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FFmpeg/libavcodec/zmbvenc.c
Andreas Rheinhardt 20f9727018 avcodec/codec_internal: Add FFCodec, hide internal part of AVCodec
Up until now, codec.h contains both public and private parts
of AVCodec. This exposes the internals of AVCodec to users
and leads them into the temptation of actually using them
and forces us to forward-declare structures and types that
users can't use at all.

This commit changes this by adding a new structure FFCodec to
codec_internal.h that extends AVCodec, i.e. contains the public
AVCodec as first member; the private fields of AVCodec are moved
to this structure, leaving codec.h clean.

Reviewed-by: Anton Khirnov <anton@khirnov.net>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
2022-03-21 01:33:09 +01:00

433 lines
13 KiB
C

/*
* 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 "codec_internal.h"
#include "encode.h"
#include "zlib_wrapper.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;
FFZStream 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;
z_stream *const zstream = &c->zstream.zstream;
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;
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(zstream);
zstream->next_in = c->work_buf;
zstream->avail_in = work_size;
zstream->total_in = 0;
zstream->next_out = c->comp_buf;
zstream->avail_out = c->comp_size;
zstream->total_out = 0;
if (deflate(zstream, Z_SYNC_FLUSH) != Z_OK) {
av_log(avctx, AV_LOG_ERROR, "Error compressing data\n");
return -1;
}
pkt_size = zstream->total_out + 1 + 6 * keyframe;
if ((ret = ff_get_encode_buffer(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
pkt->flags |= AV_PKT_FLAG_KEY;
}
memcpy(buf, c->comp_buf, zstream->total_out);
*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);
av_freep(&c->prev_buf);
ff_deflate_end(&c->zstream);
return 0;
}
/**
* Init zmbv encoder
*/
static av_cold int encode_init(AVCodecContext *avctx)
{
ZmbvEncContext * const c = avctx->priv_data;
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;
}
/* 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);
}
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;
return ff_deflate_init(&c->zstream, lvl, avctx);
}
const FFCodec ff_zmbv_encoder = {
.p.name = "zmbv",
.p.long_name = NULL_IF_CONFIG_SMALL("Zip Motion Blocks Video"),
.p.type = AVMEDIA_TYPE_VIDEO,
.p.id = AV_CODEC_ID_ZMBV,
.p.capabilities = AV_CODEC_CAP_DR1,
.priv_data_size = sizeof(ZmbvEncContext),
.init = encode_init,
.encode2 = encode_frame,
.close = encode_end,
.p.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 },
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
};