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
34 #include "libavutil/channel_layout.h"
35 #include "libavutil/float_dsp.h"
36 #include "libavutil/lfg.h"
37 #include "libavutil/mem_internal.h"
38 #include "libavutil/random_seed.h"
39
40 #define BITSTREAM_READER_LE
41 #include "avcodec.h"
42 #include "fft.h"
43 #include "get_bits.h"
44 #include "internal.h"
45 #include "nellymoser.h"
46 #include "sinewin.h"
47
48
49 typedef struct NellyMoserDecodeContext {
50 AVCodecContext* avctx;
51 AVLFG random_state;
52 GetBitContext gb;
53 float scale_bias;
54 AVFloatDSPContext *fdsp;
55 FFTContext imdct_ctx;
56 DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
57 float *imdct_out;
58 float *imdct_prev;
59 } NellyMoserDecodeContext;
60
nelly_decode_block(NellyMoserDecodeContext * s,const unsigned char block[NELLY_BLOCK_LEN],float audio[NELLY_SAMPLES])61 static void nelly_decode_block(NellyMoserDecodeContext *s,
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 = -exp2(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);
93 skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
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
decode_init(AVCodecContext * avctx)116 static av_cold int decode_init(AVCodecContext * avctx) {
117 NellyMoserDecodeContext *s = avctx->priv_data;
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
125 s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
126 if (!s->fdsp)
127 return AVERROR(ENOMEM);
128
129 s->scale_bias = 1.0/(32768*8);
130 avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
131
132 avctx->channels = 1;
133 avctx->channel_layout = AV_CH_LAYOUT_MONO;
134
135 /* Generate overlap window */
136 ff_init_ff_sine_windows(7);
137
138 return 0;
139 }
140
decode_tag(AVCodecContext * avctx,void * data,int * got_frame_ptr,AVPacket * avpkt)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 int buf_size = avpkt->size;
147 NellyMoserDecodeContext *s = avctx->priv_data;
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
163 /* get output buffer */
164 frame->nb_samples = NELLY_SAMPLES * blocks;
165 if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
166 return ret;
167 samples_flt = (float *)frame->data[0];
168
169 for (i=0 ; i<blocks ; i++) {
170 nelly_decode_block(s, buf, samples_flt);
171 samples_flt += NELLY_SAMPLES;
172 buf += NELLY_BLOCK_LEN;
173 }
174
175 *got_frame_ptr = 1;
176
177 return buf_size;
178 }
179
decode_end(AVCodecContext * avctx)180 static av_cold int decode_end(AVCodecContext * avctx) {
181 NellyMoserDecodeContext *s = avctx->priv_data;
182
183 ff_mdct_end(&s->imdct_ctx);
184 av_freep(&s->fdsp);
185
186 return 0;
187 }
188
189 AVCodec ff_nellymoser_decoder = {
190 .name = "nellymoser",
191 .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
192 .type = AVMEDIA_TYPE_AUDIO,
193 .id = AV_CODEC_ID_NELLYMOSER,
194 .priv_data_size = sizeof(NellyMoserDecodeContext),
195 .init = decode_init,
196 .close = decode_end,
197 .decode = decode_tag,
198 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_PARAM_CHANGE | AV_CODEC_CAP_CHANNEL_CONF,
199 .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
200 AV_SAMPLE_FMT_NONE },
201 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
202 };
203