mirror of https://github.com/FFmpeg/FFmpeg.git
Nicolas George
13 years ago
parent
18eb31963b
commit
160013736e
8 changed files with 446 additions and 1 deletions
@ -0,0 +1,365 @@ |
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/*
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* TED Talks captions format decoder |
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* Copyright (c) 2012 Nicolas George |
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* |
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* This file is part of FFmpeg. |
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* |
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* FFmpeg is free software; you can redistribute it and/or |
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* modify it under the terms of the GNU Lesser General Public |
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* License as published by the Free Software Foundation; either |
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* version 2.1 of the License, or (at your option) any later version. |
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* |
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* FFmpeg is distributed in the hope that it will be useful, |
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* but WITHOUT ANY WARRANTY; without even the implied warranty of |
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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* Lesser General Public License for more details. |
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* |
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* You should have received a copy of the GNU Lesser General Public |
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* License along with FFmpeg; if not, write to the Free Software |
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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*/ |
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#include "libavutil/bprint.h" |
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#include "libavutil/log.h" |
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#include "libavutil/opt.h" |
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#include "avformat.h" |
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#include "internal.h" |
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#include "subtitles.h" |
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typedef struct { |
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AVClass *class; |
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int64_t start_time; |
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FFDemuxSubtitlesQueue subs; |
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} TEDCaptionsDemuxer; |
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static const AVOption tedcaptions_options[] = { |
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{ "start_time", "set the start time (offset) of the subtitles, in ms", |
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offsetof(TEDCaptionsDemuxer, start_time), FF_OPT_TYPE_INT64, |
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{ .i64 = 15000 }, INT64_MIN, INT64_MAX, |
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AV_OPT_FLAG_SUBTITLE_PARAM | AV_OPT_FLAG_DECODING_PARAM }, |
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{ NULL }, |
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}; |
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static const AVClass tedcaptions_demuxer_class = { |
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.class_name = "tedcaptions_demuxer", |
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.item_name = av_default_item_name, |
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.option = tedcaptions_options, |
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.version = LIBAVUTIL_VERSION_INT, |
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}; |
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#define BETWEEN(a, amin, amax) ((unsigned)((a) - (amin)) <= (amax) - (amin)) |
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#define HEX_DIGIT_TEST(c) (BETWEEN(c, '0', '9') || BETWEEN((c) | 32, 'a', 'z')) |
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#define HEX_DIGIT_VAL(c) ((c) <= '9' ? (c) - '0' : ((c) | 32) - 'a' + 10) |
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#define ERR_CODE(c) (c < 0 ? c : AVERROR_INVALIDDATA) |
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static void av_bprint_utf8(AVBPrint *bp, unsigned c) |
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{ |
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int bytes, i; |
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if (c <= 0x7F) { |
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av_bprint_chars(bp, c, 1); |
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return; |
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} |
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bytes = (av_log2(c) - 2) / 5; |
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av_bprint_chars(bp, (c >> (bytes * 6)) | ((0xFF80 >> bytes) & 0xFF), 1); |
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for (i = bytes - 1; i >= 0; i--) |
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av_bprint_chars(bp, ((c >> (i * 6)) & 0x3F) | 0x80, 1); |
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} |
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static void next_byte(AVIOContext *pb, int *cur_byte) |
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{ |
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uint8_t b; |
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int ret = avio_read(pb, &b, 1); |
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*cur_byte = ret > 0 ? b : ret == 0 ? AVERROR_EOF : ret; |
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} |
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static void skip_spaces(AVIOContext *pb, int *cur_byte) |
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{ |
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while (*cur_byte == ' ' || *cur_byte == '\t' || |
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*cur_byte == '\n' || *cur_byte == '\r') |
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next_byte(pb, cur_byte); |
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} |
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static int expect_byte(AVIOContext *pb, int *cur_byte, uint8_t c) |
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{ |
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skip_spaces(pb, cur_byte); |
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if (*cur_byte != c) |
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return ERR_CODE(*cur_byte); |
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next_byte(pb, cur_byte); |
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return 0; |
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} |
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static int parse_string(AVIOContext *pb, int *cur_byte, AVBPrint *bp, int full) |
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{ |
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int ret; |
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av_bprint_init(bp, 0, full ? -1 : 1); |
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ret = expect_byte(pb, cur_byte, '"'); |
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if (ret < 0) |
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goto fail; |
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while (*cur_byte > 0 && *cur_byte != '"') { |
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if (*cur_byte == '\\') { |
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next_byte(pb, cur_byte); |
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if (*cur_byte < 0) { |
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ret = AVERROR_INVALIDDATA; |
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goto fail; |
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} |
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if ((*cur_byte | 32) == 'u') { |
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unsigned chr = 0, i; |
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for (i = 0; i < 4; i++) { |
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next_byte(pb, cur_byte); |
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if (!HEX_DIGIT_TEST(*cur_byte)) { |
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ret = ERR_CODE(*cur_byte); |
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goto fail; |
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} |
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chr = chr * 16 + HEX_DIGIT_VAL(*cur_byte); |
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} |
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av_bprint_utf8(bp, chr); |
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} else { |
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av_bprint_chars(bp, *cur_byte, 1); |
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} |
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} else { |
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av_bprint_chars(bp, *cur_byte, 1); |
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} |
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next_byte(pb, cur_byte); |
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} |
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ret = expect_byte(pb, cur_byte, '"'); |
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if (ret < 0) |
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goto fail; |
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if (full && !av_bprint_is_complete(bp)) { |
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ret = AVERROR(ENOMEM); |
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goto fail; |
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} |
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return 0; |
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fail: |
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av_bprint_finalize(bp, NULL); |
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return ret; |
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} |
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static int parse_label(AVIOContext *pb, int *cur_byte, AVBPrint *bp) |
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{ |
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int ret; |
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ret = parse_string(pb, cur_byte, bp, 0); |
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if (ret < 0) |
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return ret; |
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ret = expect_byte(pb, cur_byte, ':'); |
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if (ret < 0) |
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return ret; |
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return 0; |
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} |
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static int parse_boolean(AVIOContext *pb, int *cur_byte, int *result) |
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{ |
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const char *text[] = { "false", "true" }, *p; |
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int i; |
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skip_spaces(pb, cur_byte); |
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for (i = 0; i < 2; i++) { |
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p = text[i]; |
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if (*cur_byte != *p) |
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continue; |
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for (; *p; p++, next_byte(pb, cur_byte)) |
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if (*cur_byte != *p) |
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return AVERROR_INVALIDDATA; |
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if (BETWEEN(*cur_byte | 32, 'a', 'z')) |
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return AVERROR_INVALIDDATA; |
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*result = i; |
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return 0; |
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} |
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return AVERROR_INVALIDDATA; |
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} |
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static int parse_int(AVIOContext *pb, int *cur_byte, int64_t *result) |
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{ |
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int64_t val = 0; |
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skip_spaces(pb, cur_byte); |
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if ((unsigned)*cur_byte - '0' > 9) |
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return AVERROR_INVALIDDATA; |
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while (BETWEEN(*cur_byte, '0', '9')) { |
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val = val * 10 + (*cur_byte - '0'); |
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next_byte(pb, cur_byte); |
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} |
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*result = val; |
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return 0; |
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} |
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static int parse_file(AVIOContext *pb, FFDemuxSubtitlesQueue *subs) |
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{ |
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int ret, cur_byte, start_of_par; |
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AVBPrint label, content; |
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int64_t pos, start, duration; |
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AVPacket *pkt; |
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next_byte(pb, &cur_byte); |
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ret = expect_byte(pb, &cur_byte, '{'); |
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if (ret < 0) |
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return AVERROR_INVALIDDATA; |
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ret = parse_label(pb, &cur_byte, &label); |
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if (ret < 0 || strcmp(label.str, "captions")) |
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return AVERROR_INVALIDDATA; |
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ret = expect_byte(pb, &cur_byte, '['); |
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if (ret < 0) |
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return AVERROR_INVALIDDATA; |
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while (1) { |
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content.size = 0; |
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start = duration = AV_NOPTS_VALUE; |
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ret = expect_byte(pb, &cur_byte, '{'); |
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if (ret < 0) |
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return ret; |
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pos = avio_tell(pb) - 1; |
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while (1) { |
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ret = parse_label(pb, &cur_byte, &label); |
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if (ret < 0) |
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return ret; |
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if (!strcmp(label.str, "startOfParagraph")) { |
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ret = parse_boolean(pb, &cur_byte, &start_of_par); |
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if (ret < 0) |
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return ret; |
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} else if (!strcmp(label.str, "content")) { |
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ret = parse_string(pb, &cur_byte, &content, 1); |
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if (ret < 0) |
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return ret; |
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} else if (!strcmp(label.str, "startTime")) { |
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ret = parse_int(pb, &cur_byte, &start); |
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if (ret < 0) |
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return ret; |
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} else if (!strcmp(label.str, "duration")) { |
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ret = parse_int(pb, &cur_byte, &duration); |
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if (ret < 0) |
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return ret; |
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} else { |
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return AVERROR_INVALIDDATA; |
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} |
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skip_spaces(pb, &cur_byte); |
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if (cur_byte != ',') |
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break; |
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next_byte(pb, &cur_byte); |
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} |
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ret = expect_byte(pb, &cur_byte, '}'); |
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if (ret < 0) |
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return ret; |
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if (!content.size || start == AV_NOPTS_VALUE || |
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duration == AV_NOPTS_VALUE) |
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return AVERROR_INVALIDDATA; |
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pkt = ff_subtitles_queue_insert(subs, content.str, content.len, 0); |
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if (!pkt) |
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return AVERROR(ENOMEM); |
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pkt->pos = pos; |
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pkt->pts = start; |
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pkt->duration = duration; |
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av_bprint_finalize(&content, NULL); |
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skip_spaces(pb, &cur_byte); |
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if (cur_byte != ',') |
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break; |
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next_byte(pb, &cur_byte); |
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} |
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ret = expect_byte(pb, &cur_byte, ']'); |
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if (ret < 0) |
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return ret; |
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ret = expect_byte(pb, &cur_byte, '}'); |
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if (ret < 0) |
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return ret; |
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skip_spaces(pb, &cur_byte); |
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if (cur_byte != AVERROR_EOF) |
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return ERR_CODE(cur_byte); |
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return 0; |
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} |
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static av_cold int tedcaptions_read_header(AVFormatContext *avf) |
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{ |
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TEDCaptionsDemuxer *tc = avf->priv_data; |
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AVStream *st; |
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int ret, i; |
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AVPacket *last; |
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ret = parse_file(avf->pb, &tc->subs); |
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if (ret < 0) { |
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if (ret == AVERROR_INVALIDDATA) |
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av_log(avf, AV_LOG_ERROR, "Syntax error near offset %"PRId64".\n", |
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avio_tell(avf->pb)); |
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ff_subtitles_queue_clean(&tc->subs); |
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return ret; |
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} |
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ff_subtitles_queue_finalize(&tc->subs); |
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for (i = 0; i < tc->subs.nb_subs; i++) |
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tc->subs.subs[i].pts += tc->start_time; |
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last = &tc->subs.subs[tc->subs.nb_subs - 1]; |
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st = avformat_new_stream(avf, NULL); |
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if (!st) |
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return AVERROR(ENOMEM); |
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st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
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st->codec->codec_id = CODEC_ID_TEXT; |
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avpriv_set_pts_info(st, 64, 1, 1000); |
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st->probe_packets = 0; |
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st->start_time = 0; |
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st->duration = last->pts + last->duration; |
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st->cur_dts = 0; |
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return 0; |
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} |
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static int tedcaptions_read_packet(AVFormatContext *avf, AVPacket *packet) |
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{ |
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TEDCaptionsDemuxer *tc = avf->priv_data; |
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return ff_subtitles_queue_read_packet(&tc->subs, packet); |
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} |
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static int tedcaptions_read_close(AVFormatContext *avf) |
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{ |
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TEDCaptionsDemuxer *tc = avf->priv_data; |
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ff_subtitles_queue_clean(&tc->subs); |
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return 0; |
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} |
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static av_cold int tedcaptions_read_probe(AVProbeData *p) |
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{ |
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static const char *const tags[] = { |
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"\"captions\"", "\"duration\"", "\"content\"", |
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"\"startOfParagraph\"", "\"startTime\"", |
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}; |
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unsigned i, count = 0; |
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const char *t; |
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if (p->buf[strspn(p->buf, " \t\r\n")] != '{') |
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return 0; |
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for (i = 0; i < FF_ARRAY_ELEMS(tags); i++) { |
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if (!(t = strstr(p->buf, tags[i]))) |
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continue; |
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t += strlen(tags[i]); |
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t += strspn(t, " \t\r\n"); |
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if (*t == ':') |
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count++; |
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} |
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return count == FF_ARRAY_ELEMS(tags) ? AVPROBE_SCORE_MAX : |
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count ? AVPROBE_SCORE_MAX / 2 : 0; |
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} |
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static int tedcaptions_read_seek(AVFormatContext *avf, int stream_index, |
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int64_t min_ts, int64_t ts, int64_t max_ts, |
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int flags) |
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{ |
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TEDCaptionsDemuxer *tc = avf->priv_data; |
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return ff_subtitles_queue_seek(&tc->subs, avf, stream_index, |
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min_ts, ts, max_ts, flags); |
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} |
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AVInputFormat ff_tedcaptions_demuxer = { |
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.name = "tedcaptions", |
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.long_name = NULL_IF_CONFIG_SMALL("TED Talks captions"), |
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.priv_data_size = sizeof(TEDCaptionsDemuxer), |
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.priv_class = &tedcaptions_demuxer_class, |
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.read_header = tedcaptions_read_header, |
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.read_packet = tedcaptions_read_packet, |
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.read_close = tedcaptions_read_close, |
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.read_probe = tedcaptions_read_probe, |
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.read_seek2 = tedcaptions_read_seek, |
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}; |
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@ -0,0 +1,55 @@ |
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<!DOCTYPE html> |
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<html> |
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<head> |
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<!-- |
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This file is part of FFmpeg. |
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All scripts contained in this file can be considered public domain. |
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--> |
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<title>FFmpeg bookmarklets</title> |
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<meta charset="UTF-8"> |
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<script type="text/javascript"> |
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function convert(js) { |
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js = js.replace(/\/\*.*?\*\//g, ""); /* comments */ |
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js = js.replace(/\s+/g, " "); |
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js = js.replace(/\s+\z/, ""); |
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js = "(function(){" + js + "})();void 0"; |
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return "javascript:" + escape(js); |
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} |
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function init() { |
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var pre = document.getElementsByTagName("pre"); |
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for (var i = 0; pre.length > i; i++) { |
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document.getElementById(pre[i].id + "-link").href = convert(pre[i].textContent); |
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} |
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} |
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</script> |
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<style type="text/css"> |
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pre { border: solid black 1px; padding: 0.2ex; font-size: 80% } |
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</style> |
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</head> |
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<body onload="init()"> |
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<h1>Introduction</h1> |
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The scripts in this page are |
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<a href="http://en.wikipedia.org/wiki/Bookmarklet">bookmarklets</a>: store |
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their link version in a bookmark, and later activate the bookmark on a page |
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to run the script. |
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<h1>TED Talks captions</h1> |
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<p><a id="ted_talks_captions-link" href="#">Get links to the captions</a></p> |
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<pre id="ted_talks_captions"> |
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d = window.open("", "sub", "width=256,height=512,resizable=yes,scrollbars=yes").document; |
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l = document.getElementById("languageCode").getElementsByTagName("option"); |
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for (i = 1; i < l.length ; i++) { |
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d.body.appendChild(p = d.createElement("p")); |
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p.appendChild(a = d.createElement("a")); |
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a.appendChild(d.createTextNode(l[i].textContent)); |
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a.href="http://www.ted.com/talks/subtitles/id/" + talkID+"/lang/" + l[i].value; |
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} |
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</pre> |
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</body> |
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</html> |
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