if (ctx->sub_rect) { |
| res = (ctx->format_id == 0) ? |
| gen_sub_bitmap(ctx, &page, chop_top) : |
| gen_sub_text (ctx, &page, chop_top); |
| if (res) |
| av_freep(&ctx->sub_rect); |
| } |
| } else { |
| // FIXME: Multiple teletext pages in a single packet, some kind of buffering should be done instead of dropping the page... |
| av_log(ctx, AV_LOG_WARNING, "Missed page %s.%02x.\n", pgno_str, ev->ev.ttx_page.subno & 0xFF); |
| } |
| |
| vbi_unref_page(&page); |
| } |
| |
| static int |
| teletext_decode_frame(AVCodecContext *avctx, |
| void *data, int *data_size, |
| AVPacket *pkt) |
| { |
| TeletextContext *ctx = avctx->priv_data; |
| AVSubtitle *sub = data; |
| const uint8_t *buf = pkt->data; |
| unsigned int left = pkt->size; |
| uint8_t pesheader[45] = {0x00, 0x00, 0x01, 0xbd, 0x00, 0x00, 0x85, 0x80, 0x24, 0x21, 0x00, 0x01, 0x00, 0x01}; |
| int pesheader_size = sizeof(pesheader); |
| const uint8_t *pesheader_buf = pesheader; |
| |
| 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 (!ctx->dx && (!(ctx->dx = vbi_dvb_pes_demux_new (/* callback */ NULL, NULL)))) |
| return AVERROR(ENOMEM); |
| |
| // We allow unreasonably big packets, even if the standard only allows a max size of 1472 |
| if ((pesheader_size + left) < 184 || (pesheader_size + left) > 65504 || (pesheader_size + left) % 184 != 0) |
| return AVERROR_INVALIDDATA; |
| |
| memset(pesheader + 14, 0xff, pesheader_size - 14); |
| AV_WB16(pesheader + 4, left + pesheader_size - 6); |
| |
| /* PTS is deliberately left as 0 in the PES header, otherwise libzvbi uses |
| * it to detect dropped frames. Unforunatey the guessed packet PTS values |
| * (see mpegts demuxer) are not accurate enough to pass that test. */ |
| vbi_dvb_demux_cor(ctx->dx, ctx->sliced, 64, NULL, &pesheader_buf, &pesheader_size); |
| |
| while (left > 0) { |
| int64_t pts = 0; |
| unsigned int lines = vbi_dvb_demux_cor(ctx->dx, ctx->sliced, 64, &pts, &buf, &left); |
| #ifdef DEBUG |
| av_log(avctx, AV_LOG_DEBUG, |
| "ctx=%p buf_size=%d left=%u lines=%u pts=%f pkt_pts=%f\n", |
| ctx, pkt->size, left, lines, (double)pts/90000.0, (double)pkt->pts/90000.0); |
| #endif |
| if (lines > 0) { |
| #ifdef DEBUGx |
| int i; |
| for(i=0; i<lines; ++i) |
| av_log(avctx, AV_LOG_DEBUG, |
| "lines=%d id=%x\n", i, ctx->sliced[i].id); |
| #endif |
| vbi_decode(ctx->vbi, ctx->sliced, lines, (double)pts/90000.0); |
| ctx->lines_processed += lines; |
| } |
| } |
| |
| // is there a subtitle to pass? |
| if (ctx->sub_rect) { |
| sub->format = (ctx->sub_rect->type == SUBTITLE_TEXT ? 1: 0); |
| sub->start_display_time = 0; |
| sub->end_display_time = ctx->sub_duration; |
| sub->num_rects = 0; |
| |
| if (ctx->sub_rect->type != SUBTITLE_NONE) { |
| sub->rects = av_malloc(sizeof(*sub->rects) * 1); |
| if (sub->rects) { |
| sub->num_rects = 1; |
| sub->rects[0] = ctx->sub_rect; |
| } |
| } else { |
| av_log(avctx, AV_LOG_DEBUG, "sending empty sub\n"); |
| sub->rects = NULL; |
| } |
| if (!sub->rects) // no rect was passed |
| av_free(ctx->sub_rect); |
| ctx->sub_rect = NULL; |
| |
| *data_size = 1; |
| } else |
| *data_size = 0; |
| |
| return pkt->size; |
| } |
| |
| 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; |
| } |
| |
| ctx->dx = NULL; |
| ctx->vbi = NULL; |
| ctx->sub_rect = NULL; |
| if (!strcmp(ctx->format, "bitmap")) { |
| ctx->format_id = 0; |
| } else if (!strcmp(ctx->format, "text")) { |
| ctx->format_id = 1; |
| } else { |
| av_log(avctx, AV_LOG_ERROR, "unkown format %s\n", ctx->format); |
| return AVERROR_OPTION_NOT_FOUND; |
| } |
| |
| #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 0; |
| } |
| |
| static int teletext_close_decoder(AVCodecContext *avctx) |
| { |
| TeletextContext *ctx = avctx->priv_data; |
| |
| #ifdef DEBUG |
| av_log(avctx, AV_LOG_DEBUG, "lines_total=%u\n", ctx->lines_processed); |
| #endif |
| |
| vbi_dvb_demux_delete(ctx->dx); |
| vbi_decoder_delete(ctx->vbi); |
| ctx->dx = NULL; |
| ctx->vbi = NULL; |
| 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), AV_OPT_TYPE_STRING, {.str = "bitmap"}, 0, 0, SD}, |
| {"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 = CODEC_ID_DVB_TELETEXT, |
| .priv_data_size = sizeof(TeletextContext), |
| .init = teletext_init_decoder, |
| .close = teletext_close_decoder, |
| .decode = teletext_decode_frame, |
| .flush = teletext_flush, |
| .priv_class= &teletext_class, |
| }; |
