static int webvtt_read_header(AVFormatContext *s) { WebVTTContext *webvtt = s->priv_data; AVBPrint header, 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->codec->codec_type = AVMEDIA_TYPE_SUBTITLE; st->codec->codec_id = AV_CODEC_ID_WEBVTT; st->disposition |= webvtt->kind; av_bprint_init(&header, 0, AV_BPRINT_SIZE_UNLIMITED); 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)) 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 += 3; do p++; while (*p == ' ' || *p == '\t'); if ((ts_end = read_ts(p)) == AV_NOPTS_VALUE) break; /* optional cue settings */ p += strcspn(p, "\n\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(&webvtt->q); end: av_bprint_finalize(&cue, NULL); av_bprint_finalize(&header, NULL); return res; }