libavcodec/cook.c File Reference

Cook compatible decoder. More...

#include "libavutil/lfg.h"
#include "avcodec.h"
#include "get_bits.h"
#include "dsputil.h"
#include "bytestream.h"
#include "fft.h"
#include "libavutil/audioconvert.h"
#include "sinewin.h"
#include "cookdata.h"

Go to the source code of this file.

Data Structures

struct  cook_gains
struct  COOKSubpacket
struct  cook

Defines

#define MONO   0x1000001
#define STEREO   0x1000002
#define JOINT_STEREO   0x1000003
#define MC_COOK   0x2000000
#define SUBBAND_SIZE   20
#define MAX_SUBPACKETS   5
#define DECODE_BYTES_PAD1(bytes)   (3 - ((bytes) + 3) % 4)
#define DECODE_BYTES_PAD2(bytes)   ((bytes) % 4 + DECODE_BYTES_PAD1(2 * (bytes)))

Typedefs

typedef struct cook COOKContext

Functions

static av_cold void init_pow2table (void)
static av_cold void init_gain_table (COOKContext *q)
static av_cold int init_cook_vlc_tables (COOKContext *q)
static av_cold int init_cook_mlt (COOKContext *q)
static const float * maybe_reformat_buffer32 (COOKContext *q, const float *ptr, int n)
static av_cold void init_cplscales_table (COOKContext *q)
static int decode_bytes (const uint8_t *inbuffer, uint8_t *out, int bytes)
 Cook indata decoding, every 32 bits are XORed with 0x37c511f2.
static av_cold int cook_decode_close (AVCodecContext *avctx)
 Cook uninit.
static void decode_gain_info (GetBitContext *gb, int *gaininfo)
 Fill the gain array for the timedomain quantization.
static int decode_envelope (COOKContext *q, COOKSubpacket *p, int *quant_index_table)
 Create the quant index table needed for the envelope.
static void categorize (COOKContext *q, COOKSubpacket *p, const int *quant_index_table, int *category, int *category_index)
 Calculate the category and category_index vector.
static void expand_category (COOKContext *q, int *category, int *category_index)
 Expand the category vector.
static void scalar_dequant_float (COOKContext *q, int index, int quant_index, int *subband_coef_index, int *subband_coef_sign, float *mlt_p)
 The real requantization of the mltcoefs.
static int unpack_SQVH (COOKContext *q, COOKSubpacket *p, int category, int *subband_coef_index, int *subband_coef_sign)
 Unpack the subband_coef_index and subband_coef_sign vectors.
static void decode_vectors (COOKContext *q, COOKSubpacket *p, int *category, int *quant_index_table, float *mlt_buffer)
 Fill the mlt_buffer with mlt coefficients.
static int mono_decode (COOKContext *q, COOKSubpacket *p, float *mlt_buffer)
 function for decoding mono data
static void interpolate_float (COOKContext *q, float *buffer, int gain_index, int gain_index_next)
 the actual requantization of the timedomain samples
static void imlt_window_float (COOKContext *q, float *inbuffer, cook_gains *gains_ptr, float *previous_buffer)
 Apply transform window, overlap buffers.
static void imlt_gain (COOKContext *q, float *inbuffer, cook_gains *gains_ptr, float *previous_buffer)
 The modulated lapped transform, this takes transform coefficients and transforms them into timedomain samples.
static int decouple_info (COOKContext *q, COOKSubpacket *p, int *decouple_tab)
 function for getting the jointstereo coupling information
static void decouple_float (COOKContext *q, COOKSubpacket *p, int subband, float f1, float f2, float *decode_buffer, float *mlt_buffer1, float *mlt_buffer2)
static int joint_decode (COOKContext *q, COOKSubpacket *p, float *mlt_buffer1, float *mlt_buffer2)
 function for decoding joint stereo data
static void decode_bytes_and_gain (COOKContext *q, COOKSubpacket *p, const uint8_t *inbuffer, cook_gains *gains_ptr)
 First part of subpacket decoding: decode raw stream bytes and read gain info.
static void saturate_output_float (COOKContext *q, int chan, float *out)
 Saturate the output signal and interleave.
static void mlt_compensate_output (COOKContext *q, float *decode_buffer, cook_gains *gains_ptr, float *previous_buffer, float *out, int chan)
 Final part of subpacket decoding: Apply modulated lapped transform, gain compensation, clip and convert to integer.
static int decode_subpacket (COOKContext *q, COOKSubpacket *p, const uint8_t *inbuffer, float *outbuffer)
 Cook subpacket decoding.
static int cook_decode_frame (AVCodecContext *avctx, void *data, int *got_frame_ptr, AVPacket *avpkt)
 Cook frame decoding.
static av_cold int cook_count_channels (unsigned int mask)
static av_cold int cook_decode_init (AVCodecContext *avctx)
 Cook initialization.

Variables

static float pow2tab [127]
static float rootpow2tab [127]
AVCodec ff_cook_decoder

Detailed Description

Cook compatible decoder.

Bastardization of the G.722.1 standard. This decoder handles RealNetworks, RealAudio G2 data. Cook is identified by the codec name cook in RM files.

To use this decoder, a calling application must supply the extradata bytes provided from the RM container; 8+ bytes for mono streams and 16+ for stereo streams (maybe more).

Codec technicalities (all this assume a buffer length of 1024): Cook works with several different techniques to achieve its compression. In the timedomain the buffer is divided into 8 pieces and quantized. If two neighboring pieces have different quantization index a smooth quantization curve is used to get a smooth overlap between the different pieces. To get to the transformdomain Cook uses a modulated lapped transform. The transform domain has 50 subbands with 20 elements each. This means only a maximum of 50*20=1000 coefficients are used out of the 1024 available.

Definition in file cook.c.

Define Documentation

#define DECODE_BYTES_PAD1 ( bytes   )     (3 - ((bytes) + 3) % 4)

Definition at line 257 of file cook.c.

Referenced by cook_decode_init().

#define DECODE_BYTES_PAD2 ( bytes   )     ((bytes) % 4 + DECODE_BYTES_PAD1(2 * (bytes)))

Definition at line 258 of file cook.c.

#define JOINT_STEREO   0x1000003

Definition at line 59 of file cook.c.

#define MAX_SUBPACKETS   5

Definition at line 63 of file cook.c.

Referenced by cook_decode_init().

#define MC_COOK   0x2000000

Definition at line 60 of file cook.c.

Referenced by cook_decode_init().

#define MONO   0x1000001

Definition at line 57 of file cook.c.

Referenced by cook_decode_init(), and mp3lame_encode_init().

#define STEREO   0x1000002

Definition at line 58 of file cook.c.

#define SUBBAND_SIZE   20

Definition at line 62 of file cook.c.

Referenced by decode_vectors(), decouple_float(), joint_decode(), and scalar_dequant_float().

Typedef Documentation

typedef struct cook COOKContext

Function Documentation

static void categorize ( COOKContext *  q,
COOKSubpacket *  p,
const int *  quant_index_table,
int *  category,
int *  category_index 
) [static]

Calculate the category and category_index vector.

Parameters:
q pointer to the COOKContext
quant_index_table pointer to the array
category pointer to the category array
category_index pointer to the category_index array

Definition at line 410 of file cook.c.

Referenced by mono_decode().

static av_cold int cook_count_channels ( unsigned int  mask  )  [static]

Definition at line 1073 of file cook.c.

Referenced by cook_decode_init().

static av_cold int cook_decode_close ( AVCodecContext *  avctx  )  [static]

Cook uninit.

Definition at line 309 of file cook.c.

static int cook_decode_frame ( AVCodecContext *  avctx,
void *  data,
int *  got_frame_ptr,
AVPacket *  avpkt 
) [static]

Cook frame decoding.

Parameters:
avctx pointer to the AVCodecContext

Definition at line 980 of file cook.c.

static av_cold int cook_decode_init ( AVCodecContext *  avctx  )  [static]

Cook initialization.

Parameters:
avctx pointer to the AVCodecContext

Definition at line 1088 of file cook.c.

static int decode_bytes ( const uint8_t *  inbuffer,
uint8_t *  out,
int  bytes 
) [inline, static]

Cook indata decoding, every 32 bits are XORed with 0x37c511f2.

Why? No idea, some checksum/error detection method maybe.

Out buffer size: extra bytes are needed to cope with padding/misalignment. Subpackets passed to the decoder can contain two, consecutive half-subpackets, of identical but arbitrary size. 1234 1234 1234 1234 extraA extraB Case 1: AAAA BBBB 0 0 Case 2: AAAA ABBB BB-- 3 3 Case 3: AAAA AABB BBBB 2 2 Case 4: AAAA AAAB BBBB BB-- 1 5

Nice way to waste CPU cycles.

Parameters:
inbuffer pointer to byte array of indata
out pointer to byte array of outdata
bytes number of bytes

Definition at line 280 of file cook.c.

static void decode_bytes_and_gain ( COOKContext *  q,
COOKSubpacket *  p,
const uint8_t *  inbuffer,
cook_gains *  gains_ptr 
) [inline, static]

First part of subpacket decoding: decode raw stream bytes and read gain info.

Parameters:
q pointer to the COOKContext
inbuffer pointer to raw stream data
gains_ptr array of current/prev gain pointers

Definition at line 872 of file cook.c.

Referenced by decode_subpacket().

static int decode_envelope ( COOKContext *  q,
COOKSubpacket *  p,
int *  quant_index_table 
) [static]

Create the quant index table needed for the envelope.

Parameters:
q pointer to the COOKContext
quant_index_table pointer to the array

Definition at line 369 of file cook.c.

Referenced by mono_decode().

static void decode_gain_info ( GetBitContext *  gb,
int *  gaininfo 
) [static]

Fill the gain array for the timedomain quantization.

Parameters:
gb pointer to the GetBitContext
gaininfo array[9] of gain indexes

Definition at line 341 of file cook.c.

Referenced by decode_bytes_and_gain().

static int decode_subpacket ( COOKContext *  q,
COOKSubpacket *  p,
const uint8_t *  inbuffer,
float *  outbuffer 
) [static]

Cook subpacket decoding.

This function returns one decoded subpacket, usually 1024 samples per channel.

Parameters:
q pointer to the COOKContext
inbuffer pointer to the inbuffer
outbuffer pointer to the outbuffer

Definition at line 934 of file cook.c.

Referenced by cook_decode_frame().

static void decode_vectors ( COOKContext *  q,
COOKSubpacket *  p,
int *  category,
int *  quant_index_table,
float *  mlt_buffer 
) [static]

Fill the mlt_buffer with mlt coefficients.

Parameters:
q pointer to the COOKContext
category pointer to the category array
quant_index_table pointer to the array
mlt_buffer pointer to mlt coefficients

Definition at line 604 of file cook.c.

Referenced by mono_decode().

static void decouple_float ( COOKContext *  q,
COOKSubpacket *  p,
int  subband,
float  f1,
float  f2,
float *  decode_buffer,
float *  mlt_buffer1,
float *  mlt_buffer2 
) [static]

Definition at line 799 of file cook.c.

Referenced by cook_decode_init().

static int decouple_info ( COOKContext *  q,
COOKSubpacket *  p,
int *  decouple_tab 
) [static]

function for getting the jointstereo coupling information

Parameters:
q pointer to the COOKContext
decouple_tab decoupling array

Definition at line 762 of file cook.c.

Referenced by joint_decode().

static void expand_category ( COOKContext *  q,
int *  category,
int *  category_index 
) [inline, static]

Expand the category vector.

Parameters:
q pointer to the COOKContext
category pointer to the category array
category_index pointer to the category_index array

Definition at line 509 of file cook.c.

Referenced by mono_decode().

static void imlt_gain ( COOKContext *  q,
float *  inbuffer,
cook_gains *  gains_ptr,
float *  previous_buffer 
) [static]

The modulated lapped transform, this takes transform coefficients and transforms them into timedomain samples.

Apply transform window, overlap buffers, apply gain profile and buffer management.

Parameters:
q pointer to the COOKContext
inbuffer pointer to the mltcoefficients
gains_ptr current and previous gains
previous_buffer pointer to the previous buffer to be used for overlapping

Definition at line 731 of file cook.c.

Referenced by mlt_compensate_output().

static void imlt_window_float ( COOKContext *  q,
float *  inbuffer,
cook_gains *  gains_ptr,
float *  previous_buffer 
) [static]

Apply transform window, overlap buffers.

Parameters:
q pointer to the COOKContext
inbuffer pointer to the mltcoefficients
gains_ptr current and previous gains
previous_buffer pointer to the previous buffer to be used for overlapping

Definition at line 703 of file cook.c.

Referenced by cook_decode_init().

static av_cold int init_cook_mlt ( COOKContext *  q  )  [static]

Definition at line 218 of file cook.c.

Referenced by cook_decode_init().

static av_cold int init_cook_vlc_tables ( COOKContext *  q  )  [static]

Definition at line 188 of file cook.c.

Referenced by cook_decode_init().

static av_cold void init_cplscales_table ( COOKContext *  q  )  [static]

Definition at line 248 of file cook.c.

Referenced by cook_decode_init().

static av_cold void init_gain_table ( COOKContext *  q  )  [static]

Definition at line 178 of file cook.c.

Referenced by cook_decode_init().

static av_cold void init_pow2table ( void   )  [static]

Definition at line 168 of file cook.c.

Referenced by cook_decode_init().

static void interpolate_float ( COOKContext *  q,
float *  buffer,
int  gain_index,
int  gain_index_next 
) [static]

the actual requantization of the timedomain samples

Parameters:
q pointer to the COOKContext
buffer pointer to the timedomain buffer
gain_index index for the block multiplier
gain_index_next index for the next block multiplier

Definition at line 676 of file cook.c.

Referenced by cook_decode_init().

static int joint_decode ( COOKContext *  q,
COOKSubpacket *  p,
float *  mlt_buffer1,
float *  mlt_buffer2 
) [static]

function for decoding joint stereo data

Parameters:
q pointer to the COOKContext
mlt_buffer1 pointer to left channel mlt coefficients
mlt_buffer2 pointer to right channel mlt coefficients

Definition at line 821 of file cook.c.

Referenced by decode_subpacket().

static const float* maybe_reformat_buffer32 ( COOKContext *  q,
const float *  ptr,
int  n 
) [static]

Definition at line 242 of file cook.c.

Referenced by init_cplscales_table().

static void mlt_compensate_output ( COOKContext *  q,
float *  decode_buffer,
cook_gains *  gains_ptr,
float *  previous_buffer,
float *  out,
int  chan 
) [inline, static]

Final part of subpacket decoding: Apply modulated lapped transform, gain compensation, clip and convert to integer.

Parameters:
q pointer to the COOKContext
decode_buffer pointer to the mlt coefficients
gains_ptr array of current/prev gain pointers
previous_buffer pointer to the previous buffer to be used for overlapping
out pointer to the output buffer
chan 0: left or single channel, 1: right channel

Definition at line 916 of file cook.c.

Referenced by decode_subpacket().

static int mono_decode ( COOKContext *  q,
COOKSubpacket *  p,
float *  mlt_buffer 
) [static]

function for decoding mono data

Parameters:
q pointer to the COOKContext
mlt_buffer pointer to mlt coefficients

Definition at line 646 of file cook.c.

Referenced by decode_subpacket(), and joint_decode().

static void saturate_output_float ( COOKContext *  q,
int  chan,
float *  out 
) [static]

Saturate the output signal and interleave.

Parameters:
q pointer to the COOKContext
chan channel to saturate
out pointer to the output vector

Definition at line 895 of file cook.c.

Referenced by cook_decode_init().

static void scalar_dequant_float ( COOKContext *  q,
int  index,
int  quant_index,
int *  subband_coef_index,
int *  subband_coef_sign,
float *  mlt_p 
) [static]

The real requantization of the mltcoefs.

Parameters:
q pointer to the COOKContext
index index
quant_index quantisation index
subband_coef_index array of indexes to quant_centroid_tab
subband_coef_sign signs of coefficients
mlt_p pointer into the mlt buffer

Definition at line 531 of file cook.c.

Referenced by cook_decode_init().

static int unpack_SQVH ( COOKContext *  q,
COOKSubpacket *  p,
int  category,
int *  subband_coef_index,
int *  subband_coef_sign 
) [static]

Unpack the subband_coef_index and subband_coef_sign vectors.

Parameters:
q pointer to the COOKContext
category pointer to the category array
subband_coef_index array of indexes to quant_centroid_tab
subband_coef_sign signs of coefficients

Definition at line 560 of file cook.c.

Referenced by decode_vectors().

Variable Documentation

AVCodec ff_cook_decoder

Initial value:

 {
    .name           = "cook",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_COOK,
    .priv_data_size = sizeof(COOKContext),
    .init           = cook_decode_init,
    .close          = cook_decode_close,
    .decode         = cook_decode_frame,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("Cook / Cooker / Gecko (RealAudio G2)"),
}

Definition at line 1313 of file cook.c.

float pow2tab[127] [static]

Definition at line 162 of file cook.c.

Referenced by imlt_window_float(), init_gain_table(), init_pow2table(), and interpolate_float().

float rootpow2tab[127] [static]

Definition at line 163 of file cook.c.

Referenced by init_pow2table(), and scalar_dequant_float().

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