diff options
Diffstat (limited to 'libavformat/sccdec.c')
| -rw-r--r-- | libavformat/sccdec.c | 161 |
1 files changed, 161 insertions, 0 deletions
diff --git a/libavformat/sccdec.c b/libavformat/sccdec.c new file mode 100644 index 0000000000..ea05a24533 --- /dev/null +++ b/libavformat/sccdec.c @@ -0,0 +1,161 @@ +/* + * SCC subtitle demuxer + * Copyright (c) 2017 Paul B Mahol + * + * 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 + */ + +#include "avformat.h" +#include "demux.h" +#include "internal.h" +#include "subtitles.h" +#include "libavutil/avstring.h" +#include "libavutil/intreadwrite.h" + +typedef struct SCCContext { + FFDemuxSubtitlesQueue q; +} SCCContext; + +static int scc_probe(const AVProbeData *p) +{ + char buf[18]; + FFTextReader tr; + + ff_text_init_buf(&tr, p->buf, p->buf_size); + + while (ff_text_peek_r8(&tr) == '\r' || ff_text_peek_r8(&tr) == '\n') + ff_text_r8(&tr); + + ff_text_read(&tr, buf, sizeof(buf)); + + if (!memcmp(buf, "Scenarist_SCC V1.0", 18)) + return AVPROBE_SCORE_MAX; + + return 0; +} + +static int convert(uint8_t x) +{ + if (x >= 'a') + x -= 'a' - 10; + else if (x >= 'A') + x -= 'A' - 10; + else + x -= '0'; + return x; +} + +static int scc_read_header(AVFormatContext *s) +{ + SCCContext *scc = s->priv_data; + AVStream *st = avformat_new_stream(s, NULL); + AVPacket *sub = NULL; + ptrdiff_t len; + uint8_t out[4096]; + FFTextReader tr; + + ff_text_init_avio(s, &tr, s->pb); + + 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_EIA_608; + + while (1) { + char *saveptr = NULL, *lline; + int hh, mm, ss, fs, i; + char line[4096]; + int64_t pos, ts; + + pos = ff_text_pos(&tr); + len = ff_subtitles_read_line(&tr, line, sizeof(line)); + if (len <= 13) { + if (ff_text_eof(&tr)) + break; + continue; + } + if (av_sscanf(line, "%d:%d:%d%*[:;]%d", &hh, &mm, &ss, &fs) != 4) + continue; + + ts = (hh * 3600LL + mm * 60LL + ss) * 1000LL + fs * 33LL; + if (sub) + sub->duration = ts - sub->pts; + + lline = line; + lline += 12; + + for (i = 0; i < 4095; i += 3) { + char *ptr = av_strtok(lline, " ", &saveptr); + char c1, c2, c3, c4; + uint8_t o1, o2; + + if (!ptr) + break; + + if (av_sscanf(ptr, "%c%c%c%c", &c1, &c2, &c3, &c4) != 4) + break; + o1 = convert(c2) | (convert(c1) << 4); + o2 = convert(c4) | (convert(c3) << 4); + + lline = NULL; + + if (i > 12 && o1 == 0x94 && o2 == 0x20 && saveptr && + (av_strncasecmp(saveptr, "942f", 4) && !av_strncasecmp(saveptr, "942c", 4))) { + + sub = ff_subtitles_queue_insert(&scc->q, out, i, 0); + if (!sub) + return AVERROR(ENOMEM); + + sub->pos = pos; + pos += i; + sub->pts = ts; + sub->duration = i * 11; + ts += sub->duration; + i = 0; + } + + out[i+0] = 0xfc; + out[i+1] = o1; + out[i+2] = o2; + } + + sub = ff_subtitles_queue_insert(&scc->q, out, i, 0); + if (!sub) + return AVERROR(ENOMEM); + + sub->pos = pos; + sub->pts = ts; + } + + ff_subtitles_queue_finalize(s, &scc->q); + + return 0; +} + +const FFInputFormat ff_scc_demuxer = { + .p.name = "scc", + .p.long_name = NULL_IF_CONFIG_SMALL("Scenarist Closed Captions"), + .p.extensions = "scc", + .priv_data_size = sizeof(SCCContext), + .flags_internal = FF_INFMT_FLAG_INIT_CLEANUP, + .read_probe = scc_probe, + .read_header = scc_read_header, + .read_packet = ff_subtitles_read_packet, + .read_seek2 = ff_subtitles_read_seek, + .read_close = ff_subtitles_read_close, +}; |