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adxenc.c
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1 /*
2  * ADX ADPCM codecs
3  * Copyright (c) 2001,2003 BERO
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 "avcodec.h"
23 #include "adx.h"
24 #include "bytestream.h"
25 #include "internal.h"
26 #include "put_bits.h"
27 
28 /**
29  * @file
30  * SEGA CRI adx codecs.
31  *
32  * Reference documents:
33  * http://ku-www.ss.titech.ac.jp/~yatsushi/adx.html
34  * adx2wav & wav2adx http://www.geocities.co.jp/Playtown/2004/
35  */
36 
37 static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav,
38  ADXChannelState *prev, int channels)
39 {
40  PutBitContext pb;
41  int scale;
42  int i, j;
43  int s0, s1, s2, d;
44  int max = 0;
45  int min = 0;
46 
47  s1 = prev->s1;
48  s2 = prev->s2;
49  for (i = 0, j = 0; j < 32; i += channels, j++) {
50  s0 = wav[i];
51  d = ((s0 << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS;
52  if (max < d)
53  max = d;
54  if (min > d)
55  min = d;
56  s2 = s1;
57  s1 = s0;
58  }
59 
60  if (max == 0 && min == 0) {
61  prev->s1 = s1;
62  prev->s2 = s2;
63  memset(adx, 0, BLOCK_SIZE);
64  return;
65  }
66 
67  if (max / 7 > -min / 8)
68  scale = max / 7;
69  else
70  scale = -min / 8;
71 
72  if (scale == 0)
73  scale = 1;
74 
75  AV_WB16(adx, scale);
76 
77  init_put_bits(&pb, adx + 2, 16);
78 
79  s1 = prev->s1;
80  s2 = prev->s2;
81  for (i = 0, j = 0; j < 32; i += channels, j++) {
82  d = ((wav[i] << COEFF_BITS) - c->coeff[0] * s1 - c->coeff[1] * s2) >> COEFF_BITS;
83 
84  d = av_clip_intp2(ROUNDED_DIV(d, scale), 3);
85 
86  put_sbits(&pb, 4, d);
87 
88  s0 = ((d << COEFF_BITS) * scale + c->coeff[0] * s1 + c->coeff[1] * s2) >> COEFF_BITS;
89  s2 = s1;
90  s1 = s0;
91  }
92  prev->s1 = s1;
93  prev->s2 = s2;
94 
95  flush_put_bits(&pb);
96 }
97 
98 #define HEADER_SIZE 36
99 
100 static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize)
101 {
102  ADXContext *c = avctx->priv_data;
103 
104  bytestream_put_be16(&buf, 0x8000); /* header signature */
105  bytestream_put_be16(&buf, HEADER_SIZE - 4); /* copyright offset */
106  bytestream_put_byte(&buf, 3); /* encoding */
107  bytestream_put_byte(&buf, BLOCK_SIZE); /* block size */
108  bytestream_put_byte(&buf, 4); /* sample size */
109  bytestream_put_byte(&buf, avctx->channels); /* channels */
110  bytestream_put_be32(&buf, avctx->sample_rate); /* sample rate */
111  bytestream_put_be32(&buf, 0); /* total sample count */
112  bytestream_put_be16(&buf, c->cutoff); /* cutoff frequency */
113  bytestream_put_byte(&buf, 3); /* version */
114  bytestream_put_byte(&buf, 0); /* flags */
115  bytestream_put_be32(&buf, 0); /* unknown */
116  bytestream_put_be32(&buf, 0); /* loop enabled */
117  bytestream_put_be16(&buf, 0); /* padding */
118  bytestream_put_buffer(&buf, "(c)CRI", 6); /* copyright signature */
119 
120  return HEADER_SIZE;
121 }
122 
124 {
125  ADXContext *c = avctx->priv_data;
126 
127  if (avctx->channels > 2) {
128  av_log(avctx, AV_LOG_ERROR, "Invalid number of channels\n");
129  return AVERROR(EINVAL);
130  }
131  avctx->frame_size = BLOCK_SAMPLES;
132 
133  /* the cutoff can be adjusted, but this seems to work pretty well */
134  c->cutoff = 500;
136 
137  return 0;
138 }
139 
140 static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
141  const AVFrame *frame, int *got_packet_ptr)
142 {
143  ADXContext *c = avctx->priv_data;
144  const int16_t *samples = (const int16_t *)frame->data[0];
145  uint8_t *dst;
146  int ch, out_size, ret;
147 
148  out_size = BLOCK_SIZE * avctx->channels + !c->header_parsed * HEADER_SIZE;
149  if ((ret = ff_alloc_packet2(avctx, avpkt, out_size, 0)) < 0)
150  return ret;
151  dst = avpkt->data;
152 
153  if (!c->header_parsed) {
154  int hdrsize;
155  if ((hdrsize = adx_encode_header(avctx, dst, avpkt->size)) < 0) {
156  av_log(avctx, AV_LOG_ERROR, "output buffer is too small\n");
157  return AVERROR(EINVAL);
158  }
159  dst += hdrsize;
160  c->header_parsed = 1;
161  }
162 
163  for (ch = 0; ch < avctx->channels; ch++) {
164  adx_encode(c, dst, samples + ch, &c->prev[ch], avctx->channels);
165  dst += BLOCK_SIZE;
166  }
167 
168  *got_packet_ptr = 1;
169  return 0;
170 }
171 
173  .name = "adpcm_adx",
174  .long_name = NULL_IF_CONFIG_SMALL("SEGA CRI ADX ADPCM"),
175  .type = AVMEDIA_TYPE_AUDIO,
176  .id = AV_CODEC_ID_ADPCM_ADX,
177  .priv_data_size = sizeof(ADXContext),
179  .encode2 = adx_encode_frame,
180  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_S16,
182 };
This structure describes decoded (raw) audio or video data.
Definition: frame.h:171
static void put_sbits(PutBitContext *pb, int n, int32_t value)
Definition: put_bits.h:192
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1423
int coeff[2]
Definition: adx.h:48
#define BLOCK_SIZE
Definition: adx.h:53
AVCodec.
Definition: avcodec.h:3473
static void adx_encode(ADXContext *c, uint8_t *adx, const int16_t *wav, ADXChannelState *prev, int channels)
Definition: adxenc.c:37
void ff_adx_calculate_coeffs(int cutoff, int sample_rate, int bits, int *coeff)
Calculate LPC coefficients based on cutoff frequency and sample rate.
Definition: adx.c:26
if()
Definition: avfilter.c:975
uint8_t
#define av_cold
Definition: attributes.h:74
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1422
#define AV_WB16(p, v)
Definition: intreadwrite.h:405
#define av_log(a,...)
#define ROUNDED_DIV(a, b)
Definition: common.h:55
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define COEFF_BITS
Definition: adx.h:51
#define s2
Definition: regdef.h:39
#define HEADER_SIZE
Definition: adxenc.c:98
#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:175
#define s0
Definition: regdef.h:37
const char * name
Name of the codec implementation.
Definition: avcodec.h:3480
Libavcodec external API header.
ret
Definition: avfilter.c:974
int header_parsed
Definition: adx.h:45
AVCodec ff_adpcm_adx_encoder
Definition: adxenc.c:172
int frame_size
Number of samples per channel in an audio frame.
Definition: avcodec.h:2281
#define BLOCK_SAMPLES
Definition: adx.h:54
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:59
int sample_rate
samples per second
Definition: avcodec.h:2261
main external API structure.
Definition: avcodec.h:1501
static int adx_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
Definition: adxenc.c:140
void * buf
Definition: avisynth_c.h:553
Definition: adx.h:42
int s2
Definition: adx.h:39
#define s1
Definition: regdef.h:38
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1780
int cutoff
Definition: adx.h:47
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:182
common internal api header.
static void flush_put_bits(PutBitContext *s)
Pad the end of the output stream with zeros.
Definition: put_bits.h:101
signed 16 bits
Definition: samplefmt.h:62
static double c[64]
int s1
Definition: adx.h:39
static void init_put_bits(PutBitContext *s, uint8_t *buffer, int buffer_size)
Initialize the PutBitContext s.
Definition: put_bits.h:48
static av_cold int adx_encode_init(AVCodecContext *avctx)
Definition: adxenc.c:123
static av_always_inline void bytestream_put_buffer(uint8_t **b, const uint8_t *src, unsigned int size)
Definition: bytestream.h:368
void * priv_data
Definition: avcodec.h:1543
static int adx_encode_header(AVCodecContext *avctx, uint8_t *buf, int bufsize)
Definition: adxenc.c:100
ADXChannelState prev[2]
Definition: adx.h:44
int channels
number of audio channels
Definition: avcodec.h:2262
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
SEGA CRI adx codecs.
float min
This structure stores compressed data.
Definition: avcodec.h:1399
bitstream writer API