aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/a64multienc.c
blob: b642a575f1ce8758489ead12289c1add0050f801 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
/*
 * a64 video encoder - multicolor modes
 * Copyright (c) 2009 Tobias Bindhammer
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

/**
 * @file
 * a64 video encoder - multicolor modes
 */

#include "config_components.h"

#include "a64colors.h"
#include "a64tables.h"
#include "codec_internal.h"
#include "elbg.h"
#include "encode.h"
#include "libavutil/avassert.h"
#include "libavutil/common.h"
#include "libavutil/intreadwrite.h"

#define DITHERSTEPS   8
#define CHARSET_CHARS 256
#define INTERLACED    1
#define CROP_SCREENS  1

#define C64XRES 320
#define C64YRES 200

typedef struct A64Context {
    /* variables for multicolor modes */
    struct ELBGContext *elbg;
    AVLFG randctx;
    int mc_lifetime;
    int mc_use_5col;
    unsigned mc_frame_counter;
    int *mc_meta_charset;
    int *mc_charmap;
    int *mc_best_cb;
    int mc_luma_vals[5];
    uint8_t *mc_colram;
    uint8_t *mc_palette;
    int mc_pal_size;

    /* pts of the next packet that will be output */
    int64_t next_pts;
} A64Context;

/* gray gradient */
static const uint8_t mc_colors[5]={0x0,0xb,0xc,0xf,0x1};

/* other possible gradients - to be tested */
//static const uint8_t mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
//static const uint8_t mc_colors[5]={0x0,0x9,0x8,0xa,0x3};

static void to_meta_with_crop(AVCodecContext *avctx,
                              const AVFrame *p, int *dest)
{
    int blockx, blocky, x, y;
    int luma = 0;
    int height = FFMIN(avctx->height, C64YRES);
    int width  = FFMIN(avctx->width , C64XRES);
    uint8_t *src = p->data[0];

    for (blocky = 0; blocky < C64YRES; blocky += 8) {
        for (blockx = 0; blockx < C64XRES; blockx += 8) {
            for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
                for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
                    if(x < width && y < height) {
                        if (x + 1 < width) {
                            /* build average over 2 pixels */
                            luma = (src[(x + 0 + y * p->linesize[0])] +
                                    src[(x + 1 + y * p->linesize[0])]) / 2;
                        } else {
                            luma = src[(x + y * p->linesize[0])];
                        }
                        /* write blocks as linear data now so they are suitable for elbg */
                        dest[0] = luma;
                    }
                    dest++;
                }
            }
        }
    }
}

static void render_charset(AVCodecContext *avctx, uint8_t *charset,
                           uint8_t *colrammap)
{
    A64Context *c = avctx->priv_data;
    uint8_t row1, row2;
    int charpos, x, y;
    int a, b;
    uint8_t pix;
    int lowdiff, highdiff;
    int *best_cb = c->mc_best_cb;
    uint8_t index1[256];
    uint8_t index2[256];
    uint8_t dither[256];
    int i;
    int distance;

    /* Generate lookup-tables for dither and index before looping.
     * This code relies on c->mc_luma_vals[c->mc_pal_size - 1] being
     * the maximum of all the mc_luma_vals values and on the minimum
     * being zero; this ensures that dither is properly initialized. */
    i = 0;
    for (a=0; a < 256; a++) {
        if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
            distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
            for(b = 0; b <= distance; b++) {
                  dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
            }
            i++;
        }
        if(i >= c->mc_pal_size - 1) dither[a] = 0;
        index1[a] = i;
        index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
    }

    /* and render charset */
    for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
        lowdiff  = 0;
        highdiff = 0;
        for (y = 0; y < 8; y++) {
            row1 = 0; row2 = 0;
            for (x = 0; x < 4; x++) {
                pix = best_cb[y * 4 + x];

                /* accumulate error for brightest/darkest color */
                if (index1[pix] >= 3)
                    highdiff += pix - c->mc_luma_vals[3];
                if (index1[pix] < 1)
                    lowdiff += c->mc_luma_vals[1] - pix;

                row1 <<= 2;

                if (INTERLACED) {
                    row2 <<= 2;
                    if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
                        row1 |= 3-(index2[pix] & 3);
                    else
                        row1 |= 3-(index1[pix] & 3);

                    if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
                        row2 |= 3-(index2[pix] & 3);
                    else
                        row2 |= 3-(index1[pix] & 3);
                }
                else {
                    if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
                        row1 |= 3-(index2[pix] & 3);
                    else
                        row1 |= 3-(index1[pix] & 3);
                }
            }
            charset[y+0x000] = row1;
            if (INTERLACED) charset[y+0x800] = row2;
        }
        /* do we need to adjust pixels? */
        if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
            if (lowdiff > highdiff) {
                for (x = 0; x < 32; x++)
                    best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
            } else {
                for (x = 0; x < 32; x++)
                    best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
            }
            charpos--;          /* redo now adjusted char */
        /* no adjustment needed, all fine */
        } else {
            /* advance pointers */
            best_cb += 32;
            charset += 8;

            /* remember colorram value */
            colrammap[charpos] = (highdiff > 0);
        }
    }
}

static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
{
    A64Context *c = avctx->priv_data;

    avpriv_elbg_free(&c->elbg);

    av_freep(&c->mc_meta_charset);
    av_freep(&c->mc_best_cb);
    av_freep(&c->mc_charmap);
    av_freep(&c->mc_colram);
    return 0;
}

static av_cold int a64multi_encode_init(AVCodecContext *avctx)
{
    A64Context *c = avctx->priv_data;
    int a;
    av_lfg_init(&c->randctx, 1);

    if (avctx->global_quality < 1) {
        c->mc_lifetime = 4;
    } else {
        c->mc_lifetime = avctx->global_quality / FF_QP2LAMBDA;
    }

    av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);

    c->mc_frame_counter = 0;
    c->mc_use_5col      = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
    c->mc_pal_size      = 4 + c->mc_use_5col;

    /* precalc luma values for later use */
    for (a = 0; a < c->mc_pal_size; a++) {
        c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
                           a64_palette[mc_colors[a]][1] * 0.59 +
                           a64_palette[mc_colors[a]][2] * 0.11;
    }

    if (!(c->mc_meta_charset = av_calloc(c->mc_lifetime, 32000 * sizeof(int))) ||
       !(c->mc_best_cb       = av_malloc(CHARSET_CHARS * 32 * sizeof(int)))     ||
       !(c->mc_charmap       = av_calloc(c->mc_lifetime, 1000 * sizeof(int))) ||
       !(c->mc_colram        = av_mallocz(CHARSET_CHARS * sizeof(uint8_t)))) {
        av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
        return AVERROR(ENOMEM);
    }

    /* set up extradata */
    if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
        av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
        return AVERROR(ENOMEM);
    }
    avctx->extradata_size = 8 * 4;
    AV_WB32(avctx->extradata, c->mc_lifetime);
    AV_WB32(avctx->extradata + 16, INTERLACED);

    if (!avctx->codec_tag)
         avctx->codec_tag = AV_RL32("a64m");

    c->next_pts = AV_NOPTS_VALUE;

    return 0;
}

static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
{
    int a;
    uint8_t temp;
    /* only needs to be done in 5col mode */
    /* XXX could be squeezed to 0x80 bytes */
    for (a = 0; a < 256; a++) {
        temp  = colram[charmap[a + 0x000]] << 0;
        temp |= colram[charmap[a + 0x100]] << 1;
        temp |= colram[charmap[a + 0x200]] << 2;
        if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
        buf[a] = temp << 2;
    }
}

static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
                                 const AVFrame *p, int *got_packet)
{
    A64Context *c = avctx->priv_data;

    int frame;
    int x, y;
    int b_height;
    int b_width;

    int req_size, ret;
    uint8_t *buf = NULL;

    int *charmap     = c->mc_charmap;
    uint8_t *colram  = c->mc_colram;
    int *meta        = c->mc_meta_charset;
    int *best_cb     = c->mc_best_cb;

    int charset_size = 0x800 * (INTERLACED + 1);
    int colram_size  = 0x100 * c->mc_use_5col;
    int screen_size;

    if(CROP_SCREENS) {
        b_height = FFMIN(avctx->height,C64YRES) >> 3;
        b_width  = FFMIN(avctx->width ,C64XRES) >> 3;
        screen_size = b_width * b_height;
    } else {
        b_height = C64YRES >> 3;
        b_width  = C64XRES >> 3;
        screen_size = 0x400;
    }

    /* no data, means end encoding asap */
    if (!p) {
        /* all done, end encoding */
        if (!c->mc_lifetime) return 0;
        /* no more frames in queue, prepare to flush remaining frames */
        if (!c->mc_frame_counter) {
            c->mc_lifetime = 0;
        }
        /* still frames in queue so limit lifetime to remaining frames */
        else c->mc_lifetime = c->mc_frame_counter;
    /* still new data available */
    } else {
        /* fill up mc_meta_charset with data until lifetime exceeds */
        if (c->mc_frame_counter < c->mc_lifetime) {
            to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
            c->mc_frame_counter++;
            if (c->next_pts == AV_NOPTS_VALUE)
                c->next_pts = p->pts;
            /* lifetime is not reached so wait for next frame first */
            return 0;
        }
    }

    /* lifetime reached so now convert X frames at once */
    if (c->mc_frame_counter == c->mc_lifetime) {
        req_size = 0;
        /* any frames to encode? */
        if (c->mc_lifetime) {
            int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
            if ((ret = ff_get_encode_buffer(avctx, pkt, alloc_size, 0)) < 0)
                return ret;
            buf = pkt->data;

            /* calc optimal new charset + charmaps */
            ret = avpriv_elbg_do(&c->elbg, meta, 32, 1000 * c->mc_lifetime,
                                 best_cb, CHARSET_CHARS, 50, charmap, &c->randctx, 0);
            if (ret < 0)
                return ret;

            /* create colorram map and a c64 readable charset */
            render_charset(avctx, buf, colram);

            /* advance pointers */
            buf      += charset_size;
            req_size += charset_size;
        }

        /* write x frames to buf */
        for (frame = 0; frame < c->mc_lifetime; frame++) {
            /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
            for (y = 0; y < b_height; y++) {
                for (x = 0; x < b_width; x++) {
                    buf[y * b_width + x] = charmap[y * b_width + x];
                }
            }
            /* advance pointers */
            buf += screen_size;
            req_size += screen_size;

            /* compress and copy colram to buf */
            if (c->mc_use_5col) {
                a64_compress_colram(buf, charmap, colram);
                /* advance pointers */
                buf += colram_size;
                req_size += colram_size;
            }

            /* advance to next charmap */
            charmap += 1000;
        }

        AV_WB32(avctx->extradata + 4,  c->mc_frame_counter);
        AV_WB32(avctx->extradata + 8,  charset_size);
        AV_WB32(avctx->extradata + 12, screen_size + colram_size);

        /* reset counter */
        c->mc_frame_counter = 0;

        pkt->pts = pkt->dts = c->next_pts;
        c->next_pts         = AV_NOPTS_VALUE;

        av_assert0(pkt->size == req_size);
        *got_packet = !!req_size;
    }
    return 0;
}

#if CONFIG_A64MULTI_ENCODER
const FFCodec ff_a64multi_encoder = {
    .p.name         = "a64multi",
    .p.long_name    = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_A64_MULTI,
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
    .priv_data_size = sizeof(A64Context),
    .init           = a64multi_encode_init,
    .encode2        = a64multi_encode_frame,
    .close          = a64multi_close_encoder,
    .p.pix_fmts     = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif
#if CONFIG_A64MULTI5_ENCODER
const FFCodec ff_a64multi5_encoder = {
    .p.name         = "a64multi5",
    .p.long_name    = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
    .p.type         = AVMEDIA_TYPE_VIDEO,
    .p.id           = AV_CODEC_ID_A64_MULTI5,
    .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_DELAY,
    .priv_data_size = sizeof(A64Context),
    .init           = a64multi_encode_init,
    .encode2        = a64multi_encode_frame,
    .close          = a64multi_close_encoder,
    .p.pix_fmts     = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
    .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
};
#endif