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 "codec_internal.h"
43#include "fft.h"
44#include "get_bits.h"
45#include "internal.h"
46#include "nellymoser.h"
47#include "sinewin.h"
48
49
50typedef struct NellyMoserDecodeContext {
51    AVCodecContext* avctx;
52    AVLFG           random_state;
53    GetBitContext   gb;
54    float           scale_bias;
55    AVFloatDSPContext *fdsp;
56    FFTContext      imdct_ctx;
57    DECLARE_ALIGNED(32, float, imdct_buf)[2][NELLY_BUF_LEN];
58    float          *imdct_out;
59    float          *imdct_prev;
60} NellyMoserDecodeContext;
61
62static void nelly_decode_block(NellyMoserDecodeContext *s,
63                               const unsigned char block[NELLY_BLOCK_LEN],
64                               float audio[NELLY_SAMPLES])
65{
66    int i,j;
67    float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
68    float *aptr, *bptr, *pptr, val, pval;
69    int bits[NELLY_BUF_LEN];
70    unsigned char v;
71
72    init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
73
74    bptr = buf;
75    pptr = pows;
76    val = ff_nelly_init_table[get_bits(&s->gb, 6)];
77    for (i=0 ; i<NELLY_BANDS ; i++) {
78        if (i > 0)
79            val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
80        pval = -exp2(val/2048) * s->scale_bias;
81        for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
82            *bptr++ = val;
83            *pptr++ = pval;
84        }
85
86    }
87
88    ff_nelly_get_sample_bits(buf, bits);
89
90    for (i = 0; i < 2; i++) {
91        aptr = audio + i * NELLY_BUF_LEN;
92
93        init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
94        skip_bits_long(&s->gb, NELLY_HEADER_BITS + i*NELLY_DETAIL_BITS);
95
96        for (j = 0; j < NELLY_FILL_LEN; j++) {
97            if (bits[j] <= 0) {
98                aptr[j] = M_SQRT1_2*pows[j];
99                if (av_lfg_get(&s->random_state) & 1)
100                    aptr[j] *= -1.0;
101            } else {
102                v = get_bits(&s->gb, bits[j]);
103                aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
104            }
105        }
106        memset(&aptr[NELLY_FILL_LEN], 0,
107               (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
108
109        s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
110        s->fdsp->vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
111                                   s->imdct_out, ff_sine_128,
112                                   NELLY_BUF_LEN / 2);
113        FFSWAP(float *, s->imdct_out, s->imdct_prev);
114    }
115}
116
117static av_cold int decode_init(AVCodecContext * avctx) {
118    NellyMoserDecodeContext *s = avctx->priv_data;
119
120    s->avctx = avctx;
121    s->imdct_out = s->imdct_buf[0];
122    s->imdct_prev = s->imdct_buf[1];
123    av_lfg_init(&s->random_state, 0);
124    ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
125
126    s->fdsp = avpriv_float_dsp_alloc(avctx->flags & AV_CODEC_FLAG_BITEXACT);
127    if (!s->fdsp)
128        return AVERROR(ENOMEM);
129
130    s->scale_bias = 1.0/(32768*8);
131    avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
132
133    av_channel_layout_uninit(&avctx->ch_layout);
134    avctx->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
135
136    /* Generate overlap window */
137    ff_init_ff_sine_windows(7);
138
139    return 0;
140}
141
142static int decode_tag(AVCodecContext *avctx, AVFrame *frame,
143                      int *got_frame_ptr, AVPacket *avpkt)
144{
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
180static 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
189const FFCodec ff_nellymoser_decoder = {
190    .p.name         = "nellymoser",
191    .p.long_name    = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
192    .p.type         = AVMEDIA_TYPE_AUDIO,
193    .p.id           = AV_CODEC_ID_NELLYMOSER,
194    .priv_data_size = sizeof(NellyMoserDecodeContext),
195    .init           = decode_init,
196    .close          = decode_end,
197    FF_CODEC_DECODE_CB(decode_tag),
198    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_PARAM_CHANGE | AV_CODEC_CAP_CHANNEL_CONF,
199    .p.sample_fmts  = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
200                                                      AV_SAMPLE_FMT_NONE },
201    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
202};
203