ffmpeg/libavcodec/smcenc.c

564 lines
18 KiB
C

/*
* QuickTime Graphics (SMC) Video Encoder
* Copyright (c) 2021 The FFmpeg project
*
* 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 smcenc.c
* QT SMC Video Encoder by Paul B. Mahol
*/
#include "libavutil/common.h"
#include "avcodec.h"
#include "encode.h"
#include "internal.h"
#include "bytestream.h"
#define CPAIR 2
#define CQUAD 4
#define COCTET 8
#define COLORS_PER_TABLE 256
typedef struct SMCContext {
AVFrame *prev_frame; // buffer for previous source frame
uint8_t mono_value;
int nb_distinct;
int next_nb_distinct;
uint8_t distinct_values[16];
uint8_t next_distinct_values[16];
uint8_t color_pairs[COLORS_PER_TABLE][CPAIR];
uint8_t color_quads[COLORS_PER_TABLE][CQUAD];
uint8_t color_octets[COLORS_PER_TABLE][COCTET];
int key_frame;
} SMCContext;
#define ADVANCE_BLOCK(pixel_ptr, row_ptr, nb_blocks) \
{ \
for (int block = 0; block < nb_blocks && pixel_ptr && row_ptr; block++) { \
pixel_ptr += 4; \
if (pixel_ptr - row_ptr >= width) \
{ \
row_ptr += stride * 4; \
pixel_ptr = row_ptr; \
} \
} \
}
static int smc_cmp_values(const void *a, const void *b)
{
const uint8_t *aa = a, *bb = b;
return FFDIFFSIGN(aa[0], bb[0]);
}
static int count_distinct_items(const uint8_t *block_values,
uint8_t *distinct_values,
int size)
{
int n = 1;
distinct_values[0] = block_values[0];
for (int i = 1; i < size; i++) {
if (block_values[i] != block_values[i-1]) {
distinct_values[n] = block_values[i];
n++;
}
}
return n;
}
#define CACHE_PAIR(x) \
(s->color_pairs[i][0] == distinct_values[x] || \
s->color_pairs[i][1] == distinct_values[x])
#define CACHE_QUAD(x) \
(s->color_quads[i][0] == distinct_values[x] || \
s->color_quads[i][1] == distinct_values[x] || \
s->color_quads[i][2] == distinct_values[x] || \
s->color_quads[i][3] == distinct_values[x])
#define CACHE_OCTET(x) \
(s->color_octets[i][0] == distinct_values[x] || \
s->color_octets[i][1] == distinct_values[x] || \
s->color_octets[i][2] == distinct_values[x] || \
s->color_octets[i][3] == distinct_values[x] || \
s->color_octets[i][4] == distinct_values[x] || \
s->color_octets[i][5] == distinct_values[x] || \
s->color_octets[i][6] == distinct_values[x] || \
s->color_octets[i][7] == distinct_values[x])
static void smc_encode_stream(SMCContext *s, const AVFrame *frame,
PutByteContext *pb)
{
const uint8_t *src_pixels = (const uint8_t *)frame->data[0];
const int stride = frame->linesize[0];
const uint8_t *prev_pixels = (const uint8_t *)s->prev_frame->data[0];
uint8_t *distinct_values = s->distinct_values;
const uint8_t *pixel_ptr, *row_ptr;
const int width = frame->width;
uint8_t block_values[16];
int block_counter = 0;
int color_pair_index = 0;
int color_quad_index = 0;
int color_octet_index = 0;
int color_table_index; /* indexes to color pair, quad, or octet tables */
int total_blocks;
memset(s->color_pairs, 0, sizeof(s->color_pairs));
memset(s->color_quads, 0, sizeof(s->color_quads));
memset(s->color_octets, 0, sizeof(s->color_octets));
/* Number of 4x4 blocks in frame. */
total_blocks = ((frame->width + 3) / 4) * ((frame->height + 3) / 4);
pixel_ptr = row_ptr = src_pixels;
while (block_counter < total_blocks) {
const uint8_t *xpixel_ptr = pixel_ptr;
const uint8_t *xrow_ptr = row_ptr;
int intra_skip_blocks = 0;
int inter_skip_blocks = 0;
int coded_distinct = 0;
int coded_blocks = 0;
int cache_index;
int distinct = 0;
int blocks = 0;
while (prev_pixels && s->key_frame == 0 && block_counter + inter_skip_blocks < total_blocks) {
int compare = 0;
for (int y = 0; y < 4; y++) {
const ptrdiff_t offset = pixel_ptr - src_pixels;
const uint8_t *prev_pixel_ptr = prev_pixels + offset;
compare |= memcmp(prev_pixel_ptr + y * stride, pixel_ptr + y * stride, 4);
if (compare)
break;
}
if (compare)
break;
if (inter_skip_blocks >= 256)
break;
inter_skip_blocks++;
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
}
pixel_ptr = xpixel_ptr;
row_ptr = xrow_ptr;
while (block_counter > 0 && block_counter + intra_skip_blocks < total_blocks) {
const ptrdiff_t offset = pixel_ptr - src_pixels;
const int sy = offset / stride;
const int sx = offset % stride;
const int ny = sx < 4 ? sy - 4 : sy;
const int nx = sx < 4 ? width - 4 : sx - 4;
const uint8_t *old_pixel_ptr = src_pixels + nx + ny * stride;
int compare = 0;
for (int y = 0; y < 4; y++) {
compare |= memcmp(old_pixel_ptr + y * stride, pixel_ptr + y * stride, 4);
if (compare)
break;
}
if (compare)
break;
if (intra_skip_blocks >= 256)
break;
intra_skip_blocks++;
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
}
pixel_ptr = xpixel_ptr;
row_ptr = xrow_ptr;
while (block_counter + coded_blocks < total_blocks && coded_blocks < 256) {
for (int y = 0; y < 4; y++)
memcpy(block_values + y * 4, pixel_ptr + y * stride, 4);
qsort(block_values, 16, sizeof(block_values[0]), smc_cmp_values);
s->next_nb_distinct = count_distinct_items(block_values, s->next_distinct_values, 16);
if (coded_blocks == 0) {
memcpy(distinct_values, s->next_distinct_values, sizeof(s->distinct_values));
s->nb_distinct = s->next_nb_distinct;
} else {
if (s->next_nb_distinct != s->nb_distinct ||
memcmp(distinct_values, s->next_distinct_values, s->nb_distinct)) {
break;
}
}
s->mono_value = block_values[0];
coded_distinct = s->nb_distinct;
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
coded_blocks++;
if (coded_distinct > 1 && coded_blocks >= 16)
break;
}
pixel_ptr = xpixel_ptr;
row_ptr = xrow_ptr;
blocks = coded_blocks;
distinct = coded_distinct;
if (intra_skip_blocks > 0 && intra_skip_blocks >= inter_skip_blocks &&
intra_skip_blocks > 0) {
distinct = 17;
blocks = intra_skip_blocks;
}
if (intra_skip_blocks > 16 && intra_skip_blocks >= inter_skip_blocks &&
intra_skip_blocks > 0) {
distinct = 18;
blocks = intra_skip_blocks;
}
if (inter_skip_blocks > 0 && inter_skip_blocks > intra_skip_blocks &&
inter_skip_blocks > 0) {
distinct = 19;
blocks = inter_skip_blocks;
}
if (inter_skip_blocks > 16 && inter_skip_blocks > intra_skip_blocks &&
inter_skip_blocks > 0) {
distinct = 20;
blocks = inter_skip_blocks;
}
switch (distinct) {
case 1:
if (blocks <= 16) {
bytestream2_put_byte(pb, 0x60 | (blocks - 1));
} else {
bytestream2_put_byte(pb, 0x70);
bytestream2_put_byte(pb, blocks - 1);
}
bytestream2_put_byte(pb, s->mono_value);
ADVANCE_BLOCK(pixel_ptr, row_ptr, blocks)
break;
case 2:
cache_index = -1;
for (int i = 0; i < COLORS_PER_TABLE; i++) {
if (CACHE_PAIR(0) &&
CACHE_PAIR(1)) {
cache_index = i;
break;
}
}
if (cache_index >= 0) {
bytestream2_put_byte(pb, 0x90 | (blocks - 1));
bytestream2_put_byte(pb, cache_index);
color_table_index = cache_index;
} else {
bytestream2_put_byte(pb, 0x80 | (blocks - 1));
color_table_index = color_pair_index;
for (int i = 0; i < CPAIR; i++) {
s->color_pairs[color_table_index][i] = distinct_values[i];
bytestream2_put_byte(pb, distinct_values[i]);
}
color_pair_index++;
if (color_pair_index == COLORS_PER_TABLE)
color_pair_index = 0;
}
for (int i = 0; i < blocks; i++) {
uint8_t value = s->color_pairs[color_table_index][1];
uint16_t flags = 0;
int shift = 15;
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
flags |= (value == pixel_ptr[x + y * stride]) << shift;
shift--;
}
}
bytestream2_put_be16(pb, flags);
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
}
break;
case 3:
case 4:
cache_index = -1;
for (int i = 0; i < COLORS_PER_TABLE; i++) {
if (CACHE_QUAD(0) &&
CACHE_QUAD(1) &&
CACHE_QUAD(2) &&
CACHE_QUAD(3)) {
cache_index = i;
break;
}
}
if (cache_index >= 0) {
bytestream2_put_byte(pb, 0xB0 | (blocks - 1));
bytestream2_put_byte(pb, cache_index);
color_table_index = cache_index;
} else {
bytestream2_put_byte(pb, 0xA0 | (blocks - 1));
color_table_index = color_quad_index;
for (int i = 0; i < CQUAD; i++) {
s->color_quads[color_table_index][i] = distinct_values[i];
bytestream2_put_byte(pb, distinct_values[i]);
}
color_quad_index++;
if (color_quad_index == COLORS_PER_TABLE)
color_quad_index = 0;
}
for (int i = 0; i < blocks; i++) {
uint32_t flags = 0;
uint8_t quad[4];
int shift = 30;
for (int k = 0; k < 4; k++)
quad[k] = s->color_quads[color_table_index][k];
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
int pixel = pixel_ptr[x + y * stride];
uint32_t idx = 0;
for (int w = 0; w < CQUAD; w++) {
if (quad[w] == pixel) {
idx = w;
break;
}
}
flags |= idx << shift;
shift -= 2;
}
}
bytestream2_put_be32(pb, flags);
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
}
break;
case 5:
case 6:
case 7:
case 8:
cache_index = -1;
for (int i = 0; i < COLORS_PER_TABLE; i++) {
if (CACHE_OCTET(0) &&
CACHE_OCTET(1) &&
CACHE_OCTET(2) &&
CACHE_OCTET(3) &&
CACHE_OCTET(4) &&
CACHE_OCTET(5) &&
CACHE_OCTET(6) &&
CACHE_OCTET(7)) {
cache_index = i;
break;
}
}
if (cache_index >= 0) {
bytestream2_put_byte(pb, 0xD0 | (blocks - 1));
bytestream2_put_byte(pb, cache_index);
color_table_index = cache_index;
} else {
bytestream2_put_byte(pb, 0xC0 | (blocks - 1));
color_table_index = color_octet_index;
for (int i = 0; i < COCTET; i++) {
s->color_octets[color_table_index][i] = distinct_values[i];
bytestream2_put_byte(pb, distinct_values[i]);
}
color_octet_index++;
if (color_octet_index == COLORS_PER_TABLE)
color_octet_index = 0;
}
for (int i = 0; i < blocks; i++) {
uint64_t flags = 0;
uint8_t octet[8];
int shift = 45;
for (int k = 0; k < 8; k++)
octet[k] = s->color_octets[color_table_index][k];
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++) {
int pixel = pixel_ptr[x + y * stride];
uint64_t idx = 0;
for (int w = 0; w < COCTET; w++) {
if (octet[w] == pixel) {
idx = w;
break;
}
}
flags |= idx << shift;
shift -= 3;
}
}
bytestream2_put_be16(pb, ((flags >> 32) & 0xFFF0) | ((flags >> 8) & 0xF));
bytestream2_put_be16(pb, ((flags >> 20) & 0xFFF0) | ((flags >> 4) & 0xF));
bytestream2_put_be16(pb, ((flags >> 8) & 0xFFF0) | ((flags >> 0) & 0xF));
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
}
break;
default:
bytestream2_put_byte(pb, 0xE0 | (blocks - 1));
for (int i = 0; i < blocks; i++) {
for (int y = 0; y < 4; y++) {
for (int x = 0; x < 4; x++)
bytestream2_put_byte(pb, pixel_ptr[x + y * stride]);
}
ADVANCE_BLOCK(pixel_ptr, row_ptr, 1)
}
break;
case 17:
bytestream2_put_byte(pb, 0x20 | (blocks - 1));
ADVANCE_BLOCK(pixel_ptr, row_ptr, blocks)
break;
case 18:
bytestream2_put_byte(pb, 0x30);
bytestream2_put_byte(pb, blocks - 1);
ADVANCE_BLOCK(pixel_ptr, row_ptr, blocks)
break;
case 19:
bytestream2_put_byte(pb, 0x00 | (blocks - 1));
ADVANCE_BLOCK(pixel_ptr, row_ptr, blocks)
break;
case 20:
bytestream2_put_byte(pb, 0x10);
bytestream2_put_byte(pb, blocks - 1);
ADVANCE_BLOCK(pixel_ptr, row_ptr, blocks)
break;
}
block_counter += blocks;
}
}
static int smc_encode_init(AVCodecContext *avctx)
{
SMCContext *s = avctx->priv_data;
avctx->bits_per_coded_sample = 8;
s->prev_frame = av_frame_alloc();
if (!s->prev_frame)
return AVERROR(ENOMEM);
return 0;
}
static int smc_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *frame, int *got_packet)
{
SMCContext *s = avctx->priv_data;
const AVFrame *pict = frame;
PutByteContext pb;
uint8_t *pal;
int ret;
ret = ff_alloc_packet(avctx, pkt, 8LL * avctx->height * avctx->width);
if (ret < 0)
return ret;
if (avctx->gop_size == 0 || !s->prev_frame->data[0] ||
(avctx->frame_number % avctx->gop_size) == 0) {
s->key_frame = 1;
} else {
s->key_frame = 0;
}
bytestream2_init_writer(&pb, pkt->data, pkt->size);
bytestream2_put_be32(&pb, 0x00);
pal = av_packet_new_side_data(pkt, AV_PKT_DATA_PALETTE, AVPALETTE_SIZE);
if (!pal)
return AVERROR(ENOMEM);
memcpy(pal, frame->data[1], AVPALETTE_SIZE);
smc_encode_stream(s, pict, &pb);
av_shrink_packet(pkt, bytestream2_tell_p(&pb));
pkt->data[0] = 0x0;
// write chunk length
AV_WB24(pkt->data + 1, pkt->size);
av_frame_unref(s->prev_frame);
ret = av_frame_ref(s->prev_frame, frame);
if (ret < 0) {
av_log(avctx, AV_LOG_ERROR, "cannot add reference\n");
return ret;
}
if (s->key_frame)
pkt->flags |= AV_PKT_FLAG_KEY;
*got_packet = 1;
return 0;
}
static int smc_encode_end(AVCodecContext *avctx)
{
SMCContext *s = (SMCContext *)avctx->priv_data;
av_frame_free(&s->prev_frame);
return 0;
}
const AVCodec ff_smc_encoder = {
.name = "smc",
.long_name = NULL_IF_CONFIG_SMALL("QuickTime Graphics (SMC)"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_SMC,
.priv_data_size = sizeof(SMCContext),
.init = smc_encode_init,
.encode2 = smc_encode_frame,
.close = smc_encode_end,
.caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_PAL8,
AV_PIX_FMT_NONE},
};