2 * a64 video encoder - multicolor modes
3 * Copyright (c) 2009 Tobias Bindhammer
5 * This file is part of Libav.
7 * Libav 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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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 Libav; 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"
32 #include "libavutil/common.h"
33 #include "libavutil/intreadwrite.h"
36 #define CHARSET_CHARS 256
38 #define CROP_SCREENS 1
41 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
43 /* other possible gradients - to be tested */
44 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
45 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
47 static void to_meta_with_crop(AVCodecContext *avctx,
48 const AVFrame *p, int *dest)
50 int blockx, blocky, x, y;
52 int height = FFMIN(avctx->height, C64YRES);
53 int width = FFMIN(avctx->width , C64XRES);
54 uint8_t *src = p->data[0];
56 for (blocky = 0; blocky < C64YRES; blocky += 8) {
57 for (blockx = 0; blockx < C64XRES; blockx += 8) {
58 for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
59 for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
60 if(x < width && y < height) {
61 /* build average over 2 pixels */
62 luma = (src[(x + 0 + y * p->linesize[0])] +
63 src[(x + 1 + y * p->linesize[0])]) / 2;
64 /* write blocks as linear data now so they are suitable for elbg */
74 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
77 A64Context *c = avctx->priv_data;
82 int lowdiff, highdiff;
83 int *best_cb = c->mc_best_cb;
84 static uint8_t index1[256];
85 static uint8_t index2[256];
86 static uint8_t dither[256];
90 /* generate lookup-tables for dither and index before looping */
92 for (a=0; a < 256; a++) {
93 if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
94 distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
95 for(b = 0; b <= distance; b++) {
96 dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
100 if(i >= c->mc_pal_size - 1) dither[a] = 0;
102 index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
105 /* and render charset */
106 for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
109 for (y = 0; y < 8; y++) {
111 for (x = 0; x < 4; x++) {
112 pix = best_cb[y * 4 + x];
114 /* accumulate error for brightest/darkest color */
115 if (index1[pix] >= 3)
116 highdiff += pix - c->mc_luma_vals[3];
118 lowdiff += c->mc_luma_vals[1] - pix;
124 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
125 row1 |= 3-(index2[pix] & 3);
127 row1 |= 3-(index1[pix] & 3);
129 if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
130 row2 |= 3-(index2[pix] & 3);
132 row2 |= 3-(index1[pix] & 3);
135 if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
136 row1 |= 3-(index2[pix] & 3);
138 row1 |= 3-(index1[pix] & 3);
141 charset[y+0x000] = row1;
142 if (INTERLACED) charset[y+0x800] = row2;
144 /* do we need to adjust pixels? */
145 if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
146 if (lowdiff > highdiff) {
147 for (x = 0; x < 32; x++)
148 best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
150 for (x = 0; x < 32; x++)
151 best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
153 charpos--; /* redo now adjusted char */
154 /* no adjustment needed, all fine */
156 /* advance pointers */
160 /* remember colorram value */
161 colrammap[charpos] = (highdiff > 0);
166 static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
168 A64Context *c = avctx->priv_data;
169 av_free(c->mc_meta_charset);
170 av_free(c->mc_best_cb);
171 av_free(c->mc_charset);
172 av_free(c->mc_charmap);
173 av_free(c->mc_colram);
177 static av_cold int a64multi_encode_init(AVCodecContext *avctx)
179 A64Context *c = avctx->priv_data;
181 av_lfg_init(&c->randctx, 1);
183 if (avctx->global_quality < 1) {
186 c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
189 av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
191 c->mc_frame_counter = 0;
192 c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
193 c->mc_pal_size = 4 + c->mc_use_5col;
195 /* precalc luma values for later use */
196 for (a = 0; a < c->mc_pal_size; a++) {
197 c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
198 a64_palette[mc_colors[a]][1] * 0.59 +
199 a64_palette[mc_colors[a]][2] * 0.11;
202 if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||
203 !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
204 !(c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||
205 !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
206 !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
207 av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
208 return AVERROR(ENOMEM);
211 /* set up extradata */
212 if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
213 av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
214 return AVERROR(ENOMEM);
216 avctx->extradata_size = 8 * 4;
217 AV_WB32(avctx->extradata, c->mc_lifetime);
218 AV_WB32(avctx->extradata + 16, INTERLACED);
220 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
221 avctx->coded_frame->key_frame = 1;
222 if (!avctx->codec_tag)
223 avctx->codec_tag = AV_RL32("a64m");
225 c->next_pts = AV_NOPTS_VALUE;
230 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
234 /* only needs to be done in 5col mode */
235 /* XXX could be squeezed to 0x80 bytes */
236 for (a = 0; a < 256; a++) {
237 temp = colram[charmap[a + 0x000]] << 0;
238 temp |= colram[charmap[a + 0x100]] << 1;
239 temp |= colram[charmap[a + 0x200]] << 2;
240 if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
245 static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
246 const AVFrame *pict, int *got_packet)
248 A64Context *c = avctx->priv_data;
258 int *charmap = c->mc_charmap;
259 uint8_t *colram = c->mc_colram;
260 uint8_t *charset = c->mc_charset;
261 int *meta = c->mc_meta_charset;
262 int *best_cb = c->mc_best_cb;
264 int charset_size = 0x800 * (INTERLACED + 1);
265 int colram_size = 0x100 * c->mc_use_5col;
269 b_height = FFMIN(avctx->height,C64YRES) >> 3;
270 b_width = FFMIN(avctx->width ,C64XRES) >> 3;
271 screen_size = b_width * b_height;
273 b_height = C64YRES >> 3;
274 b_width = C64XRES >> 3;
278 /* no data, means end encoding asap */
280 /* all done, end encoding */
281 if (!c->mc_lifetime) return 0;
282 /* no more frames in queue, prepare to flush remaining frames */
283 if (!c->mc_frame_counter) {
286 /* still frames in queue so limit lifetime to remaining frames */
287 else c->mc_lifetime = c->mc_frame_counter;
288 /* still new data available */
290 /* fill up mc_meta_charset with data until lifetime exceeds */
291 if (c->mc_frame_counter < c->mc_lifetime) {
292 avctx->coded_frame->pict_type = AV_PICTURE_TYPE_I;
293 avctx->coded_frame->key_frame = 1;
294 to_meta_with_crop(avctx, pict, meta + 32000 * c->mc_frame_counter);
295 c->mc_frame_counter++;
296 if (c->next_pts == AV_NOPTS_VALUE)
297 c->next_pts = pict->pts;
298 /* lifetime is not reached so wait for next frame first */
303 /* lifetime reached so now convert X frames at once */
304 if (c->mc_frame_counter == c->mc_lifetime) {
306 /* any frames to encode? */
307 if (c->mc_lifetime) {
308 req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
309 if ((ret = ff_alloc_packet(pkt, req_size)) < 0) {
310 av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", req_size);
315 /* calc optimal new charset + charmaps */
316 ret = ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
317 CHARSET_CHARS, 50, charmap, &c->randctx);
320 ret = ff_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
321 CHARSET_CHARS, 50, charmap, &c->randctx);
325 /* create colorram map and a c64 readable charset */
326 render_charset(avctx, charset, colram);
328 /* copy charset to buf */
329 memcpy(buf, charset, charset_size);
331 /* advance pointers */
333 charset += charset_size;
336 /* write x frames to buf */
337 for (frame = 0; frame < c->mc_lifetime; frame++) {
338 /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
339 for (y = 0; y < b_height; y++) {
340 for (x = 0; x < b_width; x++) {
341 buf[y * b_width + x] = charmap[y * b_width + x];
344 /* advance pointers */
346 req_size += screen_size;
348 /* compress and copy colram to buf */
349 if (c->mc_use_5col) {
350 a64_compress_colram(buf, charmap, colram);
351 /* advance pointers */
353 req_size += colram_size;
356 /* advance to next charmap */
360 AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
361 AV_WB32(avctx->extradata + 8, charset_size);
362 AV_WB32(avctx->extradata + 12, screen_size + colram_size);
365 c->mc_frame_counter = 0;
367 pkt->pts = pkt->dts = c->next_pts;
368 c->next_pts = AV_NOPTS_VALUE;
370 pkt->size = req_size;
371 pkt->flags |= AV_PKT_FLAG_KEY;
372 *got_packet = !!req_size;
377 AVCodec ff_a64multi_encoder = {
379 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
380 .type = AVMEDIA_TYPE_VIDEO,
381 .id = AV_CODEC_ID_A64_MULTI,
382 .priv_data_size = sizeof(A64Context),
383 .init = a64multi_encode_init,
384 .encode2 = a64multi_encode_frame,
385 .close = a64multi_close_encoder,
386 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
387 .capabilities = CODEC_CAP_DELAY,
390 AVCodec ff_a64multi5_encoder = {
392 .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
393 .type = AVMEDIA_TYPE_VIDEO,
394 .id = AV_CODEC_ID_A64_MULTI5,
395 .priv_data_size = sizeof(A64Context),
396 .init = a64multi_encode_init,
397 .encode2 = a64multi_encode_frame,
398 .close = a64multi_close_encoder,
399 .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
400 .capabilities = CODEC_CAP_DELAY,