| 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 { |
| 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->codec->codec_tag = 0; |
| 86 | st->codec->codec_type = AVMEDIA_TYPE_VIDEO; |
| 87 | st->codec->codec_id = AV_CODEC_ID_ANSI; |
| 88 | |
| 89 | st->codec->width = s->width; |
| 90 | st->codec->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) { |
| 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, 0, 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 | }; |