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
10 * version 2.1 of the License, or (at your option) any later version.
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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
38 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
40 /* other possible gradients - to be tested */
41 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
42 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
44 static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
46 int blockx, blocky, x, y;
48 int height = FFMIN(avctx->height,C64YRES);
49 int width = FFMIN(avctx->width ,C64XRES);
50 uint8_t *src = p->data[0];
52 for (blocky = 0; blocky < height; blocky += 8) {
53 for (blockx = 0; blockx < C64XRES; blockx += 8) {
54 for (y = blocky; y < blocky+8 && y < height; y++) {
55 for (x = blockx; x < blockx+8 && x < C64XRES; x += 2) {
57 /* build average over 2 pixels */
58 luma = (src[(x + 0 + y * p->linesize[0])] +
59 src[(x + 1 + y * p->linesize[0])]) / 2;
60 /* write blocks as linear data now so they are suitable for elbg */
70 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
73 A64Context *c = avctx->priv_data;
78 int lowdiff, highdiff;
79 int *best_cb = c->mc_best_cb;
80 static uint8_t index1[256];
81 static uint8_t index2[256];
82 static uint8_t dither[256];
86 /* generate lookup-tables for dither and index before looping */
88 for (a=0; a < 256; a++) {
89 if(i < 4 && a == c->mc_luma_vals[i+1]) {
90 distance = c->mc_luma_vals[i+1] - c->mc_luma_vals[i];
91 for(b = 0; b <= distance; b++) {
92 dither[c->mc_luma_vals[i]+b] = b * (DITHERSTEPS - 1) / distance;
96 if(i >=4 ) dither[a] = 0;
98 index2[a] = FFMIN(i+1, 4);
100 /* and render charset */
101 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
104 for (y = 0; y < 8; y++) {
106 for (x = 0; x < 4; x++) {
107 pix = best_cb[y * 4 + x];
109 /* accumulate error for brightest/darkest color */
110 if (index1[pix] >= 3)
111 highdiff += pix - c->mc_luma_vals[3];
113 lowdiff += c->mc_luma_vals[1] - pix;
119 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
120 row1 |= 3-(index2[pix] & 3);
122 row1 |= 3-(index1[pix] & 3);
124 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
125 row2 |= 3-(index2[pix] & 3);
127 row2 |= 3-(index1[pix] & 3);
130 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
131 row1 |= 3-(index2[pix] & 3);
133 row1 |= 3-(index1[pix] & 3);
136 charset[y+0x000] = row1;
137 if(INTERLACED) charset[y+0x800] = row2;
139 /* do we need to adjust pixels? */
140 if (highdiff > 0 && lowdiff > 0) {
141 if (lowdiff > highdiff) {
142 for (x = 0; x < 32; x++)
143 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
145 for (x = 0; x < 32; x++)
146 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
148 charpos--; /* redo now adjusted char */
149 /* no adjustment needed, all fine */
151 /* advance pointers */
155 /* remember colorram value */
156 colrammap[charpos] = (highdiff > 0);
161 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
163 A64Context *c = avctx->priv_data;
164 av_free(c->mc_meta_charset);
165 av_free(c->mc_best_cb);
166 av_free(c->mc_charset);
167 av_free(c->mc_charmap);
168 av_free(c->mc_colram);
172 static av_cold int a64multi_init_encoder(AVCodecContext *avctx)
174 A64Context *c = avctx->priv_data;
176 av_lfg_init(&c->randctx, 1);
178 if (avctx->global_quality < 1) {
181 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
184 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
186 /* precalc luma values for later use */
187 for (a = 0; a < 5; a++) {
188 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
189 a64_palette[mc_colors[a]][1] * 0.59 +
190 a64_palette[mc_colors[a]][2] * 0.11;
193 c->mc_frame_counter = 0;
194 c->mc_use_5col = avctx->codec->id == CODEC_ID_A64_MULTI5;
196 if(!(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)))) {
201 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
202 return AVERROR(ENOMEM);
205 /* set up extradata */
206 if(!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
207 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
208 return AVERROR(ENOMEM);
210 avctx->extradata_size = 8 * 4;
211 AV_WB32(avctx->extradata, c->mc_lifetime);
212 AV_WB32(avctx->extradata+16, INTERLACED);
214 avcodec_get_frame_defaults(&c->picture);
215 avctx->coded_frame = &c->picture;
216 avctx->coded_frame->pict_type = FF_I_TYPE;
217 avctx->coded_frame->key_frame = 1;
218 if (!avctx->codec_tag)
219 avctx->codec_tag = AV_RL32("a64m");
224 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
228 /* only needs to be done in 5col mode */
229 /* XXX could be squeezed to 0x80 bytes */
230 for (a = 0; a < 256; a++) {
231 temp = colram[charmap[a + 0x000]] << 0;
232 temp |= colram[charmap[a + 0x100]] << 1;
233 temp |= colram[charmap[a + 0x200]] << 2;
234 if(a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
239 static int a64multi_encode_frame(AVCodecContext *avctx, unsigned char *buf,
240 int buf_size, void *data)
242 A64Context *c = avctx->priv_data;
243 AVFrame *pict = data;
244 AVFrame *const p = (AVFrame *) & c->picture;
250 int num_frames = c->mc_lifetime;
252 int *charmap = c->mc_charmap;
253 uint8_t *colram = c->mc_colram;
254 uint8_t *charset = c->mc_charset;
255 int *meta = c->mc_meta_charset;
256 int *best_cb = c->mc_best_cb;
258 int charset_size = 0x800 * (INTERLACED + 1);
259 int screen_size = 0x400;
260 int colram_size = 0x100 * c->mc_use_5col;
262 /* no data, means end encoding asap */
264 /* all done, end encoding */
265 if(!c->mc_lifetime) return 0;
266 /* no more frames in queue, prepare to flush remaining frames */
267 if(!c->mc_frame_counter) {
268 num_frames=c->mc_lifetime;
271 /* still frames in queue so limit lifetime to remaining frames */
272 else c->mc_lifetime=c->mc_frame_counter;
274 /* still new data available */
276 /* fill up mc_meta_charset with data until lifetime exceeds */
277 if (c->mc_frame_counter < c->mc_lifetime) {
279 p->pict_type = FF_I_TYPE;
281 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
282 c->mc_frame_counter++;
283 /* lifetime is not reached so wait for next frame first */
288 /* lifetime reached so now convert X frames at once */
289 if (c->mc_frame_counter == c->mc_lifetime) {
291 /* any frames to encode? */
293 /* calc optimal new charset + charmaps */
294 ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
295 ff_do_elbg (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
297 /* create colorram map and a c64 readable charset */
298 render_charset(avctx, charset, colram);
300 /* copy charset to buf */
301 memcpy(buf,charset, charset_size);
303 /* advance pointers */
305 charset += charset_size;
306 req_size += charset_size;
308 /* no charset so clean buf */
309 else memset(buf, 0, charset_size);
311 /* write x frames to buf */
312 for (frame = 0; frame < c->mc_lifetime; frame++) {
313 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
314 for (a = 0; a < 1000; a++) {
317 /* advance pointers */
319 req_size += screen_size;
321 /* compress and copy colram to buf */
323 a64_compress_colram(buf,charmap,colram);
324 /* advance pointers */
326 req_size += colram_size;
329 /* advance to next charmap */
333 AV_WB32(avctx->extradata+4, c->mc_frame_counter);
334 AV_WB32(avctx->extradata+8, charset_size);
335 AV_WB32(avctx->extradata+12, screen_size + colram_size);
338 c->mc_frame_counter = 0;
340 if (req_size > buf_size) {
341 av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", req_size, buf_size);
349 AVCodec a64multi_encoder = {
351 .type = AVMEDIA_TYPE_VIDEO,
352 .id = CODEC_ID_A64_MULTI,
353 .priv_data_size = sizeof(A64Context),
354 .init = a64multi_init_encoder,
355 .encode = a64multi_encode_frame,
356 .close = a64multi_close_encoder,
357 .pix_fmts = (enum PixelFormat[]) {PIX_FMT_GRAY8, PIX_FMT_NONE},
358 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
359 .capabilities = CODEC_CAP_DELAY,
362 AVCodec a64multi5_encoder = {
364 .type = AVMEDIA_TYPE_VIDEO,
365 .id = CODEC_ID_A64_MULTI5,
366 .priv_data_size = sizeof(A64Context),
367 .init = a64multi_init_encoder,
368 .encode = a64multi_encode_frame,
369 .close = a64multi_close_encoder,
370 .pix_fmts = (enum PixelFormat[]) {PIX_FMT_GRAY8, PIX_FMT_NONE},
371 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
372 .capabilities = CODEC_CAP_DELAY,