ra288.c
Go to the documentation of this file.
1 /*
2  * RealAudio 2.0 (28.8K)
3  * Copyright (c) 2003 the ffmpeg project
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 "avcodec.h"
23 #include "internal.h"
24 #define BITSTREAM_READER_LE
25 #include "get_bits.h"
26 #include "ra288.h"
27 #include "lpc.h"
28 #include "celp_math.h"
29 #include "celp_filters.h"
30 #include "dsputil.h"
31 
32 #define MAX_BACKWARD_FILTER_ORDER 36
33 #define MAX_BACKWARD_FILTER_LEN 40
34 #define MAX_BACKWARD_FILTER_NONREC 35
35 
36 #define RA288_BLOCK_SIZE 5
37 #define RA288_BLOCKS_PER_FRAME 32
38 
39 typedef struct {
42  DECLARE_ALIGNED(16, float, sp_lpc)[FFALIGN(36, 8)];
43  DECLARE_ALIGNED(16, float, gain_lpc)[FFALIGN(10, 8)];
44 
48  float sp_hist[111];
49 
51  float sp_rec[37];
52 
56  float gain_hist[38];
57 
59  float gain_rec[11];
60 } RA288Context;
61 
63 {
64  RA288Context *ractx = avctx->priv_data;
66  dsputil_init(&ractx->dsp, avctx);
67 
69  avctx->coded_frame = &ractx->frame;
70 
71  return 0;
72 }
73 
74 static void convolve(float *tgt, const float *src, int len, int n)
75 {
76  for (; n >= 0; n--)
77  tgt[n] = ff_dot_productf(src, src - n, len);
78 
79 }
80 
81 static void decode(RA288Context *ractx, float gain, int cb_coef)
82 {
83  int i;
84  double sumsum;
85  float sum, buffer[5];
86  float *block = ractx->sp_hist + 70 + 36; // current block
87  float *gain_block = ractx->gain_hist + 28;
88 
89  memmove(ractx->sp_hist + 70, ractx->sp_hist + 75, 36*sizeof(*block));
90 
91  /* block 46 of G.728 spec */
92  sum = 32.;
93  for (i=0; i < 10; i++)
94  sum -= gain_block[9-i] * ractx->gain_lpc[i];
95 
96  /* block 47 of G.728 spec */
97  sum = av_clipf(sum, 0, 60);
98 
99  /* block 48 of G.728 spec */
100  /* exp(sum * 0.1151292546497) == pow(10.0,sum/20) */
101  sumsum = exp(sum * 0.1151292546497) * gain * (1.0/(1<<23));
102 
103  for (i=0; i < 5; i++)
104  buffer[i] = codetable[cb_coef][i] * sumsum;
105 
106  sum = ff_dot_productf(buffer, buffer, 5) * ((1<<24)/5.);
107 
108  sum = FFMAX(sum, 1);
109 
110  /* shift and store */
111  memmove(gain_block, gain_block + 1, 9 * sizeof(*gain_block));
112 
113  gain_block[9] = 10 * log10(sum) - 32;
114 
115  ff_celp_lp_synthesis_filterf(block, ractx->sp_lpc, buffer, 5, 36);
116 }
117 
130 static void do_hybrid_window(RA288Context *ractx,
131  int order, int n, int non_rec, float *out,
132  float *hist, float *out2, const float *window)
133 {
134  int i;
135  float buffer1[MAX_BACKWARD_FILTER_ORDER + 1];
136  float buffer2[MAX_BACKWARD_FILTER_ORDER + 1];
140 
141  ractx->dsp.vector_fmul(work, window, hist, FFALIGN(order + n + non_rec, 8));
142 
143  convolve(buffer1, work + order , n , order);
144  convolve(buffer2, work + order + n, non_rec, order);
145 
146  for (i=0; i <= order; i++) {
147  out2[i] = out2[i] * 0.5625 + buffer1[i];
148  out [i] = out2[i] + buffer2[i];
149  }
150 
151  /* Multiply by the white noise correcting factor (WNCF). */
152  *out *= 257./256.;
153 }
154 
158 static void backward_filter(RA288Context *ractx,
159  float *hist, float *rec, const float *window,
160  float *lpc, const float *tab,
161  int order, int n, int non_rec, int move_size)
162 {
163  float temp[MAX_BACKWARD_FILTER_ORDER+1];
164 
165  do_hybrid_window(ractx, order, n, non_rec, temp, hist, rec, window);
166 
167  if (!compute_lpc_coefs(temp, order, lpc, 0, 1, 1))
168  ractx->dsp.vector_fmul(lpc, lpc, tab, FFALIGN(order, 8));
169 
170  memmove(hist, hist + n, move_size*sizeof(*hist));
171 }
172 
173 static int ra288_decode_frame(AVCodecContext * avctx, void *data,
174  int *got_frame_ptr, AVPacket *avpkt)
175 {
176  const uint8_t *buf = avpkt->data;
177  int buf_size = avpkt->size;
178  float *out;
179  int i, ret;
180  RA288Context *ractx = avctx->priv_data;
181  GetBitContext gb;
182 
183  if (buf_size < avctx->block_align) {
184  av_log(avctx, AV_LOG_ERROR,
185  "Error! Input buffer is too small [%d<%d]\n",
186  buf_size, avctx->block_align);
187  return AVERROR_INVALIDDATA;
188  }
189 
190  /* get output buffer */
192  if ((ret = ff_get_buffer(avctx, &ractx->frame)) < 0) {
193  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
194  return ret;
195  }
196  out = (float *)ractx->frame.data[0];
197 
198  init_get_bits(&gb, buf, avctx->block_align * 8);
199 
200  for (i=0; i < RA288_BLOCKS_PER_FRAME; i++) {
201  float gain = amptable[get_bits(&gb, 3)];
202  int cb_coef = get_bits(&gb, 6 + (i&1));
203 
204  decode(ractx, gain, cb_coef);
205 
206  memcpy(out, &ractx->sp_hist[70 + 36], RA288_BLOCK_SIZE * sizeof(*out));
207  out += RA288_BLOCK_SIZE;
208 
209  if ((i & 7) == 3) {
210  backward_filter(ractx, ractx->sp_hist, ractx->sp_rec, syn_window,
211  ractx->sp_lpc, syn_bw_tab, 36, 40, 35, 70);
212 
213  backward_filter(ractx, ractx->gain_hist, ractx->gain_rec, gain_window,
214  ractx->gain_lpc, gain_bw_tab, 10, 8, 20, 28);
215  }
216  }
217 
218  *got_frame_ptr = 1;
219  *(AVFrame *)data = ractx->frame;
220 
221  return avctx->block_align;
222 }
223 
225  .name = "real_288",
226  .type = AVMEDIA_TYPE_AUDIO,
227  .id = CODEC_ID_RA_288,
228  .priv_data_size = sizeof(RA288Context),
231  .capabilities = CODEC_CAP_DR1,
232  .long_name = NULL_IF_CONFIG_SMALL("RealAudio 2.0 (28.8K)"),
233 };
DSPContext dsp
Definition: ra288.c:41
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
static const float gain_window[FFALIGN(38, 8)]
Definition: ra288.h:122
void ff_celp_lp_synthesis_filterf(float *out, const float *filter_coeffs, const float *in, int buffer_length, int filter_length)
LP synthesis filter.
Definition: celp_filters.c:83
float ff_dot_productf(const float *a, const float *b, int length)
Return the dot product.
Definition: celp_math.c:114
Audio Video Frame.
Definition: avcodec.h:985
static void backward_filter(RA288Context *ractx, float *hist, float *rec, const float *window, float *lpc, const float *tab, int order, int n, int non_rec, int move_size)
Backward synthesis filter, find the LPC coefficients from past speech data.
Definition: ra288.c:158
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:237
#define MAX_BACKWARD_FILTER_ORDER
Definition: ra288.c:32
AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2000
AVFrame frame
Definition: ra288.c:40
int size
Definition: avcodec.h:909
#define DECLARE_ALIGNED(n, t, v)
Definition: mem.h:55
static void decode(RA288Context *ractx, float gain, int cb_coef)
Definition: ra288.c:81
static const float syn_bw_tab[FFALIGN(36, 8)]
synthesis bandwidth broadening table
Definition: ra288.h:133
float sp_lpc[FFALIGN(36, 8)]
LPC coefficients for speech data (spec: A)
Definition: ra288.c:42
AVCodec.
Definition: avcodec.h:3189
int block_align
number of bytes per packet if constant and known or 0 Used by some WAV based audio codecs...
Definition: avcodec.h:1751
static const float amptable[8]
Definition: ra288.h:28
#define FFALIGN(x, a)
Definition: common.h:60
float sp_hist[111]
speech data history (spec: SB).
Definition: ra288.c:48
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:1464
#define av_cold
Definition: attributes.h:71
#define MAX_BACKWARD_FILTER_NONREC
Definition: ra288.c:34
float gain_hist[38]
log-gain history (spec: SBLG).
Definition: ra288.c:56
const char data[16]
Definition: mxf.c:60
uint8_t * data
Definition: avcodec.h:908
bitstream reader API header.
#define LOCAL_ALIGNED_16(t, v,...)
Definition: dsputil.h:698
av_cold void dsputil_init(DSPContext *c, AVCodecContext *avctx)
Definition: dsputil.c:2789
static int init(AVCodecParserContext *s)
Definition: h264_parser.c:336
static const float syn_window[FFALIGN(111, 8)]
Definition: ra288.h:100
#define CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:719
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:191
#define MAX_BACKWARD_FILTER_LEN
Definition: ra288.c:33
static const float gain_bw_tab[FFALIGN(10, 8)]
gain bandwidth broadening table
Definition: ra288.h:143
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:140
const char * name
Name of the codec implementation.
Definition: avcodec.h:3196
static void convolve(float *tgt, const float *src, int len, int n)
Definition: ra288.c:74
#define FFMAX(a, b)
Definition: common.h:53
AVCodec ff_ra_288_decoder
Definition: ra288.c:224
static DCTELEM block[64]
Definition: dct-test.c:189
#define RA288_BLOCKS_PER_FRAME
Definition: ra288.c:37
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame)
Definition: utils.c:1867
static char buffer[20]
Definition: seek-test.c:34
static const int16_t codetable[128][5]
Definition: ra288.h:33
external API header
float sp_rec[37]
speech part of the gain autocorrelation (spec: REXP)
Definition: ra288.c:51
static int compute_lpc_coefs(const LPC_TYPE *autoc, int max_order, LPC_TYPE *lpc, int lpc_stride, int fail, int normalize)
Levinson-Durbin recursion.
Definition: lpc.h:116
float gain_lpc[FFALIGN(10, 8)]
LPC coefficients for gain (spec: GB)
Definition: ra288.c:43
main external API structure.
Definition: avcodec.h:1329
static void do_hybrid_window(RA288Context *ractx, int order, int n, int non_rec, float *out, float *hist, float *out2, const float *window)
Hybrid window filtering, see blocks 36 and 49 of the G.728 specification.
Definition: ra288.c:130
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:111
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:354
#define RA288_BLOCK_SIZE
Definition: ra288.c:36
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: avcodec.h:997
static av_cold int ra288_decode_init(AVCodecContext *avctx)
Definition: ra288.c:62
static int ra288_decode_frame(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
Definition: ra288.c:173
common internal api header.
void(* vector_fmul)(float *dst, const float *src0, const float *src1, int len)
Definition: dsputil.h:412
float gain_rec[11]
recursive part of the gain autocorrelation (spec: REXPLG)
Definition: ra288.c:59
DSP utils.
void * priv_data
Definition: avcodec.h:1531
int len
static const struct @46 tab
TwinVQ codebooks.
void avcodec_get_frame_defaults(AVFrame *pic)
Set the fields of the given AVFrame to default values.
Definition: utils.c:609
int nb_samples
number of audio samples (per channel) described by this frame
Definition: avcodec.h:1265
DSPContext.
Definition: dsputil.h:226