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"

Include dependency graph for cook.c:

Go to the source code of this file.

Data Structures
struct	cook_gains

struct	COOKSubpacket

struct	cook

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)))

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 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. More...

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. More...

static int	decode_envelope (COOKContext q, COOKSubpacket p, int *quant_index_table)
	Create the quant index table needed for the envelope. More...

static void	categorize (COOKContext q, COOKSubpacket p, const int quant_index_table, int category, int *category_index)
	Calculate the category and category_index vector. More...

static void	expand_category (COOKContext q, int category, int *category_index)
	Expand the category vector. More...

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. More...

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. More...

static void	decode_vectors (COOKContext q, COOKSubpacket p, int category, int quant_index_table, float *mlt_buffer)
	Fill the mlt_buffer with mlt coefficients. More...

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 More...

static void	imlt_window_float (COOKContext q, float inbuffer, cook_gains gains_ptr, float previous_buffer)
	Apply transform window, overlap buffers. More...

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. More...

static int	decouple_info (COOKContext q, COOKSubpacket p, int *decouple_tab)
	function for getting the jointstereo coupling information More...

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. More...

static int	joint_decode (COOKContext q, COOKSubpacket p, float mlt_buffer_left, float mlt_buffer_right)
	function for decoding joint stereo data More...

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. More...

static void	saturate_output_float (COOKContext q, float out)
	Saturate the output signal and interleave. More...

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. More...

static int	decode_subpacket (COOKContext q, COOKSubpacket p, const uint8_t inbuffer, float *outbuffer)
	Cook subpacket decoding. More...

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. More...

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

Definition at line 249 of file cook.c.

Referenced by cook_decode_init().

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

Definition at line 250 of file cook.c.

#define JOINT_STEREO 0x1000003

Definition at line 60 of file cook.c.

Referenced by cook_decode_init().

#define MAX_SUBPACKETS 5

Definition at line 64 of file cook.c.

Referenced by cook_decode_init().

#define MC_COOK 0x2000000

Definition at line 61 of file cook.c.

Referenced by cook_decode_init().

#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.

Referenced by cook_decode_frame(), and cook_decode_init().

#define SUBBAND_SIZE 20

Definition at line 63 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 399 of file cook.c.

Referenced by mono_decode().

static av_cold int cook_decode_close ( AVCodecContext * avctx )

static

Definition at line 298 of file cook.c.

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

static

Definition at line 955 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 1050 of file cook.c.

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

inlinestatic

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 272 of file cook.c.

Referenced by decode_bytes_and_gain().

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

inlinestatic

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 855 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 358 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 330 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 913 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 591 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

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

Parameters

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

Definition at line 781 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 742 of file cook.c.

Referenced by joint_decode().

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

inlinestatic

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 496 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 712 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 684 of file cook.c.

Referenced by cook_decode_init().

static av_cold int init_cook_mlt ( COOKContext * q )

static

Definition at line 216 of file cook.c.

Referenced by cook_decode_init().

static av_cold int init_cook_vlc_tables ( COOKContext * q )

static

Definition at line 185 of file cook.c.

Referenced by cook_decode_init().

static av_cold void init_cplscales_table ( COOKContext * q )

static

Definition at line 240 of file cook.c.

Referenced by cook_decode_init().

static av_cold void init_gain_table ( COOKContext * q )

static

Definition at line 175 of file cook.c.

Referenced by cook_decode_init().

static av_cold void init_pow2table ( void )

static

Definition at line 165 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 657 of file cook.c.

Referenced by cook_decode_init().

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

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 803 of file cook.c.

Referenced by decode_subpacket().

static void mlt_compensate_output	(	COOKContext *	q,
		float *	decode_buffer,
		cook_gains *	gains_ptr,
		float *	previous_buffer,
		float *	out
	)

inlinestatic

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

Definition at line 895 of file cook.c.

Referenced by decode_subpacket().

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

static

Definition at line 627 of file cook.c.

Referenced by decode_subpacket(), and joint_decode().

static void saturate_output_float	(	COOKContext *	q,
		float *	out
	)

static

Saturate the output signal and interleave.

Parameters

q	pointer to the COOKContext
out	pointer to the output vector

Definition at line 877 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 518 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 547 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)"),
    .sample_fmts    = (const enum AVSampleFormat[]) { AV_SAMPLE_FMT_FLTP,
                                                      AV_SAMPLE_FMT_NONE },
}

Definition at line 1280 of file cook.c.

float pow2tab[127]

static

Definition at line 159 of file cook.c.

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

float rootpow2tab[127]

static

Definition at line 160 of file cook.c.

Referenced by init_pow2table(), and scalar_dequant_float().

Paris Hackday Code

Data Structures

Macros

Typedefs

Functions

Variables

Detailed Description

Macro Definition Documentation

Typedef Documentation

Function Documentation

Variable Documentation