libavcodec/imc.c File Reference

IMC - Intel Music Coder A mdct based codec using a 256 points large transform divied into 32 bands with some mix of scale factors. More...

#include <math.h>
#include <stddef.h>
#include <stdio.h>
#include "avcodec.h"
#include "get_bits.h"
#include "dsputil.h"
#include "fft.h"
#include "libavutil/audioconvert.h"
#include "sinewin.h"
#include "imcdata.h"

Go to the source code of this file.

Data Structures
struct	IMCContext
Defines
#define	ALT_BITSTREAM_READER
#define	IMC_BLOCK_SIZE   64
#define	IMC_FRAME_ID   0x21
#define	BANDS   32
#define	COEFFS   256
#define	VLC_TABLES_SIZE   9512
Functions
static av_cold int	imc_decode_init (AVCodecContext *avctx)
static void	imc_calculate_coeffs (IMCContext *q, float *flcoeffs1, float *flcoeffs2, int *bandWidthT, float *flcoeffs3, float *flcoeffs5)
static void	imc_read_level_coeffs (IMCContext *q, int stream_format_code, int *levlCoeffs)
static void	imc_decode_level_coefficients (IMCContext *q, int *levlCoeffBuf, float *flcoeffs1, float *flcoeffs2)
static void	imc_decode_level_coefficients2 (IMCContext *q, int *levlCoeffBuf, float *old_floor, float *flcoeffs1, float *flcoeffs2)
static int	bit_allocation (IMCContext *q, int stream_format_code, int freebits, int flag)
	Perform bit allocation depending on bits available.
static void	imc_get_skip_coeff (IMCContext *q)
static void	imc_adjust_bit_allocation (IMCContext *q, int summer)
	Increase highest' band coefficient sizes as some bits won't be used.
static void	imc_imdct256 (IMCContext *q)
static int	inverse_quant_coeff (IMCContext *q, int stream_format_code)
static int	imc_get_coeffs (IMCContext *q)
static int	imc_decode_frame (AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)
static av_cold int	imc_decode_close (AVCodecContext *avctx)
Variables
static VLC	huffman_vlc [4][4]
static const int	vlc_offsets [17]
static VLC_TYPE	vlc_tables [VLC_TABLES_SIZE][2]
AVCodec	ff_imc_decoder

---

Detailed Description

IMC - Intel Music Coder A mdct based codec using a 256 points large transform divied into 32 bands with some mix of scale factors.

Only mono is supported.

Definition in file imc.c.

---

Define Documentation

#define ALT_BITSTREAM_READER

Definition at line 38 of file imc.c.

#define BANDS   32

Definition at line 50 of file imc.c.

Referenced by bit_allocation(), imc_adjust_bit_allocation(), imc_calculate_coeffs(), imc_decode_frame(), imc_decode_init(), imc_decode_level_coefficients(), imc_decode_level_coefficients2(), imc_get_coeffs(), imc_get_skip_coeff(), imc_read_level_coeffs(), and inverse_quant_coeff().

#define COEFFS   256

Definition at line 51 of file imc.c.

Referenced by imc_decode_frame(), imc_decode_init(), and imc_imdct256().

#define IMC_BLOCK_SIZE   64

Definition at line 48 of file imc.c.

Referenced by imc_decode_frame().

#define IMC_FRAME_ID   0x21

Definition at line 49 of file imc.c.

Referenced by imc_decode_frame().

#define VLC_TABLES_SIZE   9512

Definition at line 97 of file imc.c.

---

Function Documentation

static int bit_allocation	(	IMCContext *	q,
		int	stream_format_code,
		int	freebits,
		int	flag
	)		[static]

Perform bit allocation depending on bits available.

Definition at line 300 of file imc.c.

Referenced by imc_decode_frame().

static void imc_adjust_bit_allocation	(	IMCContext *	q,
		int	summer
	)		[static]

Increase highest' band coefficient sizes as some bits won't be used.

Definition at line 516 of file imc.c.

Referenced by imc_decode_frame().

static void imc_calculate_coeffs	(	IMCContext *	q,
		float *	flcoeffs1,
		float *	flcoeffs2,
		int *	bandWidthT,
		float *	flcoeffs3,
		float *	flcoeffs5
	)		[static]

Definition at line 166 of file imc.c.

Referenced by imc_decode_frame().

static av_cold int imc_decode_close

(

AVCodecContext *

avctx

)

[static]

Definition at line 817 of file imc.c.

static int imc_decode_frame	(	AVCodecContext *	avctx,
		void *	data,
		int *	data_size,
		AVPacket *	avpkt
	)		[static]

Definition at line 644 of file imc.c.

static av_cold int imc_decode_init

(

AVCodecContext *

avctx

)

[static]

Definition at line 105 of file imc.c.

static void imc_decode_level_coefficients	(	IMCContext *	q,
		int *	levlCoeffBuf,
		float *	flcoeffs1,
		float *	flcoeffs2
	)		[static]

Definition at line 246 of file imc.c.

Referenced by imc_decode_frame().

static void imc_decode_level_coefficients2	(	IMCContext *	q,
		int *	levlCoeffBuf,
		float *	old_floor,
		float *	flcoeffs1,
		float *	flcoeffs2
	)		[static]

Definition at line 280 of file imc.c.

Referenced by imc_decode_frame().

static int imc_get_coeffs

(

IMCContext *

q

)

[static]

Definition at line 619 of file imc.c.

Referenced by imc_decode_frame().

static void imc_get_skip_coeff

(

IMCContext *

q

)

[static]

Definition at line 462 of file imc.c.

Referenced by imc_decode_frame().

static void imc_imdct256

(

IMCContext *

q

)

[static]

Definition at line 555 of file imc.c.

Referenced by imc_decode_frame().

static void imc_read_level_coeffs	(	IMCContext *	q,
		int	stream_format_code,
		int *	levlCoeffs
	)		[static]

Definition at line 220 of file imc.c.

Referenced by imc_decode_frame().

static int inverse_quant_coeff	(	IMCContext *	q,
		int	stream_format_code
	)		[static]

Definition at line 581 of file imc.c.

Referenced by imc_decode_frame().

---

Variable Documentation

AVCodec ff_imc_decoder

Initial value:

 {
    .name = "imc",
    .type = AVMEDIA_TYPE_AUDIO,
    .id = CODEC_ID_IMC,
    .priv_data_size = sizeof(IMCContext),
    .init = imc_decode_init,
    .close = imc_decode_close,
    .decode = imc_decode_frame,
    .long_name = NULL_IF_CONFIG_SMALL("IMC (Intel Music Coder)"),
}

Definition at line 826 of file imc.c.

VLC huffman_vlc[4][4] [static]

Definition at line 95 of file imc.c.

const int vlc_offsets[17] [static]

Initial value:

 {
    0,     640, 1156, 1732, 2308, 2852, 3396, 3924,
    4452, 5220, 5860, 6628, 7268, 7908, 8424, 8936, VLC_TABLES_SIZE}

Definition at line 99 of file imc.c.

Referenced by imc_decode_init().

VLC_TYPE vlc_tables[VLC_TABLES_SIZE][2] [static]

Definition at line 103 of file imc.c.

Referenced by imc_decode_init(), and ir2_decode_init().