2 * Tele-typewriter demuxer
3 * Copyright (c) 2010 Peter Ross <pross@xvid.org>
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * Tele-typewriter demuxer
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/avstring.h"
33 #define LINE_RATE 6000 /* characters per second */
37 uint64_t fsize; /**< file size less metadata buffer */
43 static int efi_read(AVFormatContext *avctx, uint64_t start_pos)
45 TtyDemuxContext *s = avctx->priv_data;
46 ByteIOContext *pb = avctx->pb;
50 url_fseek(pb, start_pos, SEEK_SET);
51 if (get_byte(pb) != 0x1A)
54 #define GET_EFI_META(name,size) \
56 if (len < 1 || len > size) \
58 if (get_buffer(pb, buf, size) == size) { \
60 av_metadata_set2(&avctx->metadata, name, buf, 0); \
63 GET_EFI_META("filename", 12)
64 GET_EFI_META("title", 36)
70 static int read_header(AVFormatContext *avctx,
71 AVFormatParameters *ap)
73 TtyDemuxContext *s = avctx->priv_data;
74 AVStream *st = av_new_stream(avctx, 0);
76 return AVERROR(ENOMEM);
77 st->codec->codec_tag = 0;
78 st->codec->codec_type = AVMEDIA_TYPE_VIDEO;
79 st->codec->codec_id = CODEC_ID_ANSI;
80 if (ap->width) st->codec->width = ap->width;
81 if (ap->height) st->codec->height = ap->height;
83 if (!ap->time_base.num) {
84 av_set_pts_info(st, 60, 1, 25);
86 av_set_pts_info(st, 60, ap->time_base.num, ap->time_base.den);
89 /* simulate tty display speed */
90 s->chars_per_frame = FFMAX(av_q2d(st->time_base) * (ap->sample_rate ? ap->sample_rate : LINE_RATE), 1);
92 if (!url_is_streamed(avctx->pb)) {
93 s->fsize = url_fsize(avctx->pb);
94 st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame;
96 if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0)
97 efi_read(avctx, s->fsize - 51);
99 url_fseek(avctx->pb, 0, SEEK_SET);
105 static int read_packet(AVFormatContext *avctx, AVPacket *pkt)
107 TtyDemuxContext *s = avctx->priv_data;
110 if (url_feof(avctx->pb))
113 n = s->chars_per_frame;
115 // ignore metadata buffer
116 uint64_t p = url_ftell(avctx->pb);
117 if (p + s->chars_per_frame > s->fsize)
121 pkt->size = av_get_packet(avctx->pb, pkt, n);
124 pkt->flags |= PKT_FLAG_KEY;
128 AVInputFormat tty_demuxer = {
130 .long_name = NULL_IF_CONFIG_SMALL("Tele-typewriter"),
131 .priv_data_size = sizeof(TtyDemuxContext),
132 .read_header = read_header,
133 .read_packet = read_packet,
134 .extensions = "ans,art,asc,diz,ice,nfo,txt,vt",