vocdec.c
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1 /*
2  * Creative Voice File demuxer.
3  * Copyright (c) 2006 Aurelien Jacobs <aurel@gnuage.org>
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; 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 "voc.h"
24 #include "internal.h"
25 
26 
27 static int voc_probe(AVProbeData *p)
28 {
29  int version, check;
30 
31  if (memcmp(p->buf, ff_voc_magic, sizeof(ff_voc_magic) - 1))
32  return 0;
33  version = AV_RL16(p->buf + 22);
34  check = AV_RL16(p->buf + 24);
35  if (~version + 0x1234 != check)
36  return 10;
37 
38  return AVPROBE_SCORE_MAX;
39 }
40 
42 {
43  VocDecContext *voc = s->priv_data;
44  AVIOContext *pb = s->pb;
45  int header_size;
46  AVStream *st;
47 
48  avio_skip(pb, 20);
49  header_size = avio_rl16(pb) - 22;
50  if (header_size != 4) {
51  av_log(s, AV_LOG_ERROR, "unknown header size: %d\n", header_size);
52  return AVERROR(ENOSYS);
53  }
54  avio_skip(pb, header_size);
55  st = avformat_new_stream(s, NULL);
56  if (!st)
57  return AVERROR(ENOMEM);
59 
60  voc->remaining_size = 0;
61  return 0;
62 }
63 
64 int
65 voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
66 {
67  VocDecContext *voc = s->priv_data;
68  AVCodecContext *dec = st->codec;
69  AVIOContext *pb = s->pb;
70  VocType type;
71  int size, tmp_codec=-1;
72  int sample_rate = 0;
73  int channels = 1;
74 
75  while (!voc->remaining_size) {
76  type = avio_r8(pb);
77  if (type == VOC_TYPE_EOF)
78  return AVERROR(EIO);
79  voc->remaining_size = avio_rl24(pb);
80  if (!voc->remaining_size) {
81  if (!s->pb->seekable)
82  return AVERROR(EIO);
83  voc->remaining_size = avio_size(pb) - avio_tell(pb);
84  }
85  max_size -= 4;
86 
87  switch (type) {
89  dec->sample_rate = 1000000 / (256 - avio_r8(pb));
90  if (sample_rate)
91  dec->sample_rate = sample_rate;
92  dec->channels = channels;
93  tmp_codec = avio_r8(pb);
95  voc->remaining_size -= 2;
96  max_size -= 2;
97  channels = 1;
98  break;
99 
101  break;
102 
103  case VOC_TYPE_EXTENDED:
104  sample_rate = avio_rl16(pb);
105  avio_r8(pb);
106  channels = avio_r8(pb) + 1;
107  sample_rate = 256000000 / (channels * (65536 - sample_rate));
108  voc->remaining_size = 0;
109  max_size -= 4;
110  break;
111 
113  dec->sample_rate = avio_rl32(pb);
114  dec->bits_per_coded_sample = avio_r8(pb);
115  dec->channels = avio_r8(pb);
116  tmp_codec = avio_rl16(pb);
117  avio_skip(pb, 4);
118  voc->remaining_size -= 12;
119  max_size -= 12;
120  break;
121 
122  default:
123  avio_skip(pb, voc->remaining_size);
124  max_size -= voc->remaining_size;
125  voc->remaining_size = 0;
126  break;
127  }
128  }
129 
130  if (tmp_codec >= 0) {
131  tmp_codec = ff_codec_get_id(ff_voc_codec_tags, tmp_codec);
132  if (dec->codec_id == CODEC_ID_NONE)
133  dec->codec_id = tmp_codec;
134  else if (dec->codec_id != tmp_codec)
135  av_log(s, AV_LOG_WARNING, "Ignoring mid-stream change in audio codec\n");
136  if (dec->codec_id == CODEC_ID_NONE) {
137  if (s->audio_codec_id == CODEC_ID_NONE) {
138  av_log(s, AV_LOG_ERROR, "unknown codec tag\n");
139  return AVERROR(EINVAL);
140  }
141  av_log(s, AV_LOG_WARNING, "unknown codec tag\n");
142  }
143  }
144 
145  dec->bit_rate = dec->sample_rate * dec->bits_per_coded_sample;
146 
147  if (max_size <= 0)
148  max_size = 2048;
149  size = FFMIN(voc->remaining_size, max_size);
150  voc->remaining_size -= size;
151  return av_get_packet(pb, pkt, size);
152 }
153 
155 {
156  return voc_get_packet(s, pkt, s->streams[0], 0);
157 }
158 
160  .name = "voc",
161  .long_name = NULL_IF_CONFIG_SMALL("Creative Voice file format"),
162  .priv_data_size = sizeof(VocDecContext),
166  .codec_tag=(const AVCodecTag* const []){ff_voc_codec_tags, 0},
167 };
Bytestream IO Context.
Definition: avio.h:68
int64_t avio_size(AVIOContext *s)
Get the filesize.
Definition: aviobuf.c:281
int size
static int voc_read_packet(AVFormatContext *s, AVPacket *pkt)
Definition: vocdec.c:154
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:117
struct voc_dec_context VocDecContext
AVInputFormat ff_voc_demuxer
Definition: vocdec.c:159
static int voc_read_header(AVFormatContext *s, AVFormatParameters *ap)
Definition: vocdec.c:41
Format I/O context.
Definition: avformat.h:863
AVStream ** streams
Definition: avformat.h:908
static int read_header(FFV1Context *f)
Definition: ffv1.c:1513
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:269
static av_always_inline int64_t avio_tell(AVIOContext *s)
ftell() equivalent for AVIOContext.
Definition: avio.h:492
int bits_per_coded_sample
bits per sample/pixel from the demuxer (needed for huffyuv).
Definition: avcodec.h:1974
int av_get_bits_per_sample(enum CodecID codec_id)
Return codec bits per sample.
Definition: utils.c:1634
enum CodecID ff_codec_get_id(const AVCodecTag *tags, unsigned int tag)
Definition: utils.c:2206
int64_t remaining_size
Definition: voc.h:29
unsigned int avio_rl32(AVIOContext *s)
Definition: aviobuf.c:738
#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:191
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
AVStream * avformat_new_stream(AVFormatContext *s, AVCodec *c)
Add a new stream to a media file.
Definition: utils.c:2776
int avio_r8(AVIOContext *s)
Definition: aviobuf.c:632
AVCodecContext * codec
codec context
Definition: avformat.h:623
unsigned char * buf
Buffer must have AVPROBE_PADDING_SIZE of extra allocated bytes filled with zero.
Definition: avformat.h:341
int seekable
A combination of AVIO_SEEKABLE_ flags or 0 when the stream is not seekable.
Definition: avio.h:122
int bit_rate
the average bitrate
Definition: avcodec.h:1340
#define FFMIN(a, b)
Definition: common.h:55
enum voc_type VocType
static av_always_inline int64_t avio_skip(AVIOContext *s, int64_t offset)
Skip given number of bytes forward.
Definition: avio.h:483
static int read_probe(AVProbeData *p)
Definition: img2.c:185
static int voc_probe(AVProbeData *p)
Definition: vocdec.c:27
version
Definition: libspeexenc.c:304
Stream structure.
Definition: avformat.h:620
enum CodecID audio_codec_id
Forced audio codec_id.
Definition: avformat.h:1037
NULL
Definition: eval.c:50
const AVCodecTag ff_voc_codec_tags[]
Definition: voc.c:27
enum AVMediaType codec_type
Definition: avcodec.h:1574
int sample_rate
samples per second
Definition: avcodec.h:1456
AVIOContext * pb
Definition: avformat.h:896
main external API structure.
Definition: avcodec.h:1329
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
static int read_packet(AVFormatContext *ctx, AVPacket *pkt)
Definition: libcdio.c:109
This structure contains the data a format has to probe a file.
Definition: avformat.h:339
const unsigned char ff_voc_magic[21]
Definition: voc.c:25
#define AVPROBE_SCORE_MAX
maximum score, half of that is used for file-extension-based detection
Definition: avformat.h:345
unsigned int avio_rl16(AVIOContext *s)
Definition: aviobuf.c:722
AV_WL32 AV_WL24 AV_RL16
Definition: bytestream.h:89
int channels
number of audio channels
Definition: avcodec.h:1457
void * priv_data
Format private data.
Definition: avformat.h:883
const char * name
A comma separated list of short names for the format.
Definition: avformat.h:460
unsigned int avio_rl24(AVIOContext *s)
Definition: aviobuf.c:730
int voc_get_packet(AVFormatContext *s, AVPacket *pkt, AVStream *st, int max_size)
Definition: vocdec.c:65
enum CodecID codec_id
Definition: avcodec.h:1575
#define check(x, y, S, v)