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_out
[NELLY_BUF_LEN
* 2]);
54 } NellyMoserDecodeContext
;
56 static DECLARE_ALIGNED_16(float,sine_window
[128]);
58 static void overlap_and_window(NellyMoserDecodeContext
*s
, float *state
, float *audio
, float *a_in
)
63 top
= NELLY_BUF_LEN
-1;
65 while (bot
< NELLY_BUF_LEN
) {
66 audio
[bot
] = a_in
[bot
]*sine_window
[bot
]
67 +state
[bot
]*sine_window
[top
] + s
->add_bias
;
72 memcpy(state
, a_in
+ NELLY_BUF_LEN
, sizeof(float)*NELLY_BUF_LEN
);
75 static void nelly_decode_block(NellyMoserDecodeContext
*s
,
76 const unsigned char block
[NELLY_BLOCK_LEN
],
77 float audio
[NELLY_SAMPLES
])
80 float buf
[NELLY_FILL_LEN
], pows
[NELLY_FILL_LEN
];
81 float *aptr
, *bptr
, *pptr
, val
, pval
;
82 int bits
[NELLY_BUF_LEN
];
85 init_get_bits(&s
->gb
, block
, NELLY_BLOCK_LEN
* 8);
89 val
= ff_nelly_init_table
[get_bits(&s
->gb
, 6)];
90 for (i
=0 ; i
<NELLY_BANDS
; i
++) {
92 val
+= ff_nelly_delta_table
[get_bits(&s
->gb
, 5)];
93 pval
= -pow(2, val
/2048) * s
->scale_bias
;
94 for (j
= 0; j
< ff_nelly_band_sizes_table
[i
]; j
++) {
101 ff_nelly_get_sample_bits(buf
, bits
);
103 for (i
= 0; i
< 2; i
++) {
104 aptr
= audio
+ i
* NELLY_BUF_LEN
;
106 init_get_bits(&s
->gb
, block
, NELLY_BLOCK_LEN
* 8);
107 skip_bits(&s
->gb
, NELLY_HEADER_BITS
+ i
*NELLY_DETAIL_BITS
);
109 for (j
= 0; j
< NELLY_FILL_LEN
; j
++) {
111 aptr
[j
] = M_SQRT1_2
*pows
[j
];
112 if (av_random(&s
->random_state
) & 1)
115 v
= get_bits(&s
->gb
, bits
[j
]);
116 aptr
[j
] = ff_nelly_dequantization_table
[(1<<bits
[j
])-1+v
]*pows
[j
];
119 memset(&aptr
[NELLY_FILL_LEN
], 0,
120 (NELLY_BUF_LEN
- NELLY_FILL_LEN
) * sizeof(float));
122 ff_imdct_calc(&s
->imdct_ctx
, s
->imdct_out
, aptr
);
123 /* XXX: overlapping and windowing should be part of a more
124 generic imdct function */
125 overlap_and_window(s
, s
->state
, aptr
, s
->imdct_out
);
129 static av_cold
int decode_init(AVCodecContext
* avctx
) {
130 NellyMoserDecodeContext
*s
= avctx
->priv_data
;
133 av_init_random(0, &s
->random_state
);
134 ff_mdct_init(&s
->imdct_ctx
, 8, 1);
136 dsputil_init(&s
->dsp
, avctx
);
138 if(s
->dsp
.float_to_int16
== ff_float_to_int16_c
) {
140 s
->scale_bias
= 1.0/(8*32768);
143 s
->scale_bias
= 1.0/(1*8);
146 /* Generate overlap window */
148 ff_sine_window_init(sine_window
, 128);
150 avctx
->sample_fmt
= SAMPLE_FMT_S16
;
154 static int decode_tag(AVCodecContext
* avctx
,
155 void *data
, int *data_size
,
156 const uint8_t * buf
, int buf_size
) {
157 NellyMoserDecodeContext
*s
= avctx
->priv_data
;
161 samples
= (int16_t*)data
;
163 if (buf_size
< avctx
->block_align
)
176 av_log(avctx
, AV_LOG_DEBUG
, "Tag size %d.\n", buf_size
);
180 for (i
=0 ; i
<blocks
; i
++) {
181 nelly_decode_block(s
, &buf
[i
*NELLY_BLOCK_LEN
], s
->float_buf
);
182 s
->dsp
.float_to_int16(&samples
[i
*NELLY_SAMPLES
], s
->float_buf
, NELLY_SAMPLES
);
183 *data_size
+= NELLY_SAMPLES
*sizeof(int16_t);
189 static av_cold
int decode_end(AVCodecContext
* avctx
) {
190 NellyMoserDecodeContext
*s
= avctx
->priv_data
;
192 ff_mdct_end(&s
->imdct_ctx
);
196 AVCodec nellymoser_decoder
= {
200 sizeof(NellyMoserDecodeContext
),
205 .long_name
= NULL_IF_CONFIG_SMALL("Nellymoser Asao"),