diff options
Diffstat (limited to 'libavcodec/libzvbi-teletextdec.c')
| -rw-r--r-- | libavcodec/libzvbi-teletextdec.c | 570 |
1 files changed, 570 insertions, 0 deletions
diff --git a/libavcodec/libzvbi-teletextdec.c b/libavcodec/libzvbi-teletextdec.c new file mode 100644 index 0000000000..e65e3fb55f --- /dev/null +++ b/libavcodec/libzvbi-teletextdec.c @@ -0,0 +1,570 @@ +/* + * 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, +}; |