| /* |
| * Copyright (c) 2012 Clément Bœsch |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg 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 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg 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 FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| /** |
| * @file |
| * WebVTT subtitle demuxer |
| * @see http://dev.w3.org/html5/webvtt/ |
| */ |
| |
| #include "avformat.h" |
| #include "internal.h" |
| #include "subtitles.h" |
| #include "libavutil/bprint.h" |
| #include "libavutil/intreadwrite.h" |
| #include "libavutil/opt.h" |
| |
| typedef struct { |
| const AVClass *class; |
| FFDemuxSubtitlesQueue q; |
| int kind; |
| } WebVTTContext; |
| |
| static int webvtt_probe(const AVProbeData *p) |
| { |
| const uint8_t *ptr = p->buf; |
| |
| if (AV_RB24(ptr) == 0xEFBBBF) |
| ptr += 3; /* skip UTF-8 BOM */ |
| if (!strncmp(ptr, "WEBVTT", 6) && |
| (!ptr[6] || strchr("\n\r\t ", ptr[6]))) |
| return AVPROBE_SCORE_MAX; |
| return 0; |
| } |
| |
| static int64_t read_ts(const char *s) |
| { |
| int hh, mm, ss, ms; |
| if (sscanf(s, "%u:%u:%u.%u", &hh, &mm, &ss, &ms) == 4) return (hh*3600LL + mm*60LL + ss) * 1000LL + ms; |
| if (sscanf(s, "%u:%u.%u", &mm, &ss, &ms) == 3) return ( mm*60LL + ss) * 1000LL + ms; |
| return AV_NOPTS_VALUE; |
| } |
| |
| static int webvtt_read_header(AVFormatContext *s) |
| { |
| WebVTTContext *webvtt = s->priv_data; |
| AVBPrint cue; |
| int res = 0; |
| AVStream *st = avformat_new_stream(s, NULL); |
| |
| if (!st) |
| return AVERROR(ENOMEM); |
| avpriv_set_pts_info(st, 64, 1, 1000); |
| st->codecpar->codec_type = AVMEDIA_TYPE_SUBTITLE; |
| st->codecpar->codec_id = AV_CODEC_ID_WEBVTT; |
| st->disposition |= webvtt->kind; |
| |
| av_bprint_init(&cue, 0, AV_BPRINT_SIZE_UNLIMITED); |
| |
| for (;;) { |
| int i; |
| int64_t pos; |
| AVPacket *sub; |
| const char *p, *identifier, *settings; |
| int identifier_len, settings_len; |
| int64_t ts_start, ts_end; |
| |
| ff_subtitles_read_chunk(s->pb, &cue); |
| |
| if (!cue.len) |
| break; |
| |
| p = identifier = cue.str; |
| pos = avio_tell(s->pb); |
| |
| /* ignore header chunk */ |
| if (!strncmp(p, "\xEF\xBB\xBFWEBVTT", 9) || |
| !strncmp(p, "WEBVTT", 6) || |
| !strncmp(p, "NOTE", 4)) |
| continue; |
| |
| /* optional cue identifier (can be a number like in SRT or some kind of |
| * chaptering id) */ |
| for (i = 0; p[i] && p[i] != '\n' && p[i] != '\r'; i++) { |
| if (!strncmp(p + i, "-->", 3)) { |
| identifier = NULL; |
| break; |
| } |
| } |
| if (!identifier) |
| identifier_len = 0; |
| else { |
| identifier_len = strcspn(p, "\r\n"); |
| p += identifier_len; |
| if (*p == '\r') |
| p++; |
| if (*p == '\n') |
| p++; |
| } |
| |
| /* cue timestamps */ |
| if ((ts_start = read_ts(p)) == AV_NOPTS_VALUE) |
| break; |
| if (!(p = strstr(p, "-->"))) |
| break; |
| p += 2; |
| do p++; while (*p == ' ' || *p == '\t'); |
| if ((ts_end = read_ts(p)) == AV_NOPTS_VALUE) |
| break; |
| |
| /* optional cue settings */ |
| p += strcspn(p, "\n\r\t "); |
| while (*p == '\t' || *p == ' ') |
| p++; |
| settings = p; |
| settings_len = strcspn(p, "\r\n"); |
| p += settings_len; |
| if (*p == '\r') |
| p++; |
| if (*p == '\n') |
| p++; |
| |
| /* create packet */ |
| sub = ff_subtitles_queue_insert(&webvtt->q, p, strlen(p), 0); |
| if (!sub) { |
| res = AVERROR(ENOMEM); |
| goto end; |
| } |
| sub->pos = pos; |
| sub->pts = ts_start; |
| sub->duration = ts_end - ts_start; |
| |
| #define SET_SIDE_DATA(name, type) do { \ |
| if (name##_len) { \ |
| uint8_t *buf = av_packet_new_side_data(sub, type, name##_len); \ |
| if (!buf) { \ |
| res = AVERROR(ENOMEM); \ |
| goto end; \ |
| } \ |
| memcpy(buf, name, name##_len); \ |
| } \ |
| } while (0) |
| |
| SET_SIDE_DATA(identifier, AV_PKT_DATA_WEBVTT_IDENTIFIER); |
| SET_SIDE_DATA(settings, AV_PKT_DATA_WEBVTT_SETTINGS); |
| } |
| |
| ff_subtitles_queue_finalize(s, &webvtt->q); |
| |
| end: |
| if (res < 0) |
| ff_subtitles_queue_clean(&webvtt->q); |
| av_bprint_finalize(&cue, NULL); |
| return res; |
| } |
| |
| static int webvtt_read_packet(AVFormatContext *s, AVPacket *pkt) |
| { |
| WebVTTContext *webvtt = s->priv_data; |
| return ff_subtitles_queue_read_packet(&webvtt->q, pkt); |
| } |
| |
| static int webvtt_read_seek(AVFormatContext *s, int stream_index, |
| int64_t min_ts, int64_t ts, int64_t max_ts, int flags) |
| { |
| WebVTTContext *webvtt = s->priv_data; |
| return ff_subtitles_queue_seek(&webvtt->q, s, stream_index, |
| min_ts, ts, max_ts, flags); |
| } |
| |
| static int webvtt_read_close(AVFormatContext *s) |
| { |
| WebVTTContext *webvtt = s->priv_data; |
| ff_subtitles_queue_clean(&webvtt->q); |
| return 0; |
| } |
| |
| #define OFFSET(x) offsetof(WebVTTContext, x) |
| #define KIND_FLAGS AV_OPT_FLAG_SUBTITLE_PARAM|AV_OPT_FLAG_DECODING_PARAM |
| |
| static const AVOption options[] = { |
| { "kind", "Set kind of WebVTT track", OFFSET(kind), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, KIND_FLAGS, "webvtt_kind" }, |
| { "subtitles", "WebVTT subtitles kind", 0, AV_OPT_TYPE_CONST, { .i64 = 0 }, INT_MIN, INT_MAX, KIND_FLAGS, "webvtt_kind" }, |
| { "captions", "WebVTT captions kind", 0, AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_CAPTIONS }, INT_MIN, INT_MAX, KIND_FLAGS, "webvtt_kind" }, |
| { "descriptions", "WebVTT descriptions kind", 0, AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_DESCRIPTIONS }, INT_MIN, INT_MAX, KIND_FLAGS, "webvtt_kind" }, |
| { "metadata", "WebVTT metadata kind", 0, AV_OPT_TYPE_CONST, { .i64 = AV_DISPOSITION_METADATA }, INT_MIN, INT_MAX, KIND_FLAGS, "webvtt_kind" }, |
| { NULL } |
| }; |
| |
| static const AVClass webvtt_demuxer_class = { |
| .class_name = "WebVTT demuxer", |
| .item_name = av_default_item_name, |
| .option = options, |
| .version = LIBAVUTIL_VERSION_INT, |
| }; |
| |
| AVInputFormat ff_webvtt_demuxer = { |
| .name = "webvtt", |
| .long_name = NULL_IF_CONFIG_SMALL("WebVTT subtitle"), |
| .priv_data_size = sizeof(WebVTTContext), |
| .read_probe = webvtt_probe, |
| .read_header = webvtt_read_header, |
| .read_packet = webvtt_read_packet, |
| .read_seek2 = webvtt_read_seek, |
| .read_close = webvtt_read_close, |
| .extensions = "vtt", |
| .priv_class = &webvtt_demuxer_class, |
| }; |