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nellymoserdec.c
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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 "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 
116 static av_cold int decode_init(AVCodecContext * avctx) {
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  const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
146  int buf_size = avpkt->size;
148  int blocks, i, ret;
149  float *samples_flt;
150 
151  blocks = buf_size / NELLY_BLOCK_LEN;
152 
153  if (blocks <= 0) {
154  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
155  return AVERROR_INVALIDDATA;
156  }
157 
158  if (buf_size % NELLY_BLOCK_LEN) {
159  av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
160  buf_size % NELLY_BLOCK_LEN);
161  }
162  /* Normal numbers of blocks for sample rates:
163  * 8000 Hz - 1
164  * 11025 Hz - 2
165  * 16000 Hz - 3
166  * 22050 Hz - 4
167  * 44100 Hz - 8
168  */
169  if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
170  avctx->sample_rate= 11025*(blocks/2);
171 
172  /* get output buffer */
173  frame->nb_samples = NELLY_SAMPLES * blocks;
174  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
175  return ret;
176  samples_flt = (float *)frame->data[0];
177 
178  for (i=0 ; i<blocks ; i++) {
179  nelly_decode_block(s, buf, samples_flt);
180  samples_flt += NELLY_SAMPLES;
181  buf += NELLY_BLOCK_LEN;
182  }
183 
184  *got_frame_ptr = 1;
185 
186  return buf_size;
187 }
188 
189 static av_cold int decode_end(AVCodecContext * avctx) {
191 
192  ff_mdct_end(&s->imdct_ctx);
193 
194  return 0;
195 }
196 
198  .name = "nellymoser",
199  .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
200  .type = AVMEDIA_TYPE_AUDIO,
202  .priv_data_size = sizeof(NellyMoserDecodeContext),
203  .init = decode_init,
204  .close = decode_end,
205  .decode = decode_tag,
206  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
207  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
209 };