/* * 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 "libavutil/log.h" #include "libavutil/dict.h" #include "libavutil/opt.h" #include "libavutil/parseutils.h" #include "avformat.h" #include "internal.h" #include "sauce.h" typedef struct { AVClass *class; int chars_per_frame; uint64_t fsize; /**< file size less metadata buffer */ char *video_size;/**< A string describing video size, set by a private option. */ char *framerate; /**< Set by a private option. */ } 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_dict_set(&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) { TtyDemuxContext *s = avctx->priv_data; int width = 0, height = 0, ret = 0; AVStream *st = avformat_new_stream(avctx, NULL); AVRational framerate; if (!st) { ret = AVERROR(ENOMEM); goto fail; } st->codec->codec_tag = 0; st->codec->codec_type = AVMEDIA_TYPE_VIDEO; st->codec->codec_id = CODEC_ID_ANSI; if (s->video_size && (ret = av_parse_video_size(&width, &height, s->video_size)) < 0) { av_log (avctx, AV_LOG_ERROR, "Couldn't parse video size.\n"); goto fail; } if ((ret = av_parse_video_rate(&framerate, s->framerate)) < 0) { av_log(avctx, AV_LOG_ERROR, "Could not parse framerate: %s.\n", s->framerate); goto fail; } st->codec->width = width; st->codec->height = height; avpriv_set_pts_info(st, 60, framerate.den, framerate.num); /* simulate tty display speed */ s->chars_per_frame = FFMAX(av_q2d(st->time_base)*s->chars_per_frame, 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); } fail: return ret; } 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; } #define OFFSET(x) offsetof(TtyDemuxContext, x) #define DEC AV_OPT_FLAG_DECODING_PARAM static const AVOption options[] = { { "chars_per_frame", "", offsetof(TtyDemuxContext, chars_per_frame), AV_OPT_TYPE_INT, {.dbl = 6000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM}, { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC }, { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC }, { NULL }, }; static const AVClass tty_demuxer_class = { .class_name = "TTY demuxer", .item_name = av_default_item_name, .option = options, .version = LIBAVUTIL_VERSION_INT, }; 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", .priv_class = &tty_demuxer_class, };