FFmpeg: libavformat/mm.c Source File

FFmpeg
mm.c
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1 /*
2  * American Laser Games MM Format Demuxer
3  * Copyright (c) 2006 Peter Ross
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  * American Laser Games MM Format Demuxer
25  * by Peter Ross (pross@xvid.org)
26  *
27  * The MM format was used by IBM-PC ports of ALG's "arcade shooter" games,
28  * including Mad Dog McCree and Crime Patrol.
29  *
30  * Technical details here:
31  * http://wiki.multimedia.cx/index.php?title=American_Laser_Games_MM
32  */
33 
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/intreadwrite.h"
36 #include "avformat.h"
37 #include "demux.h"
38 #include "internal.h"
39 
40  #define MM_PREAMBLE_SIZE 6
41 
42  #define MM_TYPE_HEADER 0x0
43  #define MM_TYPE_INTER 0x5
44  #define MM_TYPE_INTRA 0x8
45  #define MM_TYPE_INTRA_HH 0xc
46  #define MM_TYPE_INTER_HH 0xd
47  #define MM_TYPE_INTRA_HHV 0xe
48  #define MM_TYPE_INTER_HHV 0xf
49  #define MM_TYPE_AUDIO 0x15
50  #define MM_TYPE_PALETTE 0x31
51 
52  #define MM_HEADER_LEN_V 0x16 /* video only */
53  #define MM_HEADER_LEN_AV 0x18 /* video + audio */
54 
55  #define MM_PALETTE_COUNT 128
56  #define MM_PALETTE_SIZE (MM_PALETTE_COUNT*3)
57 
58  typedef struct MmDemuxContext {
59   unsigned int audio_pts, video_pts;
60 } MmDemuxContext;
61 
62  static int probe(const AVProbeData *p)
63 {
64  int len, type, fps, w, h;
65  if (p->buf_size < MM_HEADER_LEN_AV + MM_PREAMBLE_SIZE)
66  return 0;
67  /* the first chunk is always the header */
68  if (AV_RL16(&p->buf[0]) != MM_TYPE_HEADER)
69  return 0;
70  len = AV_RL32(&p->buf[2]);
71  if (len != MM_HEADER_LEN_V && len != MM_HEADER_LEN_AV)
72  return 0;
73  fps = AV_RL16(&p->buf[8]);
74  w = AV_RL16(&p->buf[12]);
75  h = AV_RL16(&p->buf[14]);
76  if (!fps || fps > 60 || !w || w > 2048 || !h || h > 2048)
77  return 0;
78  type = AV_RL16(&p->buf[len]);
79  if (!type || type > 0x31)
80  return 0;
81 
82  /* only return half certainty since this check is a bit sketchy */
83  return AVPROBE_SCORE_EXTENSION;
84 }
85 
86  static int read_header(AVFormatContext *s)
87 {
88  MmDemuxContext *mm = s->priv_data;
89  AVIOContext *pb = s->pb;
90  AVStream *st;
91 
92  unsigned int type, length;
93  unsigned int frame_rate, width, height;
94 
95  type = avio_rl16(pb);
96  length = avio_rl32(pb);
97 
98  if (type != MM_TYPE_HEADER || length < 10)
99  return AVERROR_INVALIDDATA;
100 
101  /* read header */
102  avio_rl16(pb); /* total number of chunks */
103  frame_rate = avio_rl16(pb);
104  avio_rl16(pb); /* ibm-pc video bios mode */
105  width = avio_rl16(pb);
106  height = avio_rl16(pb);
107  avio_skip(pb, length - 10); /* unknown data */
108 
109  /* video stream */
110  st = avformat_new_stream(s, NULL);
111  if (!st)
112  return AVERROR(ENOMEM);
113  st->codecpar->codec_type = AVMEDIA_TYPE_VIDEO;
114  st->codecpar->codec_id = AV_CODEC_ID_MMVIDEO;
115  st->codecpar->codec_tag = 0; /* no fourcc */
116  st->codecpar->width = width;
117  st->codecpar->height = height;
118  avpriv_set_pts_info(st, 64, 1, frame_rate);
119 
120  /* audio stream */
121  if (length == MM_HEADER_LEN_AV) {
122  st = avformat_new_stream(s, NULL);
123  if (!st)
124  return AVERROR(ENOMEM);
125  st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
126  st->codecpar->codec_tag = 0; /* no fourcc */
127  st->codecpar->codec_id = AV_CODEC_ID_PCM_U8;
128  st->codecpar->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
129  st->codecpar->sample_rate = 8000;
130  avpriv_set_pts_info(st, 64, 1, 8000); /* 8000 hz */
131  }
132 
133  mm->audio_pts = 0;
134  mm->video_pts = 0;
135  return 0;
136 }
137 
138  static int read_packet(AVFormatContext *s,
139  AVPacket *pkt)
140 {
141  MmDemuxContext *mm = s->priv_data;
142  AVIOContext *pb = s->pb;
143  unsigned char preamble[MM_PREAMBLE_SIZE];
144  unsigned int type, length;
145  int ret;
146 
147  while(1) {
148 
149  if (avio_read(pb, preamble, MM_PREAMBLE_SIZE) != MM_PREAMBLE_SIZE) {
150  return AVERROR(EIO);
151  }
152 
153  type = AV_RL16(&preamble[0]);
154  length = AV_RL16(&preamble[2]);
155 
156  switch(type) {
157  case MM_TYPE_PALETTE :
158  case MM_TYPE_INTER :
159  case MM_TYPE_INTRA :
160  case MM_TYPE_INTRA_HH :
161  case MM_TYPE_INTER_HH :
162  case MM_TYPE_INTRA_HHV :
163  case MM_TYPE_INTER_HHV :
164  /* output preamble + data */
165  if ((ret = av_new_packet(pkt, length + MM_PREAMBLE_SIZE)) < 0)
166  return ret;
167  memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
168  if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
169  return AVERROR(EIO);
170  pkt->size = length + MM_PREAMBLE_SIZE;
171  pkt->stream_index = 0;
172  pkt->pts = mm->video_pts;
173  if (type!=MM_TYPE_PALETTE)
174  mm->video_pts++;
175  return 0;
176 
177  case MM_TYPE_AUDIO :
178  if (s->nb_streams < 2)
179  return AVERROR_INVALIDDATA;
180  if ((ret = av_get_packet(s->pb, pkt, length)) < 0)
181  return ret;
182  pkt->stream_index = 1;
183  pkt->pts = mm->audio_pts++;
184  return 0;
185 
186  default :
187  av_log(s, AV_LOG_INFO, "unknown chunk type 0x%x\n", type);
188  avio_skip(pb, length);
189  }
190  }
191 }
192 
193  const FFInputFormat ff_mm_demuxer = {
194  .p.name = "mm",
195  .p.long_name = NULL_IF_CONFIG_SMALL("American Laser Games MM"),
196  .priv_data_size = sizeof(MmDemuxContext),
197  .read_probe = probe,
198  .read_header = read_header,
199  .read_packet = read_packet,
200 };
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
AVCodecParameters::codec_type
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:51
MmDemuxContext::video_pts
unsigned int video_pts
Definition: mm.c:59
avformat_new_stream
AVStream * avformat_new_stream(AVFormatContext *s, const struct AVCodec *c)
Add a new stream to a media file.
read_packet
static int read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: mm.c:138
MM_TYPE_INTER_HHV
#define MM_TYPE_INTER_HHV
Definition: mm.c:48
MM_TYPE_INTER
#define MM_TYPE_INTER
Definition: mm.c:43
w
uint8_t w
Definition: llviddspenc.c:38
AVPacket::data
uint8_t * data
Definition: packet.h:539
AVCodecParameters::codec_tag
uint32_t codec_tag
Additional information about the codec (corresponds to the AVI FOURCC).
Definition: codec_par.h:59
AVProbeData::buf_size
int buf_size
Size of buf except extra allocated bytes.
Definition: avformat.h:454
avpriv_set_pts_info
void avpriv_set_pts_info(AVStream *st, int pts_wrap_bits, unsigned int pts_num, unsigned int pts_den)
Set the time base and wrapping info for a given stream.
Definition: avformat.c:860
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
avio_rl16
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:714
MM_TYPE_INTRA_HHV
#define MM_TYPE_INTRA_HHV
Definition: mm.c:47
pkt
AVPacket * pkt
Definition: movenc.c:60
MM_TYPE_INTRA_HH
#define MM_TYPE_INTRA_HH
Definition: mm.c:45
intreadwrite.h
s
#define s(width, name)
Definition: cbs_vp9.c:198
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: packet.c:98
AVInputFormat::name
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:553
AVProbeData::buf
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:453
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
AVCodecParameters::width
int width
Video only.
Definition: codec_par.h:134
AV_RL16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_RL16
Definition: bytestream.h:94
MM_TYPE_HEADER
#define MM_TYPE_HEADER
Definition: mm.c:42
probe
static int probe(const AVProbeData *p)
Definition: mm.c:62
AVFormatContext
Format I/O context.
Definition: avformat.h:1287
internal.h
AVStream::codecpar
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:771
NULL
#define NULL
Definition: coverity.c:32
AVProbeData
This structure contains the data a format has to probe a file.
Definition: avformat.h:451
MM_PREAMBLE_SIZE
#define MM_PREAMBLE_SIZE
Definition: mm.c:40
AVCodecParameters::ch_layout
AVChannelLayout ch_layout
Audio only.
Definition: codec_par.h:180
AVPROBE_SCORE_EXTENSION
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:461
AVCodecParameters::sample_rate
int sample_rate
Audio only.
Definition: codec_par.h:184
avio_rl32
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:730
AVIOContext
Bytestream IO Context.
Definition: avio.h:160
MmDemuxContext::audio_pts
unsigned int audio_pts
Definition: mm.c:59
AVPacket::size
int size
Definition: packet.h:540
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:94
height
#define height
Definition: dsp.h:85
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:311
FFInputFormat::p
AVInputFormat p
The public AVInputFormat.
Definition: demux.h:41
AV_CODEC_ID_MMVIDEO
@ AV_CODEC_ID_MMVIDEO
Definition: codec_id.h:132
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:191
MM_TYPE_PALETTE
#define MM_TYPE_PALETTE
Definition: mm.c:50
MM_HEADER_LEN_AV
#define MM_HEADER_LEN_AV
Definition: mm.c:53
AVPacket::pts
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:532
AVCodecParameters::height
int height
Definition: codec_par.h:135
MM_TYPE_INTER_HH
#define MM_TYPE_INTER_HH
Definition: mm.c:46
demux.h
len
int len
Definition: vorbis_enc_data.h:426
av_get_packet
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:91
MmDemuxContext
Definition: mm.c:58
ret
ret
Definition: filter_design.txt:187
AVStream
Stream structure.
Definition: avformat.h:748
avformat.h
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
channel_layout.h
MM_TYPE_INTRA
#define MM_TYPE_INTRA
Definition: mm.c:44
ff_mm_demuxer
const FFInputFormat ff_mm_demuxer
Definition: mm.c:193
avio_read
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:612
AVPacket::stream_index
int stream_index
Definition: packet.h:541
avio_skip
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:318
MM_TYPE_AUDIO
#define MM_TYPE_AUDIO
Definition: mm.c:49
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
read_probe
static int read_probe(const AVProbeData *p)
Definition: cdg.c:30
AV_CODEC_ID_PCM_U8
@ AV_CODEC_ID_PCM_U8
Definition: codec_id.h:333
AV_CHANNEL_LAYOUT_MONO
#define AV_CHANNEL_LAYOUT_MONO
Definition: channel_layout.h:386
AVCodecParameters::codec_id
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:55
AVPacket
This structure stores compressed data.
Definition: packet.h:516
FFInputFormat
Definition: demux.h:37
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:27
MM_HEADER_LEN_V
#define MM_HEADER_LEN_V
Definition: mm.c:52
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
h
h
Definition: vp9dsp_template.c:2070
width
#define width
Definition: dsp.h:85
read_header
static int read_header(AVFormatContext *s)
Definition: mm.c:86
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