/* * Tele-typewriter demuxer * Copyright (c) 2010 Peter Ross <pross@xvid.org> * * This file is part of Libav. * * Libav 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. * * Libav 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 Libav; if not, write to the Free Software * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA */ /** * @file * Tele-typewriter demuxer */ #include "libavutil/intreadwrite.h" #include "libavutil/avstring.h" #include "avformat.h" #include "sauce.h" #define LINE_RATE 6000 /* characters per second */ typedef struct { int chars_per_frame; uint64_t fsize; /**< file size less metadata buffer */ } TtyDemuxContext; /** * Parse EFI header */ static int efi_read(AVFormatContext *avctx, uint64_t start_pos) { TtyDemuxContext *s = avctx->priv_data; AVIOContext *pb = avctx->pb; char buf[37]; int len; avio_seek(pb, start_pos, SEEK_SET); if (avio_r8(pb) != 0x1A) return -1; #define GET_EFI_META(name,size) \ len = avio_r8(pb); \ if (len < 1 || len > size) \ return -1; \ if (avio_read(pb, buf, size) == size) { \ buf[len] = 0; \ av_metadata_set2(&avctx->metadata, name, buf, 0); \ } GET_EFI_META("filename", 12) GET_EFI_META("title", 36) s->fsize = start_pos; return 0; } static int read_header(AVFormatContext *avctx, AVFormatParameters *ap) { TtyDemuxContext *s = avctx->priv_data; AVStream *st = av_new_stream(avctx, 0); if (!st) return AVERROR(ENOMEM); st->codec->codec_tag = 0; st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = CODEC_ID_ANSI; if (ap->width) st->codec->width = ap->width; if (ap->height) st->codec->height = ap->height; if (!ap->time_base.num) { av_set_pts_info(st, 60, 1, 25); } else { av_set_pts_info(st, 60, ap->time_base.num, ap->time_base.den); } /* simulate tty display speed */ s->chars_per_frame = FFMAX(av_q2d(st->time_base) * (ap->sample_rate ? ap->sample_rate : LINE_RATE), 1); if (avctx->pb->seekable) { s->fsize = avio_size(avctx->pb); st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame; if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0) efi_read(avctx, s->fsize - 51); avio_seek(avctx->pb, 0, SEEK_SET); } return 0; } static int read_packet(AVFormatContext *avctx, AVPacket *pkt) { TtyDemuxContext *s = avctx->priv_data; int n; if (avctx->pb->eof_reached) return AVERROR_EOF; n = s->chars_per_frame; if (s->fsize) { // ignore metadata buffer uint64_t p = avio_tell(avctx->pb); if (p + s->chars_per_frame > s->fsize) n = s->fsize - p; } pkt->size = av_get_packet(avctx->pb, pkt, n); if (pkt->size <= 0) return AVERROR(EIO); pkt->flags |= AV_PKT_FLAG_KEY; return 0; } AVInputFormat ff_tty_demuxer = { .name = "tty", .long_name = NULL_IF_CONFIG_SMALL("Tele-typewriter"), .priv_data_size = sizeof(TtyDemuxContext), .read_header = read_header, .read_packet = read_packet, .extensions = "ans,art,asc,diz,ice,nfo,txt,vt", };