libswscale/slice.c - third_party/ffmpeg - Git at Google

 /*
  * Copyright (C) 2015 Pedro Arthur <bygrandao@gmail.com>
  *
  * This file is part of FFmpeg.
  *
  * FFmpeg is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public
  * License as published by the Free Software Foundation; either
  * version 2.1 of the License, or (at your option) any later version.
  *
  * FFmpeg is distributed in the hope that it will be useful,
  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  * Lesser General Public License for more details.
  *
  * You should have received a copy of the GNU Lesser General Public
  * License along with FFmpeg; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */

 #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 vectorial 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 relative)
 {
     int i = 0;

     const int start[4] = {lumY,
                           chrY,
                           chrY,
                           lumY};

     const int end[4] = {lumY +lumH,
                         chrY + chrH,
                         chrY + chrH,
                         lumY + lumH};

     uint8_t *const src_[4] = {src[0] + (relative ? 0 : start[0]) * stride[0],
                               src[1] + (relative ? 0 : start[1]) * stride[1],
                               src[2] + (relative ? 0 : start[2]) * stride[2],
                               src[3] + (relative ? 0 : start[3]) * stride[3]};

     s->width = srcW;

     for (i = 0; i < 4; ++i) {
         int j;
         int first = s->plane[i].sliceY;
         int n = s->plane[i].available_lines;
         int lines = end[i] - start[i];
         int tot_lines = end[i] - first;

         if (start[i] >= first && n >= tot_lines) {
             s->plane[i].sliceH = FFMAX(tot_lines, s->plane[i].sliceH);
             for (j = 0; j < lines; j+= 1)
                 s->plane[i].line[start[i] - first + j] = src_[i] +  j * stride[i];
         } else {
             s->plane[i].sliceY = start[i];
             lines = lines > n ? n : lines;
             s->plane[i].sliceH = lines;
             for (j = 0; j < lines; j+= 1)
                 s->plane[i].line[j] = src_[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;
         }
     }
 }

 /*
  Calculates the minimum ring buffer size, it should be able to store vFilterSize
  more n lines where n is the max difference between each adjacent slice which
  outputs a line.
  The n lines are needed only when there is not enough src lines to output a single
  dst line, then we should buffer these lines to process them on the next call to scale.
 */
 static void get_min_buffer_size(SwsContext *c, int *out_lum_size, int *out_chr_size)
 {
     int lumY;
     int dstH = c->dstH;
     int chrDstH = c->chrDstH;
     int *lumFilterPos = c->vLumFilterPos;
     int *chrFilterPos = c->vChrFilterPos;
     int lumFilterSize = c->vLumFilterSize;
     int chrFilterSize = c->vChrFilterSize;
     int chrSubSample = c->chrSrcVSubSample;

     *out_lum_size = lumFilterSize;
     *out_chr_size = chrFilterSize;

     for (lumY = 0; lumY < dstH; lumY++) {
         int chrY      = (int64_t)lumY * chrDstH / dstH;
         int nextSlice = FFMAX(lumFilterPos[lumY] + lumFilterSize - 1,
                               ((chrFilterPos[chrY] + chrFilterSize - 1)
                                << chrSubSample));

         nextSlice >>= chrSubSample;
         nextSlice <<= chrSubSample;
         (*out_lum_size) = FFMAX((*out_lum_size), nextSlice - lumFilterPos[lumY]);
         (*out_chr_size) = FFMAX((*out_chr_size), (nextSlice >> chrSubSample) - chrFilterPos[chrY]);
     }
 }


 int ff_init_filters(SwsContext * c)
 {
     int i;
     int index;
     int num_ydesc;
     int num_cdesc;
     int num_vdesc = isPlanarYUV(c->dstFormat) && !isGray(c->dstFormat) ? 2 : 1;
     int need_lum_conv = c->lumToYV12 || c->readLumPlanar || c->alpToYV12 || c->readAlpPlanar;
     int need_chr_conv = c->chrToYV12 || c->readChrPlanar;
     int need_gamma = c->is_internal_gamma;
     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;

     int lumBufSize;
     int chrBufSize;

     get_min_buffer_size(c, &lumBufSize, &chrBufSize);
     lumBufSize = FFMAX(lumBufSize, c->vLumFilterSize + MAX_LINES_AHEAD);
     chrBufSize = FFMAX(chrBufSize, c->vChrFilterSize + MAX_LINES_AHEAD);

     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) + 2;
     c->numDesc = num_ydesc + num_cdesc + num_vdesc + (need_gamma ? 2 : 0);
     c->descIndex[0] = num_ydesc + (need_gamma ? 1 : 0);
     c->descIndex[1] = num_ydesc + num_cdesc + (need_gamma ? 1 : 0);


     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-2; ++i) {
         res = alloc_slice(&c->slice[i], c->srcFormat, lumBufSize, chrBufSize, 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;
     }
     // horizontal scaler output
     res = alloc_slice(&c->slice[i], c->srcFormat, lumBufSize, chrBufSize, 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);

     // vertical scaler output
     ++i;
     res = alloc_slice(&c->slice[i], c->dstFormat, c->dstH, c->chrDstH, c->chrDstHSubSample, c->chrDstVSubSample, 0);
     if (res < 0) goto cleanup;

     index = 0;
     srcIdx = 0;
     dstIdx = 1;

     if (need_gamma) {
         res = ff_init_gamma_convert(c->desc + index, c->slice + srcIdx, c->inv_gamma);
         if (res < 0) goto cleanup;
         ++index;
     }

     if (need_lum_conv) {
         res = ff_init_desc_fmt_convert(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], pal);
         if (res < 0) goto cleanup;
         c->desc[index].alpha = c->needAlpha;
         ++index;
         srcIdx = dstIdx;
     }


     dstIdx = FFMAX(num_ydesc, num_cdesc);
     res = ff_init_desc_hscale(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], c->hLumFilter, c->hLumFilterPos, c->hLumFilterSize, c->lumXInc);
     if (res < 0) goto cleanup;
     c->desc[index].alpha = c->needAlpha;


     ++index;
     {
         srcIdx = 0;
         dstIdx = 1;
         if (need_chr_conv) {
             res = ff_init_desc_cfmt_convert(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], pal);
             if (res < 0) goto cleanup;
             ++index;
             srcIdx = dstIdx;
         }

         dstIdx = FFMAX(num_ydesc, num_cdesc);
         if (c->needs_hcscale)
             res = ff_init_desc_chscale(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], c->hChrFilter, c->hChrFilterPos, c->hChrFilterSize, c->chrXInc);
         else
             res = ff_init_desc_no_chr(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx]);
         if (res < 0) goto cleanup;
     }

     ++index;
     {
         srcIdx = c->numSlice - 2;
         dstIdx = c->numSlice - 1;
         res = ff_init_vscale(c, c->desc + index, c->slice + srcIdx, c->slice + dstIdx);
         if (res < 0) goto cleanup;
     }

     ++index;
     if (need_gamma) {
         res = ff_init_gamma_convert(c->desc + index, c->slice + dstIdx, c->gamma);
         if (res < 0) goto cleanup;
     }

     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;
 }
	/*
	* Copyright (C) 2015 Pedro Arthur <bygrandao@gmail.com>
	*
	* This file is part of FFmpeg.
	*
	* FFmpeg is free software; you can redistribute it and/or
	* modify it under the terms of the GNU Lesser General Public
	* License as published by the Free Software Foundation; either
	* version 2.1 of the License, or (at your option) any later version.
	*
	* FFmpeg is distributed in the hope that it will be useful,
	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	* Lesser General Public License for more details.
	*
	* You should have received a copy of the GNU Lesser General Public
	* License along with FFmpeg; if not, write to the Free Software
	* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
	*/

	#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 vectorial 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 relative)
	{
	int i = 0;

	const int start[4] = {lumY,
	chrY,
	chrY,
	lumY};

	const int end[4] = {lumY +lumH,
	chrY + chrH,
	chrY + chrH,
	lumY + lumH};

	uint8_t const src_[4] = {src[0] + (relative ? 0 : start[0]) stride[0],
	src[1] + (relative ? 0 : start[1]) * stride[1],
	src[2] + (relative ? 0 : start[2]) * stride[2],
	src[3] + (relative ? 0 : start[3]) * stride[3]};

	s->width = srcW;

	for (i = 0; i < 4; ++i) {
	int j;
	int first = s->plane[i].sliceY;
	int n = s->plane[i].available_lines;
	int lines = end[i] - start[i];
	int tot_lines = end[i] - first;

	if (start[i] >= first && n >= tot_lines) {
	s->plane[i].sliceH = FFMAX(tot_lines, s->plane[i].sliceH);
	for (j = 0; j < lines; j+= 1)
	s->plane[i].line[start[i] - first + j] = src_[i] + j * stride[i];
	} else {
	s->plane[i].sliceY = start[i];
	lines = lines > n ? n : lines;
	s->plane[i].sliceH = lines;
	for (j = 0; j < lines; j+= 1)
	s->plane[i].line[j] = src_[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;
	}
	}
	}

	/*
	Calculates the minimum ring buffer size, it should be able to store vFilterSize
	more n lines where n is the max difference between each adjacent slice which
	outputs a line.
	The n lines are needed only when there is not enough src lines to output a single
	dst line, then we should buffer these lines to process them on the next call to scale.
	*/
	static void get_min_buffer_size(SwsContext c, int out_lum_size, int *out_chr_size)
	{
	int lumY;
	int dstH = c->dstH;
	int chrDstH = c->chrDstH;
	int *lumFilterPos = c->vLumFilterPos;
	int *chrFilterPos = c->vChrFilterPos;
	int lumFilterSize = c->vLumFilterSize;
	int chrFilterSize = c->vChrFilterSize;
	int chrSubSample = c->chrSrcVSubSample;

	*out_lum_size = lumFilterSize;
	*out_chr_size = chrFilterSize;

	for (lumY = 0; lumY < dstH; lumY++) {
	int chrY = (int64_t)lumY * chrDstH / dstH;
	int nextSlice = FFMAX(lumFilterPos[lumY] + lumFilterSize - 1,
	((chrFilterPos[chrY] + chrFilterSize - 1)
	<< chrSubSample));

	nextSlice >>= chrSubSample;
	nextSlice <<= chrSubSample;
	(out_lum_size) = FFMAX((out_lum_size), nextSlice - lumFilterPos[lumY]);
	(out_chr_size) = FFMAX((out_chr_size), (nextSlice >> chrSubSample) - chrFilterPos[chrY]);
	}
	}



	int ff_init_filters(SwsContext * c)
	{
	int i;
	int index;
	int num_ydesc;
	int num_cdesc;
	int num_vdesc = isPlanarYUV(c->dstFormat) && !isGray(c->dstFormat) ? 2 : 1;
	int need_lum_conv = c->lumToYV12 \|\| c->readLumPlanar \|\| c->alpToYV12 \|\| c->readAlpPlanar;
	int need_chr_conv = c->chrToYV12 \|\| c->readChrPlanar;
	int need_gamma = c->is_internal_gamma;
	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;

	int lumBufSize;
	int chrBufSize;

	get_min_buffer_size(c, &lumBufSize, &chrBufSize);
	lumBufSize = FFMAX(lumBufSize, c->vLumFilterSize + MAX_LINES_AHEAD);
	chrBufSize = FFMAX(chrBufSize, c->vChrFilterSize + MAX_LINES_AHEAD);

	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) + 2;
	c->numDesc = num_ydesc + num_cdesc + num_vdesc + (need_gamma ? 2 : 0);
	c->descIndex[0] = num_ydesc + (need_gamma ? 1 : 0);
	c->descIndex[1] = num_ydesc + num_cdesc + (need_gamma ? 1 : 0);



	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-2; ++i) {
	res = alloc_slice(&c->slice[i], c->srcFormat, lumBufSize, chrBufSize, 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;
	}
	// horizontal scaler output
	res = alloc_slice(&c->slice[i], c->srcFormat, lumBufSize, chrBufSize, 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);

	// vertical scaler output
	++i;
	res = alloc_slice(&c->slice[i], c->dstFormat, c->dstH, c->chrDstH, c->chrDstHSubSample, c->chrDstVSubSample, 0);
	if (res < 0) goto cleanup;

	index = 0;
	srcIdx = 0;
	dstIdx = 1;

	if (need_gamma) {
	res = ff_init_gamma_convert(c->desc + index, c->slice + srcIdx, c->inv_gamma);
	if (res < 0) goto cleanup;
	++index;
	}

	if (need_lum_conv) {
	res = ff_init_desc_fmt_convert(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], pal);
	if (res < 0) goto cleanup;
	c->desc[index].alpha = c->needAlpha;
	++index;
	srcIdx = dstIdx;
	}


	dstIdx = FFMAX(num_ydesc, num_cdesc);
	res = ff_init_desc_hscale(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], c->hLumFilter, c->hLumFilterPos, c->hLumFilterSize, c->lumXInc);
	if (res < 0) goto cleanup;
	c->desc[index].alpha = c->needAlpha;


	++index;
	{
	srcIdx = 0;
	dstIdx = 1;
	if (need_chr_conv) {
	res = ff_init_desc_cfmt_convert(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], pal);
	if (res < 0) goto cleanup;
	++index;
	srcIdx = dstIdx;
	}

	dstIdx = FFMAX(num_ydesc, num_cdesc);
	if (c->needs_hcscale)
	res = ff_init_desc_chscale(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx], c->hChrFilter, c->hChrFilterPos, c->hChrFilterSize, c->chrXInc);
	else
	res = ff_init_desc_no_chr(&c->desc[index], &c->slice[srcIdx], &c->slice[dstIdx]);
	if (res < 0) goto cleanup;
	}

	++index;
	{
	srcIdx = c->numSlice - 2;
	dstIdx = c->numSlice - 1;
	res = ff_init_vscale(c, c->desc + index, c->slice + srcIdx, c->slice + dstIdx);
	if (res < 0) goto cleanup;
	}

	++index;
	if (need_gamma) {
	res = ff_init_gamma_convert(c->desc + index, c->slice + dstIdx, c->gamma);
	if (res < 0) goto cleanup;
	}

	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;
	}