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| author | Michael Niedermayer <michaelni@gmx.at> | 2015-06-22 02:46:35 +0200 |
|---|---|---|
| committer | Michael Niedermayer <michaelni@gmx.at> | 2015-06-22 03:01:24 +0200 |
| commit | 4e926fb969acbb27415c2109d7339259875b6909 (patch) | |
| tree | 3c5d53ef58d42b7161d9c2f1dd27626e6b6e565b | |
| parent | b1fdf81c6eed786742c08037a9aa662ef7967ab2 (diff) | |
| download | ffmpeg-4e926fb969acbb27415c2109d7339259875b6909.tar.gz | |
avcodec/jpeg2000: Move L band scaling from the 9/7f wavelet to quantization stage
This reduces the number of operations
Its not done for 9/7i as that would overflow thanks to JPEG2000 allowing
32 decomposition levels
Signed-off-by: Michael Niedermayer <michaelni@gmx.at>
| -rw-r--r-- | libavcodec/jpeg2000.c | 5 | ||||
| -rw-r--r-- | libavcodec/jpeg2000dwt.c | 8 |
2 files changed, 9 insertions, 4 deletions
diff --git a/libavcodec/jpeg2000.c b/libavcodec/jpeg2000.c index b61e8fec33..b333aad568 100644 --- a/libavcodec/jpeg2000.c +++ b/libavcodec/jpeg2000.c @@ -315,15 +315,20 @@ int ff_jpeg2000_init_component(Jpeg2000Component *comp, break; } if (codsty->transform != FF_DWT53) { + int lband = 0; switch (bandno + (reslevelno > 0)) { case 1: case 2: band->f_stepsize *= F_LFTG_X * 2; + lband = 1; break; case 3: band->f_stepsize *= F_LFTG_X * F_LFTG_X * 4; break; } + if (codsty->transform == FF_DWT97) { + band->f_stepsize *= pow(F_LFTG_K, 2*(codsty->nreslevels2decode - reslevelno) + lband - 2); + } } /* FIXME: In openjepg code stespize = stepsize * 0.5. Why? * If not set output of entropic decoder is not correct. */ diff --git a/libavcodec/jpeg2000dwt.c b/libavcodec/jpeg2000dwt.c index dff2516d11..4201fc6e8d 100644 --- a/libavcodec/jpeg2000dwt.c +++ b/libavcodec/jpeg2000dwt.c @@ -196,7 +196,7 @@ static void dwt_encode97_float(DWTContext *s, float *t) // copy back and deinterleave for (i = mh; i < lh; i+=2, j++) - t[w*lp + j] = F_LFTG_X * l[i]; + t[w*lp + j] = l[i]; for (i = 1-mh; i < lh; i+=2, j++) t[w*lp + j] = l[i]; } @@ -213,7 +213,7 @@ static void dwt_encode97_float(DWTContext *s, float *t) // copy back and deinterleave for (i = mv; i < lv; i+=2, j++) - t[w*j + lp] = F_LFTG_X * l[i]; + t[w*j + lp] = l[i]; for (i = 1-mv; i < lv; i+=2, j++) t[w*j + lp] = l[i]; } @@ -421,7 +421,7 @@ static void dwt_decode97_float(DWTContext *s, float *t) int i, j = 0; // copy with interleaving for (i = mh; i < lh; i += 2, j++) - l[i] = data[w * lp + j] * F_LFTG_K; + l[i] = data[w * lp + j]; for (i = 1 - mh; i < lh; i += 2, j++) l[i] = data[w * lp + j]; @@ -437,7 +437,7 @@ static void dwt_decode97_float(DWTContext *s, float *t) int i, j = 0; // copy with interleaving for (i = mv; i < lv; i += 2, j++) - l[i] = data[w * j + lp] * F_LFTG_K; + l[i] = data[w * j + lp]; for (i = 1 - mv; i < lv; i += 2, j++) l[i] = data[w * j + lp]; |