[FFmpeg-cvslog] avcodec/cfhd: use LUT for 9 and 18 codebook decompanding
Paul B Mahol
git at videolan.org
Mon Aug 3 23:28:54 EEST 2020
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Mon Aug 3 09:33:36 2020 +0200| [05e58ce4e29ea47b2e06888c64055aa2f8d3e76c] | committer: Paul B Mahol
avcodec/cfhd: use LUT for 9 and 18 codebook decompanding
Also fix codebook 9 decompanding, fixing artifact with codebook 9
samples. Reused Gagandeep Singh patch.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=05e58ce4e29ea47b2e06888c64055aa2f8d3e76c
---
libavcodec/cfhd.c | 35 +++++++++++++++++++++++++----------
libavcodec/cfhd.h | 2 ++
2 files changed, 27 insertions(+), 10 deletions(-)
diff --git a/libavcodec/cfhd.c b/libavcodec/cfhd.c
index 60bba9ff81..8cd475cba4 100644
--- a/libavcodec/cfhd.c
+++ b/libavcodec/cfhd.c
@@ -46,6 +46,27 @@ static av_cold int cfhd_init(AVCodecContext *avctx)
s->avctx = avctx;
+ for (int i = 0; i < 64; i++) {
+ int val = i;
+
+ if (val >= 40) {
+ if (val >= 54) {
+ val -= 54;
+ val <<= 2;
+ val += 54;
+ }
+
+ val -= 40;
+ val <<= 2;
+ val += 40;
+ }
+
+ s->lut[0][i] = val;
+ }
+
+ for (int i = 0; i < 256; i++)
+ s->lut[1][i] = i + ((768 * i * i * i) / (256 * 256 * 256));
+
return ff_cfhd_init_vlcs(s);
}
@@ -83,16 +104,10 @@ static void init_frame_defaults(CFHDContext *s)
init_peak_table_defaults(s);
}
-/* TODO: merge with VLC tables or use LUT */
-static inline int dequant_and_decompand(int level, int quantisation, int codebook)
+static inline int dequant_and_decompand(CFHDContext *s, int level, int quantisation, int codebook)
{
if (codebook == 0 || codebook == 1) {
- int64_t abslevel = abs(level);
- if (abslevel < 256)
- return (abslevel + ((768 * abslevel * abslevel * abslevel) / (256 * 256 * 256))) *
- FFSIGN(level) * quantisation;
- else
- return level * quantisation;
+ return s->lut[codebook][abs(level)] * FFSIGN(level) * quantisation;
} else
return level * quantisation;
}
@@ -708,7 +723,7 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
if (count > expected)
break;
- coeff = dequant_and_decompand(level, s->quantisation, 0);
+ coeff = dequant_and_decompand(s, level, s->quantisation, 0);
for (i = 0; i < run; i++)
*coeff_data++ = coeff;
}
@@ -727,7 +742,7 @@ static int cfhd_decode(AVCodecContext *avctx, void *data, int *got_frame,
if (count > expected)
break;
- coeff = dequant_and_decompand(level, s->quantisation, s->codebook);
+ coeff = dequant_and_decompand(s, level, s->quantisation, s->codebook);
for (i = 0; i < run; i++)
*coeff_data++ = coeff;
}
diff --git a/libavcodec/cfhd.h b/libavcodec/cfhd.h
index 0e3155be23..7f35ac45f3 100644
--- a/libavcodec/cfhd.h
+++ b/libavcodec/cfhd.h
@@ -136,6 +136,8 @@ typedef struct CFHDContext {
CFHD_RL_VLC_ELEM table_18_rl_vlc[4572];
VLC vlc_18;
+ int lut[2][256];
+
GetBitContext gb;
int coded_width;
More information about the ffmpeg-cvslog
mailing list