FFmpeg  4.0
sdsdec.c
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1 /*
2  * MIDI Sample Dump Standard format demuxer
3  * Copyright (c) 2017 Paul B Mahol
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 #include "libavutil/intreadwrite.h"
23 #include "avformat.h"
24 #include "internal.h"
25 
26 typedef struct SDSContext {
27  uint8_t data[120];
28  int bit_depth;
29  int size;
30  void (*read_block)(const uint8_t *src, uint32_t *dst);
31 } SDSContext;
32 
33 static int sds_probe(AVProbeData *p)
34 {
35  if (AV_RB32(p->buf) == 0xF07E0001 && p->buf[20] == 0xF7 &&
36  p->buf[6] >= 8 && p->buf[6] <= 28)
38  return 0;
39 }
40 
41 static void byte2_read(const uint8_t *src, uint32_t *dst)
42 {
43  int i;
44 
45  for (i = 0; i < 120; i += 2) {
46  unsigned sample = (src[i + 0] << 25) + (src[i + 1] << 18);
47 
48  dst[i / 2] = sample;
49  }
50 }
51 
52 static void byte3_read(const uint8_t *src, uint32_t *dst)
53 {
54  int i;
55 
56  for (i = 0; i < 120; i += 3) {
57  unsigned sample;
58 
59  sample = (src[i + 0] << 25) | (src[i + 1] << 18) | (src[i + 2] << 11);
60  dst[i / 3] = sample;
61  }
62 }
63 
64 static void byte4_read(const uint8_t *src, uint32_t *dst)
65 {
66  int i;
67 
68  for (i = 0; i < 120; i += 4) {
69  unsigned sample;
70 
71  sample = (src[i + 0] << 25) | (src[i + 1] << 18) | (src[i + 2] << 11) | (src[i + 3] << 4);
72  dst[i / 4] = sample;
73  }
74 }
75 
76 #define SDS_3BYTE_TO_INT_DECODE(x) (((x) & 0x7F) | (((x) & 0x7F00) >> 1) | (((x) & 0x7F0000) >> 2))
77 
79 {
80  SDSContext *s = ctx->priv_data;
81  unsigned sample_period;
82  AVIOContext *pb = ctx->pb;
83  AVStream *st;
84 
85  st = avformat_new_stream(ctx, NULL);
86  if (!st)
87  return AVERROR(ENOMEM);
88 
89  avio_skip(pb, 4);
90  avio_skip(pb, 2);
91 
92  s->bit_depth = avio_r8(pb);
93  if (s->bit_depth < 8 || s->bit_depth > 28)
94  return AVERROR_INVALIDDATA;
95 
96  if (s->bit_depth < 14) {
98  s->size = 60 * 4;
99  } else if (s->bit_depth < 21) {
100  s->read_block = byte3_read;
101  s->size = 40 * 4;
102  } else {
103  s->read_block = byte4_read;
104  s->size = 30 * 4;
105  }
107 
108  sample_period = avio_rl24(pb);
109  sample_period = SDS_3BYTE_TO_INT_DECODE(sample_period);
110  avio_skip(pb, 11);
111 
113  st->codecpar->channels = 1;
114  st->codecpar->sample_rate = sample_period ? 1000000000 / sample_period : 16000;
115  st->duration = (avio_size(pb) - 21) / (127) * s->size / 4;
116 
117  avpriv_set_pts_info(st, 64, 1, st->codecpar->sample_rate);
118 
119  return 0;
120 }
121 
123 {
124  SDSContext *s = ctx->priv_data;
125  AVIOContext *pb = ctx->pb;
126  int64_t pos;
127  int ret;
128 
129  if (avio_feof(pb))
130  return AVERROR_EOF;
131 
132  pos = avio_tell(pb);
133  if (avio_rb16(pb) != 0xF07E)
134  return AVERROR_INVALIDDATA;
135  avio_skip(pb, 3);
136 
137  ret = av_new_packet(pkt, s->size);
138  if (ret < 0)
139  return ret;
140 
141  ret = avio_read(pb, s->data, 120);
142 
143  s->read_block(s->data, (uint32_t *)pkt->data);
144 
145  avio_skip(pb, 1); // checksum
146  if (avio_r8(pb) != 0xF7)
147  return AVERROR_INVALIDDATA;
148 
149  pkt->flags &= ~AV_PKT_FLAG_CORRUPT;
150  pkt->stream_index = 0;
151  pkt->pos = pos;
152 
153  return ret;
154 }
155 
157  .name = "sds",
158  .long_name = NULL_IF_CONFIG_SMALL("MIDI Sample Dump Standard"),
159  .priv_data_size = sizeof(SDSContext),
163  .extensions = "sds",
165 };
#define NULL
Definition: coverity.c:32
const char * s
Definition: avisynth_c.h:768
Bytestream IO Context.
Definition: avio.h:161
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:336
int64_t pos
byte position in stream, -1 if unknown
Definition: avcodec.h:1450
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:4811
#define SDS_3BYTE_TO_INT_DECODE(x)
Definition: sdsdec.c:76
enum AVCodecID codec_id
Specific type of the encoded data (the codec used).
Definition: avcodec.h:3884
int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: aviobuf.c:331
static AVPacket pkt
unsigned int avio_rb16(AVIOContext *s)
Definition: aviobuf.c:786
#define src
Definition: vp8dsp.c:254
#define sample
Format I/O context.
Definition: avformat.h:1342
uint8_t data[120]
Definition: sdsdec.c:27
uint8_t
#define AV_RB32
Definition: intreadwrite.h:130
AVStream * avformat_new_stream(AVFormatContext *s, const AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:4441
uint8_t * data
Definition: avcodec.h:1430
static int flags
Definition: log.c:55
#define AVERROR_EOF
End of file.
Definition: error.h:55
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:557
int avio_read(AVIOContext *s, unsigned char *buf, int size)
Read size bytes from AVIOContext into buf.
Definition: aviobuf.c:648
int av_new_packet(AVPacket *pkt, int size)
Allocate the payload of a packet and initialize its fields with default values.
Definition: avpacket.c:86
int bit_depth
Definition: sdsdec.c:28
#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:186
enum AVMediaType codec_type
General type of the encoded data.
Definition: avcodec.h:3880
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1436
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:639
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:450
static int sds_read_header(AVFormatContext *ctx)
Definition: sdsdec.c:78
static int read_probe(AVProbeData *pd)
Definition: jvdec.c:55
AVFormatContext * ctx
Definition: movenc.c:48
void(* read_block)(const uint8_t *src, uint32_t *dst)
Definition: sdsdec.c:30
static int read_header(FFV1Context *f)
Definition: ffv1dec.c:530
Stream structure.
Definition: avformat.h:873
static int read_packet(void *opaque, uint8_t *buf, int buf_size)
Definition: avio_reading.c:42
static void byte2_read(const uint8_t *src, uint32_t *dst)
Definition: sdsdec.c:41
typedef void(RENAME(mix_any_func_type))
AVIOContext * pb
I/O context.
Definition: avformat.h:1384
static int sds_read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: sdsdec.c:122
#define AVFMT_GENERIC_INDEX
Use generic index building code.
Definition: avformat.h:470
static int sds_probe(AVProbeData *p)
Definition: sdsdec.c:33
#define AVPROBE_SCORE_EXTENSION
score for file extension
Definition: avformat.h:458
This structure contains the data a format has to probe a file.
Definition: avformat.h:448
int64_t duration
Decoding: duration of the stream, in stream time base.
Definition: avformat.h:922
int sample_rate
Audio only.
Definition: avcodec.h:3994
Main libavformat public API header.
static void byte4_read(const uint8_t *src, uint32_t *dst)
Definition: sdsdec.c:64
#define AV_PKT_FLAG_CORRUPT
The packet content is corrupted.
Definition: avcodec.h:1463
int size
Definition: sdsdec.c:29
void * priv_data
Format private data.
Definition: avformat.h:1370
static void byte3_read(const uint8_t *src, uint32_t *dst)
Definition: sdsdec.c:52
int channels
Audio only.
Definition: avcodec.h:3990
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:647
AVCodecParameters * codecpar
Codec parameters associated with this stream.
Definition: avformat.h:1020
int avio_feof(AVIOContext *s)
feof() equivalent for AVIOContext.
Definition: aviobuf.c:358
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:762
int stream_index
Definition: avcodec.h:1432
AVInputFormat ff_sds_demuxer
Definition: sdsdec.c:156
This structure stores compressed data.
Definition: avcodec.h:1407