[FFmpeg-cvslog] avcodec/pixlet: postprocess luma using precalculated lut
Paul B Mahol
git at videolan.org
Sun Sep 6 15:02:27 EEST 2020
ffmpeg | branch: master | Paul B Mahol <onemda at gmail.com> | Sun Sep 6 13:44:52 2020 +0200| [bc8662984261f422b49fdfff4cb273adde06917a] | committer: Paul B Mahol
avcodec/pixlet: postprocess luma using precalculated lut
Realtime decoding speed raises from 1.08 to 1.84 for
1504x846, 25391 kb/s, 24 fps video.
> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=bc8662984261f422b49fdfff4cb273adde06917a
---
libavcodec/pixlet.c | 34 ++++++++++++++++++++++++++--------
1 file changed, 26 insertions(+), 8 deletions(-)
diff --git a/libavcodec/pixlet.c b/libavcodec/pixlet.c
index 78f571cd5f..42acd683fa 100644
--- a/libavcodec/pixlet.c
+++ b/libavcodec/pixlet.c
@@ -58,6 +58,7 @@ typedef struct PixletContext {
int16_t *filter[2];
int16_t *prediction;
int64_t scaling[4][2][NB_LEVELS];
+ uint16_t lut[65536];
SubBand band[4][NB_LEVELS * 3 + 1];
} PixletContext;
@@ -462,11 +463,27 @@ static void reconstruction(AVCodecContext *avctx, int16_t *dest,
}
}
-static void postprocess_luma(AVFrame *frame, int w, int h, int depth)
+static void build_luma_lut(AVCodecContext *avctx, int depth)
{
+ PixletContext *ctx = avctx->priv_data;
+ int max = (1 << depth) - 1;
+
+ if (ctx->depth == depth)
+ return;
+ ctx->depth = depth;
+
+ for (int i = 0; i < FF_ARRAY_ELEMS(ctx->lut); i++)
+ ctx->lut[i] = ((int64_t)i * i * 65535LL) / max / max;
+}
+
+static void postprocess_luma(AVCodecContext *avctx, AVFrame *frame,
+ int w, int h, int depth)
+{
+ PixletContext *ctx = avctx->priv_data;
uint16_t *dsty = (uint16_t *)frame->data[0];
int16_t *srcy = (int16_t *)frame->data[0];
ptrdiff_t stridey = frame->linesize[0] / 2;
+ uint16_t *lut = ctx->lut;
int i, j;
for (j = 0; j < h; j++) {
@@ -476,8 +493,7 @@ static void postprocess_luma(AVFrame *frame, int w, int h, int depth)
else if (srcy[i] > ((1 << depth) - 1))
dsty[i] = 65535;
else
- dsty[i] = ((int64_t) srcy[i] * srcy[i] * 65535) /
- ((1 << depth) - 1) / ((1 << depth) - 1);
+ dsty[i] = lut[srcy[i]];
}
dsty += stridey;
srcy += stridey;
@@ -591,7 +607,7 @@ static int pixlet_decode_frame(AVCodecContext *avctx, void *data,
int i, w, h, width, height, ret, version;
AVFrame *p = data;
ThreadFrame frame = { .f = data };
- uint32_t pktsize;
+ uint32_t pktsize, depth;
bytestream2_init(&ctx->gb, avpkt->data, avpkt->size);
@@ -623,12 +639,14 @@ static int pixlet_decode_frame(AVCodecContext *avctx, void *data,
ctx->levels = bytestream2_get_be32(&ctx->gb);
if (ctx->levels != NB_LEVELS)
return AVERROR_INVALIDDATA;
- ctx->depth = bytestream2_get_be32(&ctx->gb);
- if (ctx->depth < 8 || ctx->depth > 15) {
- avpriv_request_sample(avctx, "Depth %d", ctx->depth);
+ depth = bytestream2_get_be32(&ctx->gb);
+ if (depth < 8 || depth > 15) {
+ avpriv_request_sample(avctx, "Depth %d", depth);
return AVERROR_INVALIDDATA;
}
+ build_luma_lut(avctx, depth);
+
ret = ff_set_dimensions(avctx, w, h);
if (ret < 0)
return ret;
@@ -667,7 +685,7 @@ static int pixlet_decode_frame(AVCodecContext *avctx, void *data,
break;
}
- postprocess_luma(frame.f, ctx->w, ctx->h, ctx->depth);
+ postprocess_luma(avctx, frame.f, ctx->w, ctx->h, ctx->depth);
postprocess_chroma(frame.f, ctx->w >> 1, ctx->h >> 1, ctx->depth);
*got_frame = 1;
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