FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/a64multienc.c
Date: 2022-07-04 19:11:22
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Lines: 0 161 0.0%
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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 "config_components.h"
28
29 #include "a64colors.h"
30 #include "a64tables.h"
31 #include "codec_internal.h"
32 #include "elbg.h"
33 #include "encode.h"
34 #include "libavutil/avassert.h"
35 #include "libavutil/common.h"
36 #include "libavutil/intreadwrite.h"
37
38 #define DITHERSTEPS 8
39 #define CHARSET_CHARS 256
40 #define INTERLACED 1
41 #define CROP_SCREENS 1
42
43 #define C64XRES 320
44 #define C64YRES 200
45
46 typedef struct A64Context {
47 /* variables for multicolor modes */
48 struct ELBGContext *elbg;
49 AVLFG randctx;
50 int mc_lifetime;
51 int mc_use_5col;
52 unsigned mc_frame_counter;
53 int *mc_meta_charset;
54 int *mc_charmap;
55 int *mc_best_cb;
56 int mc_luma_vals[5];
57 uint8_t *mc_colram;
58 uint8_t *mc_palette;
59 int mc_pal_size;
60
61 /* pts of the next packet that will be output */
62 int64_t next_pts;
63 } A64Context;
64
65 /* gray gradient */
66 static const uint8_t mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
67
68 /* other possible gradients - to be tested */
69 //static const uint8_t mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
70 //static const uint8_t mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
71
72 static void to_meta_with_crop(AVCodecContext *avctx,
73 const AVFrame *p, int *dest)
74 {
75 int blockx, blocky, x, y;
76 int luma = 0;
77 int height = FFMIN(avctx->height, C64YRES);
78 int width = FFMIN(avctx->width , C64XRES);
79 uint8_t *src = p->data[0];
80
81 for (blocky = 0; blocky < C64YRES; blocky += 8) {
82 for (blockx = 0; blockx < C64XRES; blockx += 8) {
83 for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
84 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
85 if(x < width && y < height) {
86 if (x + 1 < width) {
87 /* build average over 2 pixels */
88 luma = (src[(x + 0 + y * p->linesize[0])] +
89 src[(x + 1 + y * p->linesize[0])]) / 2;
90 } else {
91 luma = src[(x + y * p->linesize[0])];
92 }
93 /* write blocks as linear data now so they are suitable for elbg */
94 dest[0] = luma;
95 }
96 dest++;
97 }
98 }
99 }
100 }
101 }
102
103 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
104 uint8_t *colrammap)
105 {
106 A64Context *c = avctx->priv_data;
107 uint8_t row1, row2;
108 int charpos, x, y;
109 int a, b;
110 uint8_t pix;
111 int lowdiff, highdiff;
112 int *best_cb = c->mc_best_cb;
113 uint8_t index1[256];
114 uint8_t index2[256];
115 uint8_t dither[256];
116 int i;
117 int distance;
118
119 /* Generate lookup-tables for dither and index before looping.
120 * This code relies on c->mc_luma_vals[c->mc_pal_size - 1] being
121 * the maximum of all the mc_luma_vals values and on the minimum
122 * being zero; this ensures that dither is properly initialized. */
123 i = 0;
124 for (a=0; a < 256; a++) {
125 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
126 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
127 for(b = 0; b <= distance; b++) {
128 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
129 }
130 i++;
131 }
132 if(i >= c->mc_pal_size - 1) dither[a] = 0;
133 index1[a] = i;
134 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
135 }
136
137 /* and render charset */
138 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
139 lowdiff = 0;
140 highdiff = 0;
141 for (y = 0; y < 8; y++) {
142 row1 = 0; row2 = 0;
143 for (x = 0; x < 4; x++) {
144 pix = best_cb[y * 4 + x];
145
146 /* accumulate error for brightest/darkest color */
147 if (index1[pix] >= 3)
148 highdiff += pix - c->mc_luma_vals[3];
149 if (index1[pix] < 1)
150 lowdiff += c->mc_luma_vals[1] - pix;
151
152 row1 <<= 2;
153
154 if (INTERLACED) {
155 row2 <<= 2;
156 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
157 row1 |= 3-(index2[pix] & 3);
158 else
159 row1 |= 3-(index1[pix] & 3);
160
161 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
162 row2 |= 3-(index2[pix] & 3);
163 else
164 row2 |= 3-(index1[pix] & 3);
165 }
166 else {
167 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
168 row1 |= 3-(index2[pix] & 3);
169 else
170 row1 |= 3-(index1[pix] & 3);
171 }
172 }
173 charset[y+0x000] = row1;
174 if (INTERLACED) charset[y+0x800] = row2;
175 }
176 /* do we need to adjust pixels? */
177 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
178 if (lowdiff > highdiff) {
179 for (x = 0; x < 32; x++)
180 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
181 } else {
182 for (x = 0; x < 32; x++)
183 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
184 }
185 charpos--; /* redo now adjusted char */
186 /* no adjustment needed, all fine */
187 } else {
188 /* advance pointers */
189 best_cb += 32;
190 charset += 8;
191
192 /* remember colorram value */
193 colrammap[charpos] = (highdiff > 0);
194 }
195 }
196 }
197
198 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
199 {
200 A64Context *c = avctx->priv_data;
201
202 avpriv_elbg_free(&c->elbg);
203
204 av_freep(&c->mc_meta_charset);
205 av_freep(&c->mc_best_cb);
206 av_freep(&c->mc_charmap);
207 av_freep(&c->mc_colram);
208 return 0;
209 }
210
211 static av_cold int a64multi_encode_init(AVCodecContext *avctx)
212 {
213 A64Context *c = avctx->priv_data;
214 int a;
215 av_lfg_init(&c->randctx, 1);
216
217 if (avctx->global_quality < 1) {
218 c->mc_lifetime = 4;
219 } else {
220 c->mc_lifetime = avctx->global_quality / FF_QP2LAMBDA;
221 }
222
223 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
224
225 c->mc_frame_counter = 0;
226 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
227 c->mc_pal_size = 4 + c->mc_use_5col;
228
229 /* precalc luma values for later use */
230 for (a = 0; a < c->mc_pal_size; a++) {
231 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
232 a64_palette[mc_colors[a]][1] * 0.59 +
233 a64_palette[mc_colors[a]][2] * 0.11;
234 }
235
236 if (!(c->mc_meta_charset = av_calloc(c->mc_lifetime, 32000 * sizeof(int))) ||
237 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
238 !(c->mc_charmap = av_calloc(c->mc_lifetime, 1000 * sizeof(int))) ||
239 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t)))) {
240 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
241 return AVERROR(ENOMEM);
242 }
243
244 /* set up extradata */
245 if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
246 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
247 return AVERROR(ENOMEM);
248 }
249 avctx->extradata_size = 8 * 4;
250 AV_WB32(avctx->extradata, c->mc_lifetime);
251 AV_WB32(avctx->extradata + 16, INTERLACED);
252
253 if (!avctx->codec_tag)
254 avctx->codec_tag = AV_RL32("a64m");
255
256 c->next_pts = AV_NOPTS_VALUE;
257
258 return 0;
259 }
260
261 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
262 {
263 int a;
264 uint8_t temp;
265 /* only needs to be done in 5col mode */
266 /* XXX could be squeezed to 0x80 bytes */
267 for (a = 0; a < 256; a++) {
268 temp = colram[charmap[a + 0x000]] << 0;
269 temp |= colram[charmap[a + 0x100]] << 1;
270 temp |= colram[charmap[a + 0x200]] << 2;
271 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
272 buf[a] = temp << 2;
273 }
274 }
275
276 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
277 const AVFrame *p, int *got_packet)
278 {
279 A64Context *c = avctx->priv_data;
280
281 int frame;
282 int x, y;
283 int b_height;
284 int b_width;
285
286 int req_size, ret;
287 uint8_t *buf = NULL;
288
289 int *charmap = c->mc_charmap;
290 uint8_t *colram = c->mc_colram;
291 int *meta = c->mc_meta_charset;
292 int *best_cb = c->mc_best_cb;
293
294 int charset_size = 0x800 * (INTERLACED + 1);
295 int colram_size = 0x100 * c->mc_use_5col;
296 int screen_size;
297
298 if(CROP_SCREENS) {
299 b_height = FFMIN(avctx->height,C64YRES) >> 3;
300 b_width = FFMIN(avctx->width ,C64XRES) >> 3;
301 screen_size = b_width * b_height;
302 } else {
303 b_height = C64YRES >> 3;
304 b_width = C64XRES >> 3;
305 screen_size = 0x400;
306 }
307
308 /* no data, means end encoding asap */
309 if (!p) {
310 /* all done, end encoding */
311 if (!c->mc_lifetime) return 0;
312 /* no more frames in queue, prepare to flush remaining frames */
313 if (!c->mc_frame_counter) {
314 c->mc_lifetime = 0;
315 }
316 /* still frames in queue so limit lifetime to remaining frames */
317 else c->mc_lifetime = c->mc_frame_counter;
318 /* still new data available */
319 } else {
320 /* fill up mc_meta_charset with data until lifetime exceeds */
321 if (c->mc_frame_counter < c->mc_lifetime) {
322 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
323 c->mc_frame_counter++;
324 if (c->next_pts == AV_NOPTS_VALUE)
325 c->next_pts = p->pts;
326 /* lifetime is not reached so wait for next frame first */
327 return 0;
328 }
329 }
330
331 /* lifetime reached so now convert X frames at once */
332 if (c->mc_frame_counter == c->mc_lifetime) {
333 req_size = 0;
334 /* any frames to encode? */
335 if (c->mc_lifetime) {
336 int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
337 if ((ret = ff_get_encode_buffer(avctx, pkt, alloc_size, 0)) < 0)
338 return ret;
339 buf = pkt->data;
340
341 /* calc optimal new charset + charmaps */
342 ret = avpriv_elbg_do(&c->elbg, meta, 32, 1000 * c->mc_lifetime,
343 best_cb, CHARSET_CHARS, 50, charmap, &c->randctx, 0);
344 if (ret < 0)
345 return ret;
346
347 /* create colorram map and a c64 readable charset */
348 render_charset(avctx, buf, colram);
349
350 /* advance pointers */
351 buf += charset_size;
352 req_size += charset_size;
353 }
354
355 /* write x frames to buf */
356 for (frame = 0; frame < c->mc_lifetime; frame++) {
357 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
358 for (y = 0; y < b_height; y++) {
359 for (x = 0; x < b_width; x++) {
360 buf[y * b_width + x] = charmap[y * b_width + x];
361 }
362 }
363 /* advance pointers */
364 buf += screen_size;
365 req_size += screen_size;
366
367 /* compress and copy colram to buf */
368 if (c->mc_use_5col) {
369 a64_compress_colram(buf, charmap, colram);
370 /* advance pointers */
371 buf += colram_size;
372 req_size += colram_size;
373 }
374
375 /* advance to next charmap */
376 charmap += 1000;
377 }
378
379 AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
380 AV_WB32(avctx->extradata + 8, charset_size);
381 AV_WB32(avctx->extradata + 12, screen_size + colram_size);
382
383 /* reset counter */
384 c->mc_frame_counter = 0;
385
386 pkt->pts = pkt->dts = c->next_pts;
387 c->next_pts = AV_NOPTS_VALUE;
388
389 av_assert0(pkt->size == req_size);
390 *got_packet = !!req_size;
391 }
392 return 0;
393 }
394
395 #if CONFIG_A64MULTI_ENCODER
396 const FFCodec ff_a64multi_encoder = {
397 .p.name = "a64multi",
398 .p.long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
399 .p.type = AVMEDIA_TYPE_VIDEO,
400 .p.id = AV_CODEC_ID_A64_MULTI,
401 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
402 .priv_data_size = sizeof(A64Context),
403 .init = a64multi_encode_init,
404 FF_CODEC_ENCODE_CB(a64multi_encode_frame),
405 .close = a64multi_close_encoder,
406 .p.pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
407 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
408 };
409 #endif
410 #if CONFIG_A64MULTI5_ENCODER
411 const FFCodec ff_a64multi5_encoder = {
412 .p.name = "a64multi5",
413 .p.long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
414 .p.type = AVMEDIA_TYPE_VIDEO,
415 .p.id = AV_CODEC_ID_A64_MULTI5,
416 .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
417 .priv_data_size = sizeof(A64Context),
418 .init = a64multi_encode_init,
419 FF_CODEC_ENCODE_CB(a64multi_encode_frame),
420 .close = a64multi_close_encoder,
421 .p.pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
422 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
423 };
424 #endif
425