lagarith.c File Reference

Lagarith lossless decoder. More...

#include "avcodec.h"
#include "get_bits.h"
#include "mathops.h"
#include "dsputil.h"
#include "lagarithrac.h"
#include "thread.h"

Go to the source code of this file.

Data Structures
struct	LagarithContext

Enumerations
enum	LagarithFrameType {   FRAME_RAW = 1, FRAME_U_RGB24 = 2, FRAME_ARITH_YUY2 = 3, FRAME_ARITH_RGB24 = 4,   FRAME_SOLID_GRAY = 5, FRAME_SOLID_COLOR = 6, FRAME_OLD_ARITH_RGB = 7, FRAME_ARITH_RGBA = 8,   FRAME_SOLID_RGBA = 9, FRAME_ARITH_YV12 = 10, FRAME_REDUCED_RES = 11 }

Functions
static uint64_t	softfloat_reciprocal (uint32_t denom)
	Compute the 52bit mantissa of 1/(double)denom.
static uint32_t	softfloat_mul (uint32_t x, uint64_t mantissa)
	(uint32_t)(x*f), where f has the given mantissa, and exponent 0 Used in combination with softfloat_reciprocal computes x/(double)denom.
static uint8_t	lag_calc_zero_run (int8_t x)
static int	lag_decode_prob (GetBitContext *gb, uint32_t *value)
static int	lag_read_prob_header (lag_rac *rac, GetBitContext *gb)
static void	add_lag_median_prediction (uint8_t *dst, uint8_t *src1, uint8_t *diff, int w, int *left, int *left_top)
static void	lag_pred_line (LagarithContext *l, uint8_t *buf, int width, int stride, int line)
static void	lag_pred_line_yuy2 (LagarithContext *l, uint8_t *buf, int width, int stride, int line, int is_luma)
static int	lag_decode_line (LagarithContext *l, lag_rac *rac, uint8_t *dst, int width, int stride, int esc_count)
static int	lag_decode_zero_run_line (LagarithContext *l, uint8_t *dst, const uint8_t *src, const uint8_t *src_end, int width, int esc_count)
static int	lag_decode_arith_plane (LagarithContext *l, uint8_t *dst, int width, int height, int stride, const uint8_t *src, int src_size)
static int	lag_decode_frame (AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
	Decode a frame.
static av_cold int	lag_decode_init (AVCodecContext *avctx)
static av_cold int	lag_decode_end (AVCodecContext *avctx)

Variables
AVCodec	ff_lagarith_decoder

Detailed Description

Lagarith lossless decoder.

Author

Nathan Caldwell

Definition in file lagarith.c.

Enumeration Type Documentation

enum LagarithFrameType

Enumerator:

FRAME_RAW	uncompressed
FRAME_U_RGB24	unaligned RGB24
FRAME_ARITH_YUY2	arithmetic coded YUY2
FRAME_ARITH_RGB24	arithmetic coded RGB24
FRAME_SOLID_GRAY	solid grayscale color frame
FRAME_SOLID_COLOR	solid non-grayscale color frame
FRAME_OLD_ARITH_RGB	obsolete arithmetic coded RGB (no longer encoded by upstream since version 1.1.0)
FRAME_ARITH_RGBA	arithmetic coded RGBA
FRAME_SOLID_RGBA	solid RGBA color frame
FRAME_ARITH_YV12	arithmetic coded YV12
FRAME_REDUCED_RES	reduced resolution YV12 frame

Definition at line 35 of file lagarith.c.

Function Documentation

static uint64_t softfloat_reciprocal ( uint32_t  denom )

static

Compute the 52bit mantissa of 1/(double)denom.

This crazy format uses floats in an entropy coder and we have to match x86 rounding exactly, thus ordinary floats aren't portable enough.

Parameters

denom

denominator

Returns

52bit mantissa

See Also

softfloat_mul

Definition at line 67 of file lagarith.c.

Referenced by lag_read_prob_header().

static uint32_t softfloat_mul ( uint32_t  x, uint64_t  mantissa  )

static

(uint32_t)(x*f), where f has the given mantissa, and exponent 0 Used in combination with softfloat_reciprocal computes x/(double)denom.

Parameters

x	32bit integer factor
mantissa	mantissa of f with exponent 0

Returns

32bit integer value (x*f)

See Also

softfloat_reciprocal

Definition at line 86 of file lagarith.c.

Referenced by lag_read_prob_header().

static uint8_t lag_calc_zero_run ( int8_t  x )

static

Definition at line 97 of file lagarith.c.

Referenced by lag_decode_line(), and lag_decode_zero_run_line().

static int lag_decode_prob ( GetBitContext *  gb, uint32_t *  value  )

static

Definition at line 102 of file lagarith.c.

Referenced by lag_read_prob_header().

static int lag_read_prob_header ( lag_rac *  rac, GetBitContext *  gb  )

static

Definition at line 136 of file lagarith.c.

Referenced by lag_decode_arith_plane().

static void add_lag_median_prediction ( uint8_t *  dst, uint8_t *  src1, uint8_t *  diff, int  w, int *  left, int *  left_top  )

static

Definition at line 230 of file lagarith.c.

Referenced by lag_pred_line().

static void lag_pred_line ( LagarithContext *  l, uint8_t *  buf, int  width, int  stride, int  line  )

static

Definition at line 254 of file lagarith.c.

Referenced by lag_decode_arith_plane().

static void lag_pred_line_yuy2 ( LagarithContext *  l, uint8_t *  buf, int  width, int  stride, int  line, int  is_luma  )

static

Definition at line 281 of file lagarith.c.

Referenced by lag_decode_arith_plane().

static int lag_decode_line ( LagarithContext *  l, lag_rac *  rac, uint8_t *  dst, int  width, int  stride, int  esc_count  )

static

Definition at line 319 of file lagarith.c.

Referenced by lag_decode_arith_plane().

static int lag_decode_zero_run_line ( LagarithContext *  l, uint8_t *  dst, const uint8_t *  src, const uint8_t *  src_end, int  width, int  esc_count  )

static

Definition at line 361 of file lagarith.c.

Referenced by lag_decode_arith_plane().

static int lag_decode_arith_plane ( LagarithContext *  l, uint8_t *  dst, int  width, int  height, int  stride, const uint8_t *  src, int  src_size  )

static

Definition at line 419 of file lagarith.c.

Referenced by lag_decode_frame().

static int lag_decode_frame ( AVCodecContext *  avctx, void *  data, int *  got_frame, AVPacket *  avpkt  )

static

Decode a frame.

Parameters

avctx	codec context
data	output AVFrame
data_size	size of output data or 0 if no picture is returned
avpkt	input packet

Returns

number of consumed bytes on success or negative if decode fails

Definition at line 525 of file lagarith.c.

static av_cold int lag_decode_init ( AVCodecContext *  avctx )

static

Definition at line 723 of file lagarith.c.

static av_cold int lag_decode_end ( AVCodecContext *  avctx )

static

Definition at line 733 of file lagarith.c.

Variable Documentation

AVCodec ff_lagarith_decoder

Initial value:

= {
    .name           = "lagarith",
    .long_name      = NULL_IF_CONFIG_SMALL("Lagarith lossless"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_LAGARITH,
    .priv_data_size = sizeof(LagarithContext),
    .init           = lag_decode_init,
    .close          = lag_decode_end,
    .decode         = lag_decode_frame,
    .capabilities   = CODEC_CAP_DR1 | CODEC_CAP_FRAME_THREADS,
}

Definition at line 742 of file lagarith.c.