FFmpeg  4.4.5
mspdec.c
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1 /*
2  * Microsoft Paint (MSP) demuxer
3  * Copyright (c) 2020 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  * Microsoft Paint (MSP) demuxer
25  */
26 
27 #include "libavutil/intreadwrite.h"
28 #include "libavutil/imgutils.h"
29 #include "avformat.h"
30 #include "internal.h"
31 
32 typedef struct {
34 } MSPContext;
35 
36 static int msp_probe(const AVProbeData *p)
37 {
38  unsigned int i, sum;
39 
40  if (p->buf_size <= 32 || (memcmp(p->buf, "DanM", 4) && memcmp(p->buf, "LinS", 4)))
41  return 0;
42 
43  sum = 0;
44  for (i = 0; i < 24; i += 2)
45  sum ^= AV_RL16(p->buf + i);
46 
47  return AV_RL16(p->buf + 24) == sum ? AVPROBE_SCORE_MAX : 0;
48 }
49 
51 {
52  MSPContext * cntx = s->priv_data;
53  AVIOContext *pb = s->pb;
54  AVStream *st;
55 
56  st = avformat_new_stream(s, NULL);
57  if (!st)
58  return AVERROR(ENOMEM);
59 
61  st->codecpar->codec_id = avio_rl32(pb) == MKTAG('D', 'a', 'n', 'M') ? AV_CODEC_ID_RAWVIDEO : AV_CODEC_ID_MSP2;
62 
63  st->codecpar->width = avio_rl16(pb);
64  st->codecpar->height = avio_rl16(pb);
66 
69  avio_skip(pb, 20);
70 
73  } else
74  cntx->packet_size = 2 * st->codecpar->height;
75 
76  if (cntx->packet_size <= 0)
77  return cntx->packet_size < 0 ? cntx->packet_size : AVERROR_INVALIDDATA;
78 
79  return 0;
80 }
81 
83 {
84  AVStream *st = s->streams[0];
85  MSPContext *cntx = s->priv_data;
86  int ret;
87 
88  ret = av_get_packet(s->pb, pkt, cntx->packet_size);
89  if (ret < 0)
90  return ret;
91 
92  if (st->codecpar->codec_id == AV_CODEC_ID_MSP2) {
93  unsigned int size, i;
94  if (pkt->size != 2 * st->codecpar->height)
95  return AVERROR_INVALIDDATA;
96  size = 0;
97  for (i = 0; i < st->codecpar->height; i++)
98  size += AV_RL16(&pkt->data[i * 2]);
99  ret = av_append_packet(s->pb, pkt, size);
100  if (ret < 0)
101  return ret;
102  }
103 
104  pkt->stream_index = 0;
106  return 0;
107 }
108 
110  .name = "msp",
111  .long_name = NULL_IF_CONFIG_SMALL("Microsoft Paint (MSP))"),
112  .read_probe = msp_probe,
113  .read_header = msp_read_header,
114  .read_packet = msp_read_packet,
115  .flags = AVFMT_NOTIMESTAMPS,
116  .priv_data_size = sizeof(MSPContext),
117 };
Main libavformat public API header.
int av_append_packet(AVIOContext *s, AVPacket *pkt, int size)
Read data and append it to the current content of the AVPacket.
Definition: utils.c:326
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
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:310
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:462
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:734
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:337
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:750
#define AV_RL16
Definition: intreadwrite.h:42
#define s(width, name)
Definition: cbs_vp9.c:257
#define MKTAG(a, b, c, d)
Definition: common.h:478
#define NULL
Definition: coverity.c:32
@ AV_CODEC_ID_RAWVIDEO
Definition: codec_id.h:62
@ AV_CODEC_ID_MSP2
Definition: codec_id.h:246
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:410
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4509
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR(e)
Definition: error.h:43
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
int av_image_get_buffer_size(enum AVPixelFormat pix_fmt, int width, int height, int align)
Return the size in bytes of the amount of data required to store an image with the given parameters.
Definition: imgutils.c:466
misc image utilities
int i
Definition: input.c:407
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static int msp_read_header(AVFormatContext *s)
Definition: mspdec.c:50
AVInputFormat ff_msp_demuxer
Definition: mspdec.c:109
static int msp_probe(const AVProbeData *p)
Definition: mspdec.c:36
static int msp_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mspdec.c:82
@ AV_PIX_FMT_MONOBLACK
Y , 1bpp, 0 is black, 1 is white, in each byte pixels are ordered from the msb to the lsb.
Definition: pixfmt.h:76
int width
Video only.
Definition: codec_par.h:126
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
Format I/O context.
Definition: avformat.h:1232
Bytestream IO Context.
Definition: avio.h:161
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:645
This structure stores compressed data.
Definition: packet.h:346
int stream_index
Definition: packet.h:371
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
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
int num
Numerator.
Definition: rational.h:59
int den
Denominator.
Definition: rational.h:60
Stream structure.
Definition: avformat.h:873
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1038
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:935
int packet_size
Definition: mspdec.c:33
AVPacket * pkt
Definition: movenc.c:59
int size