mirror of https://github.com/FFmpeg/FFmpeg.git
Clément Bœsch
12 years ago
parent
697ea4fccf
commit
2599541b3d
14 changed files with 308 additions and 3 deletions
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/*
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* Copyright (c) 2012 Clément Bœsch |
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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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/**
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* @file |
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* WebVTT subtitle decoder |
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* @see http://dev.w3.org/html5/webvtt/
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* @todo need to support extended markups and cue settings |
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*/ |
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#include "avcodec.h" |
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#include "ass.h" |
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#include "libavutil/bprint.h" |
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static const struct { |
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const char *from; |
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const char *to; |
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} webvtt_tag_replace[] = { |
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{"<i>", "{\\i1}"}, {"</i>", "{\\i0}"}, |
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{"<b>", "{\\b1}"}, {"</b>", "{\\b0}"}, |
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{"<u>", "{\\u1}"}, {"</u>", "{\\u0}"}, |
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{"{", "\\{"}, {"}", "\\}"}, // escape to avoid ASS markup conflicts
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}; |
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static int webvtt_event_to_ass(AVBPrint *buf, const char *p) |
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{ |
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int i, skip = 0; |
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while (*p) { |
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for (i = 0; i < FF_ARRAY_ELEMS(webvtt_tag_replace); i++) { |
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const char *from = webvtt_tag_replace[i].from; |
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const size_t len = strlen(from); |
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if (!strncmp(p, from, len)) { |
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av_bprintf(buf, "%s", webvtt_tag_replace[i].to); |
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p += len; |
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break; |
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} |
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} |
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if (!*p) |
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break; |
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if (*p == '<') |
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skip = 1; |
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else if (*p == '>') |
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skip = 0; |
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else if (p[0] == '\n' && p[1]) |
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av_bprintf(buf, "\\N"); |
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else if (!skip && *p != '\r') |
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av_bprint_chars(buf, *p, 1); |
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p++; |
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} |
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av_bprintf(buf, "\r\n"); |
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return 0; |
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} |
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static int webvtt_decode_frame(AVCodecContext *avctx, |
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void *data, int *got_sub_ptr, AVPacket *avpkt) |
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{ |
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AVSubtitle *sub = data; |
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const char *ptr = avpkt->data; |
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AVBPrint buf; |
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av_bprint_init(&buf, 0, AV_BPRINT_SIZE_UNLIMITED); |
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if (ptr && avpkt->size > 0 && !webvtt_event_to_ass(&buf, ptr)) { |
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int ts_start = av_rescale_q(avpkt->pts, avctx->time_base, (AVRational){1,100}); |
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int ts_duration = avpkt->duration != -1 ? |
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av_rescale_q(avpkt->duration, avctx->time_base, (AVRational){1,100}) : -1; |
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ff_ass_add_rect(sub, buf.str, ts_start, ts_duration, 0); |
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} |
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*got_sub_ptr = sub->num_rects > 0; |
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av_bprint_finalize(&buf, NULL); |
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return avpkt->size; |
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} |
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AVCodec ff_webvtt_decoder = { |
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.name = "webvtt", |
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.long_name = NULL_IF_CONFIG_SMALL("WebVTT subtitle"), |
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.type = AVMEDIA_TYPE_SUBTITLE, |
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.id = AV_CODEC_ID_WEBVTT, |
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.decode = webvtt_decode_frame, |
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.init = ff_ass_subtitle_header_default, |
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}; |
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@ -0,0 +1,188 @@ |
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/*
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* Copyright (c) 2012 Clément Bœsch |
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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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/**
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* @file |
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* WebVTT subtitle demuxer |
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* @see http://dev.w3.org/html5/webvtt/
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*/ |
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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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#include "libavutil/bprint.h" |
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#include "libavutil/intreadwrite.h" |
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typedef struct { |
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FFDemuxSubtitlesQueue q; |
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} WebVTTContext; |
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static int webvtt_probe(AVProbeData *p) |
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{ |
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const uint8_t *ptr = p->buf; |
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if (AV_RB24(ptr) == 0xEFBBBF) |
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ptr += 3; /* skip UTF-8 BOM */ |
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if (!strncmp(ptr, "WEBVTT", 6) && |
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(!ptr[6] || strchr("\n\r\t ", ptr[6]))) |
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return AVPROBE_SCORE_MAX; |
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return 0; |
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} |
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static int64_t read_ts(const char *s) |
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{ |
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int hh, mm, ss, ms; |
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if (sscanf(s, "%u:%u:%u.%u", &hh, &mm, &ss, &ms) == 4) return (hh*3600 + mm*60 + ss) * 1000 + ms; |
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if (sscanf(s, "%u:%u.%u", &mm, &ss, &ms) == 3) return ( mm*60 + ss) * 1000 + ms; |
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return AV_NOPTS_VALUE; |
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} |
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static int64_t extract_cue(AVBPrint *buf, AVIOContext *pb) |
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{ |
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int prev_chr_is_eol = 0; |
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int64_t pos = avio_tell(pb); |
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av_bprint_clear(buf); |
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for (;;) { |
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char c = avio_r8(pb); |
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if (!c) |
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break; |
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if (c == '\r' || c == '\n') { |
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if (prev_chr_is_eol) |
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break; |
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prev_chr_is_eol = (c == '\n'); |
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} else |
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prev_chr_is_eol = 0; |
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if (c != '\r') |
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av_bprint_chars(buf, c, 1); |
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} |
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av_bprint_chars(buf, '\0', 1); |
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return pos; |
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} |
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static int webvtt_read_header(AVFormatContext *s) |
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{ |
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WebVTTContext *webvtt = s->priv_data; |
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AVBPrint header, cue; |
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int res = 0; |
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AVStream *st = avformat_new_stream(s, NULL); |
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if (!st) |
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return AVERROR(ENOMEM); |
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avpriv_set_pts_info(st, 64, 1, 1000); |
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st->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; |
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st->codec->codec_id = AV_CODEC_ID_WEBVTT; |
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av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED); |
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av_bprint_init(&cue, 0, AV_BPRINT_SIZE_UNLIMITED); |
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for (;;) { |
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int i, len; |
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int64_t pos = extract_cue(&cue, s->pb); |
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AVPacket *sub; |
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const char *p = cue.str; |
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const char *identifier = p; |
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//const char *settings = NULL;
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int64_t ts_start, ts_end; |
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if (!*p) // EOF
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break; |
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/* ignore header chunk */ |
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if (!strncmp(p, "\xEF\xBB\xBFWEBVTT", 9) || |
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!strncmp(p, "WEBVTT", 6)) |
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continue; |
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/* optional cue identifier (can be a number like in SRT or some kind of
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* chaptering id), silently skip it */ |
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for (i = 0; p[i] && p[i] != '\n'; i++) { |
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if (!strncmp(p + i, "-->", 3)) { |
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identifier = NULL; |
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break; |
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} |
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} |
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if (identifier) |
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p += strcspn(p, "\n"); |
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/* cue timestamps */ |
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if ((ts_start = read_ts(p)) == AV_NOPTS_VALUE) |
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break; |
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if (!(p = strstr(p, "-->"))) |
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break; |
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p += 3; |
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do p++; while (*p == ' ' || *p == '\t'); |
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if ((ts_end = read_ts(p)) == AV_NOPTS_VALUE) |
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break; |
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/* optional cue settings, TODO: store in side_data */ |
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p += strcspn(p, "\n\t "); |
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while (*p == '\t' || *p == ' ') |
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p++; |
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if (*p != '\n') { |
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//settings = p;
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p += strcspn(p, "\n"); |
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} |
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if (*p == '\n') |
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p++; |
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/* create packet */ |
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len = cue.str + cue.len - p - 1; |
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sub = ff_subtitles_queue_insert(&webvtt->q, p, len, 0); |
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if (!sub) { |
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res = AVERROR(ENOMEM); |
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goto end; |
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} |
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sub->pos = pos; |
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sub->pts = ts_start; |
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sub->duration = ts_end - ts_start; |
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} |
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ff_subtitles_queue_finalize(&webvtt->q); |
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end: |
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av_bprint_finalize(&cue, NULL); |
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av_bprint_finalize(&header, NULL); |
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return res; |
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} |
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static int webvtt_read_packet(AVFormatContext *s, AVPacket *pkt) |
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{ |
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WebVTTContext *webvtt = s->priv_data; |
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return ff_subtitles_queue_read_packet(&webvtt->q, pkt); |
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} |
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static int webvtt_read_close(AVFormatContext *s) |
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{ |
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WebVTTContext *webvtt = s->priv_data; |
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ff_subtitles_queue_clean(&webvtt->q); |
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return 0; |
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} |
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AVInputFormat ff_webvtt_demuxer = { |
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.name = "webvtt", |
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.long_name = NULL_IF_CONFIG_SMALL("WebVTT subtitle"), |
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.priv_data_size = sizeof(WebVTTContext), |
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.read_probe = webvtt_probe, |
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.read_header = webvtt_read_header, |
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.read_packet = webvtt_read_packet, |
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.read_close = webvtt_read_close, |
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.flags = AVFMT_GENERIC_INDEX, |
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.extensions = "vtt", |
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}; |
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@ -0,0 +1 @@ |
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5384a70c89ddca4b007fb7ffba95cffb |
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