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.
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.
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
27 #include "a64colors.h"
28 #include "a64tables.h"
31 #include "libavutil/common.h"
32 #include "libavutil/intreadwrite.h"
35 #define CHARSET_CHARS 256
37 #define CROP_SCREENS 1
42 typedef struct A64Context {
43 /* general variables */
46 /* variables for multicolor modes */
50 unsigned mc_frame_counter;
60 /* pts of the next packet that will be output */
65 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
67 /* other possible gradients - to be tested */
68 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
69 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
71 static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
73 int blockx, blocky, x, y;
75 int height = FFMIN(avctx->height, C64YRES);
76 int width = FFMIN(avctx->width , C64XRES);
77 uint8_t *src = p->data[0];
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 /* build average over 2 pixels */
85 luma = (src[(x + 0 + y * p->linesize[0])] +
86 src[(x + 1 + y * p->linesize[0])]) / 2;
87 /* write blocks as linear data now so they are suitable for elbg */
97 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
100 A64Context *c = avctx->priv_data;
105 int lowdiff, highdiff;
106 int *best_cb = c->mc_best_cb;
107 static uint8_t index1[256];
108 static uint8_t index2[256];
109 static uint8_t dither[256];
113 /* generate lookup-tables for dither and index before looping */
115 for (a=0; a < 256; a++) {
116 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
117 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
118 for(b = 0; b <= distance; b++) {
119 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
123 if(i >= c->mc_pal_size - 1) dither[a] = 0;
125 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
128 /* and render charset */
129 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
132 for (y = 0; y < 8; y++) {
134 for (x = 0; x < 4; x++) {
135 pix = best_cb[y * 4 + x];
137 /* accumulate error for brightest/darkest color */
138 if (index1[pix] >= 3)
139 highdiff += pix - c->mc_luma_vals[3];
141 lowdiff += c->mc_luma_vals[1] - pix;
147 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
148 row1 |= 3-(index2[pix] & 3);
150 row1 |= 3-(index1[pix] & 3);
152 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
153 row2 |= 3-(index2[pix] & 3);
155 row2 |= 3-(index1[pix] & 3);
158 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
159 row1 |= 3-(index2[pix] & 3);
161 row1 |= 3-(index1[pix] & 3);
164 charset[y+0x000] = row1;
165 if (INTERLACED) charset[y+0x800] = row2;
167 /* do we need to adjust pixels? */
168 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
169 if (lowdiff > highdiff) {
170 for (x = 0; x < 32; x++)
171 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
173 for (x = 0; x < 32; x++)
174 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
176 charpos--; /* redo now adjusted char */
177 /* no adjustment needed, all fine */
179 /* advance pointers */
183 /* remember colorram value */
184 colrammap[charpos] = (highdiff > 0);
189 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
191 A64Context *c = avctx->priv_data;
192 av_free(c->mc_meta_charset);
193 av_free(c->mc_best_cb);
194 av_free(c->mc_charset);
195 av_free(c->mc_charmap);
196 av_free(c->mc_colram);
200 static av_cold int a64multi_init_encoder(AVCodecContext *avctx)
202 A64Context *c = avctx->priv_data;
204 av_lfg_init(&c->randctx, 1);
206 if (avctx->global_quality < 1) {
209 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
212 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
214 c->mc_frame_counter = 0;
215 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
216 c->mc_pal_size = 4 + c->mc_use_5col;
218 /* precalc luma values for later use */
219 for (a = 0; a < c->mc_pal_size; a++) {
220 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
221 a64_palette[mc_colors[a]][1] * 0.59 +
222 a64_palette[mc_colors[a]][2] * 0.11;
225 if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||
226 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
227 !(c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||
228 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
229 !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
230 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
231 return AVERROR(ENOMEM);
234 /* set up extradata */
235 if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
236 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
237 return AVERROR(ENOMEM);
239 avctx->extradata_size = 8 * 4;
240 AV_WB32(avctx->extradata, c->mc_lifetime);
241 AV_WB32(avctx->extradata + 16, INTERLACED);
243 avcodec_get_frame_defaults(&c->picture);
244 avctx->coded_frame = &c->picture;
245 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
246 avctx->coded_frame->key_frame = 1;
247 if (!avctx->codec_tag)
248 avctx->codec_tag = AV_RL32("a64m");
250 c->next_pts = AV_NOPTS_VALUE;
255 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
259 /* only needs to be done in 5col mode */
260 /* XXX could be squeezed to 0x80 bytes */
261 for (a = 0; a < 256; a++) {
262 temp = colram[charmap[a + 0x000]] << 0;
263 temp |= colram[charmap[a + 0x100]] << 1;
264 temp |= colram[charmap[a + 0x200]] << 2;
265 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
270 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
271 const AVFrame *pict, int *got_packet)
273 A64Context *c = avctx->priv_data;
274 AVFrame *const p = &c->picture;
284 int *charmap = c->mc_charmap;
285 uint8_t *colram = c->mc_colram;
286 uint8_t *charset = c->mc_charset;
287 int *meta = c->mc_meta_charset;
288 int *best_cb = c->mc_best_cb;
290 int charset_size = 0x800 * (INTERLACED + 1);
291 int colram_size = 0x100 * c->mc_use_5col;
295 b_height = FFMIN(avctx->height,C64YRES) >> 3;
296 b_width = FFMIN(avctx->width ,C64XRES) >> 3;
297 screen_size = b_width * b_height;
299 b_height = C64YRES >> 3;
300 b_width = C64XRES >> 3;
304 /* no data, means end encoding asap */
306 /* all done, end encoding */
307 if (!c->mc_lifetime) return 0;
308 /* no more frames in queue, prepare to flush remaining frames */
309 if (!c->mc_frame_counter) {
312 /* still frames in queue so limit lifetime to remaining frames */
313 else c->mc_lifetime = c->mc_frame_counter;
314 /* still new data available */
316 /* fill up mc_meta_charset with data until lifetime exceeds */
317 if (c->mc_frame_counter < c->mc_lifetime) {
319 p->pict_type = AV_PICTURE_TYPE_I;
321 to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
322 c->mc_frame_counter++;
323 if (c->next_pts == AV_NOPTS_VALUE)
324 c->next_pts = pict->pts;
325 /* lifetime is not reached so wait for next frame first */
330 /* lifetime reached so now convert X frames at once */
331 if (c->mc_frame_counter == c->mc_lifetime) {
333 /* any frames to encode? */
334 if (c->mc_lifetime) {
335 req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
336 if ((ret = ff_alloc_packet2(avctx, pkt, req_size)) < 0)
340 /* calc optimal new charset + charmaps */
341 ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
342 ff_do_elbg (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
344 /* create colorram map and a c64 readable charset */
345 render_charset(avctx, charset, colram);
347 /* copy charset to buf */
348 memcpy(buf, charset, charset_size);
350 /* advance pointers */
352 charset += charset_size;
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];
363 /* advance pointers */
365 req_size += screen_size;
367 /* compress and copy colram to buf */
368 if (c->mc_use_5col) {
369 a64_compress_colram(buf, charmap, colram);
370 /* advance pointers */
372 req_size += colram_size;
375 /* advance to next charmap */
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);
384 c->mc_frame_counter = 0;
386 pkt->pts = pkt->dts = c->next_pts;
387 c->next_pts = AV_NOPTS_VALUE;
389 pkt->size = req_size;
390 pkt->flags |= AV_PKT_FLAG_KEY;
391 *got_packet = !!req_size;
396 #if CONFIG_A64MULTI_ENCODER
397 AVCodec ff_a64multi_encoder = {
399 .type = AVMEDIA_TYPE_VIDEO,
400 .id = AV_CODEC_ID_A64_MULTI,
401 .priv_data_size = sizeof(A64Context),
402 .init = a64multi_init_encoder,
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 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
407 .capabilities = CODEC_CAP_DELAY,
410 #if CONFIG_A64MULTI5_ENCODER
411 AVCodec ff_a64multi5_encoder = {
413 .type = AVMEDIA_TYPE_VIDEO,
414 .id = AV_CODEC_ID_A64_MULTI5,
415 .priv_data_size = sizeof(A64Context),
416 .init = a64multi_init_encoder,
417 .encode2 = a64multi_encode_frame,
418 .close = a64multi_close_encoder,
419 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
420 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
421 .capabilities = CODEC_CAP_DELAY,