2 * NellyMoser audio decoder
3 * Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
4 * 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
5 * 520e17cd55896441042b14df2566a6eb610ed444
6 * Copyright (c) 2007 Loic Minier <lool at dooz.org>
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:
16 * The above copyright notice and this permission notice shall be included in
17 * all copies or substantial portions of the Software.
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.
29 * @file nellymoserdec.c
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/
34 #include "nellymoser.h"
35 #include "libavutil/random.h"
39 #define ALT_BITSTREAM_READER_LE
40 #include "bitstream.h"
43 typedef struct NellyMoserDecodeContext {
44 AVCodecContext* avctx;
45 DECLARE_ALIGNED_16(float,float_buf[NELLY_SAMPLES]);
47 AVRandomState random_state;
52 MDCTContext imdct_ctx;
53 DECLARE_ALIGNED_16(float,imdct_tmp[NELLY_BUF_LEN]);
54 DECLARE_ALIGNED_16(float,imdct_out[NELLY_BUF_LEN * 2]);
55 } NellyMoserDecodeContext;
57 static DECLARE_ALIGNED_16(float,sine_window[128]);
59 static void overlap_and_window(NellyMoserDecodeContext *s, float *state, float *audio, float *a_in)
64 top = NELLY_BUF_LEN-1;
66 while (bot < NELLY_BUF_LEN) {
67 audio[bot] = a_in [bot]*sine_window[bot]
68 +state[bot]*sine_window[top] + s->add_bias;
73 memcpy(state, a_in + NELLY_BUF_LEN, sizeof(float)*NELLY_BUF_LEN);
76 static void nelly_decode_block(NellyMoserDecodeContext *s,
77 const unsigned char block[NELLY_BLOCK_LEN],
78 float audio[NELLY_SAMPLES])
81 float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
82 float *aptr, *bptr, *pptr, val, pval;
83 int bits[NELLY_BUF_LEN];
86 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
90 val = ff_nelly_init_table[get_bits(&s->gb, 6)];
91 for (i=0 ; i<NELLY_BANDS ; i++) {
93 val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
94 pval = -pow(2, val/2048) * s->scale_bias;
95 for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
102 ff_nelly_get_sample_bits(buf, bits);
104 for (i = 0; i < 2; i++) {
105 aptr = audio + i * NELLY_BUF_LEN;
107 init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
108 skip_bits(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
110 for (j = 0; j < NELLY_FILL_LEN; j++) {
112 aptr[j] = M_SQRT1_2*pows[j];
113 if (av_random(&s->random_state) & 1)
116 v = get_bits(&s->gb, bits[j]);
117 aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
120 memset(&aptr[NELLY_FILL_LEN], 0,
121 (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
123 s->imdct_ctx.fft.imdct_calc(&s->imdct_ctx, s->imdct_out,
125 /* XXX: overlapping and windowing should be part of a more
126 generic imdct function */
127 overlap_and_window(s, s->state, aptr, s->imdct_out);
131 static av_cold int decode_init(AVCodecContext * avctx) {
132 NellyMoserDecodeContext *s = avctx->priv_data;
135 av_init_random(0, &s->random_state);
136 ff_mdct_init(&s->imdct_ctx, 8, 1);
138 dsputil_init(&s->dsp, avctx);
140 if(s->dsp.float_to_int16 == ff_float_to_int16_c) {
142 s->scale_bias = 1.0/(8*32768);
145 s->scale_bias = 1.0/(1*8);
148 /* Generate overlap window */
150 ff_sine_window_init(sine_window, 128);
155 static int decode_tag(AVCodecContext * avctx,
156 void *data, int *data_size,
157 const uint8_t * buf, int buf_size) {
158 NellyMoserDecodeContext *s = avctx->priv_data;
162 samples = (int16_t*)data;
164 if (buf_size < avctx->block_align)
177 av_log(avctx, AV_LOG_DEBUG, "Tag size %d.\n", buf_size);
181 for (i=0 ; i<blocks ; i++) {
182 nelly_decode_block(s, &buf[i*NELLY_BLOCK_LEN], s->float_buf);
183 s->dsp.float_to_int16(&samples[i*NELLY_SAMPLES], s->float_buf, NELLY_SAMPLES);
184 *data_size += NELLY_SAMPLES*sizeof(int16_t);
190 static av_cold int decode_end(AVCodecContext * avctx) {
191 NellyMoserDecodeContext *s = avctx->priv_data;
193 ff_mdct_end(&s->imdct_ctx);
197 AVCodec nellymoser_decoder = {
201 sizeof(NellyMoserDecodeContext),
206 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),