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libavcodec
nellymoserdec.c
Go to the documentation of this file.
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/*
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* NellyMoser audio decoder
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* Copyright (c) 2007 a840bda5870ba11f19698ff6eb9581dfb0f95fa5,
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* 539459aeb7d425140b62a3ec7dbf6dc8e408a306, and
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* 520e17cd55896441042b14df2566a6eb610ed444
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* Copyright (c) 2007 Loic Minier <lool at dooz.org>
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* Benjamin Larsson
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*
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* 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:
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*
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* The above copyright notice and this permission notice shall be included in
17
* all copies or substantial portions of the Software.
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*
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* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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* 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
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* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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* DEALINGS IN THE SOFTWARE.
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*/
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/**
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* @file
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* The 3 alphanumeric copyright notices are md5summed they are from the original
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* implementors. The original code is available from http://code.google.com/p/nelly2pcm/
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*/
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34
#include "
libavutil/channel_layout.h
"
35
#include "
libavutil/float_dsp.h
"
36
#include "
libavutil/lfg.h
"
37
#include "
libavutil/random_seed.h
"
38
#include "
avcodec.h
"
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#include "
fft.h
"
40
#include "
fmtconvert.h
"
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#include "
internal.h
"
42
#include "
nellymoser.h
"
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#include "
sinewin.h
"
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#define BITSTREAM_READER_LE
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#include "
get_bits.h
"
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typedef
struct
NellyMoserDecodeContext
{
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AVCodecContext
*
avctx
;
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AVLFG
random_state
;
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GetBitContext
gb
;
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float
scale_bias
;
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AVFloatDSPContext
fdsp
;
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FFTContext
imdct_ctx
;
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DECLARE_ALIGNED
(32,
float
,
imdct_buf
)[2][
NELLY_BUF_LEN
];
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float
*
imdct_out
;
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float
*
imdct_prev
;
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}
NellyMoserDecodeContext
;
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static
void
nelly_decode_block
(
NellyMoserDecodeContext
*
s
,
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const
unsigned
char
block
[
NELLY_BLOCK_LEN
],
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float
audio[
NELLY_SAMPLES
])
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{
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int
i,j;
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float
buf
[
NELLY_FILL_LEN
], pows[
NELLY_FILL_LEN
];
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float
*aptr, *bptr, *pptr,
val
, pval;
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int
bits
[
NELLY_BUF_LEN
];
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unsigned
char
v
;
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init_get_bits
(&s->
gb
,
block
, NELLY_BLOCK_LEN * 8);
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bptr =
buf
;
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pptr = pows;
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val =
ff_nelly_init_table
[
get_bits
(&s->
gb
, 6)];
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for
(i=0 ; i<
NELLY_BANDS
; i++) {
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if
(i > 0)
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val +=
ff_nelly_delta_table
[
get_bits
(&s->
gb
, 5)];
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pval = -pow(2, val/2048) * s->
scale_bias
;
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for
(j = 0; j <
ff_nelly_band_sizes_table
[i]; j++) {
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*bptr++ =
val
;
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*pptr++ = pval;
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}
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}
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ff_nelly_get_sample_bits
(buf, bits);
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for
(i = 0; i < 2; i++) {
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aptr = audio + i *
NELLY_BUF_LEN
;
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init_get_bits
(&s->
gb
,
block
, NELLY_BLOCK_LEN * 8);
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skip_bits_long
(&s->
gb
,
NELLY_HEADER_BITS
+ i*
NELLY_DETAIL_BITS
);
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for
(j = 0; j <
NELLY_FILL_LEN
; j++) {
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if
(bits[j] <= 0) {
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aptr[j] =
M_SQRT1_2
*pows[j];
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if
(
av_lfg_get
(&s->
random_state
) & 1)
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aptr[j] *= -1.0;
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}
else
{
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v =
get_bits
(&s->
gb
, bits[j]);
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aptr[j] =
ff_nelly_dequantization_table
[(1<<bits[j])-1+v]*pows[j];
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}
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}
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memset(&aptr[NELLY_FILL_LEN], 0,
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(NELLY_BUF_LEN - NELLY_FILL_LEN) *
sizeof
(
float
));
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s->
imdct_ctx
.
imdct_half
(&s->
imdct_ctx
, s->
imdct_out
, aptr);
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s->
fdsp
.
vector_fmul_window
(aptr, s->
imdct_prev
+ NELLY_BUF_LEN / 2,
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s->
imdct_out
, ff_sine_128,
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NELLY_BUF_LEN / 2);
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FFSWAP
(
float
*, s->
imdct_out
, s->
imdct_prev
);
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}
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}
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116
static
av_cold
int
decode_init
(
AVCodecContext
* avctx) {
117
NellyMoserDecodeContext
*
s
= avctx->
priv_data
;
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s->
avctx
= avctx;
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s->
imdct_out
= s->
imdct_buf
[0];
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s->
imdct_prev
= s->
imdct_buf
[1];
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av_lfg_init
(&s->
random_state
, 0);
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ff_mdct_init
(&s->
imdct_ctx
, 8, 1, 1.0);
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avpriv_float_dsp_init
(&s->
fdsp
, avctx->
flags
&
CODEC_FLAG_BITEXACT
);
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127
s->
scale_bias
= 1.0/(32768*8);
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avctx->
sample_fmt
=
AV_SAMPLE_FMT_FLT
;
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/* Generate overlap window */
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if
(!ff_sine_128[127])
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ff_init_ff_sine_windows
(7);
133
134
avctx->
channels
= 1;
135
avctx->
channel_layout
=
AV_CH_LAYOUT_MONO
;
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return
0;
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}
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140
static
int
decode_tag
(
AVCodecContext
*avctx,
void
*
data
,
141
int
*got_frame_ptr,
AVPacket
*avpkt)
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{
143
AVFrame
*
frame
=
data
;
144
const
uint8_t
*
buf
= avpkt->
data
;
145
const
uint8_t
*side=
av_packet_get_side_data
(avpkt,
'F'
, NULL);
146
int
buf_size = avpkt->
size
;
147
NellyMoserDecodeContext
*
s
= avctx->
priv_data
;
148
int
blocks, i,
ret
;
149
float
*samples_flt;
150
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blocks = buf_size /
NELLY_BLOCK_LEN
;
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153
if
(blocks <= 0) {
154
av_log
(avctx,
AV_LOG_ERROR
,
"Packet is too small\n"
);
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return
AVERROR_INVALIDDATA
;
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}
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if
(buf_size %
NELLY_BLOCK_LEN
) {
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av_log
(avctx,
AV_LOG_WARNING
,
"Leftover bytes: %d.\n"
,
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buf_size % NELLY_BLOCK_LEN);
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}
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/* Normal numbers of blocks for sample rates:
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* 8000 Hz - 1
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* 11025 Hz - 2
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* 16000 Hz - 3
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* 22050 Hz - 4
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* 44100 Hz - 8
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*/
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if
(side && blocks>1 && avctx->
sample_rate
%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
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avctx->
sample_rate
= 11025*(blocks/2);
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/* get output buffer */
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frame->
nb_samples
=
NELLY_SAMPLES
* blocks;
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if
((ret =
ff_get_buffer
(avctx, frame, 0)) < 0)
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return
ret;
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samples_flt = (
float
*)frame->
data
[0];
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for
(i=0 ; i<blocks ; i++) {
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nelly_decode_block
(s, buf, samples_flt);
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samples_flt +=
NELLY_SAMPLES
;
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buf +=
NELLY_BLOCK_LEN
;
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}
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*got_frame_ptr = 1;
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return
buf_size;
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}
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static
av_cold
int
decode_end
(
AVCodecContext
* avctx) {
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NellyMoserDecodeContext
*
s
= avctx->
priv_data
;
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ff_mdct_end
(&s->
imdct_ctx
);
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return
0;
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}
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AVCodec
ff_nellymoser_decoder
= {
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.
name
=
"nellymoser"
,
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.type =
AVMEDIA_TYPE_AUDIO
,
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.id =
AV_CODEC_ID_NELLYMOSER
,
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.priv_data_size =
sizeof
(
NellyMoserDecodeContext
),
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.
init
=
decode_init
,
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.
close
=
decode_end
,
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.
decode
=
decode_tag
,
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.capabilities =
CODEC_CAP_DR1
|
CODEC_CAP_PARAM_CHANGE
,
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.long_name =
NULL_IF_CONFIG_SMALL
(
"Nellymoser Asao"
),
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.sample_fmts = (
const
enum
AVSampleFormat
[]) {
AV_SAMPLE_FMT_FLT
,
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AV_SAMPLE_FMT_NONE
},
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};
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1.8.2