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/*
* 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 "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,
AVFormatParameters *ap)
{
TtyDemuxContext *s = avctx->priv_data;
int width = 0, height = 0, ret = 0;
AVStream *st = av_new_stream(avctx, 0);
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;
}
#if FF_API_FORMAT_PARAMETERS
if (ap->width > 0)
width = ap->width;
if (ap->height > 0)
height = ap->height;
if (ap->time_base.num)
framerate = (AVRational){ap->time_base.den, ap->time_base.num};
#endif
st->codec->width = width;
st->codec->height = height;
av_set_pts_info(st, 60, framerate.den, framerate.num);
/* simulate tty display speed */
#if FF_API_FORMAT_PARAMETERS
if (ap->sample_rate)
s->chars_per_frame = ap->sample_rate;
#endif
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), FF_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), FF_OPT_TYPE_STRING, {.str = NULL}, 0, 0, DEC },
{ "framerate", "", OFFSET(framerate), FF_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,
};
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