Libav
smjpegdec.c
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1 /*
2  * SMJPEG demuxer
3  * Copyright (c) 2011 Paul B Mahol
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 
27 #include "avformat.h"
28 #include "internal.h"
29 #include "riff.h"
30 #include "smjpeg.h"
31 
32 typedef struct SMJPEGContext {
36 
37 static int smjpeg_probe(AVProbeData *p)
38 {
39  if (!memcmp(p->buf, SMJPEG_MAGIC, 8))
40  return AVPROBE_SCORE_MAX;
41  return 0;
42 }
43 
45 {
46  SMJPEGContext *sc = s->priv_data;
47  AVStream *ast = NULL, *vst = NULL;
48  AVIOContext *pb = s->pb;
49  uint32_t version, htype, hlength, duration;
50  char *comment;
51 
52  avio_skip(pb, 8); // magic
53  version = avio_rb32(pb);
54  if (version)
55  avpriv_request_sample(s, "Unknown version %d", version);
56 
57  duration = avio_rb32(pb); // in msec
58 
59  while (!pb->eof_reached) {
60  htype = avio_rl32(pb);
61  switch (htype) {
62  case SMJPEG_TXT:
63  hlength = avio_rb32(pb);
64  if (!hlength || hlength > 512)
65  return AVERROR_INVALIDDATA;
66  comment = av_malloc(hlength + 1);
67  if (!comment)
68  return AVERROR(ENOMEM);
69  if (avio_read(pb, comment, hlength) != hlength) {
70  av_freep(&comment);
71  av_log(s, AV_LOG_ERROR, "error when reading comment\n");
72  return AVERROR_INVALIDDATA;
73  }
74  comment[hlength] = 0;
75  av_dict_set(&s->metadata, "comment", comment,
77  break;
78  case SMJPEG_SND:
79  if (ast) {
80  avpriv_request_sample(s, "Multiple audio streams");
81  return AVERROR_PATCHWELCOME;
82  }
83  hlength = avio_rb32(pb);
84  if (hlength < 8)
85  return AVERROR_INVALIDDATA;
86  ast = avformat_new_stream(s, 0);
87  if (!ast)
88  return AVERROR(ENOMEM);
90  ast->codec->sample_rate = avio_rb16(pb);
92  ast->codec->channels = avio_r8(pb);
93  ast->codec->codec_tag = avio_rl32(pb);
95  ast->codec->codec_tag);
96  ast->duration = duration;
97  sc->audio_stream_index = ast->index;
98  avpriv_set_pts_info(ast, 32, 1, 1000);
99  avio_skip(pb, hlength - 8);
100  break;
101  case SMJPEG_VID:
102  if (vst) {
103  avpriv_request_sample(s, "Multiple video streams");
104  return AVERROR_INVALIDDATA;
105  }
106  hlength = avio_rb32(pb);
107  if (hlength < 12)
108  return AVERROR_INVALIDDATA;
109  avio_skip(pb, 4); // number of frames
110  vst = avformat_new_stream(s, 0);
111  if (!vst)
112  return AVERROR(ENOMEM);
113  vst->codec->codec_type = AVMEDIA_TYPE_VIDEO;
114  vst->codec->width = avio_rb16(pb);
115  vst->codec->height = avio_rb16(pb);
116  vst->codec->codec_tag = avio_rl32(pb);
117  vst->codec->codec_id = ff_codec_get_id(ff_codec_smjpeg_video_tags,
118  vst->codec->codec_tag);
119  vst->duration = duration;
120  sc->video_stream_index = vst->index;
121  avpriv_set_pts_info(vst, 32, 1, 1000);
122  avio_skip(pb, hlength - 12);
123  break;
124  case SMJPEG_HEND:
125  return 0;
126  default:
127  av_log(s, AV_LOG_ERROR, "unknown header %x\n", htype);
128  return AVERROR_INVALIDDATA;
129  }
130  }
131 
132  return AVERROR_EOF;
133 }
134 
136 {
137  SMJPEGContext *sc = s->priv_data;
138  uint32_t dtype, size, timestamp;
139  int64_t pos;
140  int ret;
141 
142  if (s->pb->eof_reached)
143  return AVERROR_EOF;
144  pos = avio_tell(s->pb);
145  dtype = avio_rl32(s->pb);
146  switch (dtype) {
147  case SMJPEG_SNDD:
148  timestamp = avio_rb32(s->pb);
149  size = avio_rb32(s->pb);
150  ret = av_get_packet(s->pb, pkt, size);
151  pkt->stream_index = sc->audio_stream_index;
152  pkt->pts = timestamp;
153  pkt->pos = pos;
154  break;
155  case SMJPEG_VIDD:
156  timestamp = avio_rb32(s->pb);
157  size = avio_rb32(s->pb);
158  ret = av_get_packet(s->pb, pkt, size);
159  pkt->stream_index = sc->video_stream_index;
160  pkt->pts = timestamp;
161  pkt->pos = pos;
162  break;
163  case SMJPEG_DONE:
164  ret = AVERROR_EOF;
165  break;
166  default:
167  av_log(s, AV_LOG_ERROR, "unknown chunk %x\n", dtype);
168  ret = AVERROR_INVALIDDATA;
169  break;
170  }
171  return ret;
172 }
173 
175  .name = "smjpeg",
176  .long_name = NULL_IF_CONFIG_SMALL("Loki SDL MJPEG"),
177  .priv_data_size = sizeof(SMJPEGContext),
181  .extensions = "mjpg",
183 };
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
Bytestream IO Context.
Definition: avio.h:68
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
int size
#define SMJPEG_DONE
Definition: smjpeg.h:34
enum AVCodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:2074
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1002
AVInputFormat ff_smjpeg_demuxer
Definition: smjpegdec.c:174
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:3208
int index
stream index in AVFormatContext
Definition: avformat.h:684
#define SMJPEG_HEND
Definition: smjpeg.h:35
SMJPEG common code.
const AVCodecTag ff_codec_smjpeg_video_tags[]
Definition: smjpeg.c:31
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:574
static int64_t duration
Definition: avplay.c:246
void av_freep(void *arg)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc() and set the pointer ...
Definition: mem.c:198
Format I/O context.
Definition: avformat.h:871
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
unsigned int avio_rb32(AVIOContext *s)
Definition: aviobuf.c:589
static int smjpeg_probe(AVProbeData *p)
Definition: smjpegdec.c:37
#define SMJPEG_SND
Definition: smjpeg.h:36
static int smjpeg_read_header(AVFormatContext *s)
Definition: smjpegdec.c:44
static int flags
Definition: log.c:44
#define SMJPEG_VIDD
Definition: smjpeg.h:40
#define AVERROR_EOF
End of file.
Definition: error.h:51
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:118
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:219
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:2481
int video_stream_index
Definition: smjpegdec.c:34
#define SMJPEG_TXT
Definition: smjpeg.h:38
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:446
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
AVDictionary * metadata
Metadata that applies to the whole file.
Definition: avformat.h:1064
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:558
#define AVERROR(e)
Definition: error.h:43
#define SMJPEG_MAGIC
Definition: smjpeg.h:32
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:142
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:148
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2662
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:437
AVCodecContext * codec
Codec context associated with this stream.
Definition: avformat.h:702
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:390
#define AV_DICT_DONT_STRDUP_VAL
Take ownership of a value that's been allocated with av_malloc() and chilren.
Definition: dict.h:66
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: avio.h:210
internal header for RIFF based (de)muxers do NOT include this in end user applications ...
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:536
Stream structure.
Definition: avformat.h:683
#define AVERROR_PATCHWELCOME
Not yet implemented in Libav, patches welcome.
Definition: error.h:57
NULL
Definition: eval.c:55
enum AVMediaType codec_type
Definition: avcodec.h:1062
version
Definition: ffv1enc.c:1080
enum AVCodecID codec_id
Definition: avcodec.h:1065
int sample_rate
samples per second
Definition: avcodec.h:1779
AVIOContext * pb
I/O context.
Definition: avformat.h:913
int audio_stream_index
Definition: smjpegdec.c:33
#define SMJPEG_VID
Definition: smjpeg.h:39
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1080
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:114
int av_dict_set(AVDictionary **pm, const char *key, const char *value, int flags)
Set the given entry in *pm, overwriting an existing entry.
Definition: dict.c:62
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:408
This structure contains the data a format has to probe a file.
Definition: avformat.h:388
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:734
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:395
Main libavformat public API header.
#define SMJPEG_SNDD
Definition: smjpeg.h:37
static int smjpeg_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: smjpegdec.c:135
const AVCodecTag ff_codec_smjpeg_audio_tags[]
Definition: smjpeg.c:36
int eof_reached
true if eof reached
Definition: avio.h:96
int channels
number of audio channels
Definition: avcodec.h:1780
void * priv_data
Format private data.
Definition: avformat.h:899
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:516
int stream_index
Definition: avcodec.h:975
This structure stores compressed data.
Definition: avcodec.h:950
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:966