FFmpeg
rawdec.c
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1 /*
2  * RAW demuxers
3  * Copyright (c) 2001 Fabrice Bellard
4  * Copyright (c) 2005 Alex Beregszaszi
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22 
23 #include "avformat.h"
24 #include "internal.h"
25 #include "avio_internal.h"
26 #include "rawdec.h"
27 #include "libavutil/opt.h"
28 #include "libavutil/parseutils.h"
29 #include "libavutil/pixdesc.h"
30 #include "libavutil/avassert.h"
31 #include "libavutil/intreadwrite.h"
32 
33 #define RAW_PACKET_SIZE 1024
34 
36 {
38  int ret, size;
39 
40  size = raw->raw_packet_size;
41 
42  if ((ret = av_new_packet(pkt, size)) < 0)
43  return ret;
44 
45  pkt->pos= avio_tell(s->pb);
46  pkt->stream_index = 0;
47  ret = avio_read_partial(s->pb, pkt->data, size);
48  if (ret < 0) {
49  av_packet_unref(pkt);
50  return ret;
51  }
52  av_shrink_packet(pkt, ret);
53  return ret;
54 }
55 
57 {
59  if (!st)
60  return AVERROR(ENOMEM);
64  st->start_time = 0;
65  /* the parameters will be extracted from the compressed bitstream */
66 
67  return 0;
68 }
69 
70 /* MPEG-1/H.263 input */
72 {
73  AVStream *st;
75  int ret = 0;
76 
77 
78  st = avformat_new_stream(s, NULL);
79  if (!st) {
80  ret = AVERROR(ENOMEM);
81  goto fail;
82  }
83 
87 
88  st->internal->avctx->framerate = s1->framerate;
89  avpriv_set_pts_info(st, 64, 1, 1200000);
90 
91 fail:
92  return ret;
93 }
94 
96 {
98  if (!st)
99  return AVERROR(ENOMEM);
102  st->start_time = 0;
103  return 0;
104 }
105 
107 {
109  if (!st)
110  return AVERROR(ENOMEM);
113  st->start_time = 0;
114  return 0;
115 }
116 
117 /* Note: Do not forget to add new entries to the Makefile as well. */
118 
119 #define OFFSET(x) offsetof(FFRawVideoDemuxerContext, x)
120 #define DEC AV_OPT_FLAG_DECODING_PARAM
122  { "framerate", "", OFFSET(framerate), AV_OPT_TYPE_VIDEO_RATE, {.str = "25"}, 0, INT_MAX, DEC},
123  { "raw_packet_size", "", OFFSET(raw_packet_size), AV_OPT_TYPE_INT, {.i64 = RAW_PACKET_SIZE }, 1, INT_MAX, DEC},
124  { NULL },
125 };
126 #undef OFFSET
127 #define OFFSET(x) offsetof(FFRawDemuxerContext, x)
129  { "raw_packet_size", "", OFFSET(raw_packet_size), AV_OPT_TYPE_INT, {.i64 = RAW_PACKET_SIZE }, 1, INT_MAX, DEC},
130  { NULL },
131 };
132 
133 #if CONFIG_DATA_DEMUXER
134 FF_RAW_DEMUXER_CLASS(raw_data)
135 
137  .name = "data",
138  .long_name = NULL_IF_CONFIG_SMALL("raw data"),
139  .read_header = ff_raw_data_read_header,
140  .read_packet = ff_raw_read_partial_packet,
141  .raw_codec_id = AV_CODEC_ID_NONE,
142  .flags = AVFMT_NOTIMESTAMPS,
143  .priv_data_size = sizeof(FFRawDemuxerContext),\
144  .priv_class = &raw_data_demuxer_class,\
145 };
146 #endif
147 
148 #if CONFIG_MJPEG_DEMUXER
149 static int mjpeg_probe(const AVProbeData *p)
150 {
151  int i;
152  int state = -1;
153  int nb_invalid = 0;
154  int nb_frames = 0;
155 
156  for (i = 0; i < p->buf_size - 1; i++) {
157  int c;
158  if (p->buf[i] != 0xFF)
159  continue;
160  c = p->buf[i+1];
161  switch (c) {
162  case 0xD8:
163  state = 0xD8;
164  break;
165  case 0xC0:
166  case 0xC1:
167  case 0xC2:
168  case 0xC3:
169  case 0xC5:
170  case 0xC6:
171  case 0xC7:
172  case 0xF7:
173  if (state == 0xD8) {
174  state = 0xC0;
175  } else
176  nb_invalid++;
177  break;
178  case 0xDA:
179  if (state == 0xC0) {
180  state = 0xDA;
181  } else
182  nb_invalid++;
183  break;
184  case 0xD9:
185  if (state == 0xDA) {
186  state = 0xD9;
187  nb_frames++;
188  } else
189  nb_invalid++;
190  break;
191  default:
192  if ( (c >= 0x02 && c <= 0xBF)
193  || c == 0xC8) {
194  nb_invalid++;
195  }
196  }
197  }
198 
199  if (nb_invalid*4 + 1 < nb_frames) {
200  static const char ct_jpeg[] = "\r\nContent-Type: image/jpeg\r\n";
201  int i;
202 
203  for (i=0; i<FFMIN(p->buf_size - (int)sizeof(ct_jpeg), 100); i++)
204  if (!memcmp(p->buf + i, ct_jpeg, sizeof(ct_jpeg) - 1))
206 
207  if (nb_invalid == 0 && nb_frames > 2)
208  return AVPROBE_SCORE_EXTENSION / 2;
209  return AVPROBE_SCORE_EXTENSION / 4;
210  }
211 
212  return 0;
213 }
214 
215 FF_DEF_RAWVIDEO_DEMUXER2(mjpeg, "raw MJPEG video", mjpeg_probe, "mjpg,mjpeg,mpo", AV_CODEC_ID_MJPEG, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)
216 #endif
const AVOption ff_rawvideo_options[]
Definition: rawdec.c:121
#define NULL
Definition: coverity.c:32
AVRational framerate
Definition: avcodec.h:2069
AVOption.
Definition: opt.h:248
int ff_raw_data_read_header(AVFormatContext *s)
Definition: rawdec.c:106
AVInputFormat ff_data_demuxer
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:383
void av_shrink_packet(AVPacket *pkt, int size)
Reduce packet size, correctly zeroing padding.
Definition: avpacket.c:103
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:4869
#define FF_DEF_RAWVIDEO_DEMUXER2(shortname, longname, probe, ext, id, flag)
Definition: rawdec.h:71
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
int avio_read_partial(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:706
static AVPacket pkt
int framerate
Definition: h264_levels.c:65
int ff_raw_subtitle_read_header(AVFormatContext *s)
Definition: rawdec.c:95
Format I/O context.
Definition: avformat.h:1351
Opaque data information usually continuous.
Definition: avutil.h:203
AVOptions.
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
enum AVStreamParseType need_parsing
Definition: avformat.h:1094
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4450
uint8_t * data
Definition: packet.h:363
ptrdiff_t size
Definition: opengl_enc.c:100
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:799
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:88
const AVOption ff_raw_options[]
Definition: rawdec.c:128
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawdec.c:35
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:153
ff_const59 struct AVInputFormat * iformat
The input container format.
Definition: avformat.h:1363
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
simple assert() macros that are a bit more flexible than ISO C assert().
#define FF_RAW_DEMUXER_CLASS(name)
Definition: rawdec.h:55
#define fail()
Definition: checkasm.h:123
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
static struct @322 state
#define FFMIN(a, b)
Definition: common.h:96
int ff_raw_audio_read_header(AVFormatContext *s)
Definition: rawdec.c:56
#define s(width, name)
Definition: cbs_vp9.c:257
#define RAW_PACKET_SIZE
Definition: rawdec.c:33
#define OFFSET(x)
Definition: rawdec.c:127
Stream structure.
Definition: avformat.h:876
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:462
AVStreamInternal * internal
An opaque field for libavformat internal usage.
Definition: avformat.h:1231
AVIOContext * pb
I/O context.
Definition: avformat.h:1393
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:606
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
offset must point to AVRational
Definition: opt.h:238
#define s1
Definition: regdef.h:38
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
misc parsing utilities
int raw_codec_id
Raw demuxers store their codec ID here.
Definition: avformat.h:696
Main libavformat public API header.
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base...
Definition: avformat.h:915
AVRational framerate
AVRational describing framerate, set by a private option.
Definition: rawdec.h:34
void * priv_data
Format private data.
Definition: avformat.h:1379
AVCodecContext * avctx
The codec context used by avformat_find_stream_info, the parser, etc.
Definition: internal.h:169
#define DEC
Definition: rawdec.c:120
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:650
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1023
int stream_index
Definition: packet.h:365
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
int ff_raw_video_read_header(AVFormatContext *s)
Definition: rawdec.c:71
This structure stores compressed data.
Definition: packet.h:340
int i
Definition: input.c:407