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ffmpeg/libavcodec/a64multienc.c

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/*
* a64 video encoder - multicolor modes
* Copyright (c) 2009 Tobias Bindhammer
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* a64 video encoder - multicolor modes
*/
#include "a64enc.h"
#include "a64colors.h"
#include "a64tables.h"
#include "elbg.h"
#include "internal.h"
#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"
#define DITHERSTEPS 8
#define CHARSET_CHARS 256
#define INTERLACED 1
#define CROP_SCREENS 1
/* gray gradient */
static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
/* other possible gradients - to be tested */
//static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
//static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
{
int blockx, blocky, x, y;
int luma = 0;
int height = FFMIN(avctx->height, C64YRES);
int width = FFMIN(avctx->width , C64XRES);
uint8_t *src = p->data[0];
for (blocky = 0; blocky < C64YRES; blocky += 8) {
for (blockx = 0; blockx < C64XRES; blockx += 8) {
for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
if(x < width && y < height) {
/* build average over 2 pixels */
luma = (src[(x + 0 + y * p->linesize[0])] +
src[(x + 1 + y * p->linesize[0])]) / 2;
/* write blocks as linear data now so they are suitable for elbg */
dest[0] = luma;
}
dest++;
}
}
}
}
}
static void render_charset(AVCodecContext *avctx, uint8_t *charset,
uint8_t *colrammap)
{
A64Context *c = avctx->priv_data;
uint8_t row1, row2;
int charpos, x, y;
int a, b;
uint8_t pix;
int lowdiff, highdiff;
int *best_cb = c->mc_best_cb;
static uint8_t index1[256];
static uint8_t index2[256];
static uint8_t dither[256];
int i;
int distance;
/* generate lookup-tables for dither and index before looping */
i = 0;
for (a=0; a < 256; a++) {
if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
for(b = 0; b <= distance; b++) {
dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
}
i++;
}
if(i >= c->mc_pal_size - 1) dither[a] = 0;
index1[a] = i;
index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
}
/* and render charset */
for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
lowdiff = 0;
highdiff = 0;
for (y = 0; y < 8; y++) {
row1 = 0; row2 = 0;
for (x = 0; x < 4; x++) {
pix = best_cb[y * 4 + x];
/* accumulate error for brightest/darkest color */
if (index1[pix] >= 3)
highdiff += pix - c->mc_luma_vals[3];
if (index1[pix] < 1)
lowdiff += c->mc_luma_vals[1] - pix;
row1 <<= 2;
if (INTERLACED) {
row2 <<= 2;
if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
row1 |= 3-(index2[pix] & 3);
else
row1 |= 3-(index1[pix] & 3);
if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
row2 |= 3-(index2[pix] & 3);
else
row2 |= 3-(index1[pix] & 3);
}
else {
if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
row1 |= 3-(index2[pix] & 3);
else
row1 |= 3-(index1[pix] & 3);
}
}
charset[y+0x000] = row1;
if (INTERLACED) charset[y+0x800] = row2;
}
/* do we need to adjust pixels? */
if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
if (lowdiff > highdiff) {
for (x = 0; x < 32; x++)
best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
} else {
for (x = 0; x < 32; x++)
best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
}
charpos--; /* redo now adjusted char */
/* no adjustment needed, all fine */
} else {
/* advance pointers */
best_cb += 32;
charset += 8;
/* remember colorram value */
colrammap[charpos] = (highdiff > 0);
}
}
}
static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
{
A64Context *c = avctx->priv_data;
av_frame_free(&avctx->coded_frame);
av_free(c->mc_meta_charset);
av_free(c->mc_best_cb);
av_free(c->mc_charset);
av_free(c->mc_charmap);
av_free(c->mc_colram);
return 0;
}
static av_cold int a64multi_encode_init(AVCodecContext *avctx)
{
A64Context *c = avctx->priv_data;
int a;
av_lfg_init(&c->randctx, 1);
if (avctx->global_quality < 1) {
c->mc_lifetime = 4;
} else {
c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
}
av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
c->mc_frame_counter = 0;
c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
c->mc_pal_size = 4 + c->mc_use_5col;
/* precalc luma values for later use */
for (a = 0; a < c->mc_pal_size; a++) {
c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
a64_palette[mc_colors[a]][1] * 0.59 +
a64_palette[mc_colors[a]][2] * 0.11;
}
if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||
!(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
!(c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||
!(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
!(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
return AVERROR(ENOMEM);
}
/* set up extradata */
if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
return AVERROR(ENOMEM);
}
avctx->extradata_size = 8 * 4;
AV_WB32(avctx->extradata, c->mc_lifetime);
AV_WB32(avctx->extradata + 16, INTERLACED);
avctx->coded_frame = av_frame_alloc();
if (!avctx->coded_frame) {
a64multi_close_encoder(avctx);
return AVERROR(ENOMEM);
}
avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
avctx->coded_frame->key_frame = 1;
if (!avctx->codec_tag)
avctx->codec_tag = AV_RL32("a64m");
c->next_pts = AV_NOPTS_VALUE;
return 0;
}
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
{
int a;
uint8_t temp;
/* only needs to be done in 5col mode */
/* XXX could be squeezed to 0x80 bytes */
for (a = 0; a < 256; a++) {
temp = colram[charmap[a + 0x000]] << 0;
temp |= colram[charmap[a + 0x100]] << 1;
temp |= colram[charmap[a + 0x200]] << 2;
if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
buf[a] = temp << 2;
}
}
static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
const AVFrame *pict, int *got_packet)
{
A64Context *c = avctx->priv_data;
AVFrame *const p = avctx->coded_frame;
int frame;
int x, y;
int b_height;
int b_width;
int req_size, ret;
uint8_t *buf;
int *charmap = c->mc_charmap;
uint8_t *colram = c->mc_colram;
uint8_t *charset = c->mc_charset;
int *meta = c->mc_meta_charset;
int *best_cb = c->mc_best_cb;
int charset_size = 0x800 * (INTERLACED + 1);
int colram_size = 0x100 * c->mc_use_5col;
int screen_size;
if(CROP_SCREENS) {
b_height = FFMIN(avctx->height,C64YRES) >> 3;
b_width = FFMIN(avctx->width ,C64XRES) >> 3;
screen_size = b_width * b_height;
} else {
b_height = C64YRES >> 3;
b_width = C64XRES >> 3;
screen_size = 0x400;
}
/* no data, means end encoding asap */
if (!pict) {
/* all done, end encoding */
if (!c->mc_lifetime) return 0;
/* no more frames in queue, prepare to flush remaining frames */
if (!c->mc_frame_counter) {
c->mc_lifetime = 0;
}
/* still frames in queue so limit lifetime to remaining frames */
else c->mc_lifetime = c->mc_frame_counter;
/* still new data available */
} else {
/* fill up mc_meta_charset with data until lifetime exceeds */
if (c->mc_frame_counter < c->mc_lifetime) {
*p = *pict;
p->pict_type = AV_PICTURE_TYPE_I;
p->key_frame = 1;
to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
c->mc_frame_counter++;
if (c->next_pts == AV_NOPTS_VALUE)
c->next_pts = pict->pts;
/* lifetime is not reached so wait for next frame first */
return 0;
}
}
/* lifetime reached so now convert X frames at once */
if (c->mc_frame_counter == c->mc_lifetime) {
req_size = 0;
/* any frames to encode? */
if (c->mc_lifetime) {
req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
if ((ret = ff_alloc_packet(pkt, req_size)) < 0) {
av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", req_size);
return ret;
}
buf = pkt->data;
/* calc optimal new charset + charmaps */
ret = ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
CHARSET_CHARS, 50, charmap, &c->randctx);
if (ret < 0)
return ret;
ret = ff_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
CHARSET_CHARS, 50, charmap, &c->randctx);
if (ret < 0)
return ret;
/* create colorram map and a c64 readable charset */
render_charset(avctx, charset, colram);
/* copy charset to buf */
memcpy(buf, charset, charset_size);
/* advance pointers */
buf += charset_size;
charset += charset_size;
}
/* write x frames to buf */
for (frame = 0; frame < c->mc_lifetime; frame++) {
/* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
for (y = 0; y < b_height; y++) {
for (x = 0; x < b_width; x++) {
buf[y * b_width + x] = charmap[y * b_width + x];
}
}
/* advance pointers */
buf += screen_size;
req_size += screen_size;
/* compress and copy colram to buf */
if (c->mc_use_5col) {
a64_compress_colram(buf, charmap, colram);
/* advance pointers */
buf += colram_size;
req_size += colram_size;
}
/* advance to next charmap */
charmap += 1000;
}
AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
AV_WB32(avctx->extradata + 8, charset_size);
AV_WB32(avctx->extradata + 12, screen_size + colram_size);
/* reset counter */
c->mc_frame_counter = 0;
pkt->pts = pkt->dts = c->next_pts;
c->next_pts = AV_NOPTS_VALUE;
pkt->size = req_size;
pkt->flags |= AV_PKT_FLAG_KEY;
*got_packet = !!req_size;
}
return 0;
}
AVCodec ff_a64multi_encoder = {
.name = "a64multi",
.long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_A64_MULTI,
.priv_data_size = sizeof(A64Context),
.init = a64multi_encode_init,
.encode2 = a64multi_encode_frame,
.close = a64multi_close_encoder,
.pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
.capabilities = CODEC_CAP_DELAY,
};
AVCodec ff_a64multi5_encoder = {
.name = "a64multi5",
.long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
.type = AVMEDIA_TYPE_VIDEO,
.id = AV_CODEC_ID_A64_MULTI5,
.priv_data_size = sizeof(A64Context),
.init = a64multi_encode_init,
.encode2 = a64multi_encode_frame,
.close = a64multi_close_encoder,
.pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
.capabilities = CODEC_CAP_DELAY,
};
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