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 
34 #include "nellymoser.h"
35 #include "libavutil/lfg.h"
36 #include "libavutil/random_seed.h"
37 #include "libavutil/audioconvert.h"
38 #include "avcodec.h"
39 #include "internal.h"
40 #include "dsputil.h"
41 #include "fft.h"
42 #include "fmtconvert.h"
43 #include "sinewin.h"
44 
45 #define BITSTREAM_READER_LE
46 #include "get_bits.h"
47 
48 
49 typedef struct NellyMoserDecodeContext {
52  float *float_buf;
56  float scale_bias;
62 
64  const unsigned char block[NELLY_BLOCK_LEN],
65  float audio[NELLY_SAMPLES])
66 {
67  int i,j;
68  float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
69  float *aptr, *bptr, *pptr, val, pval;
70  int bits[NELLY_BUF_LEN];
71  unsigned char v;
72 
73  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
74 
75  bptr = buf;
76  pptr = pows;
77  val = ff_nelly_init_table[get_bits(&s->gb, 6)];
78  for (i=0 ; i<NELLY_BANDS ; i++) {
79  if (i > 0)
80  val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
81  pval = -pow(2, val/2048) * s->scale_bias;
82  for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
83  *bptr++ = val;
84  *pptr++ = pval;
85  }
86 
87  }
88 
89  ff_nelly_get_sample_bits(buf, bits);
90 
91  for (i = 0; i < 2; i++) {
92  aptr = audio + i * NELLY_BUF_LEN;
93 
94  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
96 
97  for (j = 0; j < NELLY_FILL_LEN; j++) {
98  if (bits[j] <= 0) {
99  aptr[j] = M_SQRT1_2*pows[j];
100  if (av_lfg_get(&s->random_state) & 1)
101  aptr[j] *= -1.0;
102  } else {
103  v = get_bits(&s->gb, bits[j]);
104  aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
105  }
106  }
107  memset(&aptr[NELLY_FILL_LEN], 0,
108  (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
109 
110  s->imdct_ctx.imdct_calc(&s->imdct_ctx, s->imdct_out, aptr);
111  /* XXX: overlapping and windowing should be part of a more
112  generic imdct function */
113  s->dsp.vector_fmul_reverse(s->state, s->state, ff_sine_128, NELLY_BUF_LEN);
114  s->dsp.vector_fmul_add(aptr, s->imdct_out, ff_sine_128, s->state, NELLY_BUF_LEN);
115  memcpy(s->state, s->imdct_out + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
116  }
117 }
118 
119 static av_cold int decode_init(AVCodecContext * avctx) {
121 
122  s->avctx = avctx;
123  av_lfg_init(&s->random_state, 0);
124  ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
125 
126  dsputil_init(&s->dsp, avctx);
127 
128  if (avctx->request_sample_fmt == AV_SAMPLE_FMT_FLT) {
129  s->scale_bias = 1.0/(32768*8);
130  avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
131  } else {
132  s->scale_bias = 1.0/(1*8);
133  avctx->sample_fmt = AV_SAMPLE_FMT_S16;
134  ff_fmt_convert_init(&s->fmt_conv, avctx);
135  s->float_buf = av_mallocz(NELLY_SAMPLES * sizeof(*s->float_buf));
136  if (!s->float_buf) {
137  av_log(avctx, AV_LOG_ERROR, "error allocating float buffer\n");
138  return AVERROR(ENOMEM);
139  }
140  }
141 
142  /* Generate overlap window */
143  if (!ff_sine_128[127])
145 
147 
149  avctx->coded_frame = &s->frame;
150 
151  return 0;
152 }
153 
154 static int decode_tag(AVCodecContext *avctx, void *data,
155  int *got_frame_ptr, AVPacket *avpkt)
156 {
157  const uint8_t *buf = avpkt->data;
158  int buf_size = avpkt->size;
160  int blocks, i, ret;
161  int16_t *samples_s16;
162  float *samples_flt;
163 
164  blocks = buf_size / NELLY_BLOCK_LEN;
165  if (blocks <= 0) {
166  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
167  return AVERROR_INVALIDDATA;
168  }
169  if (buf_size % NELLY_BLOCK_LEN) {
170  av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
171  buf_size % NELLY_BLOCK_LEN);
172  }
173  /* Normal numbers of blocks for sample rates:
174  * 8000 Hz - 1
175  * 11025 Hz - 2
176  * 16000 Hz - 3
177  * 22050 Hz - 4
178  * 44100 Hz - 8
179  */
180 
181  /* get output buffer */
182  s->frame.nb_samples = NELLY_SAMPLES * blocks;
183  if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
184  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
185  return ret;
186  }
187  samples_s16 = (int16_t *)s->frame.data[0];
188  samples_flt = (float *)s->frame.data[0];
189 
190  for (i=0 ; i<blocks ; i++) {
191  if (avctx->sample_fmt == AV_SAMPLE_FMT_FLT) {
192  nelly_decode_block(s, buf, samples_flt);
193  samples_flt += NELLY_SAMPLES;
194  } else {
195  nelly_decode_block(s, buf, s->float_buf);
196  s->fmt_conv.float_to_int16(samples_s16, s->float_buf, NELLY_SAMPLES);
197  samples_s16 += NELLY_SAMPLES;
198  }
199  buf += NELLY_BLOCK_LEN;
200  }
201 
202  *got_frame_ptr = 1;
203  *(AVFrame *)data = s->frame;
204 
205  return buf_size;
206 }
207 
208 static av_cold int decode_end(AVCodecContext * avctx) {
210 
211  av_freep(&s->float_buf);
212  ff_mdct_end(&s->imdct_ctx);
213 
214  return 0;
215 }
216 
218  .name = "nellymoser",
219  .type = AVMEDIA_TYPE_AUDIO,
220  .id = CODEC_ID_NELLYMOSER,
221  .priv_data_size = sizeof(NellyMoserDecodeContext),
222  .init = decode_init,
223  .close = decode_end,
224  .decode = decode_tag,
225  .capabilities = CODEC_CAP_DR1 | CODEC_CAP_PARAM_CHANGE,
226  .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
227  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
230 };
231