Libav
nellymoserdec.c
Go to the documentation of this file.
1 /*
2  * NellyMoser audio decoder
3  * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
4  * 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
5  * 520e17cd55896441042b14df2566a6eb610ed444
6  * Copyright (c) 2007 Loic Minier <lool at dooz.org>
7  * Benjamin Larsson
8  *
9  * Permission is hereby granted, free of charge, to any person obtaining a
10  * copy of this software and associated documentation files (the "Software"),
11  * to deal in the Software without restriction, including without limitation
12  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
13  * and/or sell copies of the Software, and to permit persons to whom the
14  * Software is furnished to do so, subject to the following conditions:
15  *
16  * The above copyright notice and this permission notice shall be included in
17  * all copies or substantial portions of the Software.
18  *
19  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
22  * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
23  * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
24  * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25  * DEALINGS IN THE SOFTWARE.
26  */
27 
35 #include "libavutil/float_dsp.h"
36 #include "libavutil/lfg.h"
37 #include "libavutil/random_seed.h"
38 #include "avcodec.h"
39 #include "fft.h"
40 #include "fmtconvert.h"
41 #include "internal.h"
42 #include "nellymoser.h"
43 #include "sinewin.h"
44 
45 #define BITSTREAM_READER_LE
46 #include "get_bits.h"
47 
48 
49 typedef struct NellyMoserDecodeContext {
53  float scale_bias;
57  float *imdct_out;
58  float *imdct_prev;
60 
62  const unsigned char block[NELLY_BLOCK_LEN],
63  float audio[NELLY_SAMPLES])
64 {
65  int i,j;
66  float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
67  float *aptr, *bptr, *pptr, val, pval;
68  int bits[NELLY_BUF_LEN];
69  unsigned char v;
70 
71  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
72 
73  bptr = buf;
74  pptr = pows;
75  val = ff_nelly_init_table[get_bits(&s->gb, 6)];
76  for (i=0 ; i<NELLY_BANDS ; i++) {
77  if (i > 0)
78  val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
79  pval = -pow(2, val/2048) * s->scale_bias;
80  for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
81  *bptr++ = val;
82  *pptr++ = pval;
83  }
84 
85  }
86 
87  ff_nelly_get_sample_bits(buf, bits);
88 
89  for (i = 0; i < 2; i++) {
90  aptr = audio + i * NELLY_BUF_LEN;
91 
92  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
94 
95  for (j = 0; j < NELLY_FILL_LEN; j++) {
96  if (bits[j] <= 0) {
97  aptr[j] = M_SQRT1_2*pows[j];
98  if (av_lfg_get(&s->random_state) & 1)
99  aptr[j] *= -1.0;
100  } else {
101  v = get_bits(&s->gb, bits[j]);
102  aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
103  }
104  }
105  memset(&aptr[NELLY_FILL_LEN], 0,
106  (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
107 
108  s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
109  s->fdsp.vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
110  s->imdct_out, ff_sine_128,
111  NELLY_BUF_LEN / 2);
112  FFSWAP(float *, s->imdct_out, s->imdct_prev);
113  }
114 }
115 
118 
119  s->avctx = avctx;
120  s->imdct_out = s->imdct_buf[0];
121  s->imdct_prev = s->imdct_buf[1];
122  av_lfg_init(&s->random_state, 0);
123  ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
124 
126 
127  s->scale_bias = 1.0/(32768*8);
128  avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
129 
130  /* Generate overlap window */
131  if (!ff_sine_128[127])
133 
134  avctx->channels = 1;
136 
137  return 0;
138 }
139 
140 static int decode_tag(AVCodecContext *avctx, void *data,
141  int *got_frame_ptr, AVPacket *avpkt)
142 {
143  AVFrame *frame = data;
144  const uint8_t *buf = avpkt->data;
145  int buf_size = avpkt->size;
147  int blocks, i, ret;
148  float *samples_flt;
149 
150  blocks = buf_size / NELLY_BLOCK_LEN;
151  if (blocks <= 0) {
152  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
153  return AVERROR_INVALIDDATA;
154  }
155  if (buf_size % NELLY_BLOCK_LEN) {
156  av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
157  buf_size % NELLY_BLOCK_LEN);
158  }
159  /* Normal numbers of blocks for sample rates:
160  * 8000 Hz - 1
161  * 11025 Hz - 2
162  * 16000 Hz - 3
163  * 22050 Hz - 4
164  * 44100 Hz - 8
165  */
166 
167  /* get output buffer */
168  frame->nb_samples = NELLY_SAMPLES * blocks;
169  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0) {
170  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
171  return ret;
172  }
173  samples_flt = (float *)frame->data[0];
174 
175  for (i=0 ; i<blocks ; i++) {
176  nelly_decode_block(s, buf, samples_flt);
177  samples_flt += NELLY_SAMPLES;
178  buf += NELLY_BLOCK_LEN;
179  }
180 
181  *got_frame_ptr = 1;
182 
183  return buf_size;
184 }
185 
188 
189  ff_mdct_end(&s->imdct_ctx);
190 
191  return 0;
192 }
193 
195  .name = "nellymoser",
196  .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
197  .type = AVMEDIA_TYPE_AUDIO,
199  .priv_data_size = sizeof(NellyMoserDecodeContext),
200  .init = decode_init,
201  .close = decode_end,
202  .decode = decode_tag,
203  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
204  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
206 };
Definition: lfg.h:25
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
This structure describes decoded (raw) audio or video data.
Definition: frame.h:135
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:240
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:129
static void skip_bits_long(GetBitContext *s, int n)
Definition: get_bits.h:199
AVCodecContext * avctx
Definition: nellymoserdec.c:50
int size
Definition: avcodec.h:974
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:58
const float ff_nelly_dequantization_table[127]
Definition: nellymoser.c:40
static av_cold int decode_end(AVCodecContext *avctx)
AVCodec.
Definition: avcodec.h:2812
#define NELLY_DETAIL_BITS
Definition: nellymoser.h:42
const uint16_t ff_nelly_init_table[64]
Definition: nellymoser.c:71
static int decode(MimicContext *ctx, int quality, int num_coeffs, int is_iframe)
Definition: mimic.c:275
uint8_t bits
Definition: crc.c:251
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1815
uint8_t
#define av_cold
Definition: attributes.h:66
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:684
const char data[16]
Definition: mxf.c:70
uint8_t * data
Definition: avcodec.h:973
bitstream reader API header.
#define CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:658
static int decode_tag(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
void(* vector_fmul_window)(float *dst, const float *src0, const float *src1, const float *win, int len)
Overlap/add with window function.
Definition: float_dsp.h:103
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
#define CODEC_CAP_PARAM_CHANGE
Codec supports changed parameters at any point.
Definition: avcodec.h:763
sample_fmts
Definition: avconv_filter.c:68
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:145
int flags
CODEC_FLAG_*.
Definition: avcodec.h:1144
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2819
#define ff_mdct_init
Definition: fft.h:151
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:1868
AVCodec ff_nellymoser_decoder
Definition: fft.h:73
audio channel layout utility functions
#define NELLY_BLOCK_LEN
Definition: nellymoser.h:40
const uint8_t ff_nelly_band_sizes_table[NELLY_BANDS]
Definition: nellymoser.c:67
#define NELLY_HEADER_BITS
Definition: nellymoser.h:41
static void nelly_decode_block(NellyMoserDecodeContext *s, const unsigned char block[NELLY_BLOCK_LEN], float audio[NELLY_SAMPLES])
Definition: nellymoserdec.c:61
static av_cold int decode_init(AVCodecContext *avctx)
AVFloatDSPContext fdsp
Definition: nellymoserdec.c:54
Libavcodec external API header.
AVSampleFormat
Audio Sample Formats.
Definition: samplefmt.h:61
AV_SAMPLE_FMT_NONE
Definition: avconv_filter.c:68
main external API structure.
Definition: avcodec.h:1050
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:490
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:612
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:38
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:375
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
void(* imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:93
av_cold void avpriv_float_dsp_init(AVFloatDSPContext *fdsp, int bit_exact)
Initialize a float DSP context.
Definition: float_dsp.c:115
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
float imdct_buf[2][NELLY_BUF_LEN]
Definition: nellymoserdec.c:56
common internal api header.
#define ff_mdct_end
Definition: fft.h:152
#define NELLY_BUF_LEN
Definition: nellymoser.h:43
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
void * priv_data
Definition: avcodec.h:1092
int channels
number of audio channels
Definition: avcodec.h:1808
const int16_t ff_nelly_delta_table[32]
Definition: nellymoser.c:80
#define NELLY_BANDS
Definition: nellymoser.h:39
#define FFSWAP(type, a, b)
Definition: common.h:60
void ff_nelly_get_sample_bits(const float *buf, int *bits)
Definition: nellymoser.c:117
#define AV_CH_LAYOUT_MONO
The 3 alphanumeric copyright notices are md5summed they are from the original implementors.
#define NELLY_SAMPLES
Definition: nellymoser.h:48
This structure stores compressed data.
Definition: avcodec.h:950
#define NELLY_FILL_LEN
Definition: nellymoser.h:44
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:179
for(j=16;j >0;--j)
void ff_init_ff_sine_windows(int index)
initialize the specified entry of ff_sine_windows
static int16_t block[64]
Definition: dct-test.c:88