Chiebot-Mirror
/
FFmpeg
mirror of https://github.com/FFmpeg/FFmpeg.git
8
0
Fork 0
Code Issues Projects Releases Wiki Activity

j2k/jpeg2000: split stepsize in float & int variables

Browse Source 
This is more clear and less prone to mistakes.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
pull/23/head
Michael Niedermayer 12 years ago
parent aa0d11ed0b
commit fe7136ef82
7 changed files with 26 additions and 28 deletions
Whitespace
Show all changes Ignore whitespace when comparing lines Ignore changes in amount of whitespace Ignore changes in whitespace at EOL
Split View
Diff Options
Show Stats Download Patch File Download Diff File
  1. 18
      libavcodec/j2k.c
  2. 3
      libavcodec/j2k.h
  3. 2
      libavcodec/j2kdec.c
  4. 4
      libavcodec/j2kenc.c
  5. 18
      libavcodec/jpeg2000.c
  6. 5
      libavcodec/jpeg2000.h
  7. 4
      libavcodec/jpeg2000dec.c

18
libavcodec/j2k.c
Unescape View File

@ -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
Unescape View File

@ -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
Unescape View File

@ -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
Unescape 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
Unescape 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
Unescape 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
Unescape View File

@ -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;
}
}

Write Preview
Loading…
Cancel
Save