FFmpeg
nellymoserdec.c
Go to the documentation of this file.
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 
35 #include "libavutil/float_dsp.h"
36 #include "libavutil/lfg.h"
37 #include "libavutil/random_seed.h"
38 
39 #define BITSTREAM_READER_LE
40 #include "avcodec.h"
41 #include "fft.h"
42 #include "get_bits.h"
43 #include "internal.h"
44 #include "nellymoser.h"
45 #include "sinewin.h"
46 
47 
48 typedef struct NellyMoserDecodeContext {
52  float scale_bias;
56  float *imdct_out;
57  float *imdct_prev;
59 
61  const unsigned char block[NELLY_BLOCK_LEN],
62  float audio[NELLY_SAMPLES])
63 {
64  int i,j;
65  float buf[NELLY_FILL_LEN], pows[NELLY_FILL_LEN];
66  float *aptr, *bptr, *pptr, val, pval;
67  int bits[NELLY_BUF_LEN];
68  unsigned char v;
69 
70  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
71 
72  bptr = buf;
73  pptr = pows;
74  val = ff_nelly_init_table[get_bits(&s->gb, 6)];
75  for (i=0 ; i<NELLY_BANDS ; i++) {
76  if (i > 0)
77  val += ff_nelly_delta_table[get_bits(&s->gb, 5)];
78  pval = -exp2(val/2048) * s->scale_bias;
79  for (j = 0; j < ff_nelly_band_sizes_table[i]; j++) {
80  *bptr++ = val;
81  *pptr++ = pval;
82  }
83 
84  }
85 
86  ff_nelly_get_sample_bits(buf, bits);
87 
88  for (i = 0; i < 2; i++) {
89  aptr = audio + i * NELLY_BUF_LEN;
90 
91  init_get_bits(&s->gb, block, NELLY_BLOCK_LEN * 8);
93 
94  for (j = 0; j < NELLY_FILL_LEN; j++) {
95  if (bits[j] <= 0) {
96  aptr[j] = M_SQRT1_2*pows[j];
97  if (av_lfg_get(&s->random_state) & 1)
98  aptr[j] *= -1.0;
99  } else {
100  v = get_bits(&s->gb, bits[j]);
101  aptr[j] = ff_nelly_dequantization_table[(1<<bits[j])-1+v]*pows[j];
102  }
103  }
104  memset(&aptr[NELLY_FILL_LEN], 0,
105  (NELLY_BUF_LEN - NELLY_FILL_LEN) * sizeof(float));
106 
107  s->imdct_ctx.imdct_half(&s->imdct_ctx, s->imdct_out, aptr);
108  s->fdsp->vector_fmul_window(aptr, s->imdct_prev + NELLY_BUF_LEN / 2,
109  s->imdct_out, ff_sine_128,
110  NELLY_BUF_LEN / 2);
111  FFSWAP(float *, s->imdct_out, s->imdct_prev);
112  }
113 }
114 
117 
118  s->avctx = avctx;
119  s->imdct_out = s->imdct_buf[0];
120  s->imdct_prev = s->imdct_buf[1];
121  av_lfg_init(&s->random_state, 0);
122  ff_mdct_init(&s->imdct_ctx, 8, 1, 1.0);
123 
125  if (!s->fdsp)
126  return AVERROR(ENOMEM);
127 
128  s->scale_bias = 1.0/(32768*8);
129  avctx->sample_fmt = AV_SAMPLE_FMT_FLT;
130 
131  /* Generate overlap window */
132  if (!ff_sine_128[127])
134 
135  avctx->channels = 1;
137 
138  return 0;
139 }
140 
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  const uint8_t *side=av_packet_get_side_data(avpkt, 'F', NULL);
147  int buf_size = avpkt->size;
149  int blocks, i, ret;
150  float *samples_flt;
151 
152  blocks = buf_size / NELLY_BLOCK_LEN;
153 
154  if (blocks <= 0) {
155  av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
156  return AVERROR_INVALIDDATA;
157  }
158 
159  if (buf_size % NELLY_BLOCK_LEN) {
160  av_log(avctx, AV_LOG_WARNING, "Leftover bytes: %d.\n",
161  buf_size % NELLY_BLOCK_LEN);
162  }
163  /* Normal numbers of blocks for sample rates:
164  * 8000 Hz - 1
165  * 11025 Hz - 2
166  * 16000 Hz - 3
167  * 22050 Hz - 4
168  * 44100 Hz - 8
169  */
170  if(side && blocks>1 && avctx->sample_rate%11025==0 && (1<<((side[0]>>2)&3)) == blocks)
171  avctx->sample_rate= 11025*(blocks/2);
172 
173  /* get output buffer */
174  frame->nb_samples = NELLY_SAMPLES * blocks;
175  if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
176  return ret;
177  samples_flt = (float *)frame->data[0];
178 
179  for (i=0 ; i<blocks ; i++) {
180  nelly_decode_block(s, buf, samples_flt);
181  samples_flt += NELLY_SAMPLES;
182  buf += NELLY_BLOCK_LEN;
183  }
184 
185  *got_frame_ptr = 1;
186 
187  return buf_size;
188 }
189 
192 
193  ff_mdct_end(&s->imdct_ctx);
194  av_freep(&s->fdsp);
195 
196  return 0;
197 }
198 
200  .name = "nellymoser",
201  .long_name = NULL_IF_CONFIG_SMALL("Nellymoser Asao"),
202  .type = AVMEDIA_TYPE_AUDIO,
204  .priv_data_size = sizeof(NellyMoserDecodeContext),
205  .init = decode_init,
206  .close = decode_end,
207  .decode = decode_tag,
209  .sample_fmts = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLT,
211 };
Context structure for the Lagged Fibonacci PRNG.
Definition: lfg.h:33
#define NULL
Definition: coverity.c:32
const char const char void * val
Definition: avisynth_c.h:863
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
AVFloatDSPContext * fdsp
Definition: nellymoserdec.c:53
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
#define AV_LOG_WARNING
Something somehow does not look correct.
Definition: log.h:182
static void skip_bits_long(GetBitContext *s, int n)
Skips the specified number of bits.
Definition: get_bits.h:291
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
#define M_SQRT1_2
Definition: mathematics.h:58
AVCodecContext * avctx
Definition: nellymoserdec.c:49
int size
Definition: avcodec.h:1483
const float ff_nelly_dequantization_table[127]
Definition: nellymoser.c:39
static av_cold int decode_end(AVCodecContext *avctx)
AVCodec.
Definition: avcodec.h:3494
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
#define NELLY_DETAIL_BITS
Definition: nellymoser.h:42
const uint16_t ff_nelly_init_table[64]
Definition: nellymoser.c:70
enum AVSampleFormat sample_fmt
audio sample format
Definition: avcodec.h:2238
The exact code depends on how similar the blocks are and how related they are to the block
uint8_t
#define av_cold
Definition: attributes.h:82
#define DECLARE_ALIGNED(n, t, v)
Declare a variable that is aligned in memory.
Definition: mem.h:112
uint8_t * data
Definition: avcodec.h:1482
bitstream reader API header.
#define av_log(a,...)
static int decode_tag(AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
void(* vector_fmul_window)(float *dst, const float *src0, const float *src1, const float *win, int len)
Overlap/add with window function.
Definition: float_dsp.h:119
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
av_cold AVFloatDSPContext * avpriv_float_dsp_alloc(int bit_exact)
Allocate a float DSP context.
Definition: float_dsp.c:135
uint8_t * av_packet_get_side_data(const AVPacket *pkt, enum AVPacketSideDataType type, int *size)
Get side information from packet.
Definition: avpacket.c:350
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
int flags
AV_CODEC_FLAG_*.
Definition: avcodec.h:1650
const char * name
Name of the codec implementation.
Definition: avcodec.h:3501
uint8_t bits
Definition: vp3data.h:202
#define ff_mdct_init
Definition: fft.h:169
uint64_t channel_layout
Audio channel layout.
Definition: avcodec.h:2281
AVCodec ff_nellymoser_decoder
Definition: fft.h:88
audio channel layout utility functions
#define AV_CODEC_FLAG_BITEXACT
Use only bitexact stuff (except (I)DCT).
Definition: avcodec.h:913
#define NELLY_BLOCK_LEN
Definition: nellymoser.h:40
const uint8_t ff_nelly_band_sizes_table[NELLY_BANDS]
Definition: nellymoser.c:66
#define NELLY_HEADER_BITS
Definition: nellymoser.h:41
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
#define s(width, name)
Definition: cbs_vp9.c:257
static void nelly_decode_block(NellyMoserDecodeContext *s, const unsigned char block[NELLY_BLOCK_LEN], float audio[NELLY_SAMPLES])
Definition: nellymoserdec.c:60
static av_cold int decode_init(AVCodecContext *avctx)
Libavcodec external API header.
AVSampleFormat
Audio sample formats.
Definition: samplefmt.h:58
int sample_rate
samples per second
Definition: avcodec.h:2230
main external API structure.
Definition: avcodec.h:1570
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1968
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
Definition: lfg.h:53
void * buf
Definition: avisynth_c.h:766
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
void(* imdct_half)(struct FFTContext *s, FFTSample *output, const FFTSample *input)
Definition: fft.h:108
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
float imdct_buf[2][NELLY_BUF_LEN]
Definition: nellymoserdec.c:55
common internal api header.
#define exp2(x)
Definition: libm.h:288
#define AV_CODEC_CAP_PARAM_CHANGE
Codec supports changed parameters at any point.
Definition: avcodec.h:1050
#define ff_mdct_end
Definition: fft.h:170
#define NELLY_BUF_LEN
Definition: nellymoser.h:43
void * priv_data
Definition: avcodec.h:1597
int channels
number of audio channels
Definition: avcodec.h:2231
const int16_t ff_nelly_delta_table[32]
Definition: nellymoser.c:79
static enum AVSampleFormat sample_fmts[]
Definition: adpcmenc.c:701
#define NELLY_BANDS
Definition: nellymoser.h:39
#define av_freep(p)
#define FFSWAP(type, a, b)
Definition: common.h:99
void ff_nelly_get_sample_bits(const float *buf, int *bits)
Definition: nellymoser.c:116
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later.That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another.Frame references ownership and permissions
#define AV_CH_LAYOUT_MONO
The 3 alphanumeric copyright notices are md5summed they are from the original implementors.
#define NELLY_SAMPLES
Definition: nellymoser.h:48
This structure stores compressed data.
Definition: avcodec.h:1459
#define NELLY_FILL_LEN
Definition: nellymoser.h:44
int nb_samples
number of audio samples (per channel) described by this frame
Definition: frame.h:361
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:986
for(j=16;j >0;--j)
void AAC_RENAME() ff_init_ff_sine_windows(int index)
initialize the specified entry of ff_sine_windows