FFmpeg coverage


Directory: ../../../ffmpeg/
File: src/libavcodec/a64multienc.c
Date: 2021-09-26 18:22:30
Exec Total Coverage
Lines: 0 162 0.0%
Branches: 0 104 0.0%

Line Branch Exec Source
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 "encode.h"
31 #include "internal.h"
32 #include "libavutil/avassert.h"
33 #include "libavutil/common.h"
34 #include "libavutil/intreadwrite.h"
35
36 #define DITHERSTEPS 8
37 #define CHARSET_CHARS 256
38 #define INTERLACED 1
39 #define CROP_SCREENS 1
40
41 #define C64XRES 320
42 #define C64YRES 200
43
44 typedef struct A64Context {
45 /* variables for multicolor modes */
46 struct ELBGContext *elbg;
47 AVLFG randctx;
48 int mc_lifetime;
49 int mc_use_5col;
50 unsigned mc_frame_counter;
51 int *mc_meta_charset;
52 int *mc_charmap;
53 int *mc_best_cb;
54 int mc_luma_vals[5];
55 uint8_t *mc_colram;
56 uint8_t *mc_palette;
57 int mc_pal_size;
58
59 /* pts of the next packet that will be output */
60 int64_t next_pts;
61 } A64Context;
62
63 /* gray gradient */
64 static const uint8_t mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
65
66 /* other possible gradients - to be tested */
67 //static const uint8_t mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
68 //static const uint8_t mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
69
70 static void to_meta_with_crop(AVCodecContext *avctx,
71 const AVFrame *p, int *dest)
72 {
73 int blockx, blocky, x, y;
74 int luma = 0;
75 int height = FFMIN(avctx->height, C64YRES);
76 int width = FFMIN(avctx->width , C64XRES);
77 uint8_t *src = p->data[0];
78
79 for (blocky = 0; blocky < C64YRES; blocky += 8) {
80 for (blockx = 0; blockx < C64XRES; blockx += 8) {
81 for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
82 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
83 if(x < width && y < height) {
84 if (x + 1 < width) {
85 /* build average over 2 pixels */
86 luma = (src[(x + 0 + y * p->linesize[0])] +
87 src[(x + 1 + y * p->linesize[0])]) / 2;
88 } else {
89 luma = src[(x + y * p->linesize[0])];
90 }
91 /* write blocks as linear data now so they are suitable for elbg */
92 dest[0] = luma;
93 }
94 dest++;
95 }
96 }
97 }
98 }
99 }
100
101 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
102 uint8_t *colrammap)
103 {
104 A64Context *c = avctx->priv_data;
105 uint8_t row1, row2;
106 int charpos, x, y;
107 int a, b;
108 uint8_t pix;
109 int lowdiff, highdiff;
110 int *best_cb = c->mc_best_cb;
111 uint8_t index1[256];
112 uint8_t index2[256];
113 uint8_t dither[256];
114 int i;
115 int distance;
116
117 /* Generate lookup-tables for dither and index before looping.
118 * This code relies on c->mc_luma_vals[c->mc_pal_size - 1] being
119 * the maximum of all the mc_luma_vals values and on the minimum
120 * being zero; this ensures that dither is properly initialized. */
121 i = 0;
122 for (a=0; a < 256; a++) {
123 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
124 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
125 for(b = 0; b <= distance; b++) {
126 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
127 }
128 i++;
129 }
130 if(i >= c->mc_pal_size - 1) dither[a] = 0;
131 index1[a] = i;
132 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
133 }
134
135 /* and render charset */
136 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
137 lowdiff = 0;
138 highdiff = 0;
139 for (y = 0; y < 8; y++) {
140 row1 = 0; row2 = 0;
141 for (x = 0; x < 4; x++) {
142 pix = best_cb[y * 4 + x];
143
144 /* accumulate error for brightest/darkest color */
145 if (index1[pix] >= 3)
146 highdiff += pix - c->mc_luma_vals[3];
147 if (index1[pix] < 1)
148 lowdiff += c->mc_luma_vals[1] - pix;
149
150 row1 <<= 2;
151
152 if (INTERLACED) {
153 row2 <<= 2;
154 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
155 row1 |= 3-(index2[pix] & 3);
156 else
157 row1 |= 3-(index1[pix] & 3);
158
159 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
160 row2 |= 3-(index2[pix] & 3);
161 else
162 row2 |= 3-(index1[pix] & 3);
163 }
164 else {
165 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
166 row1 |= 3-(index2[pix] & 3);
167 else
168 row1 |= 3-(index1[pix] & 3);
169 }
170 }
171 charset[y+0x000] = row1;
172 if (INTERLACED) charset[y+0x800] = row2;
173 }
174 /* do we need to adjust pixels? */
175 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
176 if (lowdiff > highdiff) {
177 for (x = 0; x < 32; x++)
178 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
179 } else {
180 for (x = 0; x < 32; x++)
181 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
182 }
183 charpos--; /* redo now adjusted char */
184 /* no adjustment needed, all fine */
185 } else {
186 /* advance pointers */
187 best_cb += 32;
188 charset += 8;
189
190 /* remember colorram value */
191 colrammap[charpos] = (highdiff > 0);
192 }
193 }
194 }
195
196 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
197 {
198 A64Context *c = avctx->priv_data;
199
200 avpriv_elbg_free(&c->elbg);
201
202 av_freep(&c->mc_meta_charset);
203 av_freep(&c->mc_best_cb);
204 av_freep(&c->mc_charmap);
205 av_freep(&c->mc_colram);
206 return 0;
207 }
208
209 static av_cold int a64multi_encode_init(AVCodecContext *avctx)
210 {
211 A64Context *c = avctx->priv_data;
212 int a;
213 av_lfg_init(&c->randctx, 1);
214
215 if (avctx->global_quality < 1) {
216 c->mc_lifetime = 4;
217 } else {
218 c->mc_lifetime = avctx->global_quality / FF_QP2LAMBDA;
219 }
220
221 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
222
223 c->mc_frame_counter = 0;
224 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
225 c->mc_pal_size = 4 + c->mc_use_5col;
226
227 /* precalc luma values for later use */
228 for (a = 0; a < c->mc_pal_size; a++) {
229 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
230 a64_palette[mc_colors[a]][1] * 0.59 +
231 a64_palette[mc_colors[a]][2] * 0.11;
232 }
233
234 if (!(c->mc_meta_charset = av_calloc(c->mc_lifetime, 32000 * sizeof(int))) ||
235 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
236 !(c->mc_charmap = av_calloc(c->mc_lifetime, 1000 * sizeof(int))) ||
237 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t)))) {
238 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
239 return AVERROR(ENOMEM);
240 }
241
242 /* set up extradata */
243 if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
244 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
245 return AVERROR(ENOMEM);
246 }
247 avctx->extradata_size = 8 * 4;
248 AV_WB32(avctx->extradata, c->mc_lifetime);
249 AV_WB32(avctx->extradata + 16, INTERLACED);
250
251 if (!avctx->codec_tag)
252 avctx->codec_tag = AV_RL32("a64m");
253
254 c->next_pts = AV_NOPTS_VALUE;
255
256 return 0;
257 }
258
259 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
260 {
261 int a;
262 uint8_t temp;
263 /* only needs to be done in 5col mode */
264 /* XXX could be squeezed to 0x80 bytes */
265 for (a = 0; a < 256; a++) {
266 temp = colram[charmap[a + 0x000]] << 0;
267 temp |= colram[charmap[a + 0x100]] << 1;
268 temp |= colram[charmap[a + 0x200]] << 2;
269 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
270 buf[a] = temp << 2;
271 }
272 }
273
274 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
275 const AVFrame *p, int *got_packet)
276 {
277 A64Context *c = avctx->priv_data;
278
279 int frame;
280 int x, y;
281 int b_height;
282 int b_width;
283
284 int req_size, ret;
285 uint8_t *buf = NULL;
286
287 int *charmap = c->mc_charmap;
288 uint8_t *colram = c->mc_colram;
289 int *meta = c->mc_meta_charset;
290 int *best_cb = c->mc_best_cb;
291
292 int charset_size = 0x800 * (INTERLACED + 1);
293 int colram_size = 0x100 * c->mc_use_5col;
294 int screen_size;
295
296 if(CROP_SCREENS) {
297 b_height = FFMIN(avctx->height,C64YRES) >> 3;
298 b_width = FFMIN(avctx->width ,C64XRES) >> 3;
299 screen_size = b_width * b_height;
300 } else {
301 b_height = C64YRES >> 3;
302 b_width = C64XRES >> 3;
303 screen_size = 0x400;
304 }
305
306 /* no data, means end encoding asap */
307 if (!p) {
308 /* all done, end encoding */
309 if (!c->mc_lifetime) return 0;
310 /* no more frames in queue, prepare to flush remaining frames */
311 if (!c->mc_frame_counter) {
312 c->mc_lifetime = 0;
313 }
314 /* still frames in queue so limit lifetime to remaining frames */
315 else c->mc_lifetime = c->mc_frame_counter;
316 /* still new data available */
317 } else {
318 /* fill up mc_meta_charset with data until lifetime exceeds */
319 if (c->mc_frame_counter < c->mc_lifetime) {
320 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
321 c->mc_frame_counter++;
322 if (c->next_pts == AV_NOPTS_VALUE)
323 c->next_pts = p->pts;
324 /* lifetime is not reached so wait for next frame first */
325 return 0;
326 }
327 }
328
329 /* lifetime reached so now convert X frames at once */
330 if (c->mc_frame_counter == c->mc_lifetime) {
331 req_size = 0;
332 /* any frames to encode? */
333 if (c->mc_lifetime) {
334 int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
335 if ((ret = ff_get_encode_buffer(avctx, pkt, alloc_size, 0)) < 0)
336 return ret;
337 buf = pkt->data;
338
339 /* calc optimal new charset + charmaps */
340 ret = avpriv_elbg_do(&c->elbg, meta, 32, 1000 * c->mc_lifetime,
341 best_cb, CHARSET_CHARS, 50, charmap, &c->randctx, 0);
342 if (ret < 0)
343 return ret;
344
345 /* create colorram map and a c64 readable charset */
346 render_charset(avctx, buf, colram);
347
348 /* advance pointers */
349 buf += charset_size;
350 req_size += charset_size;
351 }
352
353 /* write x frames to buf */
354 for (frame = 0; frame < c->mc_lifetime; frame++) {
355 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
356 for (y = 0; y < b_height; y++) {
357 for (x = 0; x < b_width; x++) {
358 buf[y * b_width + x] = charmap[y * b_width + x];
359 }
360 }
361 /* advance pointers */
362 buf += screen_size;
363 req_size += screen_size;
364
365 /* compress and copy colram to buf */
366 if (c->mc_use_5col) {
367 a64_compress_colram(buf, charmap, colram);
368 /* advance pointers */
369 buf += colram_size;
370 req_size += colram_size;
371 }
372
373 /* advance to next charmap */
374 charmap += 1000;
375 }
376
377 AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
378 AV_WB32(avctx->extradata + 8, charset_size);
379 AV_WB32(avctx->extradata + 12, screen_size + colram_size);
380
381 /* reset counter */
382 c->mc_frame_counter = 0;
383
384 pkt->pts = pkt->dts = c->next_pts;
385 c->next_pts = AV_NOPTS_VALUE;
386
387 av_assert0(pkt->size == req_size);
388 pkt->flags |= AV_PKT_FLAG_KEY;
389 *got_packet = !!req_size;
390 }
391 return 0;
392 }
393
394 #if CONFIG_A64MULTI_ENCODER
395 const AVCodec ff_a64multi_encoder = {
396 .name = "a64multi",
397 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
398 .type = AVMEDIA_TYPE_VIDEO,
399 .id = AV_CODEC_ID_A64_MULTI,
400 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
401 .priv_data_size = sizeof(A64Context),
402 .init = a64multi_encode_init,
403 .encode2 = a64multi_encode_frame,
404 .close = a64multi_close_encoder,
405 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
406 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
407 };
408 #endif
409 #if CONFIG_A64MULTI5_ENCODER
410 const AVCodec ff_a64multi5_encoder = {
411 .name = "a64multi5",
412 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
413 .type = AVMEDIA_TYPE_VIDEO,
414 .id = AV_CODEC_ID_A64_MULTI5,
415 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
416 .priv_data_size = sizeof(A64Context),
417 .init = a64multi_encode_init,
418 .encode2 = a64multi_encode_frame,
419 .close = a64multi_close_encoder,
420 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
421 .caps_internal = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
422 };
423 #endif
424