1/* 2 * Tele-typewriter demuxer 3 * Copyright (c) 2010 Peter Ross <pross@xvid.org> 4 * 5 * This file is part of Libav. 6 * 7 * Libav 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 * Libav 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 Libav; 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 37typedef struct { 38 AVClass *class; 39 int chars_per_frame; 40 uint64_t fsize; /**< file size less metadata buffer */ 41 char *video_size;/**< A string describing video size, set by a private option. */ 42 char *framerate; /**< Set by a private option. */ 43} TtyDemuxContext; 44 45/** 46 * Parse EFI header 47 */ 48static 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 75static int read_header(AVFormatContext *avctx, 76 AVFormatParameters *ap) 77{ 78 TtyDemuxContext *s = avctx->priv_data; 79 int width = 0, height = 0, ret = 0; 80 AVStream *st = avformat_new_stream(avctx, NULL); 81 AVRational framerate; 82 83 if (!st) { 84 ret = AVERROR(ENOMEM); 85 goto fail; 86 } 87 st->codec->codec_tag = 0; 88 st->codec->codec_type = AVMEDIA_TYPE_VIDEO; 89 st->codec->codec_id = CODEC_ID_ANSI; 90 91 if (s->video_size && (ret = av_parse_video_size(&width, &height, s->video_size)) < 0) { 92 av_log (avctx, AV_LOG_ERROR, "Couldn't parse video size.\n"); 93 goto fail; 94 } 95 if ((ret = av_parse_video_rate(&framerate, s->framerate)) < 0) { 96 av_log(avctx, AV_LOG_ERROR, "Could not parse framerate: %s.\n", s->framerate); 97 goto fail; 98 } 99 st->codec->width = width; 100 st->codec->height = height; 101 avpriv_set_pts_info(st, 60, framerate.den, framerate.num); 102 103 /* simulate tty display speed */ 104 s->chars_per_frame = FFMAX(av_q2d(st->time_base)*s->chars_per_frame, 1); 105 106 if (avctx->pb->seekable) { 107 s->fsize = avio_size(avctx->pb); 108 st->duration = (s->fsize + s->chars_per_frame - 1) / s->chars_per_frame; 109 110 if (ff_sauce_read(avctx, &s->fsize, 0, 0) < 0) 111 efi_read(avctx, s->fsize - 51); 112 113 avio_seek(avctx->pb, 0, SEEK_SET); 114 } 115 116fail: 117 return ret; 118} 119 120static int read_packet(AVFormatContext *avctx, AVPacket *pkt) 121{ 122 TtyDemuxContext *s = avctx->priv_data; 123 int n; 124 125 if (avctx->pb->eof_reached) 126 return AVERROR_EOF; 127 128 n = s->chars_per_frame; 129 if (s->fsize) { 130 // ignore metadata buffer 131 uint64_t p = avio_tell(avctx->pb); 132 if (p + s->chars_per_frame > s->fsize) 133 n = s->fsize - p; 134 } 135 136 pkt->size = av_get_packet(avctx->pb, pkt, n); 137 if (pkt->size <= 0) 138 return AVERROR(EIO); 139 pkt->flags |= AV_PKT_FLAG_KEY; 140 return 0; 141} 142 143#define OFFSET(x) offsetof(TtyDemuxContext, x) 144#define DEC AV_OPT_FLAG_DECODING_PARAM 145static const AVOption options[] = { 146 { "chars_per_frame", "", offsetof(TtyDemuxContext, chars_per_frame), AV_OPT_TYPE_INT, {.dbl = 6000}, 1, INT_MAX, AV_OPT_FLAG_DECODING_PARAM}, 147 { "video_size", "A string describing frame size, such as 640x480 or hd720.", OFFSET(video_size), AV_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC }, 148 { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_STRING, {.str = "25"}, 0, 0, DEC }, 149 { NULL }, 150}; 151 152static const AVClass tty_demuxer_class = { 153 .class_name = "TTY demuxer", 154 .item_name = av_default_item_name, 155 .option = options, 156 .version = LIBAVUTIL_VERSION_INT, 157}; 158 159AVInputFormat ff_tty_demuxer = { 160 .name = "tty", 161 .long_name = NULL_IF_CONFIG_SMALL("Tele-typewriter"), 162 .priv_data_size = sizeof(TtyDemuxContext), 163 .read_header = read_header, 164 .read_packet = read_packet, 165 .extensions = "ans,art,asc,diz,ice,nfo,txt,vt", 166 .priv_class = &tty_demuxer_class, 167}; 168