libavcodec/wmalosslessdec.c File Reference

#include "libavutil/attributes.h"
#include "avcodec.h"
#include "internal.h"
#include "get_bits.h"
#include "put_bits.h"
#include "wma.h"
#include "wma_common.h"

Go to the source code of this file.

Data Structures

struct WmallChannelCtx

frame-specific decoder context for a single channel More...

struct WmallDecodeCtx

main decoder context More...

Defines

#define WMALL_MAX_CHANNELS   8

current decoder limitations

#define MAX_SUBFRAMES   32

max number of subframes per channel

#define MAX_BANDS   29

max number of scale factor bands

#define MAX_FRAMESIZE   32768

maximum compressed frame size

#define MAX_ORDER   256

#define WMALL_BLOCK_MIN_BITS   6

log2 of min block size

#define WMALL_BLOCK_MAX_BITS   12

log2 of max block size

#define WMALL_BLOCK_MAX_SIZE   (1 << WMALL_BLOCK_MAX_BITS)

maximum block size

#define WMALL_BLOCK_SIZES   (WMALL_BLOCK_MAX_BITS - WMALL_BLOCK_MIN_BITS + 1)

possible block sizes

Functions

static av_cold int decode_init (AVCodecContext *avctx)

static int decode_subframe_length (WmallDecodeCtx *s, int offset)

Decode the subframe length.

static int decode_tilehdr (WmallDecodeCtx *s)

Decode how the data in the frame is split into subframes.

static void decode_ac_filter (WmallDecodeCtx *s)

static void decode_mclms (WmallDecodeCtx *s)

static int decode_cdlms (WmallDecodeCtx *s)

static int decode_channel_residues (WmallDecodeCtx *s, int ch, int tile_size)

static void decode_lpc (WmallDecodeCtx *s)

static void clear_codec_buffers (WmallDecodeCtx *s)

static void reset_codec (WmallDecodeCtx *s)

Reset filter parameters and transient area at new seekable tile.

static void mclms_update (WmallDecodeCtx *s, int icoef, int *pred)

static void mclms_predict (WmallDecodeCtx *s, int icoef, int *pred)

static void revert_mclms (WmallDecodeCtx *s, int tile_size)

static int lms_predict (WmallDecodeCtx *s, int ich, int ilms)

static void lms_update (WmallDecodeCtx *s, int ich, int ilms, int input, int residue)

static void use_high_update_speed (WmallDecodeCtx *s, int ich)

static void use_normal_update_speed (WmallDecodeCtx *s, int ich)

static void revert_cdlms (WmallDecodeCtx *s, int ch, int coef_begin, int coef_end)

static void revert_inter_ch_decorr (WmallDecodeCtx *s, int tile_size)

static void revert_acfilter (WmallDecodeCtx *s, int tile_size)

static int decode_subframe (WmallDecodeCtx *s)

static int decode_frame (WmallDecodeCtx *s)

Decode one WMA frame.

static int remaining_bits (WmallDecodeCtx *s, GetBitContext *gb)

Calculate remaining input buffer length.

static void save_bits (WmallDecodeCtx *s, GetBitContext *gb, int len, int append)

Fill the bit reservoir with a (partial) frame.

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

static void flush (AVCodecContext *avctx)

Variables

AVCodec ff_wmalossless_decoder

Define Documentation

#define MAX_BANDS 29

max number of scale factor bands

Definition at line 36 of file wmalosslessdec.c.

Referenced by decode_init().

#define MAX_FRAMESIZE 32768

maximum compressed frame size

Definition at line 37 of file wmalosslessdec.c.

Referenced by aw_parse_coords(), aw_pulse_set1(), aw_pulse_set2(), decode_init(), decode_packet(), flush(), postfilter(), save_bits(), synth_block_fcb_acb(), synth_block_hardcoded(), synth_frame(), and synth_superframe().

#define MAX_ORDER 256

Definition at line 38 of file wmalosslessdec.c.

#define MAX_SUBFRAMES 32

max number of subframes per channel

Definition at line 35 of file wmalosslessdec.c.

Referenced by decode_init(), and decode_tilehdr().

#define WMALL_BLOCK_MAX_BITS 12

log2 of max block size

Definition at line 41 of file wmalosslessdec.c.

Referenced by decode_init().

#define WMALL_BLOCK_MAX_SIZE (1 << WMALL_BLOCK_MAX_BITS)

maximum block size

Definition at line 42 of file wmalosslessdec.c.

#define WMALL_BLOCK_MIN_BITS 6

log2 of min block size

Definition at line 40 of file wmalosslessdec.c.

#define WMALL_BLOCK_SIZES (WMALL_BLOCK_MAX_BITS - WMALL_BLOCK_MIN_BITS + 1)

possible block sizes

Definition at line 43 of file wmalosslessdec.c.

#define WMALL_MAX_CHANNELS 8

current decoder limitations

max number of handled channels

Definition at line 34 of file wmalosslessdec.c.

Referenced by decode_init(), decode_tilehdr(), and revert_mclms().

Function Documentation

static void clear_codec_buffers ( WmallDecodeCtx * s ) [static]

Definition at line 553 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void decode_ac_filter ( WmallDecodeCtx * s ) [static]

Definition at line 403 of file wmalosslessdec.c.

Referenced by decode_subframe().

static int decode_cdlms ( WmallDecodeCtx * s ) [static]

Definition at line 436 of file wmalosslessdec.c.

Referenced by decode_subframe().

static int decode_channel_residues	(	WmallDecodeCtx *	s,
		int	ch,
		int	tile_size
	)			`[static]`

Definition at line 482 of file wmalosslessdec.c.

Referenced by decode_subframe().

static int decode_frame ( WmallDecodeCtx * s ) [static]

Decode one WMA frame.

Parameters:

s

codec context

Returns:: 0 if the trailer bit indicates that this is the last frame, 1 if there are additional frames

Definition at line 1014 of file wmalosslessdec.c.

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

Definition at line 172 of file wmalosslessdec.c.

static void decode_lpc ( WmallDecodeCtx * s ) [static]

Definition at line 541 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void decode_mclms ( WmallDecodeCtx * s ) [static]

Definition at line 413 of file wmalosslessdec.c.

Referenced by decode_subframe().

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

Definition at line 1167 of file wmalosslessdec.c.

static int decode_subframe ( WmallDecodeCtx * s ) [static]

Definition at line 838 of file wmalosslessdec.c.

static int decode_subframe_length	(	WmallDecodeCtx *	s,
		int	offset
	)			`[static]`

Decode the subframe length.

Parameters:

	s	context
	offset	sample offset in the frame

Returns:: decoded subframe length on success, < 0 in case of an error

Definition at line 276 of file wmalosslessdec.c.

Referenced by decode_tilehdr().

static int decode_tilehdr ( WmallDecodeCtx * s ) [static]

Decode how the data in the frame is split into subframes.

Every WMA frame contains the encoded data for a fixed number of samples per channel. The data for every channel might be split into several subframes. This function will reconstruct the list of subframes for every channel.

If the subframes are not evenly split, the algorithm estimates the channels with the lowest number of total samples. Afterwards, for each of these channels a bit is read from the bitstream that indicates if the channel contains a subframe with the next subframe size that is going to be read from the bitstream or not. If a channel contains such a subframe, the subframe size gets added to the channel's subframe list. The algorithm repeats these steps until the frame is properly divided between the individual channels.

Parameters:

s

context

Returns:: 0 on success, < 0 in case of an error

Definition at line 318 of file wmalosslessdec.c.

Referenced by decode_frame().

static void flush ( AVCodecContext * avctx ) [static]

Definition at line 1276 of file wmalosslessdec.c.

static int lms_predict	(	WmallDecodeCtx *	s,
		int	ich,
		int	ilms
	)			`[static]`

Definition at line 686 of file wmalosslessdec.c.

Referenced by revert_cdlms().

static void lms_update	(	WmallDecodeCtx *	s,
		int	ich,
		int	ilms,
		int	input,
		int	residue
	)			`[static]`

Definition at line 698 of file wmalosslessdec.c.

Referenced by revert_cdlms().

static void mclms_predict	(	WmallDecodeCtx *	s,
		int	icoef,
		int *	pred
	)			`[static]`

Definition at line 655 of file wmalosslessdec.c.

Referenced by revert_mclms().

static void mclms_update	(	WmallDecodeCtx *	s,
		int	icoef,
		int *	pred
	)			`[static]`

Definition at line 597 of file wmalosslessdec.c.

Referenced by revert_mclms().

static int remaining_bits	(	WmallDecodeCtx *	s,
		GetBitContext *	gb
	)			`[static]`

Calculate remaining input buffer length.

Parameters:

	s	codec context
	gb	bitstream reader context

Returns:: remaining size in bits

Definition at line 1111 of file wmalosslessdec.c.

Referenced by decode_packet().

static void reset_codec ( WmallDecodeCtx * s ) [static]

Reset filter parameters and transient area at new seekable tile.

Definition at line 582 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void revert_acfilter	(	WmallDecodeCtx *	s,
		int	tile_size
	)			`[static]`

Definition at line 806 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void revert_cdlms	(	WmallDecodeCtx *	s,
		int	ch,
		int	coef_begin,
		int	coef_end
	)			`[static]`

Definition at line 775 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void revert_inter_ch_decorr	(	WmallDecodeCtx *	s,
		int	tile_size
	)			`[static]`

Definition at line 793 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void revert_mclms	(	WmallDecodeCtx *	s,
		int	tile_size
	)			`[static]`

Definition at line 677 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void save_bits	(	WmallDecodeCtx *	s,
		GetBitContext *	gb,
		int	len,
		int	append
	)			`[static]`

Fill the bit reservoir with a (partial) frame.

Parameters:

	s	codec context
	gb	bitstream reader context
	len	length of the partial frame
	append	decides whether to reset the buffer or not

Definition at line 1123 of file wmalosslessdec.c.

Referenced by decode_packet().

static void use_high_update_speed	(	WmallDecodeCtx *	s,
		int	ich
	)			`[static]`

Definition at line 740 of file wmalosslessdec.c.

Referenced by decode_subframe().

static void use_normal_update_speed	(	WmallDecodeCtx *	s,
		int	ich
	)			`[static]`

Definition at line 758 of file wmalosslessdec.c.

Referenced by decode_subframe().

Variable Documentation

AVCodec ff_wmalossless_decoder

Initial value:

 {
    .name           = "wmalossless",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_WMALOSSLESS,
    .priv_data_size = sizeof(WmallDecodeCtx),
    .init           = decode_init,
    .decode         = decode_packet,
    .flush          = flush,
    .capabilities   = CODEC_CAP_SUBFRAMES | CODEC_CAP_DR1 | CODEC_CAP_DELAY,
    .long_name      = NULL_IF_CONFIG_SMALL("Windows Media Audio Lossless"),
}

Definition at line 1289 of file wmalosslessdec.c.


Data Structures
struct	WmallChannelCtx
	frame-specific decoder context for a single channel More...
struct	WmallDecodeCtx
	main decoder context More...
Defines
#define	WMALL_MAX_CHANNELS 8
	current decoder limitations
#define	MAX_SUBFRAMES 32
	max number of subframes per channel
#define	MAX_BANDS 29
	max number of scale factor bands
#define	MAX_FRAMESIZE 32768
	maximum compressed frame size
#define	MAX_ORDER 256
#define	WMALL_BLOCK_MIN_BITS 6
	log2 of min block size
#define	WMALL_BLOCK_MAX_BITS 12
	log2 of max block size
#define	WMALL_BLOCK_MAX_SIZE (1 << WMALL_BLOCK_MAX_BITS)
	maximum block size
#define	WMALL_BLOCK_SIZES (WMALL_BLOCK_MAX_BITS - WMALL_BLOCK_MIN_BITS + 1)
	possible block sizes
Functions
static av_cold int	decode_init (AVCodecContext *avctx)
static int	decode_subframe_length (WmallDecodeCtx *s, int offset)
	Decode the subframe length.
static int	decode_tilehdr (WmallDecodeCtx *s)
	Decode how the data in the frame is split into subframes.
static void	decode_ac_filter (WmallDecodeCtx *s)
static void	decode_mclms (WmallDecodeCtx *s)
static int	decode_cdlms (WmallDecodeCtx *s)
static int	decode_channel_residues (WmallDecodeCtx *s, int ch, int tile_size)
static void	decode_lpc (WmallDecodeCtx *s)
static void	clear_codec_buffers (WmallDecodeCtx *s)
static void	reset_codec (WmallDecodeCtx *s)
	Reset filter parameters and transient area at new seekable tile.
static void	mclms_update (WmallDecodeCtx s, int icoef, int pred)
static void	mclms_predict (WmallDecodeCtx s, int icoef, int pred)
static void	revert_mclms (WmallDecodeCtx *s, int tile_size)
static int	lms_predict (WmallDecodeCtx *s, int ich, int ilms)
static void	lms_update (WmallDecodeCtx *s, int ich, int ilms, int input, int residue)
static void	use_high_update_speed (WmallDecodeCtx *s, int ich)
static void	use_normal_update_speed (WmallDecodeCtx *s, int ich)
static void	revert_cdlms (WmallDecodeCtx *s, int ch, int coef_begin, int coef_end)
static void	revert_inter_ch_decorr (WmallDecodeCtx *s, int tile_size)
static void	revert_acfilter (WmallDecodeCtx *s, int tile_size)
static int	decode_subframe (WmallDecodeCtx *s)
static int	decode_frame (WmallDecodeCtx *s)
	Decode one WMA frame.
static int	remaining_bits (WmallDecodeCtx s, GetBitContext gb)
	Calculate remaining input buffer length.
static void	save_bits (WmallDecodeCtx s, GetBitContext gb, int len, int append)
	Fill the bit reservoir with a (partial) frame.
static int	decode_packet (AVCodecContext avctx, void data, int got_frame_ptr, AVPacket avpkt)
static void	flush (AVCodecContext *avctx)
Variables
AVCodec	ff_wmalossless_decoder