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jpeg2000: Compute quantization for 'scalar derived' in the correct case.

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Scalar derived case is represented by the JPEG2K_QSTY_SI define.

Signed-off-by: Luca Barbato <lu_zero@gentoo.org>
This commit is contained in:
Michael Niedermayer 2013-07-01 10:01:19 +02:00 committed by Luca Barbato
parent 4e11b15534
commit 952f7ed3c0
1 changed files with 8 additions and 8 deletions
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16
libavcodec/jpeg2000.c
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@ -284,14 +284,14 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
int numbps;
case JPEG2000_QSTY_NONE:
/* TODO: to verify. No quantization in this case */
numbps = cbps +
lut_gain[codsty->transform][bandno + (reslevelno > 0)];
band->stepsize = (float)SHL(2048 + qntsty->mant[gbandno],
2 + numbps - qntsty->expn[gbandno]);
band->f_stepsize = 1;
break;
case JPEG2000_QSTY_SI:
/*TODO: Compute formula to implement. */
band->stepsize = (float) (1 << 13);
numbps = cbps +
lut_gain[codsty->transform == FF_DWT53][bandno + (reslevelno > 0)];
band->stepsize = (float)SHL(2048 + qntsty->mant[gbandno],
2 + numbps - qntsty->expn[gbandno]);
break;
case JPEG2000_QSTY_SE:
/* Exponent quantization step.
@ -305,15 +305,15 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp,
gain = cbps;
band->stepsize = pow(2.0, gain - qntsty->expn[gbandno]);
band->stepsize *= (float)qntsty->mant[gbandno] / 2048.0 + 1.0;
/* FIXME: In openjepg code stespize = stepsize * 0.5. Why?
* If not set output of entropic decoder is not correct. */
band->stepsize *= 0.5;
break;
default:
band->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));