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 {
37  FFRawDemuxerContext *raw = s->priv_data;
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) {
50  return ret;
51  }
53  return ret;
54 }
55 
57 {
59  if (!st)
60  return AVERROR(ENOMEM);
62  st->codecpar->codec_id = s->iformat->raw_codec_id;
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;
74  FFRawVideoDemuxerContext *s1 = s->priv_data;
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 
85  st->codecpar->codec_id = s->iformat->raw_codec_id;
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);
101  st->codecpar->codec_id = s->iformat->raw_codec_id;
102  st->start_time = 0;
103  return 0;
104 }
105 
107 {
109  if (!st)
110  return AVERROR(ENOMEM);
112  st->codecpar->codec_id = s->iformat->raw_codec_id;
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  if (!nb_invalid && nb_frames)
212  return AVPROBE_SCORE_EXTENSION / 4;
213 
214  return 0;
215 }
216 
217 FF_DEF_RAWVIDEO_DEMUXER2(mjpeg, "raw MJPEG video", mjpeg_probe, "mjpg,mjpeg,mpo", AV_CODEC_ID_MJPEG, AVFMT_GENERIC_INDEX|AVFMT_NOTIMESTAMPS)
218 #endif
av_packet_unref
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:403
AVMEDIA_TYPE_SUBTITLE
@ AVMEDIA_TYPE_SUBTITLE
Definition: avutil.h:204
ff_raw_video_read_header
int ff_raw_video_read_header(AVFormatContext *s)
Definition: rawdec.c:71
AVERROR
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
opt.h
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4374
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
AVStreamInternal::avctx
AVCodecContext * avctx
The codec context used by avformat_find_stream_info, the parser, etc.
Definition: internal.h:192
AV_OPT_TYPE_VIDEO_RATE
@ AV_OPT_TYPE_VIDEO_RATE
offset must point to AVRational
Definition: opt.h:238
AVFMT_NOTIMESTAMPS
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:462
ff_raw_data_read_header
int ff_raw_data_read_header(AVFormatContext *s)
Definition: rawdec.c:106
state
static struct @321 state
pixdesc.h
AVPacket::data
uint8_t * data
Definition: packet.h:365
AVStream::internal
AVStreamInternal * internal
An opaque field for libavformat internal usage.
Definition: avformat.h:1008
AVOption
AVOption.
Definition: opt.h:248
ff_raw_subtitle_read_header
int ff_raw_subtitle_read_header(AVFormatContext *s)
Definition: rawdec.c:95
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:444
AVCodecContext::framerate
AVRational framerate
Definition: avcodec.h:1816
framerate
int framerate
Definition: h264_levels.c:65
fail
#define fail()
Definition: checkasm.h:134
av_shrink_packet
void av_shrink_packet(AVPacket *pkt, int size)
Reduce packet size, correctly zeroing padding.
Definition: avpacket.c:109
avio_tell
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
FFRawDemuxerContext
Definition: rawdec.h:37
AVFMT_GENERIC_INDEX
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:463
avassert.h
pkt
AVPacket * pkt
Definition: movenc.c:59
AVInputFormat
Definition: avformat.h:616
ff_raw_read_partial_packet
int ff_raw_read_partial_packet(AVFormatContext *s, AVPacket *pkt)
Definition: rawdec.c:35
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:257
av_new_packet
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:94
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:621
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
s1
#define s1
Definition: regdef.h:38
FFRawDemuxerContext::raw_packet_size
int raw_packet_size
Definition: rawdec.h:39
AVMEDIA_TYPE_DATA
@ AVMEDIA_TYPE_DATA
Opaque data information usually continuous.
Definition: avutil.h:203
ff_data_demuxer
const AVInputFormat ff_data_demuxer
AVFormatContext
Format I/O context.
Definition: avformat.h:1106
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:979
NULL
#define NULL
Definition: coverity.c:32
rawdec.h
ff_raw_options
const AVOption ff_raw_options[]
Definition: rawdec.c:128
parseutils.h
ff_raw_audio_read_header
int ff_raw_audio_read_header(AVFormatContext *s)
Definition: rawdec.c:56
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
RAW_PACKET_SIZE
#define RAW_PACKET_SIZE
Definition: rawdec.c:33
c
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
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:451
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:117
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:4799
size
int size
Definition: twinvq_data.h:10344
FFRawVideoDemuxerContext
Definition: rawdec.h:29
FFMIN
#define FFMIN(a, b)
Definition: common.h:105
OFFSET
#define OFFSET(x)
Definition: rawdec.c:127
AV_CODEC_ID_MJPEG
@ AV_CODEC_ID_MJPEG
Definition: codec_id.h:56
i
int i
Definition: input.c:407
AV_CODEC_ID_NONE
@ AV_CODEC_ID_NONE
Definition: codec_id.h:47
avio_internal.h
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:832
AVStreamInternal::need_parsing
enum AVStreamParseType need_parsing
Definition: internal.h:378
avformat.h
AV_OPT_TYPE_INT
@ AV_OPT_TYPE_INT
Definition: opt.h:225
FF_DEF_RAWVIDEO_DEMUXER2
#define FF_DEF_RAWVIDEO_DEMUXER2(shortname, longname, probe, ext, id, flag)
Definition: rawdec.h:71
AVSTREAM_PARSE_FULL_RAW
@ AVSTREAM_PARSE_FULL_RAW
full parsing and repack with timestamp and position generation by parser for raw this assumes that ea...
Definition: avformat.h:757
AVPacket::stream_index
int stream_index
Definition: packet.h:367
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
DEC
#define DEC
Definition: rawdec.c:120
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVPacket
This structure stores compressed data.
Definition: packet.h:342
AVPacket::pos
int64_t pos
byte position in stream, -1 if unknown
Definition: packet.h:385
ff_rawvideo_options
const AVOption ff_rawvideo_options[]
Definition: rawdec.c:121
AVStream::start_time
int64_t start_time
Decoding: pts of the first frame of the stream in presentation order, in stream time base.
Definition: avformat.h:865
avio_read_partial
int avio_read_partial(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:687
FF_RAW_DEMUXER_CLASS
#define FF_RAW_DEMUXER_CLASS(name)
Definition: rawdec.h:55