libavcodec/zmbvenc.c - manifest_repos/ffmpeg - Git at Google

 /*
  * Zip Motion Blocks Video (ZMBV) encoder
  * Copyright (c) 2006 Konstantin Shishkov
  *
  * 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
  */

 /**
  * @file
  * Zip Motion Blocks Video encoder
  */

 #include <stdio.h>
 #include <stdlib.h>

 #include "libavutil/common.h"
 #include "libavutil/intreadwrite.h"
 #include "avcodec.h"
 #include "internal.h"

 #include <zlib.h>

 /* Frame header flags */
 #define ZMBV_KEYFRAME 1
 #define ZMBV_DELTAPAL 2

 /* Motion block width/height (maximum allowed value is 255)
  * Note: histogram datatype in block_cmp() must be big enough to hold values
  * up to (4 * ZMBV_BLOCK * ZMBV_BLOCK)
  */
 #define ZMBV_BLOCK 16

 /* Keyframe header format values */
 enum ZmbvFormat {
     ZMBV_FMT_NONE  = 0,
     ZMBV_FMT_1BPP  = 1,
     ZMBV_FMT_2BPP  = 2,
     ZMBV_FMT_4BPP  = 3,
     ZMBV_FMT_8BPP  = 4,
     ZMBV_FMT_15BPP = 5,
     ZMBV_FMT_16BPP = 6,
     ZMBV_FMT_24BPP = 7,
     ZMBV_FMT_32BPP = 8
 };

 /**
  * Encoder context
  */
 typedef struct ZmbvEncContext {
     AVCodecContext *avctx;

     int lrange, urange;
     uint8_t *comp_buf, *work_buf;
     uint8_t pal[768];
     uint32_t pal2[256]; //for quick comparisons
     uint8_t *prev, *prev_buf;
     int pstride;
     int comp_size;
     int keyint, curfrm;
     int bypp;
     enum ZmbvFormat fmt;
     z_stream zstream;

     int score_tab[ZMBV_BLOCK * ZMBV_BLOCK * 4 + 1];
 } ZmbvEncContext;


 /** Block comparing function
  * XXX should be optimized and moved to DSPContext
  */
 static inline int block_cmp(ZmbvEncContext *c, uint8_t *src, int stride,
                             uint8_t *src2, int stride2, int bw, int bh,
                             int *xored)
 {
     int sum = 0;
     int i, j;
     uint16_t histogram[256] = {0};
     int bw_bytes = bw * c->bypp;

     /* Build frequency histogram of byte values for src[] ^ src2[] */
     for(j = 0; j < bh; j++){
         for(i = 0; i < bw_bytes; i++){
             int t = src[i] ^ src2[i];
             histogram[t]++;
         }
         src += stride;
         src2 += stride2;
     }

     /* If not all the xored values were 0, then the blocks are different */
     *xored = (histogram[0] < bw_bytes * bh);

     /* Exit early if blocks are equal */
     if (!*xored) return 0;

     /* Sum the entropy of all values */
     for(i = 0; i < 256; i++)
         sum += c->score_tab[histogram[i]];

     return sum;
 }

 /** Motion estimation function
  * TODO make better ME decisions
  */
 static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
                    int pstride, int x, int y, int *mx, int *my, int *xored)
 {
     int dx, dy, txored, tv, bv, bw, bh;
     int mx0, my0;

     mx0 = *mx;
     my0 = *my;
     bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
     bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);

     /* Try (0,0) */
     bv = block_cmp(c, src, sstride, prev, pstride, bw, bh, xored);
     *mx = *my = 0;
     if(!bv) return 0;

     /* Try previous block's MV (if not 0,0) */
     if (mx0 || my0){
         tv = block_cmp(c, src, sstride, prev + mx0 * c->bypp + my0 * pstride, pstride, bw, bh, &txored);
         if(tv < bv){
             bv = tv;
             *mx = mx0;
             *my = my0;
             *xored = txored;
             if(!bv) return 0;
         }
     }

     /* Try other MVs from top-to-bottom, left-to-right */
     for(dy = -c->lrange; dy <= c->urange; dy++){
         for(dx = -c->lrange; dx <= c->urange; dx++){
             if(!dx && !dy) continue; // we already tested this block
             if(dx == mx0 && dy == my0) continue; // this one too
             tv = block_cmp(c, src, sstride, prev + dx * c->bypp + dy * pstride, pstride, bw, bh, &txored);
             if(tv < bv){
                  bv = tv;
                  *mx = dx;
                  *my = dy;
                  *xored = txored;
                  if(!bv) return 0;
              }
          }
     }
     return bv;
 }

 static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                         const AVFrame *pict, int *got_packet)
 {
     ZmbvEncContext * const c = avctx->priv_data;
     const AVFrame * const p = pict;
     uint8_t *src, *prev, *buf;
     uint32_t *palptr;
     int keyframe, chpal;
     int fl;
     int work_size = 0, pkt_size;
     int bw, bh;
     int i, j, ret;

     keyframe = !c->curfrm;
     c->curfrm++;
     if(c->curfrm == c->keyint)
         c->curfrm = 0;
 #if FF_API_CODED_FRAME
 FF_DISABLE_DEPRECATION_WARNINGS
     avctx->coded_frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
     avctx->coded_frame->key_frame = keyframe;
 FF_ENABLE_DEPRECATION_WARNINGS
 #endif

     palptr = (avctx->pix_fmt == AV_PIX_FMT_PAL8) ? (uint32_t *)p->data[1] : NULL;
     chpal = !keyframe && palptr && memcmp(palptr, c->pal2, 1024);

     src = p->data[0];
     prev = c->prev;
     if(chpal){
         uint8_t tpal[3];
         for(i = 0; i < 256; i++){
             AV_WB24(tpal, palptr[i]);
             c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
             c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
             c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
             c->pal[i * 3 + 0] = tpal[0];
             c->pal[i * 3 + 1] = tpal[1];
             c->pal[i * 3 + 2] = tpal[2];
         }
         memcpy(c->pal2, palptr, 1024);
     }
     if(keyframe){
         if (palptr){
             for(i = 0; i < 256; i++){
                 AV_WB24(c->pal+(i*3), palptr[i]);
             }
             memcpy(c->work_buf, c->pal, 768);
             memcpy(c->pal2, palptr, 1024);
             work_size = 768;
         }
         for(i = 0; i < avctx->height; i++){
             memcpy(c->work_buf + work_size, src, avctx->width * c->bypp);
             src += p->linesize[0];
             work_size += avctx->width * c->bypp;
         }
     }else{
         int x, y, bh2, bw2, xored;
         uint8_t *tsrc, *tprev;
         uint8_t *mv;
         int mx = 0, my = 0;

         bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
         bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
         mv = c->work_buf + work_size;
         memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
         work_size += (bw * bh * 2 + 3) & ~3;
         /* for now just XOR'ing */
         for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
             bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
             for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
                 bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);

                 tsrc = src + x * c->bypp;
                 tprev = prev + x * c->bypp;

                 zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
                 mv[0] = (mx * 2) | !!xored;
                 mv[1] = my * 2;
                 tprev += mx * c->bypp + my * c->pstride;
                 if(xored){
                     for(j = 0; j < bh2; j++){
                         for(i = 0; i < bw2 * c->bypp; i++)
                             c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
                         tsrc += p->linesize[0];
                         tprev += c->pstride;
                     }
                 }
             }
             src += p->linesize[0] * ZMBV_BLOCK;
             prev += c->pstride * ZMBV_BLOCK;
         }
     }
     /* save the previous frame */
     src = p->data[0];
     prev = c->prev;
     for(i = 0; i < avctx->height; i++){
         memcpy(prev, src, avctx->width * c->bypp);
         prev += c->pstride;
         src += p->linesize[0];
     }

     if (keyframe)
         deflateReset(&c->zstream);

     c->zstream.next_in = c->work_buf;
     c->zstream.avail_in = work_size;
     c->zstream.total_in = 0;

     c->zstream.next_out = c->comp_buf;
     c->zstream.avail_out = c->comp_size;
     c->zstream.total_out = 0;
     if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
         av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
         return -1;
     }

     pkt_size = c->zstream.total_out + 1 + 6*keyframe;
     if ((ret = ff_alloc_packet2(avctx, pkt, pkt_size, 0)) < 0)
         return ret;
     buf = pkt->data;

     fl = (keyframe ? ZMBV_KEYFRAME : 0) | (chpal ? ZMBV_DELTAPAL : 0);
     *buf++ = fl;
     if (keyframe) {
         *buf++ = 0; // hi ver
         *buf++ = 1; // lo ver
         *buf++ = 1; // comp
         *buf++ = c->fmt; // format
         *buf++ = ZMBV_BLOCK; // block width
         *buf++ = ZMBV_BLOCK; // block height
     }
     memcpy(buf, c->comp_buf, c->zstream.total_out);

     pkt->flags |= AV_PKT_FLAG_KEY*keyframe;
     *got_packet = 1;

     return 0;
 }

 static av_cold int encode_end(AVCodecContext *avctx)
 {
     ZmbvEncContext * const c = avctx->priv_data;

     av_freep(&c->comp_buf);
     av_freep(&c->work_buf);

     deflateEnd(&c->zstream);
     av_freep(&c->prev_buf);

     return 0;
 }

 /**
  * Init zmbv encoder
  */
 static av_cold int encode_init(AVCodecContext *avctx)
 {
     ZmbvEncContext * const c = avctx->priv_data;
     int zret; // Zlib return code
     int i;
     int lvl = 9;
     int prev_size, prev_offset;

     switch (avctx->pix_fmt) {
     case AV_PIX_FMT_PAL8:
         c->fmt = ZMBV_FMT_8BPP;
         c->bypp = 1;
         break;
     case AV_PIX_FMT_RGB555LE:
         c->fmt = ZMBV_FMT_15BPP;
         c->bypp = 2;
         break;
     case AV_PIX_FMT_RGB565LE:
         c->fmt = ZMBV_FMT_16BPP;
         c->bypp = 2;
         break;
 #ifdef ZMBV_ENABLE_24BPP
     case AV_PIX_FMT_BGR24:
         c->fmt = ZMBV_FMT_24BPP;
         c->bypp = 3;
         break;
 #endif //ZMBV_ENABLE_24BPP
     case AV_PIX_FMT_BGR0:
         c->fmt = ZMBV_FMT_32BPP;
         c->bypp = 4;
         break;
     default:
         av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
         return AVERROR(EINVAL);
     }

     /* Entropy-based score tables for comparing blocks.
      * Suitable for blocks up to (ZMBV_BLOCK * ZMBV_BLOCK) bytes.
      * Scores are nonnegative, lower is better.
      */
     for(i = 1; i <= ZMBV_BLOCK * ZMBV_BLOCK * c->bypp; i++)
         c->score_tab[i] = -i * log2(i / (double)(ZMBV_BLOCK * ZMBV_BLOCK * c->bypp)) * 256;

     c->avctx = avctx;

     c->curfrm = 0;
     c->keyint = avctx->keyint_min;

     /* Motion estimation range: maximum distance is -64..63 */
     c->lrange = c->urange = 8;
     if(avctx->me_range > 0){
         c->lrange = FFMIN(avctx->me_range, 64);
         c->urange = FFMIN(avctx->me_range, 63);
     }

     if(avctx->compression_level >= 0)
         lvl = avctx->compression_level;
     if(lvl < 0 || lvl > 9){
         av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
         return AVERROR(EINVAL);
     }

     // Needed if zlib unused or init aborted before deflateInit
     memset(&c->zstream, 0, sizeof(z_stream));
     c->comp_size = avctx->width * c->bypp * avctx->height + 1024 +
         ((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
     if (!(c->work_buf = av_malloc(c->comp_size))) {
         av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
         return AVERROR(ENOMEM);
     }
     /* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
     c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
                            ((c->comp_size + 63) >> 6) + 11;

     /* Allocate compression buffer */
     if (!(c->comp_buf = av_malloc(c->comp_size))) {
         av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
         return AVERROR(ENOMEM);
     }

     /* Allocate prev buffer - pad around the image to allow out-of-edge ME:
      * - The image should be padded with `lrange` rows before and `urange` rows
      *   after.
      * - The stride should be padded with `lrange` pixels, then rounded up to a
      *   multiple of 16 bytes.
      * - The first row should also be padded with `lrange` pixels before, then
      *   aligned up to a multiple of 16 bytes.
      */
     c->pstride = FFALIGN((avctx->width + c->lrange) * c->bypp, 16);
     prev_size = FFALIGN(c->lrange * c->bypp, 16) + c->pstride * (c->lrange + avctx->height + c->urange);
     prev_offset = FFALIGN(c->lrange * c->bypp, 16) + c->pstride * c->lrange;
     if (!(c->prev_buf = av_mallocz(prev_size))) {
         av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
         return AVERROR(ENOMEM);
     }
     c->prev = c->prev_buf + prev_offset;

     c->zstream.zalloc = Z_NULL;
     c->zstream.zfree = Z_NULL;
     c->zstream.opaque = Z_NULL;
     zret = deflateInit(&c->zstream, lvl);
     if (zret != Z_OK) {
         av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
         return -1;
     }

     return 0;
 }

 AVCodec ff_zmbv_encoder = {
     .name           = "zmbv",
     .long_name      = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
     .type           = AVMEDIA_TYPE_VIDEO,
     .id             = AV_CODEC_ID_ZMBV,
     .priv_data_size = sizeof(ZmbvEncContext),
     .init           = encode_init,
     .encode2        = encode_frame,
     .close          = encode_end,
     .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_PAL8,
                                                      AV_PIX_FMT_RGB555LE,
                                                      AV_PIX_FMT_RGB565LE,
 #ifdef ZMBV_ENABLE_24BPP
                                                      AV_PIX_FMT_BGR24,
 #endif //ZMBV_ENABLE_24BPP
                                                      AV_PIX_FMT_BGR0,
                                                      AV_PIX_FMT_NONE },
 };
	/*
	* Zip Motion Blocks Video (ZMBV) encoder
	* Copyright (c) 2006 Konstantin Shishkov
	*
	* 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
	*/

	/**
	* @file
	* Zip Motion Blocks Video encoder
	*/

	#include <stdio.h>
	#include <stdlib.h>

	#include "libavutil/common.h"
	#include "libavutil/intreadwrite.h"
	#include "avcodec.h"
	#include "internal.h"

	#include <zlib.h>

	/* Frame header flags */
	#define ZMBV_KEYFRAME 1
	#define ZMBV_DELTAPAL 2

	/* Motion block width/height (maximum allowed value is 255)
	* Note: histogram datatype in block_cmp() must be big enough to hold values
	* up to (4 * ZMBV_BLOCK * ZMBV_BLOCK)
	*/
	#define ZMBV_BLOCK 16

	/* Keyframe header format values */
	enum ZmbvFormat {
	ZMBV_FMT_NONE = 0,
	ZMBV_FMT_1BPP = 1,
	ZMBV_FMT_2BPP = 2,
	ZMBV_FMT_4BPP = 3,
	ZMBV_FMT_8BPP = 4,
	ZMBV_FMT_15BPP = 5,
	ZMBV_FMT_16BPP = 6,
	ZMBV_FMT_24BPP = 7,
	ZMBV_FMT_32BPP = 8
	};

	/**
	* Encoder context
	*/
	typedef struct ZmbvEncContext {
	AVCodecContext *avctx;

	int lrange, urange;
	uint8_t comp_buf, work_buf;
	uint8_t pal[768];
	uint32_t pal2[256]; //for quick comparisons
	uint8_t prev, prev_buf;
	int pstride;
	int comp_size;
	int keyint, curfrm;
	int bypp;
	enum ZmbvFormat fmt;
	z_stream zstream;

	int score_tab[ZMBV_BLOCK * ZMBV_BLOCK * 4 + 1];
	} ZmbvEncContext;


	/** Block comparing function
	* XXX should be optimized and moved to DSPContext
	*/
	static inline int block_cmp(ZmbvEncContext c, uint8_t src, int stride,
	uint8_t *src2, int stride2, int bw, int bh,
	int *xored)
	{
	int sum = 0;
	int i, j;
	uint16_t histogram[256] = {0};
	int bw_bytes = bw * c->bypp;

	/* Build frequency histogram of byte values for src[] ^ src2[] */
	for(j = 0; j < bh; j++){
	for(i = 0; i < bw_bytes; i++){
	int t = src[i] ^ src2[i];
	histogram[t]++;
	}
	src += stride;
	src2 += stride2;
	}

	/* If not all the xored values were 0, then the blocks are different */
	xored = (histogram[0] < bw_bytes bh);

	/* Exit early if blocks are equal */
	if (!*xored) return 0;

	/* Sum the entropy of all values */
	for(i = 0; i < 256; i++)
	sum += c->score_tab[histogram[i]];

	return sum;
	}

	/** Motion estimation function
	* TODO make better ME decisions
	*/
	static int zmbv_me(ZmbvEncContext c, uint8_t src, int sstride, uint8_t *prev,
	int pstride, int x, int y, int mx, int my, int *xored)
	{
	int dx, dy, txored, tv, bv, bw, bh;
	int mx0, my0;

	mx0 = *mx;
	my0 = *my;
	bw = FFMIN(ZMBV_BLOCK, c->avctx->width - x);
	bh = FFMIN(ZMBV_BLOCK, c->avctx->height - y);

	/* Try (0,0) */
	bv = block_cmp(c, src, sstride, prev, pstride, bw, bh, xored);
	mx = my = 0;
	if(!bv) return 0;

	/* Try previous block's MV (if not 0,0) */
	if (mx0 \|\| my0){
	tv = block_cmp(c, src, sstride, prev + mx0 * c->bypp + my0 * pstride, pstride, bw, bh, &txored);
	if(tv < bv){
	bv = tv;
	*mx = mx0;
	*my = my0;
	*xored = txored;
	if(!bv) return 0;
	}
	}

	/* Try other MVs from top-to-bottom, left-to-right */
	for(dy = -c->lrange; dy <= c->urange; dy++){
	for(dx = -c->lrange; dx <= c->urange; dx++){
	if(!dx && !dy) continue; // we already tested this block
	if(dx == mx0 && dy == my0) continue; // this one too
	tv = block_cmp(c, src, sstride, prev + dx * c->bypp + dy * pstride, pstride, bw, bh, &txored);
	if(tv < bv){
	bv = tv;
	*mx = dx;
	*my = dy;
	*xored = txored;
	if(!bv) return 0;
	}
	}
	}
	return bv;
	}

	static int encode_frame(AVCodecContext avctx, AVPacket pkt,
	const AVFrame pict, int got_packet)
	{
	ZmbvEncContext * const c = avctx->priv_data;
	const AVFrame * const p = pict;
	uint8_t src, prev, *buf;
	uint32_t *palptr;
	int keyframe, chpal;
	int fl;
	int work_size = 0, pkt_size;
	int bw, bh;
	int i, j, ret;

	keyframe = !c->curfrm;
	c->curfrm++;
	if(c->curfrm == c->keyint)
	c->curfrm = 0;
	#if FF_API_CODED_FRAME
	FF_DISABLE_DEPRECATION_WARNINGS
	avctx->coded_frame->pict_type = keyframe ? AV_PICTURE_TYPE_I : AV_PICTURE_TYPE_P;
	avctx->coded_frame->key_frame = keyframe;
	FF_ENABLE_DEPRECATION_WARNINGS
	#endif

	palptr = (avctx->pix_fmt == AV_PIX_FMT_PAL8) ? (uint32_t *)p->data[1] : NULL;
	chpal = !keyframe && palptr && memcmp(palptr, c->pal2, 1024);

	src = p->data[0];
	prev = c->prev;
	if(chpal){
	uint8_t tpal[3];
	for(i = 0; i < 256; i++){
	AV_WB24(tpal, palptr[i]);
	c->work_buf[work_size++] = tpal[0] ^ c->pal[i * 3 + 0];
	c->work_buf[work_size++] = tpal[1] ^ c->pal[i * 3 + 1];
	c->work_buf[work_size++] = tpal[2] ^ c->pal[i * 3 + 2];
	c->pal[i * 3 + 0] = tpal[0];
	c->pal[i * 3 + 1] = tpal[1];
	c->pal[i * 3 + 2] = tpal[2];
	}
	memcpy(c->pal2, palptr, 1024);
	}
	if(keyframe){
	if (palptr){
	for(i = 0; i < 256; i++){
	AV_WB24(c->pal+(i*3), palptr[i]);
	}
	memcpy(c->work_buf, c->pal, 768);
	memcpy(c->pal2, palptr, 1024);
	work_size = 768;
	}
	for(i = 0; i < avctx->height; i++){
	memcpy(c->work_buf + work_size, src, avctx->width * c->bypp);
	src += p->linesize[0];
	work_size += avctx->width * c->bypp;
	}
	}else{
	int x, y, bh2, bw2, xored;
	uint8_t tsrc, tprev;
	uint8_t *mv;
	int mx = 0, my = 0;

	bw = (avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
	bh = (avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK;
	mv = c->work_buf + work_size;
	memset(c->work_buf + work_size, 0, (bw * bh * 2 + 3) & ~3);
	work_size += (bw * bh * 2 + 3) & ~3;
	/* for now just XOR'ing */
	for(y = 0; y < avctx->height; y += ZMBV_BLOCK) {
	bh2 = FFMIN(avctx->height - y, ZMBV_BLOCK);
	for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
	bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);

	tsrc = src + x * c->bypp;
	tprev = prev + x * c->bypp;

	zmbv_me(c, tsrc, p->linesize[0], tprev, c->pstride, x, y, &mx, &my, &xored);
	mv[0] = (mx * 2) \| !!xored;
	mv[1] = my * 2;
	tprev += mx * c->bypp + my * c->pstride;
	if(xored){
	for(j = 0; j < bh2; j++){
	for(i = 0; i < bw2 * c->bypp; i++)
	c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
	tsrc += p->linesize[0];
	tprev += c->pstride;
	}
	}
	}
	src += p->linesize[0] * ZMBV_BLOCK;
	prev += c->pstride * ZMBV_BLOCK;
	}
	}
	/* save the previous frame */
	src = p->data[0];
	prev = c->prev;
	for(i = 0; i < avctx->height; i++){
	memcpy(prev, src, avctx->width * c->bypp);
	prev += c->pstride;
	src += p->linesize[0];
	}

	if (keyframe)
	deflateReset(&c->zstream);

	c->zstream.next_in = c->work_buf;
	c->zstream.avail_in = work_size;
	c->zstream.total_in = 0;

	c->zstream.next_out = c->comp_buf;
	c->zstream.avail_out = c->comp_size;
	c->zstream.total_out = 0;
	if(deflate(&c->zstream, Z_SYNC_FLUSH) != Z_OK){
	av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
	return -1;
	}

	pkt_size = c->zstream.total_out + 1 + 6*keyframe;
	if ((ret = ff_alloc_packet2(avctx, pkt, pkt_size, 0)) < 0)
	return ret;
	buf = pkt->data;

	fl = (keyframe ? ZMBV_KEYFRAME : 0) \| (chpal ? ZMBV_DELTAPAL : 0);
	*buf++ = fl;
	if (keyframe) {
	*buf++ = 0; // hi ver
	*buf++ = 1; // lo ver
	*buf++ = 1; // comp
	*buf++ = c->fmt; // format
	*buf++ = ZMBV_BLOCK; // block width
	*buf++ = ZMBV_BLOCK; // block height
	}
	memcpy(buf, c->comp_buf, c->zstream.total_out);

	pkt->flags \|= AV_PKT_FLAG_KEY*keyframe;
	*got_packet = 1;

	return 0;
	}

	static av_cold int encode_end(AVCodecContext *avctx)
	{
	ZmbvEncContext * const c = avctx->priv_data;

	av_freep(&c->comp_buf);
	av_freep(&c->work_buf);

	deflateEnd(&c->zstream);
	av_freep(&c->prev_buf);

	return 0;
	}

	/**
	* Init zmbv encoder
	*/
	static av_cold int encode_init(AVCodecContext *avctx)
	{
	ZmbvEncContext * const c = avctx->priv_data;
	int zret; // Zlib return code
	int i;
	int lvl = 9;
	int prev_size, prev_offset;

	switch (avctx->pix_fmt) {
	case AV_PIX_FMT_PAL8:
	c->fmt = ZMBV_FMT_8BPP;
	c->bypp = 1;
	break;
	case AV_PIX_FMT_RGB555LE:
	c->fmt = ZMBV_FMT_15BPP;
	c->bypp = 2;
	break;
	case AV_PIX_FMT_RGB565LE:
	c->fmt = ZMBV_FMT_16BPP;
	c->bypp = 2;
	break;
	#ifdef ZMBV_ENABLE_24BPP
	case AV_PIX_FMT_BGR24:
	c->fmt = ZMBV_FMT_24BPP;
	c->bypp = 3;
	break;
	#endif //ZMBV_ENABLE_24BPP
	case AV_PIX_FMT_BGR0:
	c->fmt = ZMBV_FMT_32BPP;
	c->bypp = 4;
	break;
	default:
	av_log(avctx, AV_LOG_INFO, "unsupported pixel format\n");
	return AVERROR(EINVAL);
	}

	/* Entropy-based score tables for comparing blocks.
	* Suitable for blocks up to (ZMBV_BLOCK * ZMBV_BLOCK) bytes.
	* Scores are nonnegative, lower is better.
	*/
	for(i = 1; i <= ZMBV_BLOCK * ZMBV_BLOCK * c->bypp; i++)
	c->score_tab[i] = -i * log2(i / (double)(ZMBV_BLOCK * ZMBV_BLOCK * c->bypp)) * 256;

	c->avctx = avctx;

	c->curfrm = 0;
	c->keyint = avctx->keyint_min;

	/* Motion estimation range: maximum distance is -64..63 */
	c->lrange = c->urange = 8;
	if(avctx->me_range > 0){
	c->lrange = FFMIN(avctx->me_range, 64);
	c->urange = FFMIN(avctx->me_range, 63);
	}

	if(avctx->compression_level >= 0)
	lvl = avctx->compression_level;
	if(lvl < 0 \|\| lvl > 9){
	av_log(avctx, AV_LOG_ERROR, "Compression level should be 0-9, not %i\n", lvl);
	return AVERROR(EINVAL);
	}

	// Needed if zlib unused or init aborted before deflateInit
	memset(&c->zstream, 0, sizeof(z_stream));
	c->comp_size = avctx->width * c->bypp * avctx->height + 1024 +
	((avctx->width + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * ((avctx->height + ZMBV_BLOCK - 1) / ZMBV_BLOCK) * 2 + 4;
	if (!(c->work_buf = av_malloc(c->comp_size))) {
	av_log(avctx, AV_LOG_ERROR, "Can't allocate work buffer.\n");
	return AVERROR(ENOMEM);
	}
	/* Conservative upper bound taken from zlib v1.2.1 source via lcl.c */
	c->comp_size = c->comp_size + ((c->comp_size + 7) >> 3) +
	((c->comp_size + 63) >> 6) + 11;

	/* Allocate compression buffer */
	if (!(c->comp_buf = av_malloc(c->comp_size))) {
	av_log(avctx, AV_LOG_ERROR, "Can't allocate compression buffer.\n");
	return AVERROR(ENOMEM);
	}

	/* Allocate prev buffer - pad around the image to allow out-of-edge ME:
	* - The image should be padded with `lrange` rows before and `urange` rows
	* after.
	* - The stride should be padded with `lrange` pixels, then rounded up to a
	* multiple of 16 bytes.
	* - The first row should also be padded with `lrange` pixels before, then
	* aligned up to a multiple of 16 bytes.
	*/
	c->pstride = FFALIGN((avctx->width + c->lrange) * c->bypp, 16);
	prev_size = FFALIGN(c->lrange * c->bypp, 16) + c->pstride * (c->lrange + avctx->height + c->urange);
	prev_offset = FFALIGN(c->lrange * c->bypp, 16) + c->pstride * c->lrange;
	if (!(c->prev_buf = av_mallocz(prev_size))) {
	av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
	return AVERROR(ENOMEM);
	}
	c->prev = c->prev_buf + prev_offset;

	c->zstream.zalloc = Z_NULL;
	c->zstream.zfree = Z_NULL;
	c->zstream.opaque = Z_NULL;
	zret = deflateInit(&c->zstream, lvl);
	if (zret != Z_OK) {
	av_log(avctx, AV_LOG_ERROR, "Inflate init error: %d\n", zret);
	return -1;
	}

	return 0;
	}

	AVCodec ff_zmbv_encoder = {
	.name = "zmbv",
	.long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
	.type = AVMEDIA_TYPE_VIDEO,
	.id = AV_CODEC_ID_ZMBV,
	.priv_data_size = sizeof(ZmbvEncContext),
	.init = encode_init,
	.encode2 = encode_frame,
	.close = encode_end,
	.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_PAL8,
	AV_PIX_FMT_RGB555LE,
	AV_PIX_FMT_RGB565LE,
	#ifdef ZMBV_ENABLE_24BPP
	AV_PIX_FMT_BGR24,
	#endif //ZMBV_ENABLE_24BPP
	AV_PIX_FMT_BGR0,
	AV_PIX_FMT_NONE },
	};