2 * a64 video encoder - multicolor modes
3 * Copyright (c) 2009 Tobias Bindhammer
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
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15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 * a64 video encoder - multicolor modes
28 #include "a64colors.h"
29 #include "a64tables.h"
31 #include "libavutil/intreadwrite.h"
34 #define CHARSET_CHARS 256
39 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
41 /* other possible gradients - to be tested */
42 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
43 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
45 static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
47 int blockx, blocky, x, y;
49 int height = FFMIN(avctx->height,C64YRES);
50 int width = FFMIN(avctx->width ,C64XRES);
51 uint8_t *src = p->data[0];
53 for (blocky = 0; blocky < height; blocky += 8) {
54 for (blockx = 0; blockx < C64XRES; blockx += 8) {
55 for (y = blocky; y < blocky+8 && y < height; y++) {
56 for (x = blockx; x < blockx+8 && x < C64XRES; x += 2) {
58 /* build average over 2 pixels */
59 luma = (src[(x + 0 + y * p->linesize[0])] +
60 src[(x + 1 + y * p->linesize[0])]) / 2;
61 /* write blocks as linear data now so they are suitable for elbg */
71 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
74 A64Context *c = avctx->priv_data;
79 int lowdiff, highdiff;
80 int *best_cb = c->mc_best_cb;
81 static uint8_t index1[256];
82 static uint8_t index2[256];
83 static uint8_t dither[256];
87 /* generate lookup-tables for dither and index before looping */
89 for (a=0; a < 256; a++) {
90 if(i < 4 && a == c->mc_luma_vals[i+1]) {
91 distance = c->mc_luma_vals[i+1] - c->mc_luma_vals[i];
92 for(b = 0; b <= distance; b++) {
93 dither[c->mc_luma_vals[i]+b] = b * (DITHERSTEPS - 1) / distance;
97 if(i >=4 ) dither[a] = 0;
99 index2[a] = FFMIN(i+1, 4);
101 /* and render charset */
102 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
105 for (y = 0; y < 8; y++) {
107 for (x = 0; x < 4; x++) {
108 pix = best_cb[y * 4 + x];
110 /* accumulate error for brightest/darkest color */
111 if (index1[pix] >= 3)
112 highdiff += pix - c->mc_luma_vals[3];
114 lowdiff += c->mc_luma_vals[1] - pix;
120 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
121 row1 |= 3-(index2[pix] & 3);
123 row1 |= 3-(index1[pix] & 3);
125 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
126 row2 |= 3-(index2[pix] & 3);
128 row2 |= 3-(index1[pix] & 3);
131 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
132 row1 |= 3-(index2[pix] & 3);
134 row1 |= 3-(index1[pix] & 3);
137 charset[y+0x000] = row1;
138 if(INTERLACED) charset[y+0x800] = row2;
140 /* do we need to adjust pixels? */
141 if (highdiff > 0 && lowdiff > 0) {
142 if (lowdiff > highdiff) {
143 for (x = 0; x < 32; x++)
144 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
146 for (x = 0; x < 32; x++)
147 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
149 charpos--; /* redo now adjusted char */
150 /* no adjustment needed, all fine */
152 /* advance pointers */
156 /* remember colorram value */
157 colrammap[charpos] = (highdiff > 0);
162 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
164 A64Context *c = avctx->priv_data;
165 av_free(c->mc_meta_charset);
166 av_free(c->mc_best_cb);
167 av_free(c->mc_charset);
168 av_free(c->mc_charmap);
169 av_free(c->mc_colram);
173 static av_cold int a64multi_init_encoder(AVCodecContext *avctx)
175 A64Context *c = avctx->priv_data;
177 av_lfg_init(&c->randctx, 1);
179 if (avctx->global_quality < 1) {
182 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
185 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
187 /* precalc luma values for later use */
188 for (a = 0; a < 5; a++) {
189 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
190 a64_palette[mc_colors[a]][1] * 0.59 +
191 a64_palette[mc_colors[a]][2] * 0.11;
194 c->mc_frame_counter = 0;
195 c->mc_use_5col = avctx->codec->id == CODEC_ID_A64_MULTI5;
196 c->mc_meta_charset = av_malloc (32000 * c->mc_lifetime * sizeof(int));
197 c->mc_best_cb = av_malloc (CHARSET_CHARS * 32 * sizeof(int));
198 c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int));
199 c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t));
200 c->mc_charset = av_malloc (0x800 * (INTERLACED+1) * sizeof(uint8_t));
202 avcodec_get_frame_defaults(&c->picture);
203 avctx->coded_frame = &c->picture;
204 avctx->coded_frame->pict_type = FF_I_TYPE;
205 avctx->coded_frame->key_frame = 1;
206 if (!avctx->codec_tag)
207 avctx->codec_tag = AV_RL32("a64m");
212 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
216 /* only needs to be done in 5col mode */
217 /* XXX could be squeezed to 0x80 bytes */
218 for (a = 0; a < 256; a++) {
219 temp = colram[charmap[a + 0x000]] << 0;
220 temp |= colram[charmap[a + 0x100]] << 1;
221 temp |= colram[charmap[a + 0x200]] << 2;
222 if(a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
227 static int a64multi_encode_frame(AVCodecContext *avctx, unsigned char *buf,
228 int buf_size, void *data)
230 A64Context *c = avctx->priv_data;
231 AVFrame *pict = data;
232 AVFrame *const p = (AVFrame *) & c->picture;
238 int num_frames = LIFETIME;
240 int *charmap = c->mc_charmap;
241 uint8_t *colram = c->mc_colram;
242 uint8_t *charset = c->mc_charset;
243 int *meta = c->mc_meta_charset;
244 int *best_cb = c->mc_best_cb;
246 /* no data, means end encoding asap */
248 /* all done, end encoding */
249 if(!c->mc_lifetime) return 0;
250 /* no more frames in queue, prepare to flush remaining frames */
251 if(!c->mc_frame_counter) {
252 num_frames=c->mc_lifetime;
255 /* still frames in queue so limit lifetime to remaining frames */
256 else c->mc_lifetime=c->mc_frame_counter;
258 /* still new data available */
260 /* fill up mc_meta_charset with data until lifetime exceeds */
261 if (c->mc_frame_counter < c->mc_lifetime) {
263 p->pict_type = FF_I_TYPE;
265 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
266 c->mc_frame_counter++;
267 /* lifetime is not reached so wait for next frame first */
272 /* lifetime reached so now convert X frames at once */
273 if (c->mc_frame_counter == c->mc_lifetime) {
275 /* any frames to encode? */
277 /* calc optimal new charset + charmaps */
278 ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
279 ff_do_elbg (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
281 /* create colorram map and a c64 readable charset */
282 render_charset(avctx, charset, colram);
284 /* copy charset to buf */
285 memcpy(buf,charset,0x800*(INTERLACED+1));
287 /* advance pointers */
288 buf += 0x800*(INTERLACED+1);
289 charset += 0x800*(INTERLACED+1);
290 req_size += 0x800*(INTERLACED+1);
292 /* no charset so clean buf */
293 else memset(buf,0,0x800*(INTERLACED+1));
295 /* write x frames to buf */
296 for (frame = 0; frame < c->mc_lifetime; frame++) {
297 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
298 for (a = 0; a < 1000; a++) {
301 /* advance pointers */
305 /* compress and copy colram to buf */
307 a64_compress_colram(buf,charmap,colram);
308 /* advance pointers */
313 /* advance to next charmap */
318 c->mc_frame_counter = 0;
320 if (req_size > buf_size) {
321 av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", req_size, buf_size);
329 AVCodec a64multi_encoder = {
331 .type = AVMEDIA_TYPE_VIDEO,
332 .id = CODEC_ID_A64_MULTI,
333 .priv_data_size = sizeof(A64Context),
334 .init = a64multi_init_encoder,
335 .encode = a64multi_encode_frame,
336 .close = a64multi_close_encoder,
337 .pix_fmts = (enum PixelFormat[]) {PIX_FMT_GRAY8, PIX_FMT_NONE},
338 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
339 .capabilities = CODEC_CAP_DELAY,
342 AVCodec a64multi5_encoder = {
344 .type = AVMEDIA_TYPE_VIDEO,
345 .id = CODEC_ID_A64_MULTI5,
346 .priv_data_size = sizeof(A64Context),
347 .init = a64multi_init_encoder,
348 .encode = a64multi_encode_frame,
349 .close = a64multi_close_encoder,
350 .pix_fmts = (enum PixelFormat[]) {PIX_FMT_GRAY8, PIX_FMT_NONE},
351 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
352 .capabilities = CODEC_CAP_DELAY,