swscale: refactor horizontal scaling

+ split color conversion from scaling
- disabled gamma correction, until it's refactored too

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

7 files changed, 751 insertions, 11 deletions

diff --git a/libswscale/Makefile b/libswscale/Makefile
index b11e789237..b2b638138f 100644
--- a/libswscale/Makefile
+++ b/libswscale/Makefile
@@ -15,6 +15,8 @@ OBJS = alphablend.o                                     \
        swscale_unscaled.o                               \
        utils.o                                          \
        yuv2rgb.o                                        \
+       slice.o                                          \
+       hscale.o                                         \
 
 OBJS-$(CONFIG_SHARED)        += log2_tab.o
 
diff --git a/libswscale/hscale.c b/libswscale/hscale.c
new file mode 100644
index 0000000000..c8543a2b36
--- /dev/null
+++ b/libswscale/hscale.c
@@ -0,0 +1,254 @@
+#include "swscale_internal.h"
+
+static int lum_h_scale(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
+{
+    FilterContext *instance = desc->instance;
+    int srcW = desc->src->width;
+    int dstW = desc->dst->width;
+    int xInc = instance->xInc;
+
+    int i;
+    for (i = 0; i < sliceH; ++i) {
+        uint8_t ** src = desc->src->plane[0].line;
+        uint8_t ** dst = desc->dst->plane[0].line;
+        int src_pos = sliceY+i - desc->src->plane[0].sliceY;
+        int dst_pos = sliceY+i - desc->dst->plane[0].sliceY;
+
+
+        if (c->hyscale_fast) {
+            c->hyscale_fast(c, (int16_t*)dst[dst_pos], dstW, src[src_pos], srcW, xInc);
+        } else {
+            c->hyScale(c, (int16_t*)dst[dst_pos], dstW, (const uint8_t *)src[src_pos], instance->filter,
+                       instance->filter_pos, instance->filter_size);
+        }
+
+        if (c->lumConvertRange)
+            c->lumConvertRange((int16_t*)dst[dst_pos], dstW);
+
+        desc->dst->plane[0].sliceH += 1;
+
+        if (desc->alpha) {
+            src = desc->src->plane[3].line;
+            dst = desc->dst->plane[3].line;
+
+            src_pos = sliceY+i - desc->src->plane[3].sliceY;
+            dst_pos = sliceY+i - desc->dst->plane[3].sliceY;
+
+            desc->dst->plane[3].sliceH += 1;
+
+            if (c->hyscale_fast) {
+                c->hyscale_fast(c, (int16_t*)dst[dst_pos], dstW, src[src_pos], srcW, xInc);
+            } else {
+                c->hyScale(c, (int16_t*)dst[dst_pos], dstW, (const uint8_t *)src[src_pos], instance->filter,
+                            instance->filter_pos, instance->filter_size);
+            }
+        }
+    }
+
+    return sliceH;
+}
+
+static int lum_convert(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
+{
+    int srcW = desc->src->width;
+    ColorContext * instance = desc->instance;
+    uint32_t * pal = instance->pal;
+    int i;
+
+    desc->dst->plane[0].sliceY = sliceY;
+    desc->dst->plane[0].sliceH = sliceH;
+    desc->dst->plane[3].sliceY = sliceY;
+    desc->dst->plane[3].sliceH = sliceH;
+
+    for (i = 0; i < sliceH; ++i) {
+        int sp0 = sliceY+i - desc->src->plane[0].sliceY;
+        int sp1 = ((sliceY+i) >> desc->src->v_chr_sub_sample) - desc->src->plane[1].sliceY;
+        const uint8_t * src[4] = { desc->src->plane[0].line[sp0],
+                        desc->src->plane[1].line[sp1],
+                        desc->src->plane[2].line[sp1],
+                        desc->src->plane[3].line[sp0]};
+        uint8_t * dst = desc->dst->plane[0].line[i];
+
+        if (c->lumToYV12) {
+            c->lumToYV12(dst, src[0], src[1], src[2], srcW, pal);
+        } else if (c->readLumPlanar) {
+            c->readLumPlanar(dst, src, srcW, c->input_rgb2yuv_table);
+        }
+
+
+        if (desc->alpha) {
+            dst = desc->dst->plane[3].line[i];
+            if (c->alpToYV12) {
+                c->alpToYV12(dst, src[3], src[1], src[2], srcW, pal);
+            } else if (c->readAlpPlanar) {
+                c->readAlpPlanar(dst, src, srcW, NULL);
+            }
+        }
+    }
+
+    return sliceH;
+}
+
+int ff_init_desc_fmt_convert(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst, uint32_t *pal)
+{
+    ColorContext * li = av_malloc(sizeof(ColorContext));
+    if (!li)
+        return AVERROR(ENOMEM);
+    li->pal = pal;
+    desc->instance = li;
+
+    desc->alpha = isALPHA(src->fmt) && isALPHA(dst->fmt);
+    desc->src =src;
+    desc->dst = dst;
+    desc->process = &lum_convert;
+
+    return 0;
+}
+
+
+int ff_init_desc_hscale(SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst, uint16_t *filter, int * filter_pos, int filter_size, int xInc)
+{
+    FilterContext *li = av_malloc(sizeof(FilterContext));
+    if (!li)
+        return AVERROR(ENOMEM);
+
+    li->filter = filter;
+    li->filter_pos = filter_pos;
+    li->filter_size = filter_size;
+    li->xInc = xInc;
+
+    desc->instance = li;
+
+    desc->alpha = isALPHA(src->fmt) && isALPHA(dst->fmt);
+    desc->src = src;
+    desc->dst = dst;
+
+    desc->process = &lum_h_scale;
+
+    return 0;
+}
+
+static int chr_h_scale(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
+{
+    FilterContext *instance = desc->instance;
+    int srcW = FF_CEIL_RSHIFT(desc->src->width, desc->src->h_chr_sub_sample);
+    int dstW = FF_CEIL_RSHIFT(desc->dst->width, desc->dst->h_chr_sub_sample);
+    int xInc = instance->xInc;
+
+    uint8_t ** src1 = desc->src->plane[1].line;
+    uint8_t ** dst1 = desc->dst->plane[1].line;
+    uint8_t ** src2 = desc->src->plane[2].line;
+    uint8_t ** dst2 = desc->dst->plane[2].line;
+
+    int src_pos1 = sliceY - desc->src->plane[1].sliceY;
+    int dst_pos1 = sliceY - desc->dst->plane[1].sliceY;
+
+    int src_pos2 = sliceY - desc->src->plane[2].sliceY;
+    int dst_pos2 = sliceY - desc->dst->plane[2].sliceY;
+
+    int i;
+    for (i = 0; i < sliceH; ++i) {
+        if (c->hcscale_fast) {
+            c->hcscale_fast(c, (uint16_t*)dst1[dst_pos1+i], (uint16_t*)dst2[dst_pos2+i], dstW, src1[src_pos1+i], src2[src_pos2+i], srcW, xInc);
+        } else {
+            c->hcScale(c, (uint16_t*)dst1[dst_pos1+i], dstW, src1[src_pos1+i], instance->filter, instance->filter_pos, instance->filter_size);
+            c->hcScale(c, (uint16_t*)dst2[dst_pos2+i], dstW, src2[src_pos2+i], instance->filter, instance->filter_pos, instance->filter_size);
+        }
+
+        if (c->chrConvertRange)
+            c->chrConvertRange((uint16_t*)dst1[dst_pos1+i], (uint16_t*)dst2[dst_pos2+i], dstW);
+
+        desc->dst->plane[1].sliceH += 1;
+        desc->dst->plane[2].sliceH += 1;
+    }
+    return sliceH;
+}
+
+static int chr_convert(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
+{
+    int srcW = FF_CEIL_RSHIFT(desc->src->width, desc->src->h_chr_sub_sample);
+    ColorContext * instance = desc->instance;
+    uint32_t * pal = instance->pal;
+
+    int sp0 = (sliceY - (desc->src->plane[0].sliceY >> desc->src->v_chr_sub_sample)) << desc->src->v_chr_sub_sample;
+    int sp1 = sliceY - desc->src->plane[1].sliceY;
+
+    int i;
+
+    desc->dst->plane[1].sliceY = sliceY;
+    desc->dst->plane[1].sliceH = sliceH;
+    desc->dst->plane[2].sliceY = sliceY;
+    desc->dst->plane[2].sliceH = sliceH;
+
+    for (i = 0; i < sliceH; ++i) {
+        const uint8_t * src[4] = { desc->src->plane[0].line[sp0+i],
+                        desc->src->plane[1].line[sp1+i],
+                        desc->src->plane[2].line[sp1+i],
+                        desc->src->plane[3].line[sp0+i]};
+
+        uint8_t * dst1 = desc->dst->plane[1].line[i];
+        uint8_t * dst2 = desc->dst->plane[2].line[i];
+        if (c->chrToYV12) {
+            c->chrToYV12(dst1, dst2, src[0], src[1], src[2], srcW, pal);
+        } else if (c->readChrPlanar) {
+            c->readChrPlanar(dst1, dst2, src, srcW, c->input_rgb2yuv_table);
+        }
+    }
+    return sliceH;
+}
+
+int ff_init_desc_cfmt_convert(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst, uint32_t *pal)
+{
+    ColorContext * li = av_malloc(sizeof(ColorContext));
+    if (!li)
+        return AVERROR(ENOMEM);
+    li->pal = pal;
+    desc->instance = li;
+
+    desc->src =src;
+    desc->dst = dst;
+    desc->process = &chr_convert;
+
+    return 0;
+}
+
+int ff_init_desc_chscale(SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst, uint16_t *filter, int * filter_pos, int filter_size, int xInc)
+{
+    FilterContext *li = av_malloc(sizeof(FilterContext));
+    if (!li)
+        return AVERROR(ENOMEM);
+
+    li->filter = filter;
+    li->filter_pos = filter_pos;
+    li->filter_size = filter_size;
+    li->xInc = xInc;
+
+    desc->instance = li;
+
+    desc->alpha = isALPHA(src->fmt) && isALPHA(dst->fmt);
+    desc->src = src;
+    desc->dst = dst;
+
+    desc->process = &chr_h_scale;
+
+    return 0;
+}
+
+static int no_chr_scale(SwsContext *c, SwsFilterDescriptor *desc, int sliceY, int sliceH)
+{
+    desc->dst->plane[1].sliceY = sliceY + sliceH - desc->dst->plane[1].available_lines;
+    desc->dst->plane[1].sliceH = desc->dst->plane[1].available_lines;
+    desc->dst->plane[2].sliceY = sliceY + sliceH - desc->dst->plane[2].available_lines;
+    desc->dst->plane[2].sliceH = desc->dst->plane[2].available_lines;
+    return 0;
+}
+
+int ff_init_desc_no_chr(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst)
+{
+    desc->src = src;
+    desc->dst = dst;
+    desc->alpha = 0;
+    desc->instance = NULL;
+    desc->process = &no_chr_scale;
+    return 0;
+}
diff --git a/libswscale/slice.c b/libswscale/slice.c
new file mode 100644
index 0000000000..3a8001fdeb
--- /dev/null
+++ b/libswscale/slice.c
@@ -0,0 +1,295 @@
+#include "swscale_internal.h"
+
+static void free_lines(SwsSlice *s)
+{
+    int i;
+    for (i = 0; i < 2; ++i) {
+        int n = s->plane[i].available_lines;
+        int j;
+        for (j = 0; j < n; ++j) {
+            av_freep(&s->plane[i].line[j]);
+            if (s->is_ring)
+               s->plane[i].line[j+n] = NULL;
+        }
+    }
+
+    for (i = 0; i < 4; ++i)
+        memset(s->plane[i].line, 0, sizeof(uint8_t*) * s->plane[i].available_lines * (s->is_ring ? 3 : 1));
+    s->should_free_lines = 0;
+}
+
+/*
+ slice lines contains extra bytes for vetorial code thus @size
+ is the allocated memory size and @width is the number of pixels
+*/
+static int alloc_lines(SwsSlice *s, int size, int width)
+{
+    int i;
+    int idx[2] = {3, 2};
+
+    s->should_free_lines = 1;
+    s->width = width;
+
+    for (i = 0; i < 2; ++i) {
+        int n = s->plane[i].available_lines;
+        int j;
+        int ii = idx[i];
+
+        av_assert0(n == s->plane[ii].available_lines);
+        for (j = 0; j < n; ++j) {
+            // chroma plane line U and V are expected to be contiguous in memory
+            // by mmx vertical scaler code
+            s->plane[i].line[j] = av_malloc(size * 2 + 32);
+            if (!s->plane[i].line[j]) {
+                free_lines(s);
+                return AVERROR(ENOMEM);
+            }
+            s->plane[ii].line[j] = s->plane[i].line[j] + size + 16;
+            if (s->is_ring) {
+               s->plane[i].line[j+n] = s->plane[i].line[j];
+               s->plane[ii].line[j+n] = s->plane[ii].line[j];
+            }
+        }
+    }
+
+    return 0;
+}
+
+static int alloc_slice(SwsSlice *s, enum AVPixelFormat fmt, int lumLines, int chrLines, int h_sub_sample, int v_sub_sample, int ring)
+{
+    int i;
+    int size[4] = { lumLines,
+                    chrLines,
+                    chrLines,
+                    lumLines };
+
+    s->h_chr_sub_sample = h_sub_sample;
+    s->v_chr_sub_sample = v_sub_sample;
+    s->fmt = fmt;
+    s->is_ring = ring;
+    s->should_free_lines = 0;
+
+    for (i = 0; i < 4; ++i) {
+        int n = size[i] * ( ring == 0 ? 1 : 3);
+        s->plane[i].line = av_mallocz_array(sizeof(uint8_t*), n);
+        if (!s->plane[i].line)
+            return AVERROR(ENOMEM);
+
+        s->plane[i].tmp = ring ? s->plane[i].line + size[i] * 2 : NULL;
+        s->plane[i].available_lines = size[i];
+        s->plane[i].sliceY = 0;
+        s->plane[i].sliceH = 0;
+    }
+    return 0;
+}
+
+static void free_slice(SwsSlice *s)
+{
+    int i;
+    if (s) {
+        if (s->should_free_lines)
+            free_lines(s);
+        for (i = 0; i < 4; ++i) {
+            av_freep(&s->plane[i].line);
+            s->plane[i].tmp = NULL;
+        }
+    }
+}
+
+int ff_rotate_slice(SwsSlice *s, int lum, int chr)
+{
+    int i;
+    if (lum) {
+        for (i = 0; i < 4; i+=3) {
+            int n = s->plane[i].available_lines;
+            int l = lum - s->plane[i].sliceY;
+
+            if (l >= n * 2) {
+                s->plane[i].sliceY += n;
+                s->plane[i].sliceH -= n;
+            }
+        }
+    }
+    if (chr) {
+        for (i = 1; i < 3; ++i) {
+            int n = s->plane[i].available_lines;
+            int l = chr - s->plane[i].sliceY;
+
+            if (l >= n * 2) {
+                s->plane[i].sliceY += n;
+                s->plane[i].sliceH -= n;
+            }
+        }
+    }
+    return 0;
+}
+
+int ff_init_slice_from_src(SwsSlice * s, uint8_t *src[4], int stride[4], int srcW, int lumY, int lumH, int chrY, int chrH)
+{
+    int i = 0;
+
+    const int start[4] = {lumY,
+                    chrY,
+                    chrY,
+                    lumY};
+
+    const int end[4] = {lumY +lumH,
+                        chrY + chrH,
+                        chrY + chrH,
+                        lumY + lumH};
+
+    s->width = srcW;
+
+    for (i = 0; i < 4; ++i) {
+        int j;
+        int lines = end[i];
+        lines = s->plane[i].available_lines < lines ? s->plane[i].available_lines : lines;
+
+        if (end[i] > s->plane[i].sliceY+s->plane[i].sliceH) {
+            if (start[i] <= s->plane[i].sliceY+1)
+                s->plane[i].sliceY = FFMIN(start[i], s->plane[i].sliceY);
+            else
+                s->plane[i].sliceY = start[i];
+            s->plane[i].sliceH = end[i] - s->plane[i].sliceY;
+        } else {
+            if (end[i] >= s->plane[i].sliceY)
+                s->plane[i].sliceH = s->plane[i].sliceY + s->plane[i].sliceH - start[i];
+            else
+                s->plane[i].sliceH = end[i] - start[i];
+            s->plane[i].sliceY = start[i];
+        }
+
+        for (j = start[i]; j < lines; j+= 1)
+            s->plane[i].line[j] = src[i] + (start[i] + j) * stride[i];
+
+    }
+
+    return 0;
+}
+
+static void fill_ones(SwsSlice *s, int n, int is16bit)
+{
+    int i;
+    for (i = 0; i < 4; ++i) {
+        int j;
+        int size = s->plane[i].available_lines;
+        for (j = 0; j < size; ++j) {
+            int k;
+            int end = is16bit ? n>>1: n;
+            // fill also one extra element
+            end += 1;
+            if (is16bit)
+                for (k = 0; k < end; ++k)
+                    ((int32_t*)(s->plane[i].line[j]))[k] = 1<<18;
+            else
+                for (k = 0; k < end; ++k)
+                    ((int16_t*)(s->plane[i].line[j]))[k] = 1<<14;
+        }
+    }
+}
+
+int ff_init_filters(SwsContext * c)
+{
+    int i;
+    int index;
+    int num_ydesc;
+    int num_cdesc;
+    int need_lum_conv = c->lumToYV12 || c->readLumPlanar || c->alpToYV12 || c->readAlpPlanar;
+    int need_chr_conv = c->chrToYV12 || c->readChrPlanar;
+    int srcIdx, dstIdx;
+    int dst_stride = FFALIGN(c->dstW * sizeof(int16_t) + 66, 16);
+
+    uint32_t * pal = usePal(c->srcFormat) ? c->pal_yuv : (uint32_t*)c->input_rgb2yuv_table;
+    int res = 0;
+
+    if (c->dstBpc == 16)
+        dst_stride <<= 1;
+
+    num_ydesc = need_lum_conv ? 2 : 1;
+    num_cdesc = need_chr_conv ? 2 : 1;
+
+    c->numSlice = FFMAX(num_ydesc, num_cdesc) + 1;
+    c->numDesc = num_ydesc + num_cdesc;
+    c->descIndex[0] = num_ydesc;
+    c->descIndex[1] = num_ydesc + num_cdesc;
+
+
+
+    c->desc = av_mallocz_array(sizeof(SwsFilterDescriptor), c->numDesc);
+    if (!c->desc)
+        return AVERROR(ENOMEM);
+    c->slice = av_mallocz_array(sizeof(SwsSlice), c->numSlice);
+
+
+    res = alloc_slice(&c->slice[0], c->srcFormat, c->srcH, c->chrSrcH, c->chrSrcHSubSample, c->chrSrcVSubSample, 0);
+    if (res < 0) goto cleanup;
+    for (i = 1; i < c->numSlice-1; ++i) {
+        res = alloc_slice(&c->slice[i], c->srcFormat, c->vLumFilterSize, c->vChrFilterSize, c->chrSrcHSubSample, c->chrSrcVSubSample, 0);
+        if (res < 0) goto cleanup;
+        res = alloc_lines(&c->slice[i], FFALIGN(c->srcW*2+78, 16), c->srcW);
+        if (res < 0) goto cleanup;
+    }
+    res = alloc_slice(&c->slice[i], c->srcFormat, c->vLumFilterSize, c->vChrFilterSize, c->chrDstHSubSample, c->chrDstVSubSample, 1);
+    if (res < 0) goto cleanup;
+    res = alloc_lines(&c->slice[i], dst_stride, c->dstW);
+    if (res < 0) goto cleanup;
+
+    fill_ones(&c->slice[i], dst_stride>>1, c->dstBpc == 16);
+
+    index = 0;
+    srcIdx = 0;
+    dstIdx = 1;
+
+    if (need_lum_conv) {
+        ff_init_desc_fmt_convert(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], pal);
+        c->desc[index].alpha = c->alpPixBuf != 0;
+        ++index;
+        srcIdx = dstIdx;
+    }
+
+
+    dstIdx = FFMAX(num_ydesc, num_cdesc);
+    ff_init_desc_hscale(&c->desc[index], &c->slice[index], &c->slice[dstIdx], c->hLumFilter, c->hLumFilterPos, c->hLumFilterSize, c->lumXInc);
+    c->desc[index].alpha = c->alpPixBuf != 0;
+
+
+    ++index;
+    {
+        srcIdx = 0;
+        dstIdx = 1;
+        if (need_chr_conv) {
+            ff_init_desc_cfmt_convert(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], pal);
+            ++index;
+            srcIdx = dstIdx;
+        }
+
+        dstIdx = FFMAX(num_ydesc, num_cdesc);
+        if (c->needs_hcscale)
+            ff_init_desc_chscale(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], c->hChrFilter, c->hChrFilterPos, c->hChrFilterSize, c->chrXInc);
+        else
+            ff_init_desc_no_chr(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx]);
+    }
+
+    return 0;
+
+cleanup:
+    ff_free_filters(c);
+    return res;
+}
+
+int ff_free_filters(SwsContext *c)
+{
+    int i;
+    if (c->desc) {
+        for (i = 0; i < c->numDesc; ++i)
+            av_freep(&c->desc[i].instance);
+        av_freep(&c->desc);
+    }
+
+    if (c->slice) {
+        for (i = 0; i < c->numSlice; ++i)
+            free_slice(&c->slice[i]);
+        av_freep(&c->slice);
+    }
+    return 0;
+}
diff --git a/libswscale/swscale.c b/libswscale/swscale.c
index 1945e1dc9b..e96c7eead1 100644
--- a/libswscale/swscale.c
+++ b/libswscale/swscale.c
@@ -371,6 +371,15 @@ static int swscale(SwsContext *c, const uint8_t *src[],
     int lastInChrBuf = c->lastInChrBuf;
     int perform_gamma = c->is_internal_gamma;
 
+    int numDesc = c->numDesc;
+    int lumStart = 0;
+    int lumEnd = c->descIndex[0];
+    int chrStart = lumEnd;
+    int chrEnd = c->descIndex[1];
+    SwsSlice *src_slice = &c->slice[lumStart];
+    SwsSlice *dst_slice = &c->slice[c->numSlice-1];
+    SwsFilterDescriptor *desc = c->desc;
+
 
     if (!usePal(c->srcFormat)) {
         pal = c->input_rgb2yuv_table;
@@ -439,6 +448,23 @@ static int swscale(SwsContext *c, const uint8_t *src[],
     }
     lastDstY = dstY;
 
+#define NEW_FILTER 1
+
+    ff_init_slice_from_src(src_slice, (uint8_t**)src, srcStride, c->srcW,
+            srcSliceY, srcSliceH,
+            chrSrcSliceY, chrSrcSliceH);
+
+    dst_slice->plane[0].sliceY = lastInLumBuf + 1;
+    dst_slice->plane[1].sliceY = lastInChrBuf + 1;
+    dst_slice->plane[2].sliceY = lastInChrBuf + 1;
+    dst_slice->plane[3].sliceY = lastInLumBuf + 1;
+
+    dst_slice->plane[0].sliceH =
+    dst_slice->plane[1].sliceH =
+    dst_slice->plane[2].sliceH =
+    dst_slice->plane[3].sliceH = 0;
+    dst_slice->width = dstW;
+
     for (; dstY < dstH; dstY++) {
         const int chrDstY = dstY >> c->chrDstVSubSample;
         uint8_t *dest[4]  = {
@@ -460,12 +486,23 @@ static int swscale(SwsContext *c, const uint8_t *src[],
         int lastLumSrcY2 = FFMIN(c->srcH,    firstLumSrcY2 + vLumFilterSize) - 1;
         int lastChrSrcY  = FFMIN(c->chrSrcH, firstChrSrcY  + vChrFilterSize) - 1;
         int enough_lines;
+        int i;
 
         // handle holes (FAST_BILINEAR & weird filters)
-        if (firstLumSrcY > lastInLumBuf)
+        if (firstLumSrcY > lastInLumBuf) {
             lastInLumBuf = firstLumSrcY - 1;
-        if (firstChrSrcY > lastInChrBuf)
+            dst_slice->plane[0].sliceY = lastInLumBuf + 1;
+            dst_slice->plane[3].sliceY = lastInLumBuf + 1;
+            dst_slice->plane[0].sliceH =
+            dst_slice->plane[3].sliceH = 0;
+        }
+        if (firstChrSrcY > lastInChrBuf) {
             lastInChrBuf = firstChrSrcY - 1;
+            dst_slice->plane[1].sliceY = lastInChrBuf + 1;
+            dst_slice->plane[2].sliceY = lastInChrBuf + 1;
+            dst_slice->plane[1].sliceH =
+            dst_slice->plane[2].sliceH = 0;
+        }
         av_assert0(firstLumSrcY >= lastInLumBuf - vLumBufSize + 1);
         av_assert0(firstChrSrcY >= lastInChrBuf - vChrBufSize + 1);
 
@@ -486,6 +523,22 @@ static int swscale(SwsContext *c, const uint8_t *src[],
                           lastLumSrcY, lastChrSrcY);
         }
 
+#if NEW_FILTER
+        ff_rotate_slice(dst_slice, lastLumSrcY, lastChrSrcY);
+
+        if (lastInLumBuf < lastLumSrcY)
+            for (i = lumStart; i < lumEnd; ++i)
+                desc[i].process(c, &desc[i], lastInLumBuf + 1, lastLumSrcY - lastInLumBuf);
+        lumBufIndex += lastLumSrcY - lastInLumBuf;
+        lastInLumBuf = lastLumSrcY;
+
+        if (lastInChrBuf < lastChrSrcY)
+            for (i = chrStart; i < chrEnd; ++i)
+                desc[i].process(c, &desc[i], lastInChrBuf + 1, lastChrSrcY - lastInChrBuf);
+        chrBufIndex += lastChrSrcY - lastInChrBuf;
+        lastInChrBuf = lastChrSrcY;
+
+#else
         // Do horizontal scaling
         while (lastInLumBuf < lastLumSrcY) {
             const uint8_t *src1[4] = {
@@ -499,8 +552,8 @@ static int swscale(SwsContext *c, const uint8_t *src[],
             av_assert0(lastInLumBuf + 1 - srcSliceY < srcSliceH);
             av_assert0(lastInLumBuf + 1 - srcSliceY >= 0);
 
-            if (perform_gamma)
-                gamma_convert((uint8_t **)src1, srcW, c->inv_gamma);
+            //if (perform_gamma)
+            //    gamma_convert((uint8_t **)src1, srcW, c->inv_gamma);
 
             hyscale(c, lumPixBuf[lumBufIndex], dstW, src1, srcW, lumXInc,
                     hLumFilter, hLumFilterPos, hLumFilterSize,
@@ -535,6 +588,7 @@ static int swscale(SwsContext *c, const uint8_t *src[],
             DEBUG_BUFFERS("\t\tchrBufIndex %d: lastInChrBuf: %d\n",
                           chrBufIndex, lastInChrBuf);
         }
+#endif
         // wrap buf index around to stay inside the ring buffer
         if (lumBufIndex >= vLumBufSize)
             lumBufIndex -= vLumBufSize;
@@ -560,11 +614,19 @@ static int swscale(SwsContext *c, const uint8_t *src[],
         }
 
         {
+#if NEW_FILTER
+            const int16_t **lumSrcPtr  = (const int16_t **)(void*) dst_slice->plane[0].line + firstLumSrcY - dst_slice->plane[0].sliceY;
+            const int16_t **chrUSrcPtr = (const int16_t **)(void*) dst_slice->plane[1].line + firstChrSrcY - dst_slice->plane[1].sliceY;
+            const int16_t **chrVSrcPtr = (const int16_t **)(void*) dst_slice->plane[2].line + firstChrSrcY - dst_slice->plane[2].sliceY;
+            const int16_t **alpSrcPtr  = (CONFIG_SWSCALE_ALPHA && alpPixBuf) ?
+                                         (const int16_t **)(void*) dst_slice->plane[3].line + firstLumSrcY - dst_slice->plane[3].sliceY : NULL;
+#else
             const int16_t **lumSrcPtr  = (const int16_t **)(void*) lumPixBuf  + lumBufIndex + firstLumSrcY - lastInLumBuf + vLumBufSize;
             const int16_t **chrUSrcPtr = (const int16_t **)(void*) chrUPixBuf + chrBufIndex + firstChrSrcY - lastInChrBuf + vChrBufSize;
             const int16_t **chrVSrcPtr = (const int16_t **)(void*) chrVPixBuf + chrBufIndex + firstChrSrcY - lastInChrBuf + vChrBufSize;
             const int16_t **alpSrcPtr  = (CONFIG_SWSCALE_ALPHA && alpPixBuf) ?
                                          (const int16_t **)(void*) alpPixBuf + lumBufIndex + firstLumSrcY - lastInLumBuf + vLumBufSize : NULL;
+#endif
             int16_t *vLumFilter = c->vLumFilter;
             int16_t *vChrFilter = c->vChrFilter;
 
@@ -629,8 +691,10 @@ static int swscale(SwsContext *c, const uint8_t *src[],
                     }
                 }
             } else if (yuv2packedX) {
+#if !NEW_FILTER
                 av_assert1(lumSrcPtr  + vLumFilterSize - 1 < (const int16_t **)lumPixBuf  + vLumBufSize * 2);
                 av_assert1(chrUSrcPtr + vChrFilterSize - 1 < (const int16_t **)chrUPixBuf + vChrBufSize * 2);
+#endif
                 if (c->yuv2packed1 && vLumFilterSize == 1 &&
                     vChrFilterSize <= 2) { // unscaled RGB
                     int chrAlpha = vChrFilterSize == 1 ? 0 : vChrFilter[2 * dstY + 1];
@@ -663,8 +727,8 @@ static int swscale(SwsContext *c, const uint8_t *src[],
                          chrUSrcPtr, chrVSrcPtr, vChrFilterSize,
                          alpSrcPtr, dest, dstW, dstY);
             }
-            if (perform_gamma)
-                gamma_convert(dest, dstW, c->gamma);
+            //if (perform_gamma)
+            //    gamma_convert(dest, dstW, c->gamma);
         }
     }
     if (isPlanar(dstFormat) && isALPHA(dstFormat) && !alpPixBuf) {
@@ -1151,4 +1215,3 @@ int attribute_align_arg sws_scale(struct SwsContext *c,
     av_free(rgb0_tmp);
     return ret;
 }
-
diff --git a/libswscale/swscale_internal.h b/libswscale/swscale_internal.h
index 852dd94b21..2e69e27901 100644
--- a/libswscale/swscale_internal.h
+++ b/libswscale/swscale_internal.h
@@ -276,6 +276,9 @@ typedef void (*yuv2anyX_fn)(struct SwsContext *c, const int16_t *lumFilter,
                             const int16_t **alpSrc, uint8_t **dest,
                             int dstW, int y);
 
+struct SwsSlice;
+struct SwsFilterDescriptor;
+
 /* This struct should be aligned on at least a 32-byte boundary. */
 typedef struct SwsContext {
     /**
@@ -326,6 +329,12 @@ typedef struct SwsContext {
     uint16_t *gamma;
     uint16_t *inv_gamma;
 
+    int numDesc;
+    int descIndex[2];
+    int numSlice;
+    struct SwsSlice *slice;
+    struct SwsFilterDescriptor *desc;
+
     uint32_t pal_yuv[256];
     uint32_t pal_rgb[256];
 
@@ -934,4 +943,95 @@ static inline void fillPlane16(uint8_t *plane, int stride, int width, int height
     }
 }
 
+#define MAX_SLICE_PLANES 4
+
+/// Slice plane
+typedef struct SwsPlane
+{
+    int available_lines;    ///< max number of lines that can be hold by this plane
+    int sliceY;             ///< index of first line
+    int sliceH;             ///< number of lines
+    uint8_t **line;         ///< line buffer
+    uint8_t **tmp;          ///< Tmp line buffer used by mmx code
+} SwsPlane;
+
+/**
+ * Struct which defines a slice of an image to be scaled or a output for
+ * a scaled slice.
+ * A slice can also be used as intermediate ring buffer for scaling steps.
+ */
+typedef struct SwsSlice
+{
+    int width;              ///< Slice line width
+    int h_chr_sub_sample;   ///< horizontal chroma subsampling factor
+    int v_chr_sub_sample;   ///< vertical chroma subsampling factor
+    int is_ring;            ///< flag to identify if this slice is a ring buffer
+    int should_free_lines;  ///< flag to identify if there are dynamic allocated lines
+    enum AVPixelFormat fmt; ///< planes pixel format
+    SwsPlane plane[MAX_SLICE_PLANES];   ///< color planes
+} SwsSlice;
+
+/**
+ * Struct which holds all necessary data for processing a slice.
+ * A processing step can be a color conversion or horizontal/vertical scaling.
+ */
+typedef struct SwsFilterDescriptor
+{
+    SwsSlice *src;  ///< Source slice
+    SwsSlice *dst;  ///< Output slice
+
+    int alpha;      ///< Flag for processing alpha channel
+    void *instance; ///< Filter instance data
+
+    /// Function for processing input slice sliceH lines starting from line sliceY
+    int (*process)(SwsContext *c, struct SwsFilterDescriptor *desc, int sliceY, int sliceH);
+} SwsFilterDescriptor;
+
+/// Color conversion instance data
+typedef struct ColorContext
+{
+    uint32_t *pal;
+} ColorContext;
+
+/// Scaler instance data
+typedef struct FilterContext
+{
+    uint16_t *filter;
+    int *filter_pos;
+    int filter_size;
+    int xInc;
+} FilterContext;
+
+// warp input lines in the form (src + width*i + j) to slice format (line[i][j])
+int ff_init_slice_from_src(SwsSlice * s, uint8_t *src[4], int stride[4], int srcW, int lumY, int lumH, int chrY, int chrH);
+
+// Initialize scaler filter descriptor chain
+int ff_init_filters(SwsContext *c);
+
+// Free all filter data
+int ff_free_filters(SwsContext *c);
+
+/*
+ function for applying ring buffer logic into slice s
+ It checks if the slice can hold more @lum lines, if yes
+ do nothing otherwise remove @lum least used lines.
+ It applyes the same procedure for @chr lines.
+*/
+int ff_rotate_slice(SwsSlice *s, int lum, int chr);
+
+
+/// initializes lum pixel format conversion descriptor
+int ff_init_desc_fmt_convert(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst, uint32_t *pal);
+
+/// initializes lum horizontal scaling descriptor
+int ff_init_desc_hscale(SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst, uint16_t *filter, int * filter_pos, int filter_size, int xInc);
+
+/// initializes chr prixel format conversion descriptor
+int ff_init_desc_cfmt_convert(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst, uint32_t *pal);
+
+/// initializes chr horizontal scaling descriptor
+int ff_init_desc_chscale(SwsFilterDescriptor *desc, SwsSlice *src, SwsSlice *dst, uint16_t *filter, int * filter_pos, int filter_size, int xInc);
+
+int ff_init_desc_no_chr(SwsFilterDescriptor *desc, SwsSlice * src, SwsSlice *dst);
+
 #endif /* SWSCALE_SWSCALE_INTERNAL_H */
diff --git a/libswscale/utils.c b/libswscale/utils.c
index 1f4dc7d692..181a48ad21 100644
--- a/libswscale/utils.c
+++ b/libswscale/utils.c
@@ -1702,7 +1702,7 @@ av_cold int sws_init_context(SwsContext *c, SwsFilter *srcFilter,
     }
 
     c->swscale = ff_getSwsFunc(c);
-    return 0;
+    return ff_init_filters(c);
 fail: // FIXME replace things by appropriate error codes
     if (ret == RETCODE_USE_CASCADE)  {
         int tmpW = sqrt(srcW * (int64_t)dstW);
@@ -2219,6 +2219,7 @@ void sws_freeContext(SwsContext *c)
     av_freep(&c->gamma);
     av_freep(&c->inv_gamma);
 
+    ff_free_filters(c);
 
     av_free(c);
 }
diff --git a/libswscale/x86/swscale.c b/libswscale/x86/swscale.c
index d611b76c73..83c01a0f9e 100644
--- a/libswscale/x86/swscale.c
+++ b/libswscale/x86/swscale.c
@@ -85,9 +85,17 @@ void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrB
 {
     const int dstH= c->dstH;
     const int flags= c->flags;
+#define NEW_FILTER 1
+#if NEW_FILTER
+    SwsPlane *lumPlane = &c->slice[c->numSlice-1].plane[0];
+    SwsPlane *chrUPlane = &c->slice[c->numSlice-1].plane[1];
+    SwsPlane *alpPlane = &c->slice[c->numSlice-1].plane[3];
+#else
     int16_t **lumPixBuf= c->lumPixBuf;
     int16_t **chrUPixBuf= c->chrUPixBuf;
     int16_t **alpPixBuf= c->alpPixBuf;
+#endif
+    int hasAlpha = c->alpPixBuf != NULL;
     const int vLumBufSize= c->vLumBufSize;
     const int vChrBufSize= c->vChrBufSize;
     int32_t *vLumFilterPos= c->vLumFilterPos;
@@ -110,13 +118,22 @@ void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrB
         c->greenDither= ff_dither4[dstY&1];
     c->redDither= ff_dither8[(dstY+1)&1];
     if (dstY < dstH - 2) {
+#if NEW_FILTER
+        const int16_t **lumSrcPtr  = (const int16_t **)(void*) lumPlane->line + firstLumSrcY - lumPlane->sliceY;
+        const int16_t **chrUSrcPtr = (const int16_t **)(void*) chrUPlane->line + firstChrSrcY - chrUPlane->sliceY;
+        const int16_t **alpSrcPtr  = (CONFIG_SWSCALE_ALPHA && c->alpPixBuf) ? (const int16_t **)(void*) alpPlane->line + firstLumSrcY - alpPlane->sliceY : NULL;
+#else
         const int16_t **lumSrcPtr= (const int16_t **)(void*) lumPixBuf + lumBufIndex + firstLumSrcY - lastInLumBuf + vLumBufSize;
         const int16_t **chrUSrcPtr= (const int16_t **)(void*) chrUPixBuf + chrBufIndex + firstChrSrcY - lastInChrBuf + vChrBufSize;
         const int16_t **alpSrcPtr= (CONFIG_SWSCALE_ALPHA && alpPixBuf) ? (const int16_t **)(void*) alpPixBuf + lumBufIndex + firstLumSrcY - lastInLumBuf + vLumBufSize : NULL;
+#endif
         int i;
-
         if (firstLumSrcY < 0 || firstLumSrcY + vLumFilterSize > c->srcH) {
+#if NEW_FILTER
+            const int16_t **tmpY = (const int16_t **) lumPlane->tmp;
+#else
             const int16_t **tmpY = (const int16_t **) lumPixBuf + 2 * vLumBufSize;
+#endif
             int neg = -firstLumSrcY, i, end = FFMIN(c->srcH - firstLumSrcY, vLumFilterSize);
             for (i = 0; i < neg;            i++)
                 tmpY[i] = lumSrcPtr[neg];
@@ -127,7 +144,11 @@ void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrB
             lumSrcPtr = tmpY;
 
             if (alpSrcPtr) {
+#if NEW_FILTER
+                const int16_t **tmpA = (const int16_t **) alpPlane->tmp;
+#else
                 const int16_t **tmpA = (const int16_t **) alpPixBuf + 2 * vLumBufSize;
+#endif
                 for (i = 0; i < neg;            i++)
                     tmpA[i] = alpSrcPtr[neg];
                 for (     ; i < end;            i++)
@@ -138,7 +159,11 @@ void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrB
             }
         }
         if (firstChrSrcY < 0 || firstChrSrcY + vChrFilterSize > c->chrSrcH) {
+#if NEW_FILTER
+            const int16_t **tmpU = (const int16_t **) chrUPlane->tmp;
+#else
             const int16_t **tmpU = (const int16_t **) chrUPixBuf + 2 * vChrBufSize;
+#endif
             int neg = -firstChrSrcY, i, end = FFMIN(c->chrSrcH - firstChrSrcY, vChrFilterSize);
             for (i = 0; i < neg;            i++) {
                 tmpU[i] = chrUSrcPtr[neg];
@@ -160,7 +185,7 @@ void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrB
                 lumMmxFilter[s*i+APCK_COEF/4  ]=
                 lumMmxFilter[s*i+APCK_COEF/4+1]= vLumFilter[dstY*vLumFilterSize + i    ]
                 + (vLumFilterSize>1 ? vLumFilter[dstY*vLumFilterSize + i + 1]<<16 : 0);
-                if (CONFIG_SWSCALE_ALPHA && alpPixBuf) {
+                if (CONFIG_SWSCALE_ALPHA && hasAlpha) {
                     *(const void**)&alpMmxFilter[s*i              ]= alpSrcPtr[i  ];
                     *(const void**)&alpMmxFilter[s*i+APCK_PTR2/4  ]= alpSrcPtr[i+(vLumFilterSize>1)];
                     alpMmxFilter[s*i+APCK_COEF/4  ]=
@@ -180,7 +205,7 @@ void ff_updateMMXDitherTables(SwsContext *c, int dstY, int lumBufIndex, int chrB
                 lumMmxFilter[4*i+2]=
                 lumMmxFilter[4*i+3]=
                 ((uint16_t)vLumFilter[dstY*vLumFilterSize + i])*0x10001U;
-                if (CONFIG_SWSCALE_ALPHA && alpPixBuf) {
+                if (CONFIG_SWSCALE_ALPHA && hasAlpha) {
                     *(const void**)&alpMmxFilter[4*i+0]= alpSrcPtr[i];
                     alpMmxFilter[4*i+2]=
                     alpMmxFilter[4*i+3]= lumMmxFilter[4*i+2];