FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
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 
28 /**
29  * @file
30  * The 3 alphanumeric copyright notices are md5summed they are from the original
31  * implementors. The original code is available from http://code.google.com/p/nelly2pcm/
32  */
33 
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 "internal.h"
41 #include "nellymoser.h"
42 #include "sinewin.h"
43 
44 #define BITSTREAM_READER_LE
45 #include "get_bits.h"
46 
47 
48 typedef struct NellyMoserDecodeContext {
52  float scale_bias;
56  float *imdct_out;
57  float *imdct_prev;
59 
61  const unsigned char block[NELLY_BLOCK_LEN],
62  float audio[NELLY_SAMPLES])
63 {
64  int i,j;
65  float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
66  float *aptr, *bptr, *pptr, val, pval;
67  int bits[NELLY_BUF_LEN];
68  unsigned char v;
69 
70  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
71 
72  bptr = buf;
73  pptr = pows;
74  val = ff_nelly_init_table[get_bits(&s->gb, 6)];
75  for (i=0 ; i<NELLY_BANDS ; i++) {
76  if (i > 0)
77  val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
78  pval = -exp2(val/2048) * s->scale_bias;
79  for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
80  *bptr++ = val;
81  *pptr++ = pval;
82  }
83 
84  }
85 
86  ff_nelly_get_sample_bits(buf, bits);
87 
88  for (i = 0; i < 2; i++) {
89  aptr = audio + i * NELLY_BUF_LEN;
90 
91  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
93 
94  for (j = 0; j < NELLY_FILL_LEN; j++) {
95  if (bits[j] <= 0) {
96  aptr[j] = M_SQRT1_2*pows[j];
97  if (av_lfg_get(&s->random_state) & 1)
98  aptr[j] *= -1.0;
99  } else {
100  v = get_bits(&s->gb, bits[j]);
101  aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
102  }
103  }
104  memset(&aptr[NELLY_FILL_LEN], 0,
105  (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
106 
107  s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
108  s->fdsp->vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
109  s->imdct_out, ff_sine_128,
110  NELLY_BUF_LEN / 2);
111  FFSWAP(float *, s->imdct_out, s->imdct_prev);
112  }
113 }
114 
115 static av_cold int decode_init(AVCodecContext * avctx) {
117 
118  s->avctx = avctx;
119  s->imdct_out = s->imdct_buf[0];
120  s->imdct_prev = s->imdct_buf[1];
121  av_lfg_init(&s->random_state, 0);
122  ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
123 
125  if (!s->fdsp)
126  return AVERROR(ENOMEM);
127 
128  s->scale_bias = 1.0/(32768*8);
129  avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
130 
131  /* Generate overlap window */
132  if (!ff_sine_128[127])
134 
135  avctx->channels = 1;
137 
138  return 0;
139 }
140 
141 static int decode_tag(AVCodecContext *avctx, void *data,
142  int *got_frame_ptr, AVPacket *avpkt)
143 {
144  AVFrame *frame = data;
145  const uint8_t *buf = avpkt->data;
146  const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
147  int buf_size = avpkt->size;
149  int blocks, i, ret;
150  float *samples_flt;
151 
152  blocks = buf_size / NELLY_BLOCK_LEN;
153 
154  if (blocks <= 0) {
155  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
156  return AVERROR_INVALIDDATA;
157  }
158 
159  if (buf_size % NELLY_BLOCK_LEN) {
160  av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
161  buf_size % NELLY_BLOCK_LEN);
162  }
163  /* Normal numbers of blocks for sample rates:
164  * 8000 Hz - 1
165  * 11025 Hz - 2
166  * 16000 Hz - 3
167  * 22050 Hz - 4
168  * 44100 Hz - 8
169  */
170  if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
171  avctx->sample_rate= 11025*(blocks/2);
172 
173  /* get output buffer */
174  frame->nb_samples = NELLY_SAMPLES * blocks;
175  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
176  return ret;
177  samples_flt = (float *)frame->data[0];
178 
179  for (i=0 ; i<blocks ; i++) {
180  nelly_decode_block(s, buf, samples_flt);
181  samples_flt += NELLY_SAMPLES;
182  buf += NELLY_BLOCK_LEN;
183  }
184 
185  *got_frame_ptr = 1;
186 
187  return buf_size;
188 }
189 
190 static av_cold int decode_end(AVCodecContext * avctx) {
192 
193  ff_mdct_end(&s->imdct_ctx);
194  av_freep(&s->fdsp);
195 
196  return 0;
197 }
198 
200  .name = "nellymoser",
201  .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
202  .type = AVMEDIA_TYPE_AUDIO,
204  .priv_data_size = sizeof(NellyMoserDecodeContext),
205  .init = decode_init,
206  .close = decode_end,
207  .decode = decode_tag,
209  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
211 };
Definition: lfg.h:25
#define NULL
Definition: coverity.c:32
const char const char void * val
Definition: avisynth_c.h:634
const char * s
Definition: avisynth_c.h:631
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
AVFloatDSPContext * fdsp
Definition: nellymoserdec.c:53
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:260
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
static void skip_bits_long(GetBitContext *s, int n)
Definition: get_bits.h:217
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
#define M_SQRT1_2
Definition: mathematics.h:52
AVCodecContext * avctx
Definition: nellymoserdec.c:49
int size
Definition: avcodec.h:1578
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:53
const float ff_nelly_dequantization_table[127]
Definition: nellymoser.c:40
static av_cold int decode_end(AVCodecContext *avctx)
AVCodec.
Definition: avcodec.h:3535
#define NELLY_DETAIL_BITS
Definition: nellymoser.h:42
const uint16_t ff_nelly_init_table[64]
Definition: nellymoser.c:71
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
uint8_t bits
Definition: crc.c:296
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2411
uint8_t
#define av_cold
Definition: attributes.h:82
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1577
bitstream reader API header.
#define av_log(a,...)
static int decode_tag(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#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:176
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1737
const char * name
Name of the codec implementation.
Definition: avcodec.h:3542
#define ff_mdct_init
Definition: fft.h:169
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2454
AVCodec ff_nellymoser_decoder
Definition: fft.h:88
audio channel layout utility functions
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:880
#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:60
static av_cold int decode_init(AVCodecContext *avctx)
Libavcodec external API header.
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
int sample_rate
samples per second
Definition: avcodec.h:2403
main external API structure.
Definition: avcodec.h:1642
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:928
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:38
void * buf
Definition: avisynth_c.h:553
void(* imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:108
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:418
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
av_cold AVFloatDSPContext * avpriv_float_dsp_alloc(int bit_exact)
Allocate a float DSP context.
Definition: float_dsp.c:119
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:194
float imdct_buf[2][NELLY_BUF_LEN]
Definition: nellymoserdec.c:55
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:722
common internal api header.
#define exp2(x)
Definition: libm.h:288
#define AV_CODEC_CAP_PARAM_CHANGE
Codec supports changed parameters at any point.
Definition: avcodec.h:1024
#define ff_mdct_end
Definition: fft.h:170
#define NELLY_BUF_LEN
Definition: nellymoser.h:43
void * priv_data
Definition: avcodec.h:1684
int channels
number of audio channels
Definition: avcodec.h:2404
const int16_t ff_nelly_delta_table[32]
Definition: nellymoser.c:80
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
#define NELLY_BANDS
Definition: nellymoser.h:39
#define av_freep(p)
uint8_t * av_packet_get_side_data(AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:320
#define FFSWAP(type, a, b)
Definition: common.h:99
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:1554
#define NELLY_FILL_LEN
Definition: nellymoser.h:44
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:237
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:953
for(j=16;j >0;--j)
void AAC_RENAME() ff_init_ff_sine_windows(int index)
initialize the specified entry of ff_sine_windows
static int16_t block[64]
Definition: dct-test.c:112