FFmpeg
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;
105  pkt->flags |= AV_PKT_FLAG_KEY;
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 };
#define NULL
Definition: coverity.c:32
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
misc image utilities
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
AVRational sample_aspect_ratio
sample aspect ratio (0 if unknown)
Definition: avformat.h:946
int num
Numerator.
Definition: rational.h:59
int size
Definition: packet.h:364
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:341
static AVPacket pkt
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:91
Format I/O context.
Definition: avformat.h:1243
static int msp_read_header(AVFormatContext *s)
Definition: mspdec.c:50
int packet_size
Definition: mspdec.c:33
int width
Video only.
Definition: codec_par.h:126
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4489
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1311
uint8_t * data
Definition: packet.h:363
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
ptrdiff_t size
Definition: opengl_enc.c:100
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:320
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:401
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
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:754
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:115
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:369
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 int msp_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mspdec.c:82
#define s(width, name)
Definition: cbs_vp9.c:257
Stream structure.
Definition: avformat.h:884
#define AVFMT_NOTIMESTAMPS
Format does not need / have any timestamps.
Definition: avformat.h:462
AVIOContext * pb
I/O context.
Definition: avformat.h:1285
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:738
Y , 1bpp, 0 is black, 1 is white, in each byte pixels are ordered from the msb to the lsb...
Definition: pixfmt.h:76
Main libavformat public API header.
static int msp_probe(const AVProbeData *p)
Definition: mspdec.c:36
int den
Denominator.
Definition: rational.h:60
void * priv_data
Format private data.
Definition: avformat.h:1271
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:654
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1049
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
#define MKTAG(a, b, c, d)
Definition: common.h:478
AVInputFormat ff_msp_demuxer
Definition: mspdec.c:109
This structure stores compressed data.
Definition: packet.h:340
int i
Definition: input.c:407