1 /*
2 * a64 video encoder - multicolor modes
3 * Copyright (c) 2009 Tobias Bindhammer
4 *
5 * This file is part of FFmpeg.
6 *
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
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
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
20 */
21
22 /**
23 * @file
24 * a64 video encoder - multicolor modes
25 */
26
27 #include "a64colors.h"
28 #include "a64tables.h"
29 #include "elbg.h"
30 #include "internal.h"
31 #include "libavutil/avassert.h"
32 #include "libavutil/common.h"
33 #include "libavutil/intreadwrite.h"
34
35 #define DITHERSTEPS 8
36 #define CHARSET_CHARS 256
37 #define INTERLACED 1
38 #define CROP_SCREENS 1
39
40 #define C64XRES 320
41 #define C64YRES 200
42
43 typedef struct A64Context {
44 /* variables for multicolor modes */
45 AVLFG randctx;
46 int mc_lifetime;
47 int mc_use_5col;
48 unsigned mc_frame_counter;
49 int *mc_meta_charset;
50 int *mc_charmap;
51 int *mc_best_cb;
52 int mc_luma_vals[5];
53 uint8_t *mc_charset;
54 uint8_t *mc_colram;
55 uint8_t *mc_palette;
56 int mc_pal_size;
57
58 /* pts of the next packet that will be output */
59 int64_t next_pts;
60 } A64Context;
61
62 /* gray gradient */
63 static const uint8_t mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
64
65 /* other possible gradients - to be tested */
66 //static const uint8_t mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
67 //static const uint8_t mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
68
to_meta_with_crop(AVCodecContext * avctx,const AVFrame * p,int * dest)69 static void to_meta_with_crop(AVCodecContext *avctx,
70 const AVFrame *p, int *dest)
71 {
72 int blockx, blocky, x, y;
73 int luma = 0;
74 int height = FFMIN(avctx->height, C64YRES);
75 int width = FFMIN(avctx->width , C64XRES);
76 uint8_t *src = p->data[0];
77
78 for (blocky = 0; blocky < C64YRES; blocky += 8) {
79 for (blockx = 0; blockx < C64XRES; blockx += 8) {
80 for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
81 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
82 if(x < width && y < height) {
83 if (x + 1 < width) {
84 /* build average over 2 pixels */
85 luma = (src[(x + 0 + y * p->linesize[0])] +
86 src[(x + 1 + y * p->linesize[0])]) / 2;
87 } else {
88 luma = src[(x + y * p->linesize[0])];
89 }
90 /* write blocks as linear data now so they are suitable for elbg */
91 dest[0] = luma;
92 }
93 dest++;
94 }
95 }
96 }
97 }
98 }
99
render_charset(AVCodecContext * avctx,uint8_t * charset,uint8_t * colrammap)100 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
101 uint8_t *colrammap)
102 {
103 A64Context *c = avctx->priv_data;
104 uint8_t row1, row2;
105 int charpos, x, y;
106 int a, b;
107 uint8_t pix;
108 int lowdiff, highdiff;
109 int *best_cb = c->mc_best_cb;
110 static uint8_t index1[256];
111 static uint8_t index2[256];
112 static uint8_t dither[256];
113 int i;
114 int distance;
115
116 /* generate lookup-tables for dither and index before looping */
117 i = 0;
118 for (a=0; a < 256; a++) {
119 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
120 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
121 for(b = 0; b <= distance; b++) {
122 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
123 }
124 i++;
125 }
126 if(i >= c->mc_pal_size - 1) dither[a] = 0;
127 index1[a] = i;
128 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
129 }
130
131 /* and render charset */
132 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
133 lowdiff = 0;
134 highdiff = 0;
135 for (y = 0; y < 8; y++) {
136 row1 = 0; row2 = 0;
137 for (x = 0; x < 4; x++) {
138 pix = best_cb[y * 4 + x];
139
140 /* accumulate error for brightest/darkest color */
141 if (index1[pix] >= 3)
142 highdiff += pix - c->mc_luma_vals[3];
143 if (index1[pix] < 1)
144 lowdiff += c->mc_luma_vals[1] - pix;
145
146 row1 <<= 2;
147
148 if (INTERLACED) {
149 row2 <<= 2;
150 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
151 row1 |= 3-(index2[pix] & 3);
152 else
153 row1 |= 3-(index1[pix] & 3);
154
155 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
156 row2 |= 3-(index2[pix] & 3);
157 else
158 row2 |= 3-(index1[pix] & 3);
159 }
160 else {
161 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
162 row1 |= 3-(index2[pix] & 3);
163 else
164 row1 |= 3-(index1[pix] & 3);
165 }
166 }
167 charset[y+0x000] = row1;
168 if (INTERLACED) charset[y+0x800] = row2;
169 }
170 /* do we need to adjust pixels? */
171 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
172 if (lowdiff > highdiff) {
173 for (x = 0; x < 32; x++)
174 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
175 } else {
176 for (x = 0; x < 32; x++)
177 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
178 }
179 charpos--; /* redo now adjusted char */
180 /* no adjustment needed, all fine */
181 } else {
182 /* advance pointers */
183 best_cb += 32;
184 charset += 8;
185
186 /* remember colorram value */
187 colrammap[charpos] = (highdiff > 0);
188 }
189 }
190 }
191
a64multi_close_encoder(AVCodecContext * avctx)192 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
193 {
194 A64Context *c = avctx->priv_data;
195 av_freep(&c->mc_meta_charset);
196 av_freep(&c->mc_best_cb);
197 av_freep(&c->mc_charset);
198 av_freep(&c->mc_charmap);
199 av_freep(&c->mc_colram);
200 return 0;
201 }
202
a64multi_encode_init(AVCodecContext * avctx)203 static av_cold int a64multi_encode_init(AVCodecContext *avctx)
204 {
205 A64Context *c = avctx->priv_data;
206 int a;
207 av_lfg_init(&c->randctx, 1);
208
209 if (avctx->global_quality < 1) {
210 c->mc_lifetime = 4;
211 } else {
212 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
213 }
214
215 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
216
217 c->mc_frame_counter = 0;
218 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
219 c->mc_pal_size = 4 + c->mc_use_5col;
220
221 /* precalc luma values for later use */
222 for (a = 0; a < c->mc_pal_size; a++) {
223 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
224 a64_palette[mc_colors[a]][1] * 0.59 +
225 a64_palette[mc_colors[a]][2] * 0.11;
226 }
227
228 if (!(c->mc_meta_charset = av_mallocz_array(c->mc_lifetime, 32000 * sizeof(int))) ||
229 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
230 !(c->mc_charmap = av_mallocz_array(c->mc_lifetime, 1000 * sizeof(int))) ||
231 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
232 !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
233 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
234 return AVERROR(ENOMEM);
235 }
236
237 /* set up extradata */
238 if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
239 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
240 return AVERROR(ENOMEM);
241 }
242 avctx->extradata_size = 8 * 4;
243 AV_WB32(avctx->extradata, c->mc_lifetime);
244 AV_WB32(avctx->extradata + 16, INTERLACED);
245
246 if (!avctx->codec_tag)
247 avctx->codec_tag = AV_RL32("a64m");
248
249 c->next_pts = AV_NOPTS_VALUE;
250
251 return 0;
252 }
253
a64_compress_colram(unsigned char * buf,int * charmap,uint8_t * colram)254 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
255 {
256 int a;
257 uint8_t temp;
258 /* only needs to be done in 5col mode */
259 /* XXX could be squeezed to 0x80 bytes */
260 for (a = 0; a < 256; a++) {
261 temp = colram[charmap[a + 0x000]] << 0;
262 temp |= colram[charmap[a + 0x100]] << 1;
263 temp |= colram[charmap[a + 0x200]] << 2;
264 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
265 buf[a] = temp << 2;
266 }
267 }
268
a64multi_encode_frame(AVCodecContext * avctx,AVPacket * pkt,const AVFrame * p,int * got_packet)269 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
270 const AVFrame *p, int *got_packet)
271 {
272 A64Context *c = avctx->priv_data;
273
274 int frame;
275 int x, y;
276 int b_height;
277 int b_width;
278
279 int req_size, ret;
280 uint8_t *buf = NULL;
281
282 int *charmap = c->mc_charmap;
283 uint8_t *colram = c->mc_colram;
284 uint8_t *charset = c->mc_charset;
285 int *meta = c->mc_meta_charset;
286 int *best_cb = c->mc_best_cb;
287
288 int charset_size = 0x800 * (INTERLACED + 1);
289 int colram_size = 0x100 * c->mc_use_5col;
290 int screen_size;
291
292 if(CROP_SCREENS) {
293 b_height = FFMIN(avctx->height,C64YRES) >> 3;
294 b_width = FFMIN(avctx->width ,C64XRES) >> 3;
295 screen_size = b_width * b_height;
296 } else {
297 b_height = C64YRES >> 3;
298 b_width = C64XRES >> 3;
299 screen_size = 0x400;
300 }
301
302 /* no data, means end encoding asap */
303 if (!p) {
304 /* all done, end encoding */
305 if (!c->mc_lifetime) return 0;
306 /* no more frames in queue, prepare to flush remaining frames */
307 if (!c->mc_frame_counter) {
308 c->mc_lifetime = 0;
309 }
310 /* still frames in queue so limit lifetime to remaining frames */
311 else c->mc_lifetime = c->mc_frame_counter;
312 /* still new data available */
313 } else {
314 /* fill up mc_meta_charset with data until lifetime exceeds */
315 if (c->mc_frame_counter < c->mc_lifetime) {
316 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
317 c->mc_frame_counter++;
318 if (c->next_pts == AV_NOPTS_VALUE)
319 c->next_pts = p->pts;
320 /* lifetime is not reached so wait for next frame first */
321 return 0;
322 }
323 }
324
325 /* lifetime reached so now convert X frames at once */
326 if (c->mc_frame_counter == c->mc_lifetime) {
327 req_size = 0;
328 /* any frames to encode? */
329 if (c->mc_lifetime) {
330 int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
331 if ((ret = ff_alloc_packet2(avctx, pkt, alloc_size, 0)) < 0)
332 return ret;
333 buf = pkt->data;
334
335 /* calc optimal new charset + charmaps */
336 ret = avpriv_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
337 CHARSET_CHARS, 50, charmap, &c->randctx);
338 if (ret < 0)
339 return ret;
340 ret = avpriv_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
341 CHARSET_CHARS, 50, charmap, &c->randctx);
342 if (ret < 0)
343 return ret;
344
345 /* create colorram map and a c64 readable charset */
346 render_charset(avctx, charset, colram);
347
348 /* copy charset to buf */
349 memcpy(buf, charset, charset_size);
350
351 /* advance pointers */
352 buf += charset_size;
353 req_size += charset_size;
354 }
355
356 /* write x frames to buf */
357 for (frame = 0; frame < c->mc_lifetime; frame++) {
358 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
359 for (y = 0; y < b_height; y++) {
360 for (x = 0; x < b_width; x++) {
361 buf[y * b_width + x] = charmap[y * b_width + x];
362 }
363 }
364 /* advance pointers */
365 buf += screen_size;
366 req_size += screen_size;
367
368 /* compress and copy colram to buf */
369 if (c->mc_use_5col) {
370 a64_compress_colram(buf, charmap, colram);
371 /* advance pointers */
372 buf += colram_size;
373 req_size += colram_size;
374 }
375
376 /* advance to next charmap */
377 charmap += 1000;
378 }
379
380 AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
381 AV_WB32(avctx->extradata + 8, charset_size);
382 AV_WB32(avctx->extradata + 12, screen_size + colram_size);
383
384 /* reset counter */
385 c->mc_frame_counter = 0;
386
387 pkt->pts = pkt->dts = c->next_pts;
388 c->next_pts = AV_NOPTS_VALUE;
389
390 av_assert0(pkt->size >= req_size);
391 pkt->size = req_size;
392 pkt->flags |= AV_PKT_FLAG_KEY;
393 *got_packet = !!req_size;
394 }
395 return 0;
396 }
397
398 #if CONFIG_A64MULTI_ENCODER
399 AVCodec ff_a64multi_encoder = {
400 .name = "a64multi",
401 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
402 .type = AVMEDIA_TYPE_VIDEO,
403 .id = AV_CODEC_ID_A64_MULTI,
404 .priv_data_size = sizeof(A64Context),
405 .init = a64multi_encode_init,
406 .encode2 = a64multi_encode_frame,
407 .close = a64multi_close_encoder,
408 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
409 .capabilities = AV_CODEC_CAP_DELAY,
410 };
411 #endif
412 #if CONFIG_A64MULTI5_ENCODER
413 AVCodec ff_a64multi5_encoder = {
414 .name = "a64multi5",
415 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
416 .type = AVMEDIA_TYPE_VIDEO,
417 .id = AV_CODEC_ID_A64_MULTI5,
418 .priv_data_size = sizeof(A64Context),
419 .init = a64multi_encode_init,
420 .encode2 = a64multi_encode_frame,
421 .close = a64multi_close_encoder,
422 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
423 .capabilities = AV_CODEC_CAP_DELAY,
424 };
425 #endif
426