svq1dec.c File Reference

Sorenson Vector Quantizer #1 (SVQ1) video codec. More...

#include "avcodec.h"
#include "get_bits.h"
#include "h263.h"
#include "hpeldsp.h"
#include "internal.h"
#include "mathops.h"
#include "svq1.h"

Classes
struct	svq1_pmv_s
struct	SVQ1Context

Macros
#define	SVQ1_PROCESS_VECTOR()
#define	SVQ1_ADD_CODEBOOK()
#define	SVQ1_CALC_CODEBOOK_ENTRIES(cbook)

Typedefs
typedef struct svq1_pmv_s	svq1_pmv
typedef struct SVQ1Context	SVQ1Context

Variables
AVCodec	ff_svq1_decoder

Detailed Description

Sorenson Vector Quantizer #1 (SVQ1) video codec.

For more information of the SVQ1 algorithm, visit: http://www.pcisys.net/~melanson/codecs/

Macro Definition Documentation

SVQ1_ADD_CODEBOOK

#define SVQ1_ADD_CODEBOOK

(

)

Value:

/* add codebook entries to vector */                                \
    for (j = 0; j < stages; j++) {                                      \
        n3  = codebook[entries[j]] ^ 0x80808080;                        \
        n1 += (n3 & 0xFF00FF00) >> 8;                                   \
        n2 +=  n3 & 0x00FF00FF;                                         \
    }                                                                   \
                                                                        \
    /* clip to [0..255] */                                              \
    if (n1 & 0xFF00FF00) {                                              \
        n3  = (n1 >> 15  & 0x00010001 | 0x01000100) - 0x00010001;       \
        n1 += 0x7F007F00;                                               \
        n1 |= (~n1 >> 15 & 0x00010001 | 0x01000100) - 0x00010001;       \
        n1 &= n3 & 0x00FF00FF;                                          \
    }                                                                   \
                                                                        \
    if (n2 & 0xFF00FF00) {                                              \
        n3  = (n2 >> 15  & 0x00010001 | 0x01000100) - 0x00010001;       \
        n2 += 0x7F007F00;                                               \
        n2 |= (~n2 >> 15 & 0x00010001 | 0x01000100) - 0x00010001;       \
        n2 &= n3 & 0x00FF00FF;                                          \
    }

SVQ1_CALC_CODEBOOK_ENTRIES

#define SVQ1_CALC_CODEBOOK_ENTRIES

(

cbook

)

Value:

codebook = (const uint32_t *)cbook[level];                          \
    if (stages > 0)                                                     \
        bit_cache = get_bits(bitbuf, 4 * stages);                       \
    /* calculate codebook entries for this vector */                    \
    for (j = 0; j < stages; j++) {                                      \
        entries[j] = (((bit_cache >> (4 * (stages - j - 1))) & 0xF) +   \
                      16 * j) << (level + 1);                           \
    }                                                                   \
    mean -= stages * 128;                                               \
    n4    = (mean << 16) + mean;

SVQ1_PROCESS_VECTOR

#define SVQ1_PROCESS_VECTOR

(

)

Value:

for (; level > 0; i++) {                                            \
        /* process next depth */                                        \
        if (i == m) {                                                   \
            m = n;                                                      \
            if (--level == 0)                                           \
                break;                                                  \
        }                                                               \
        /* divide block if next bit set */                              \
        if (!get_bits1(bitbuf))                                         \
            break;                                                      \
        /* add child nodes */                                           \
        list[n++] = list[i];                                            \
        list[n++] = list[i] + (((level & 1) ? pitch : 1) << ((level >> 1) + 1));\
    }

Variable Documentation

ff_svq1_decoder

AVCodec ff_svq1_decoder

Initial value:

= {
    .name           = "svq1",
    .long_name      = NULL_IF_CONFIG_SMALL("Sorenson Vector Quantizer 1 / Sorenson Video 1 / SVQ1"),
    .type           = AVMEDIA_TYPE_VIDEO,
    .id             = AV_CODEC_ID_SVQ1,
    .priv_data_size = sizeof(SVQ1Context),
    .init           = svq1_decode_init,
    .close          = svq1_decode_end,
    .decode         = svq1_decode_frame,
    .capabilities   = AV_CODEC_CAP_DR1,
    .flush          = svq1_flush,
    .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV410P,
                                                     AV_PIX_FMT_NONE },
}