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avcodec/pixlet: fix architecture-dependent code and values

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The constants used in the decoder used floating point precision,
and this caused different values to be generated on different
architectures.

So, eradicate floating point numbers and use fixed point (32.32)
arithmetics everywhere, replacing constants with precomputed integer
values.

Signed-off-by: Vittorio Giovara <vittorio.giovara at gmail.com>
Signed-off-by: Paul B Mahol <onemda@gmail.com>
This commit is contained in:
Vittorio Giovara 2017-03-07 13:57:34 +01:00 committed by Paul B Mahol
parent b6eaa3928e
commit a6b1180e39
1 changed files with 30 additions and 27 deletions
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57
libavcodec/pixlet.c
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@ -55,7 +55,7 @@ typedef struct PixletContext {
int16_t *filter[2];
int16_t *prediction;
float scaling[4][2][NB_LEVELS];
int64_t scaling[4][2][NB_LEVELS];
SubBand band[4][NB_LEVELS * 3 + 1];
} PixletContext;
@ -360,11 +360,11 @@ static void lowpass_prediction(int16_t *dst, int16_t *pred, int width, int heigh
}
}
static void filter(int16_t *dest, int16_t *tmp, unsigned size, float SCALE)
static void filterfn(int16_t *dest, int16_t *tmp, unsigned size, int64_t scale)
{
int16_t *low, *high, *ll, *lh, *hl, *hh;
int hsize, i, j;
float value;
int64_t value;
hsize = size >> 1;
low = tmp + 4;
@ -385,33 +385,33 @@ static void filter(int16_t *dest, int16_t *tmp, unsigned size, float SCALE)
}
for (i = 0; i < hsize; i++) {
value = low [i+1] * -0.07576144003329376f +
low [i ] * 0.8586296626673486f +
low [i-1] * -0.07576144003329376f +
high[i ] * 0.3535533905932737f +
high[i-1] * 0.3535533905932737f;
dest[i * 2] = av_clipf(value * SCALE, INT16_MIN, INT16_MAX);
value = (int64_t) low [i + 1] * -INT64_C(325392907) +
(int64_t) low [i + 0] * INT64_C(3687786320) +
(int64_t) low [i - 1] * -INT64_C(325392907) +
(int64_t) high[i + 0] * INT64_C(1518500249) +
(int64_t) high[i - 1] * INT64_C(1518500249);
dest[i * 2] = av_clip_int16(((value >> 32) * scale) >> 32);
}
for (i = 0; i < hsize; i++) {
value = low [i+2] * -0.01515228715813062f +
low [i+1] * 0.3687056777514043f +
low [i ] * 0.3687056777514043f +
low [i-1] * -0.01515228715813062f +
high[i+1] * 0.07071067811865475f +
high[i ] * -0.8485281374238569f +
high[i-1] * 0.07071067811865475f;
dest[i * 2 + 1] = av_clipf(value * SCALE, INT16_MIN, INT16_MAX);
value = (int64_t) low [i + 2] * -INT64_C(65078576) +
(int64_t) low [i + 1] * INT64_C(1583578880) +
(int64_t) low [i + 0] * INT64_C(1583578880) +
(int64_t) low [i - 1] * -INT64_C(65078576) +
(int64_t) high[i + 1] * INT64_C(303700064) +
(int64_t) high[i + 0] * -INT64_C(3644400640) +
(int64_t) high[i - 1] * INT64_C(303700064);
dest[i * 2 + 1] = av_clip_int16(((value >> 32) * scale) >> 32);
}
}
static void reconstruction(AVCodecContext *avctx,
int16_t *dest, unsigned width, unsigned height, ptrdiff_t stride, int nb_levels,
float *scaling_H, float *scaling_V)
int64_t *scaling_H, int64_t *scaling_V)
{
PixletContext *ctx = avctx->priv_data;
unsigned scaled_width, scaled_height;
float scale_H, scale_V;
int64_t scale_H, scale_V;
int16_t *ptr, *tmp;
int i, j, k;
@ -427,7 +427,7 @@ static void reconstruction(AVCodecContext *avctx,
ptr = dest;
for (j = 0; j < scaled_height; j++) {
filter(ptr, ctx->filter[1], scaled_width, scale_V);
filterfn(ptr, ctx->filter[1], scaled_width, scale_V);
ptr += stride;
}
@ -438,7 +438,7 @@ static void reconstruction(AVCodecContext *avctx,
ptr += stride;
}
filter(tmp, ctx->filter[1], scaled_height, scale_H);
filterfn(tmp, ctx->filter[1], scaled_height, scale_H);
ptr = dest + j;
for (k = 0; k < scaled_height; k++) {
@ -449,19 +449,22 @@ static void reconstruction(AVCodecContext *avctx,
}
}
#define SQR(a) ((a) * (a))
static void postprocess_luma(AVFrame *frame, int w, int h, int depth)
{
uint16_t *dsty = (uint16_t *)frame->data[0];
int16_t *srcy = (int16_t *)frame->data[0];
ptrdiff_t stridey = frame->linesize[0] / 2;
const float factor = 1.0f / ((1 << depth) - 1);
int i, j;
for (j = 0; j < h; j++) {
for (i = 0; i < w; i++) {
dsty[i] = SQR(FFMAX(srcy[i], 0) * factor) * 65535;
if (srcy[i] <= 0)
dsty[i] = 0;
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 += stridey;
srcy += stridey;
@ -507,8 +510,8 @@ static int decode_plane(AVCodecContext *avctx, int plane, AVPacket *avpkt, AVFra
if (!h || !v)
return AVERROR_INVALIDDATA;
ctx->scaling[plane][H][i] = 1000000.0f / h;
ctx->scaling[plane][V][i] = 1000000.0f / v;
ctx->scaling[plane][H][i] = (1000000ULL << 32) / h;
ctx->scaling[plane][V][i] = (1000000ULL << 32) / v;
}
bytestream2_skip(&ctx->gb, 4);