FFmpeg: libavformat/tty.c Source File

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tty.c
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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 };
NULL
#define NULL
Definition: coverity.c:32
s
const char * s
Definition: avisynth_c.h:768
AVIOContext
Bytestream IO Context.
Definition: avio.h:161
avio_size
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:334
AVOption
AVOption.
Definition: opt.h:246
LIBAVUTIL_VERSION_INT
#define LIBAVUTIL_VERSION_INT
Definition: version.h:86
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *s, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: utils.c:4737
AV_OPT_TYPE_INT
Definition: opt.h:223
TtyDemuxContext::fsize
uint64_t fsize
file size less metadata buffer
Definition: tty.c:40
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:4152
AVRational::num
int num
Numerator.
Definition: rational.h:59
AVPacket::size
int size
Definition: avcodec.h:1680
avio_seek
int64_t avio_seek(AVIOContext *s, int64_t offset, int whence)
fseek() equivalent for AVIOContext.
Definition: aviobuf.c:244
AV_CODEC_ID_ANSI
Definition: avcodec.h:362
pkt
static AVPacket pkt
Definition: demuxing_decoding.c:54
TtyDemuxContext::framerate
AVRational framerate
Set by a private option.
Definition: tty.c:42
AVFormatContext
Format I/O context.
Definition: avformat.h:1349
AVClass::class_name
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
dict.h
Public dictionary API.
AVCodecParameters::width
int width
Video only.
Definition: avcodec.h:4218
opt.h
AVOptions.
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4367
OFFSET
#define OFFSET(x)
Definition: tty.c:136
av_q2d
static double av_q2d(AVRational a)
Convert an AVRational to a double.
Definition: rational.h:104
AVERROR_EOF
#define AVERROR_EOF
End of file.
Definition: error.h:55
av_get_packet
int av_get_packet(AVIOContext *s, AVPacket *pkt, int size)
Allocate and read the payload of a packet and initialize its fields with default values.
Definition: utils.c:289
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:556
GET_EFI_META
#define GET_EFI_META(name, size)
AV_PKT_FLAG_KEY
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1711
TtyDemuxContext::height
int height
Set by a private option.
Definition: tty.c:41
av_default_item_name
av_default_item_name
Definition: libopenh264enc.c:78
AVERROR
#define AVERROR(e)
Definition: error.h:43
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:179
ff_sauce_read
int ff_sauce_read(AVFormatContext *avctx, uint64_t *fsize, int *got_width, int get_height)
Definition: sauce.c:32
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:4148
options
static const AVOption options[]
Definition: tty.c:138
width
uint16_t width
Definition: gdv.c:47
AVStream::avg_frame_rate
AVRational avg_frame_rate
Average framerate.
Definition: avformat.h:970
FFMAX
#define FFMAX(a, b)
Definition: common.h:94
fail
#define fail()
Definition: checkasm.h:109
AVPacket::flags
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1685
avio_r8
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:628
AVIOContext::seekable
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:261
DEC
#define DEC
Definition: tty.c:137
read_header
static int read_header(AVFormatContext *avctx)
Definition: tty.c:75
n
int n
Definition: avisynth_c.h:684
AVStream
Stream structure.
Definition: avformat.h:889
AVIO_SEEKABLE_NORMAL
#define AVIO_SEEKABLE_NORMAL
Seeking works like for a local file.
Definition: avio.h:40
tty_demuxer_class
static const AVClass tty_demuxer_class
Definition: tty.c:145
AVFormatContext::pb
AVIOContext * pb
I/O context.
Definition: avformat.h:1391
ff_tty_demuxer
AVInputFormat ff_tty_demuxer
Definition: tty.c:152
buf
void * buf
Definition: avisynth_c.h:690
AVClass
Describe the class of an AVClass context structure.
Definition: log.h:67
AVRational
Rational number (pair of numerator and denominator).
Definition: rational.h:58
AV_OPT_FLAG_DECODING_PARAM
#define AV_OPT_FLAG_DECODING_PARAM
a generic parameter which can be set by the user for demuxing or decoding
Definition: opt.h:277
AV_OPT_TYPE_VIDEO_RATE
offset must point to AVRational
Definition: opt.h:236
AV_OPT_TYPE_IMAGE_SIZE
offset must point to two consecutive integers
Definition: opt.h:233
parseutils.h
misc parsing utilities
sauce.h
SAUCE header parser.
AVStream::duration
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:946
efi_read
static int efi_read(AVFormatContext *avctx, uint64_t start_pos)
Parse EFI header.
Definition: tty.c:48
avformat.h
Main libavformat public API header.
if
if(ret< 0)
Definition: vf_mcdeint.c:279
TtyDemuxContext::chars_per_frame
int chars_per_frame
Definition: tty.c:39
AVRational::den
int den
Denominator.
Definition: rational.h:60
len
int len
Definition: vorbis_enc_data.h:452
AVFormatContext::priv_data
void * priv_data
Format private data.
Definition: avformat.h:1377
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:664
AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AVStream::codecpar
AVCodecParameters * codecpar
Definition: avformat.h:1252
avio_feof
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:356
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: avcodec.h:4156
AVStream::time_base
AVRational time_base
This is the fundamental unit of time (in seconds) in terms of which frame timestamps are represented...
Definition: avformat.h:926
AVPacket
This structure stores compressed data.
Definition: avcodec.h:1656
read_packet
static int read_packet(AVFormatContext *avctx, AVPacket *pkt)
Definition: tty.c:111
TtyDemuxContext::width
int width
Definition: tty.c:41
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