Cook compatible decoder. More...

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

Data Structures
struct	cook_gains

struct	COOKSubpacket

struct	COOKContext

Macros
#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)))

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 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)

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)

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)
	function decouples a pair of signals from a single signal via multiplication.

static int	joint_decode (COOKContext q, COOKSubpacket p, float mlt_buffer_left, float mlt_buffer_right)
	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, 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)
	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)

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.

Macro Definition Documentation

#define MONO 0x1000001

Definition at line 58 of file cook.c.

Referenced by cook_decode_init(), libshine_encode_init(), and mp3lame_encode_init().

#define STEREO 0x1000002

Definition at line 59 of file cook.c.

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

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

q	pointer to the COOKContext
quant_index_table	pointer to the array

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

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

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

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

q	pointer to the COOKContext
subband	index of the current subband
f1	multiplier for channel 1 extraction
f2	multiplier for channel 2 extraction
decode_buffer	input buffer
mlt_buffer1	pointer to left channel mlt coefficients
mlt_buffer2	pointer to right channel mlt coefficients

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

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

q	pointer to the COOKContext
inbuffer	pointer to the inbuffer
outbuffer	pointer to the outbuffer

Data Structures

Macros

Functions

Variables

Detailed Description

Macro Definition Documentation

Function Documentation

Variable Documentation