[FFmpeg-cvslog] jpeg2000: Compute quantization for 'scalar derived' in the correct case.
Michael Niedermayer
git at videolan.org
Wed Jul 3 15:25:39 CEST 2013
ffmpeg | branch: master | Michael Niedermayer <michaelni at gmx.at> | Mon Jul 1 10:01:19 2013 +0200| [952f7ed3c0b036c1a53834cf2015072a90a1f0ae] | committer: Luca Barbato
jpeg2000: Compute quantization for 'scalar derived' in the correct case.
Scalar derived case is represented by the JPEG2K_QSTY_SI define.
Signed-off-by: Luca Barbato <lu_zero at gentoo.org>
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=952f7ed3c0b036c1a53834cf2015072a90a1f0ae
---
libavcodec/jpeg2000.c | 16 ++++++++--------
1 file changed, 8 insertions(+), 8 deletions(-)
diff --git a/libavcodec/jpeg2000.c b/libavcodec/jpeg2000.c
index b3182d6..54550bc 100644
--- a/libavcodec/jpeg2000.c
+++ b/libavcodec/jpeg2000.c
@@ -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));
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