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libavcodec/zmbvenc: Add support for RGB formats

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This consists mostly of the following changes:
- add newly supported pixel formats (RGB555LE, RGB565LE, BGR0)
- select the ZMBV format (c->fmt) and bytes per pixel (c->bypp) based on
  avctx->pix_fmt
- multiply widths/x-values by c->bypp, in places where bytes, not pixels, are
  expected
- disable palette-writing code for non-palette pix_fmts
- make a note about histogram[]'s datatype (it could need increasing if
  ZMBV_BLOCK is increased)
- adjust the c->score_tab length to take up to (and including) 4 times the
  number of pixels in a block
- initialise c->score_tab up to c->bypp * the number of pixels

Note: the ZmbvFormat enum allows for additional bit depths:
- 1,2,4-bit (palette)
- 24-bit (RGB)

At time of writing the specifics of these (e.g. channel order, bit alignment)
are not currently defined, and DOSBox only implements support for 8/15/16/32
bpp.
One might expect the 24-bit format - if implemented - to be BGR24, to have the
same channel order as BGR0.
However, the decoder in zmbv.c has been guessed to use RGB24, so I have chosen
to not contradict this, and omitted specific support for this format.
This commit is contained in:
Matthew Fearnley 2019-03-07 14:42:09 +00:00 committed by Tomas Härdin
parent c2a221c5ae
commit 0321370601
1 changed files with 77 additions and 27 deletions
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104
libavcodec/zmbvenc.c
View File

@ -34,11 +34,29 @@
#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
*/
@ -53,9 +71,11 @@ typedef struct ZmbvEncContext {
int pstride;
int comp_size;
int keyint, curfrm;
int bypp;
enum ZmbvFormat fmt;
z_stream zstream;
int score_tab[ZMBV_BLOCK * ZMBV_BLOCK + 1];
int score_tab[ZMBV_BLOCK * ZMBV_BLOCK * 4 + 1];
} ZmbvEncContext;
@ -69,10 +89,11 @@ static inline int block_cmp(ZmbvEncContext *c, uint8_t *src, int stride,
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; i++){
for(i = 0; i < bw_bytes; i++){
int t = src[i] ^ src2[i];
histogram[t]++;
}
@ -81,7 +102,7 @@ static inline int block_cmp(ZmbvEncContext *c, uint8_t *src, int stride,
}
/* If not all the xored values were 0, then the blocks are different */
*xored = (histogram[0] < bw * bh);
*xored = (histogram[0] < bw_bytes * bh);
/* Exit early if blocks are equal */
if (!*xored) return 0;
@ -114,7 +135,7 @@ static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
/* Try previous block's MV (if not 0,0) */
if (mx0 || my0){
tv = block_cmp(c, src, sstride, prev + mx0 + my0 * pstride, pstride, bw, bh, &txored);
tv = block_cmp(c, src, sstride, prev + mx0 * c->bypp + my0 * pstride, pstride, bw, bh, &txored);
if(tv < bv){
bv = tv;
*mx = mx0;
@ -129,7 +150,7 @@ static int zmbv_me(ZmbvEncContext *c, uint8_t *src, int sstride, uint8_t *prev,
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 + dy * pstride, pstride, bw, bh, &txored);
tv = block_cmp(c, src, sstride, prev + dx * c->bypp + dy * pstride, pstride, bw, bh, &txored);
if(tv < bv){
bv = tv;
*mx = dx;
@ -165,9 +186,10 @@ FF_DISABLE_DEPRECATION_WARNINGS
avctx->coded_frame->key_frame = keyframe;
FF_ENABLE_DEPRECATION_WARNINGS
#endif
chpal = !keyframe && memcmp(p->data[1], c->pal2, 1024);
palptr = (uint32_t*)p->data[1];
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){
@ -181,19 +203,21 @@ FF_ENABLE_DEPRECATION_WARNINGS
c->pal[i * 3 + 1] = tpal[1];
c->pal[i * 3 + 2] = tpal[2];
}
memcpy(c->pal2, p->data[1], 1024);
memcpy(c->pal2, palptr, 1024);
}
if(keyframe){
for(i = 0; i < 256; i++){
AV_WB24(c->pal+(i*3), palptr[i]);
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;
}
memcpy(c->work_buf, c->pal, 768);
memcpy(c->pal2, p->data[1], 1024);
work_size = 768;
for(i = 0; i < avctx->height; i++){
memcpy(c->work_buf + work_size, src, avctx->width);
memcpy(c->work_buf + work_size, src, avctx->width * c->bypp);
src += p->linesize[0];
work_size += avctx->width;
work_size += avctx->width * c->bypp;
}
}else{
int x, y, bh2, bw2, xored;
@ -212,16 +236,16 @@ FF_ENABLE_DEPRECATION_WARNINGS
for(x = 0; x < avctx->width; x += ZMBV_BLOCK, mv += 2) {
bw2 = FFMIN(avctx->width - x, ZMBV_BLOCK);
tsrc = src + x;
tprev = prev + x;
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 + my * c->pstride;
tprev += mx * c->bypp + my * c->pstride;
if(xored){
for(j = 0; j < bh2; j++){
for(i = 0; i < bw2; i++)
for(i = 0; i < bw2 * c->bypp; i++)
c->work_buf[work_size++] = tsrc[i] ^ tprev[i];
tsrc += p->linesize[0];
tprev += c->pstride;
@ -236,7 +260,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
src = p->data[0];
prev = c->prev;
for(i = 0; i < avctx->height; i++){
memcpy(prev, src, avctx->width);
memcpy(prev, src, avctx->width * c->bypp);
prev += c->pstride;
src += p->linesize[0];
}
@ -267,7 +291,7 @@ FF_ENABLE_DEPRECATION_WARNINGS
*buf++ = 0; // hi ver
*buf++ = 1; // lo ver
*buf++ = 1; // comp
*buf++ = 4; // format - 8bpp
*buf++ = c->fmt; // format
*buf++ = ZMBV_BLOCK; // block width
*buf++ = ZMBV_BLOCK; // block height
}
@ -303,12 +327,34 @@ static av_cold int encode_init(AVCodecContext *avctx)
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;
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; i++)
c->score_tab[i] = -i * log2(i / (double)(ZMBV_BLOCK * ZMBV_BLOCK)) * 256;
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;
@ -331,7 +377,7 @@ static av_cold int encode_init(AVCodecContext *avctx)
// Needed if zlib unused or init aborted before deflateInit
memset(&c->zstream, 0, sizeof(z_stream));
c->comp_size = avctx->width * avctx->height + 1024 +
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");
@ -355,8 +401,8 @@ static av_cold int encode_init(AVCodecContext *avctx)
* - 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, 16);
prev_size = FFALIGN(c->lrange, 16) + c->pstride * (c->lrange + avctx->height + c->urange);
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, 16) + c->pstride * c->lrange;
if (!(c->prev_buf = av_mallocz(prev_size))) {
av_log(avctx, AV_LOG_ERROR, "Can't allocate picture.\n");
@ -385,5 +431,9 @@ AVCodec ff_zmbv_encoder = {
.init = encode_init,
.encode2 = encode_frame,
.close = encode_end,
.pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_PAL8, AV_PIX_FMT_NONE },
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_PAL8,
AV_PIX_FMT_RGB555LE,
AV_PIX_FMT_RGB565LE,
AV_PIX_FMT_BGR0,
AV_PIX_FMT_NONE },
};