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j2k/jpeg2000: split stepsize in float & int variables

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This is more clear and less prone to mistakes.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
This commit is contained in:
Michael Niedermayer 2013-05-28 22:12:34 +02:00
parent aa0d11ed0b
commit fe7136ef82
7 changed files with 26 additions and 28 deletions
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18
libavcodec/j2k.c
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@ -248,7 +248,6 @@ int ff_j2k_init_component(Jpeg2000Component *comp,
Jpeg2000Band *band = reslevel->band + bandno;
int cblkno, precno;
int nb_precincts;
double stepsize;
/* TODO: Implementation of quantization step not finished,
* see ISO/IEC 15444-1:2002 E.1 and A.6.4. */
@ -257,13 +256,13 @@ int ff_j2k_init_component(Jpeg2000Component *comp,
int numbps;
case JPEG2000_QSTY_NONE:
/* TODO: to verify. No quantization in this case */
stepsize = 1;
band->f_stepsize = 1;
break;
case JPEG2000_QSTY_SI:
/*TODO: Compute formula to implement. */
numbps = cbps +
lut_gain[codsty->transform][bandno + (reslevelno > 0)];
stepsize = SHL(2048 + qntsty->mant[gbandno],
band->f_stepsize = SHL(2048 + qntsty->mant[gbandno],
2 + numbps - qntsty->expn[gbandno]);
break;
case JPEG2000_QSTY_SE:
@ -276,21 +275,20 @@ int ff_j2k_init_component(Jpeg2000Component *comp,
* but it works (compared to OpenJPEG). Why?
* Further investigation needed. */
gain = cbps;
stepsize = pow(2.0, gain - qntsty->expn[gbandno]);
stepsize *= (qntsty->mant[gbandno] / 2048.0 + 1.0);
band->f_stepsize = pow(2.0, gain - qntsty->expn[gbandno]);
band->f_stepsize *= (qntsty->mant[gbandno] / 2048.0 + 1.0);
break;
default:
stepsize = 0;
band->f_stepsize = 0;
av_log(avctx, AV_LOG_ERROR, "Unknown quantization format\n");
break;
}
/* FIXME: In openjepg code stespize = stepsize * 0.5. Why?
* If not set output of entropic decoder is not correct. */
if (!av_codec_is_encoder(avctx->codec))
stepsize *= 0.5;
/* BITEXACT computing case --> convert to int */
// if (avctx->flags & CODEC_FLAG_BITEXACT)
band->stepsize = stepsize * (1 << 16);
band->f_stepsize *= 0.5;
band->i_stepsize = band->f_stepsize * (1 << 16);
/* computation of tbx_0, tbx_1, tby_0, tby_1
* see ISO/IEC 15444-1:2002 B.5 eq. B-15 and tbl B.1

3
libavcodec/j2k.h
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@ -179,7 +179,8 @@ typedef struct Jpeg2000Prec {
typedef struct Jpeg2000Band {
uint16_t coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
uint16_t log2_cblk_width, log2_cblk_height;
uint32_t stepsize; // quantization stepsize (* 2^13)
int i_stepsize; // quantization stepsize
float f_stepsize; // quantization stepsize
Jpeg2000Prec *prec;
} Jpeg2000Band; // subband

2
libavcodec/j2kdec.c
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@ -827,7 +827,7 @@ static void dequantization_int(int x, int y, Jpeg2000Cblk *cblk,
for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
idx = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
datap[idx] =
((int32_t)(t1->data[j][i]) * ((int32_t)band->stepsize) + (1 << 15)) >> 16;
((int32_t)(t1->data[j][i]) * band->i_stepsize + (1 << 15)) >> 16;
}
}

4
libavcodec/j2kenc.c
View File

@ -802,7 +802,7 @@ static void truncpasses(Jpeg2000EncoderContext *s, Jpeg2000Tile *tile)
Jpeg2000Cblk *cblk = prec->cblk + cblkno;
cblk->ninclpasses = getcut(cblk, s->lambda,
(int64_t)dwt_norms[codsty->transform][bandpos][lev] * (int64_t)band->stepsize >> 16);
(int64_t)dwt_norms[codsty->transform][bandpos][lev] * (int64_t)band->i_stepsize >> 16);
}
}
}
@ -863,7 +863,7 @@ static int encode_tile(Jpeg2000EncoderContext *s, Jpeg2000Tile *tile, int tileno
int *ptr = t1.data[y-yy0];
for (x = xx0; x < xx1; x++){
*ptr = (comp->data[(comp->coord[0][1] - comp->coord[0][0]) * y + x]);
*ptr = (int64_t)*ptr * (int64_t)(16384 * 65536 / band->stepsize) >> 14 - NMSEDEC_FRACBITS;
*ptr = (int64_t)*ptr * (int64_t)(16384 * 65536 / band->i_stepsize) >> 14 - NMSEDEC_FRACBITS;
ptr++;
}
}

18
libavcodec/jpeg2000.c
View File

@ -267,13 +267,13 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
int numbps;
case JPEG2000_QSTY_NONE:
/* TODO: to verify. No quantization in this case */
band->stepsize = (float) (1 << 13);
band->f_stepsize = (float) (1 << 13);
break;
case JPEG2000_QSTY_SI:
/*TODO: Compute formula to implement. */
numbps = cbps +
lut_gain[codsty->transform][bandno + (reslevelno > 0)];
band->stepsize = (float)SHL(2048 + qntsty->mant[gbandno],
band->f_stepsize = (float)SHL(2048 + qntsty->mant[gbandno],
2 + numbps - qntsty->expn[gbandno]);
break;
case JPEG2000_QSTY_SE:
@ -286,20 +286,20 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
* but it works (compared to OpenJPEG). Why?
* Further investigation needed. */
gain = cbps;
band->stepsize = pow(2.0, gain - qntsty->expn[gbandno]);
band->stepsize *= (float)qntsty->mant[gbandno] / 2048.0 + 1.0;
band->f_stepsize = pow(2.0, gain - qntsty->expn[gbandno]);
band->f_stepsize *= (float)qntsty->mant[gbandno] / 2048.0 + 1.0;
break;
default:
band->stepsize = 0;
band->f_stepsize = 0;
av_log(avctx, AV_LOG_ERROR, "Unknown quantization format\n");
break;
}
/* FIXME: In openjepg code stespize = stepsize * 0.5. Why?
* If not set output of entropic decoder is not correct. */
band->stepsize *= 0.5;
/* BITEXACT computing case --> convert to int */
if (avctx->flags & CODEC_FLAG_BITEXACT)
band->stepsize = (int32_t)(band->stepsize * (1 << 16));
if (!av_codec_is_encoder(avctx->codec))
band->f_stepsize *= 0.5;
band->i_stepsize = (int32_t)(band->f_stepsize * (1 << 16));
/* computation of tbx_0, tbx_1, tby_0, tby_1
* see ISO/IEC 15444-1:2002 B.5 eq. B-15 and tbl B.1

5
libavcodec/jpeg2000.h
View File

@ -176,12 +176,11 @@ typedef struct Jpeg2000Prec {
uint16_t coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
} Jpeg2000Prec; // precinct
/* TODO: stepsize can be float or integer depending on
* reversible or irreversible transformation. */
typedef struct Jpeg2000Band {
uint16_t coord[2][2]; // border coordinates {{x0, x1}, {y0, y1}}
uint16_t log2_cblk_width, log2_cblk_height;
float stepsize; // quantization stepsize
int i_stepsize; // quantization stepsize
float f_stepsize; // quantization stepsize
Jpeg2000Prec *prec;
} Jpeg2000Band; // subband

4
libavcodec/jpeg2000dec.c
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@ -930,7 +930,7 @@ static void dequantization_float(int x, int y, Jpeg2000Cblk *cblk,
for (j = 0; j < (cblk->coord[1][1] - cblk->coord[1][0]); ++j)
for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
idx = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
datap[idx] = (float)(t1->data[j][i]) * ((float)band->stepsize);
datap[idx] = (float)(t1->data[j][i]) * band->f_stepsize;
}
}
@ -946,7 +946,7 @@ static void dequantization_int(int x, int y, Jpeg2000Cblk *cblk,
for (i = 0; i < (cblk->coord[0][1] - cblk->coord[0][0]); ++i) {
idx = (comp->coord[0][1] - comp->coord[0][0]) * j + i;
datap[idx] =
((int32_t)(t1->data[j][i]) * ((int32_t)band->stepsize) + (1 << 15)) >> 16;
((int32_t)(t1->data[j][i]) * band->i_stepsize + (1 << 15)) >> 16;
}
}