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ffmpeg/libavcodec/zmbvenc.c

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/*
* 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 << 1) | !!xored;
mv[1] = my << 1;
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 },
};
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