FFmpeg
dsicinaudio.c
Go to the documentation of this file.
1 /*
2  * Delphine Software International CIN audio decoder
3  * Copyright (c) 2006 Gregory Montoir (cyx@users.sourceforge.net)
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  * Delphine Software International CIN audio decoder
25  */
26 
28 #include "libavutil/intreadwrite.h"
29 
30 #include "avcodec.h"
31 #include "codec_internal.h"
32 #include "decode.h"
33 #include "mathops.h"
34 
35 typedef struct CinAudioContext {
37  int delta;
39 
40 
41 /* table defining a geometric sequence with multiplier = 32767 ^ (1 / 128) */
42 static const int16_t cinaudio_delta16_table[256] = {
43  0, 0, 0, 0, 0, 0, 0, 0,
44  0, 0, 0, 0, 0, 0, 0, 0,
45  0, 0, 0, -30210, -27853, -25680, -23677, -21829,
46  -20126, -18556, -17108, -15774, -14543, -13408, -12362, -11398,
47  -10508, -9689, -8933, -8236, -7593, -7001, -6455, -5951,
48  -5487, -5059, -4664, -4300, -3964, -3655, -3370, -3107,
49  -2865, -2641, -2435, -2245, -2070, -1908, -1759, -1622,
50  -1495, -1379, -1271, -1172, -1080, -996, -918, -847,
51  -781, -720, -663, -612, -564, -520, -479, -442,
52  -407, -376, -346, -319, -294, -271, -250, -230,
53  -212, -196, -181, -166, -153, -141, -130, -120,
54  -111, -102, -94, -87, -80, -74, -68, -62,
55  -58, -53, -49, -45, -41, -38, -35, -32,
56  -30, -27, -25, -23, -21, -20, -18, -17,
57  -15, -14, -13, -12, -11, -10, -9, -8,
58  -7, -6, -5, -4, -3, -2, -1, 0,
59  0, 1, 2, 3, 4, 5, 6, 7,
60  8, 9, 10, 11, 12, 13, 14, 15,
61  17, 18, 20, 21, 23, 25, 27, 30,
62  32, 35, 38, 41, 45, 49, 53, 58,
63  62, 68, 74, 80, 87, 94, 102, 111,
64  120, 130, 141, 153, 166, 181, 196, 212,
65  230, 250, 271, 294, 319, 346, 376, 407,
66  442, 479, 520, 564, 612, 663, 720, 781,
67  847, 918, 996, 1080, 1172, 1271, 1379, 1495,
68  1622, 1759, 1908, 2070, 2245, 2435, 2641, 2865,
69  3107, 3370, 3655, 3964, 4300, 4664, 5059, 5487,
70  5951, 6455, 7001, 7593, 8236, 8933, 9689, 10508,
71  11398, 12362, 13408, 14543, 15774, 17108, 18556, 20126,
72  21829, 23677, 25680, 27853, 30210, 0, 0, 0,
73  0, 0, 0, 0, 0, 0, 0, 0,
74  0, 0, 0, 0, 0, 0, 0, 0
75 };
76 
78 {
79  CinAudioContext *cin = avctx->priv_data;
80 
81  cin->initial_decode_frame = 1;
82  cin->delta = 0;
86 
87  return 0;
88 }
89 
91  int *got_frame_ptr, AVPacket *avpkt)
92 {
93  const uint8_t *buf = avpkt->data;
94  CinAudioContext *cin = avctx->priv_data;
95  const uint8_t *buf_end = buf + avpkt->size;
96  int16_t *samples;
97  int delta, ret;
98 
99  /* get output buffer */
100  frame->nb_samples = avpkt->size - cin->initial_decode_frame;
101  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
102  return ret;
103  samples = (int16_t *)frame->data[0];
104 
105  delta = cin->delta;
106  if (cin->initial_decode_frame) {
107  cin->initial_decode_frame = 0;
108  delta = sign_extend(AV_RL16(buf), 16);
109  buf += 2;
110  *samples++ = delta;
111  }
112  while (buf < buf_end) {
113  delta += cinaudio_delta16_table[*buf++];
115  *samples++ = delta;
116  }
117  cin->delta = delta;
118 
119  *got_frame_ptr = 1;
120 
121  return avpkt->size;
122 }
123 
125  .p.name = "dsicinaudio",
126  CODEC_LONG_NAME("Delphine Software International CIN audio"),
127  .p.type = AVMEDIA_TYPE_AUDIO,
128  .p.id = AV_CODEC_ID_DSICINAUDIO,
129  .priv_data_size = sizeof(CinAudioContext),
132  .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
133 };
CinAudioContext::delta
int delta
Definition: dsicinaudio.c:37
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:340
AVPacket::data
uint8_t * data
Definition: packet.h:522
FFCodec
Definition: codec_internal.h:127
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:361
FFCodec::p
AVCodec p
The public AVCodec.
Definition: codec_internal.h:131
AVCodecContext::ch_layout
AVChannelLayout ch_layout
Audio channel layout.
Definition: avcodec.h:2111
CinAudioContext
Definition: dsicinaudio.c:35
av_cold
#define av_cold
Definition: attributes.h:90
FF_CODEC_DECODE_CB
#define FF_CODEC_DECODE_CB(func)
Definition: codec_internal.h:306
AV_CODEC_ID_DSICINAUDIO
@ AV_CODEC_ID_DSICINAUDIO
Definition: codec_id.h:469
intreadwrite.h
AVMEDIA_TYPE_AUDIO
@ AVMEDIA_TYPE_AUDIO
Definition: avutil.h:202
decode.h
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
CODEC_LONG_NAME
#define CODEC_LONG_NAME(str)
Definition: codec_internal.h:272
frame
static AVFrame * frame
Definition: demux_decode.c:54
if
if(ret)
Definition: filter_design.txt:179
av_clip_int16
#define av_clip_int16
Definition: common.h:113
mathops.h
AV_CODEC_CAP_CHANNEL_CONF
#define AV_CODEC_CAP_CHANNEL_CONF
Codec should fill in channel configuration and samplerate instead of container.
Definition: codec.h:106
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1618
init
int(* init)(AVBSFContext *ctx)
Definition: dts2pts.c:365
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:523
AVChannelLayout
An AVChannelLayout holds information about the channel layout of audio data.
Definition: channel_layout.h:313
codec_internal.h
AVCodecContext::sample_fmt
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1084
ff_dsicinaudio_decoder
const FFCodec ff_dsicinaudio_decoder
Definition: dsicinaudio.c:124
cinaudio_decode_init
static av_cold int cinaudio_decode_init(AVCodecContext *avctx)
Definition: dsicinaudio.c:77
AVFrame::nb_samples
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:420
delta
float delta
Definition: vorbis_enc_data.h:430
AV_SAMPLE_FMT_S16
@ AV_SAMPLE_FMT_S16
signed 16 bits
Definition: samplefmt.h:58
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:194
cinaudio_decode_frame
static int cinaudio_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)
Definition: dsicinaudio.c:90
avcodec.h
ret
ret
Definition: filter_design.txt:187
AVCodecContext
main external API structure.
Definition: avcodec.h:445
channel_layout.h
av_channel_layout_uninit
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
Definition: channel_layout.c:662
sign_extend
static av_const int sign_extend(int val, unsigned bits)
Definition: mathops.h:133
samples
Filter the word “frame” indicates either a video frame or a group of audio samples
Definition: filter_design.txt:8
cinaudio_delta16_table
static const int16_t cinaudio_delta16_table[256]
Definition: dsicinaudio.c:42
AV_CHANNEL_LAYOUT_MONO
#define AV_CHANNEL_LAYOUT_MONO
Definition: channel_layout.h:388
AVPacket
This structure stores compressed data.
Definition: packet.h:499
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:472
CinAudioContext::initial_decode_frame
int initial_decode_frame
Definition: dsicinaudio.c:36