blob: 8d48f2c45c12d3a58f6c754300e039ab42ac5ea8
1 | /* |
2 | * Tele-typewriter demuxer |
3 | * Copyright (c) 2010 Peter Ross <pross@xvid.org> |
4 | * |
5 | * This file is part of FFmpeg. |
6 | * |
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. |
11 | * |
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. |
16 | * |
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 |
20 | */ |
21 | |
22 | /** |
23 | * @file |
24 | * Tele-typewriter demuxer |
25 | */ |
26 | |
27 | #include "libavutil/intreadwrite.h" |
28 | #include "libavutil/avstring.h" |
29 | #include "libavutil/log.h" |
30 | #include "libavutil/dict.h" |
31 | #include "libavutil/opt.h" |
32 | #include "libavutil/parseutils.h" |
33 | #include "avformat.h" |
34 | #include "internal.h" |
35 | #include "sauce.h" |
36 | |
37 | typedef struct TtyDemuxContext { |
38 | AVClass *class; |
39 | int chars_per_frame; |
40 | uint64_t fsize; /**< file size less metadata buffer */ |
41 | int width, height; /**< Set by a private option. */ |
42 | AVRational framerate; /**< Set by a private option. */ |
43 | } TtyDemuxContext; |
44 | |
45 | /** |
46 | * Parse EFI header |
47 | */ |
48 | static int efi_read(AVFormatContext *avctx, uint64_t start_pos) |
49 | { |
50 | TtyDemuxContext *s = avctx->priv_data; |
51 | AVIOContext *pb = avctx->pb; |
52 | char buf[37]; |
53 | int len; |
54 | |
55 | avio_seek(pb, start_pos, SEEK_SET); |
56 | if (avio_r8(pb) != 0x1A) |
57 | return -1; |
58 | |
59 | #define GET_EFI_META(name,size) \ |
60 | len = avio_r8(pb); \ |
61 | if (len < 1 || len > size) \ |
62 | return -1; \ |
63 | if (avio_read(pb, buf, size) == size) { \ |
64 | buf[len] = 0; \ |
65 | av_dict_set(&avctx->metadata, name, buf, 0); \ |
66 | } |
67 | |
68 | GET_EFI_META("filename", 12) |
69 | GET_EFI_META("title", 36) |
70 | |
71 | s->fsize = start_pos; |
72 | return 0; |
73 | } |
74 | |
75 | static int read_header(AVFormatContext *avctx) |
76 | { |
77 | TtyDemuxContext *s = avctx->priv_data; |
78 | int ret = 0; |
79 | AVStream *st = avformat_new_stream(avctx, NULL); |
80 | |
81 | if (!st) { |
82 | ret = AVERROR(ENOMEM); |
83 | goto fail; |
84 | } |
85 | st->codecpar->codec_tag = 0; |
86 | st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO; |
87 | st->codecpar->codec_id = AV_CODEC_ID_ANSI; |
88 | |
89 | st->codecpar->width = s->width; |
90 | st->codecpar->height = s->height; |
91 | avpriv_set_pts_info(st, 60, s->framerate.den, s->framerate.num); |
92 | st->avg_frame_rate = s->framerate; |
93 | |
94 | /* simulate tty display speed */ |
95 | s->chars_per_frame = FFMAX(av_q2d(st->time_base)*s->chars_per_frame, 1); |
96 | |
97 | if (avctx->pb->seekable & AVIO_SEEKABLE_NORMAL) { |
98 | s->fsize = avio_size(avctx->pb); |
99 | st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame; |
100 | |
101 | if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0) |
102 | efi_read(avctx, s->fsize - 51); |
103 | |
104 | avio_seek(avctx->pb, 0, SEEK_SET); |
105 | } |
106 | |
107 | fail: |
108 | return ret; |
109 | } |
110 | |
111 | static int read_packet(AVFormatContext *avctx, AVPacket *pkt) |
112 | { |
113 | TtyDemuxContext *s = avctx->priv_data; |
114 | int n; |
115 | |
116 | if (avio_feof(avctx->pb)) |
117 | return AVERROR_EOF; |
118 | |
119 | n = s->chars_per_frame; |
120 | if (s->fsize) { |
121 | // ignore metadata buffer |
122 | uint64_t p = avio_tell(avctx->pb); |
123 | if (p == s->fsize) |
124 | return AVERROR_EOF; |
125 | if (p + s->chars_per_frame > s->fsize) |
126 | n = s->fsize - p; |
127 | } |
128 | |
129 | pkt->size = av_get_packet(avctx->pb, pkt, n); |
130 | if (pkt->size < 0) |
131 | return pkt->size; |
132 | pkt->flags |= AV_PKT_FLAG_KEY; |
133 | return 0; |
134 | } |
135 | |
136 | #define OFFSET(x) offsetof(TtyDemuxContext, x) |
137 | #define DEC AV_OPT_FLAG_DECODING_PARAM |
138 | static const AVOption options[] = { |
139 | { "chars_per_frame", "", offsetof(TtyDemuxContext, chars_per_frame), AV_OPT_TYPE_INT, {.i64 = 6000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM}, |
140 | { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(width), AV_OPT_TYPE_IMAGE_SIZE, {.str = NULL}, 0, 0, DEC }, |
141 | { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC }, |
142 | { NULL }, |
143 | }; |
144 | |
145 | static const AVClass tty_demuxer_class = { |
146 | .class_name = "TTY demuxer", |
147 | .item_name = av_default_item_name, |
148 | .option = options, |
149 | .version = LIBAVUTIL_VERSION_INT, |
150 | }; |
151 | |
152 | AVInputFormat ff_tty_demuxer = { |
153 | .name = "tty", |
154 | .long_name = NULL_IF_CONFIG_SMALL("Tele-typewriter"), |
155 | .priv_data_size = sizeof(TtyDemuxContext), |
156 | .read_header = read_header, |
157 | .read_packet = read_packet, |
158 | .extensions = "ans,art,asc,diz,ice,nfo,txt,vt", |
159 | .priv_class = &tty_demuxer_class, |
160 | }; |
161 |