lavf: TED Talks JSON captions demuxer.
This commit is contained in:
Nicolas George
parent
18eb31963b
commit
160013736e
@ -39,6 +39,7 @@ version <next>:
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- Paris Audio File demuxer
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- Virtual concatenation demuxer
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- VobSub demuxer
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- JSON captions for TED talks decoding support
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version 1.0:
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@ -215,4 +215,25 @@ backslash or single quotes.
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@end table
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@section tedcaptions
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JSON captions used for @url{http://www.ted.com/, TED Talks}.
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TED does not provide links to the captions, but they can be guessed from the
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page. The file @file{tools/bookmarklets.html} from the FFmpeg source tree
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contains a bookmarklet to expose them.
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This demuxer accepts the following option:
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@table @option
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@item start_time
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Set the start time of the TED talk, in milliseconds. The default is 15000
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(15s). It is used to sync the captions with the downloadable videos, because
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they include a 15s intro.
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@end table
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Example: convert the captions to a format most players understand:
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@example
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ffmpeg -i http://www.ted.com/talks/subtitles/id/1/lang/en talk1-en.srt
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@end example
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@c man end INPUT DEVICES
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@ -924,6 +924,7 @@ performance on systems without hardware floating point support).
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@item SAMI @tab @tab X @tab @tab X
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@item SubRip (SRT) @tab X @tab X @tab X @tab X
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@item SubViewer @tab @tab X @tab @tab X
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@item TED Talks captions @tab @tab X @tab @tab X
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@item VobSub (IDX+SUB) @tab @tab X @tab @tab X
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@item 3GPP Timed Text @tab @tab @tab X @tab X
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@item WebVTT @tab @tab X @tab @tab X
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@ -346,6 +346,7 @@ OBJS-$(CONFIG_SUBVIEWER_DEMUXER) += subviewerdec.o
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OBJS-$(CONFIG_SWF_DEMUXER) += swfdec.o swf.o
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OBJS-$(CONFIG_SWF_MUXER) += swfenc.o swf.o
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OBJS-$(CONFIG_TAK_DEMUXER) += takdec.o apetag.o img2.o rawdec.o
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OBJS-$(CONFIG_TEDCAPTIONS_DEMUXER) += tedcaptionsdec.o
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OBJS-$(CONFIG_THP_DEMUXER) += thp.o
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OBJS-$(CONFIG_TIERTEXSEQ_DEMUXER) += tiertexseq.o
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OBJS-$(CONFIG_MKVTIMESTAMP_V2_MUXER) += mkvtimestamp_v2.o
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@ -244,6 +244,7 @@ void av_register_all(void)
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REGISTER_DEMUXER (SUBVIEWER, subviewer);
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REGISTER_MUXDEMUX (SWF, swf);
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REGISTER_DEMUXER (TAK, tak);
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REGISTER_DEMUXER (TEDCAPTIONS, tedcaptions);
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REGISTER_MUXER (TG2, tg2);
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REGISTER_MUXER (TGP, tgp);
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REGISTER_DEMUXER (THP, thp);
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365
libavformat/tedcaptionsdec.c
Normal file
365
libavformat/tedcaptionsdec.c
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@ -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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@ -30,7 +30,7 @@
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#include "libavutil/avutil.h"
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#define LIBAVFORMAT_VERSION_MAJOR 54
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#define LIBAVFORMAT_VERSION_MINOR 48
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#define LIBAVFORMAT_VERSION_MINOR 49
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#define LIBAVFORMAT_VERSION_MICRO 100
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|
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#define LIBAVFORMAT_VERSION_INT AV_VERSION_INT(LIBAVFORMAT_VERSION_MAJOR, \
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|
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55
tools/bookmarklets.html
Normal file
55
tools/bookmarklets.html
Normal file
@ -0,0 +1,55 @@
|
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<!DOCTYPE html>
|
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<html>
|
||||
<head>
|
||||
<!--
|
||||
This file is part of FFmpeg.
|
||||
|
||||
All scripts contained in this file can be considered public domain.
|
||||
-->
|
||||
<title>FFmpeg bookmarklets</title>
|
||||
<meta charset="UTF-8">
|
||||
<script type="text/javascript">
|
||||
function convert(js) {
|
||||
js = js.replace(/\/\*.*?\*\//g, ""); /* comments */
|
||||
js = js.replace(/\s+/g, " ");
|
||||
js = js.replace(/\s+\z/, "");
|
||||
js = "(function(){" + js + "})();void 0";
|
||||
return "javascript:" + escape(js);
|
||||
}
|
||||
function init() {
|
||||
var pre = document.getElementsByTagName("pre");
|
||||
for (var i = 0; pre.length > i; i++) {
|
||||
document.getElementById(pre[i].id + "-link").href = convert(pre[i].textContent);
|
||||
}
|
||||
}
|
||||
</script>
|
||||
<style type="text/css">
|
||||
pre { border: solid black 1px; padding: 0.2ex; font-size: 80% }
|
||||
</style>
|
||||
</head>
|
||||
<body onload="init()">
|
||||
|
||||
<h1>Introduction</h1>
|
||||
|
||||
The scripts in this page are
|
||||
<a href="http://en.wikipedia.org/wiki/Bookmarklet">bookmarklets</a>: store
|
||||
their link version in a bookmark, and later activate the bookmark on a page
|
||||
to run the script.
|
||||
|
||||
<h1>TED Talks captions</h1>
|
||||
|
||||
<p><a id="ted_talks_captions-link" href="#">Get links to the captions</a></p>
|
||||
|
||||
<pre id="ted_talks_captions">
|
||||
d = window.open("", "sub", "width=256,height=512,resizable=yes,scrollbars=yes").document;
|
||||
l = document.getElementById("languageCode").getElementsByTagName("option");
|
||||
for (i = 1; i < l.length ; i++) {
|
||||
d.body.appendChild(p = d.createElement("p"));
|
||||
p.appendChild(a = d.createElement("a"));
|
||||
a.appendChild(d.createTextNode(l[i].textContent));
|
||||
a.href="http://www.ted.com/talks/subtitles/id/" + talkID+"/lang/" + l[i].value;
|
||||
}
|
||||
</pre>
|
||||
|
||||
</body>
|
||||
</html>
|
||||
Loading…
x
Reference in New Issue
Block a user