FFmpeg  4.3.6
alp.c
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1 /*
2  * LEGO Racers ALP (.tun & .pcm) demuxer
3  *
4  * Copyright (C) 2020 Zane van Iperen (zane@zanevaniperen.com)
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 #include "avformat.h"
23 #include "internal.h"
24 #include "libavutil/intreadwrite.h"
25 #include "libavutil/internal.h"
26 
27 #define ALP_TAG MKTAG('A', 'L', 'P', ' ')
28 #define ALP_MAX_READ_SIZE 4096
29 
30 typedef struct ALPHeader {
31  uint32_t magic; /*< Magic Number, {'A', 'L', 'P', ' '} */
32  uint32_t header_size; /*< Header size (after this). */
33  char adpcm[6]; /*< "ADPCM" */
34  uint8_t unk1; /*< Unknown */
35  uint8_t num_channels; /*< Channel Count. */
36  uint32_t sample_rate; /*< Sample rate, only if header_size >= 12. */
37 } ALPHeader;
38 
39 static int alp_probe(const AVProbeData *p)
40 {
41  uint32_t i;
42 
43  if (AV_RL32(p->buf) != ALP_TAG)
44  return 0;
45 
46  /* Only allowed header sizes are 8 and 12. */
47  i = AV_RL32(p->buf + 4);
48  if (i != 8 && i != 12)
49  return 0;
50 
51  if (strncmp("ADPCM", p->buf + 8, 6) != 0)
52  return 0;
53 
54  return AVPROBE_SCORE_MAX - 1;
55 }
56 
58 {
59  int ret;
60  AVStream *st;
61  ALPHeader hdr;
62  AVCodecParameters *par;
63 
64  if ((hdr.magic = avio_rl32(s->pb)) != ALP_TAG)
65  return AVERROR_INVALIDDATA;
66 
67  hdr.header_size = avio_rl32(s->pb);
68 
69  if (hdr.header_size != 8 && hdr.header_size != 12) {
70  return AVERROR_INVALIDDATA;
71  }
72 
73  if ((ret = avio_read(s->pb, hdr.adpcm, sizeof(hdr.adpcm))) < 0)
74  return ret;
75  else if (ret != sizeof(hdr.adpcm))
76  return AVERROR(EIO);
77 
78  if (strncmp("ADPCM", hdr.adpcm, sizeof(hdr.adpcm)) != 0)
79  return AVERROR_INVALIDDATA;
80 
81  hdr.unk1 = avio_r8(s->pb);
82  hdr.num_channels = avio_r8(s->pb);
83 
84  if (hdr.header_size == 8) {
85  /* .TUN music file */
86  hdr.sample_rate = 22050;
87  } else {
88  /* .PCM sound file */
89  hdr.sample_rate = avio_rl32(s->pb);
90  }
91 
92  if (hdr.sample_rate > 44100) {
93  avpriv_request_sample(s, "Sample Rate > 44100");
94  return AVERROR_PATCHWELCOME;
95  }
96 
97  if (!(st = avformat_new_stream(s, NULL)))
98  return AVERROR(ENOMEM);
99 
100  par = st->codecpar;
103  par->format = AV_SAMPLE_FMT_S16;
104  par->sample_rate = hdr.sample_rate;
105  par->channels = hdr.num_channels;
106 
107  if (hdr.num_channels == 1)
109  else if (hdr.num_channels == 2)
111  else
112  return AVERROR_INVALIDDATA;
113 
114  par->bits_per_coded_sample = 4;
115  par->bits_per_raw_sample = 16;
116  par->block_align = 1;
117  par->bit_rate = par->channels *
118  par->sample_rate *
120 
121  avpriv_set_pts_info(st, 64, 1, par->sample_rate);
122  return 0;
123 }
124 
126 {
127  int ret;
128  AVCodecParameters *par = s->streams[0]->codecpar;
129 
130  if ((ret = av_get_packet(s->pb, pkt, ALP_MAX_READ_SIZE)) < 0)
131  return ret;
132 
133  pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
134  pkt->stream_index = 0;
135  pkt->duration = ret * 2 / par->channels;
136 
137  return 0;
138 }
139 
141  .name = "alp",
142  .long_name = NULL_IF_CONFIG_SMALL("LEGO Racers ALP"),
143  .read_probe = alp_probe,
144  .read_header = alp_read_header,
145  .read_packet = alp_read_packet
146 };
#define NULL
Definition: coverity.c:32
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
static int alp_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: alp.c:125
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:4948
#define avpriv_request_sample(...)
static int alp_read_header(AVFormatContext *s)
Definition: alp.c:57
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: codec_par.h:60
static AVPacket pkt
#define AV_CH_LAYOUT_STEREO
This struct describes the properties of an encoded stream.
Definition: codec_par.h:52
Format I/O context.
Definition: avformat.h:1351
uint8_t
int64_t duration
Duration of this packet in AVStream->time_base units, 0 if unknown.
Definition: packet.h:373
#define ALP_MAX_READ_SIZE
Definition: alp.c:28
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4526
AVStream ** streams
A list of all streams in the file.
Definition: avformat.h:1419
uint32_t header_size
Definition: alp.c:32
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:307
uint8_t unk1
Definition: alp.c:34
uint64_t channel_layout
Audio only.
Definition: codec_par.h:162
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:625
int64_t bit_rate
The average bitrate of the encoded data (in bits per second).
Definition: codec_par.h:89
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:269
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:747
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:188
enum AVMediaType codec_type
General type of the encoded data.
Definition: codec_par.h:56
Definition: alp.c:30
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:361
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:616
uint8_t num_channels
Definition: alp.c:35
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:443
common internal API header
int block_align
Audio only.
Definition: codec_par.h:177
uint32_t magic
Definition: alp.c:31
AVInputFormat ff_alp_demuxer
Definition: alp.c:140
#define s(width, name)
Definition: cbs_vp9.c:257
#define AV_RL32
Definition: intreadwrite.h:146
static int alp_probe(const AVProbeData *p)
Definition: alp.c:39
Stream structure.
Definition: avformat.h:876
#define AVERROR_PATCHWELCOME
Not yet implemented in FFmpeg, patches welcome.
Definition: error.h:62
AVIOContext * pb
I/O context.
Definition: avformat.h:1393
uint32_t sample_rate
Definition: alp.c:36
char adpcm[6]
Definition: alp.c:33
This structure contains the data a format has to probe a file.
Definition: avformat.h:441
int bits_per_raw_sample
This is the number of valid bits in each output sample.
Definition: codec_par.h:115
int sample_rate
Audio only.
Definition: codec_par.h:170
#define AVPROBE_SCORE_MAX
maximum score
Definition: avformat.h:453
Main libavformat public API header.
signed 16 bits
Definition: samplefmt.h:61
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: packet.h:389
#define ALP_TAG
Definition: alp.c:27
int bits_per_coded_sample
The number of bits per sample in the codedwords.
Definition: codec_par.h:102
int channels
Audio only.
Definition: codec_par.h:166
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:650
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1023
int stream_index
Definition: packet.h:357
#define AV_CH_LAYOUT_MONO
This structure stores compressed data.
Definition: packet.h:332