Statistics
| Branch: | Revision:

ffmpeg / libavcodec / a64multienc.c @ 90a3ffe2

History | View | Annotate | Download (13.1 KB)

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 "a64enc.h"
28
#include "a64colors.h"
29
#include "a64tables.h"
30
#include "elbg.h"
31
#include "libavutil/intreadwrite.h"
32

    
33
#define DITHERSTEPS   8
34
#define CHARSET_CHARS 256
35
#define INTERLACED    1
36
#define CROP_SCREENS  1
37

    
38
/* gray gradient */
39
static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
40

    
41
/* other possible gradients - to be tested */
42
//static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
43
//static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
44

    
45
static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
46
{
47
    int blockx, blocky, x, y;
48
    int luma = 0;
49
    int height = FFMIN(avctx->height,C64YRES);
50
    int width  = FFMIN(avctx->width ,C64XRES);
51
    uint8_t *src = p->data[0];
52

    
53
    for (blocky = 0; blocky < C64YRES; blocky += 8) {
54
        for (blockx = 0; blockx < C64XRES; blockx += 8) {
55
            for (y = blocky; y < blocky+8 && y < C64YRES; y++) {
56
                for (x = blockx; x < blockx+8 && x < C64XRES; x += 2) {
57
                    if(x < width && y < height) {
58
                        /* build average over 2 pixels */
59
                        luma = (src[(x + 0 + y * p->linesize[0])] +
60
                                src[(x + 1 + y * p->linesize[0])]) / 2;
61
                        /* write blocks as linear data now so they are suitable for elbg */
62
                        dest[0] = luma;
63
                    }
64
                    dest++;
65
                }
66
            }
67
        }
68
    }
69
}
70

    
71
static void render_charset(AVCodecContext *avctx, uint8_t *charset,
72
                           uint8_t *colrammap)
73
{
74
    A64Context *c = avctx->priv_data;
75
    uint8_t row1, row2;
76
    int charpos, x, y;
77
    int a, b;
78
    uint8_t pix;
79
    int lowdiff, highdiff;
80
    int *best_cb = c->mc_best_cb;
81
    static uint8_t index1[256];
82
    static uint8_t index2[256];
83
    static uint8_t dither[256];
84
    int i;
85
    int distance;
86

    
87
    /* generate lookup-tables for dither and index before looping */
88
    i = 0;
89
    for (a=0; a < 256; a++) {
90
        if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i+1]) {
91
            distance = c->mc_luma_vals[i+1] - c->mc_luma_vals[i];
92
            for(b = 0; b <= distance; b++) {
93
                  dither[c->mc_luma_vals[i]+b] = b * (DITHERSTEPS - 1) / distance;
94
            }
95
            i++;
96
        }
97
        if(i >= c->mc_pal_size - 1) dither[a] = 0;
98
        index1[a] = i;
99
        index2[a] = FFMIN(i+1, c->mc_pal_size - 1);
100
    }
101
    /* and render charset */
102
    for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
103
        lowdiff  = 0;
104
        highdiff = 0;
105
        for (y = 0; y < 8; y++) {
106
            row1 = 0; row2 = 0;
107
            for (x = 0; x < 4; x++) {
108
                pix = best_cb[y * 4 + x];
109

    
110
                /* accumulate error for brightest/darkest color */
111
                if (index1[pix] >= 3)
112
                    highdiff += pix - c->mc_luma_vals[3];
113
                if (index1[pix] < 1)
114
                    lowdiff += c->mc_luma_vals[1] - pix;
115

    
116
                row1 <<= 2;
117

    
118
                if(INTERLACED) {
119
                    row2 <<= 2;
120
                    if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
121
                        row1 |= 3-(index2[pix] & 3);
122
                    else
123
                        row1 |= 3-(index1[pix] & 3);
124

    
125
                    if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
126
                        row2 |= 3-(index2[pix] & 3);
127
                    else
128
                        row2 |= 3-(index1[pix] & 3);
129
                }
130
                else {
131
                    if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
132
                        row1 |= 3-(index2[pix] & 3);
133
                    else
134
                        row1 |= 3-(index1[pix] & 3);
135
                }
136
            }
137
            charset[y+0x000] = row1;
138
            if(INTERLACED) charset[y+0x800] = row2;
139
        }
140
        /* do we need to adjust pixels? */
141
        if (highdiff > 0 && lowdiff > 0) {
142
            if (lowdiff > highdiff) {
143
                for (x = 0; x < 32; x++)
144
                    best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
145
            } else {
146
                for (x = 0; x < 32; x++)
147
                    best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
148
            }
149
            charpos--;          /* redo now adjusted char */
150
        /* no adjustment needed, all fine */
151
        } else {
152
            /* advance pointers */
153
            best_cb += 32;
154
            charset += 8;
155

    
156
            /* remember colorram value */
157
            colrammap[charpos] = (highdiff > 0);
158
        }
159
    }
160
}
161

    
162
static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
163
{
164
    A64Context *c = avctx->priv_data;
165
    av_free(c->mc_meta_charset);
166
    av_free(c->mc_best_cb);
167
    av_free(c->mc_charset);
168
    av_free(c->mc_charmap);
169
    av_free(c->mc_colram);
170
    return 0;
171
}
172

    
173
static av_cold int a64multi_init_encoder(AVCodecContext *avctx)
174
{
175
    A64Context *c = avctx->priv_data;
176
    int a;
177
    av_lfg_init(&c->randctx, 1);
178

    
179
    if (avctx->global_quality < 1) {
180
        c->mc_lifetime = 4;
181
    } else {
182
        c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
183
    }
184

    
185
    av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
186

    
187
    c->mc_frame_counter = 0;
188
    c->mc_use_5col      = avctx->codec->id == CODEC_ID_A64_MULTI5;
189
    c->mc_pal_size      = 4 + c->mc_use_5col;
190

    
191
    /* precalc luma values for later use */
192
    for (a = 0; a < c->mc_pal_size; a++) {
193
        c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
194
                           a64_palette[mc_colors[a]][1] * 0.59 +
195
                           a64_palette[mc_colors[a]][2] * 0.11;
196
    }
197

    
198
    if(!(c->mc_meta_charset  = av_malloc (32000 * c->mc_lifetime * sizeof(int))) ||
199
       !(c->mc_best_cb       = av_malloc (CHARSET_CHARS * 32 * sizeof(int)))     ||
200
       !(c->mc_charmap       = av_mallocz(1000 * c->mc_lifetime * sizeof(int)))  ||
201
       !(c->mc_colram        = av_mallocz(CHARSET_CHARS * sizeof(uint8_t)))      ||
202
       !(c->mc_charset       = av_malloc (0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
203
        av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
204
        return AVERROR(ENOMEM);
205
    }
206

    
207
    /* set up extradata */
208
    if(!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
209
        av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
210
        return AVERROR(ENOMEM);
211
    }
212
    avctx->extradata_size = 8 * 4;
213
    AV_WB32(avctx->extradata, c->mc_lifetime);
214
    AV_WB32(avctx->extradata+16, INTERLACED);
215

    
216
    avcodec_get_frame_defaults(&c->picture);
217
    avctx->coded_frame            = &c->picture;
218
    avctx->coded_frame->pict_type = FF_I_TYPE;
219
    avctx->coded_frame->key_frame = 1;
220
    if (!avctx->codec_tag)
221
         avctx->codec_tag = AV_RL32("a64m");
222

    
223
    return 0;
224
}
225

    
226
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
227
{
228
    int a;
229
    uint8_t temp;
230
    /* only needs to be done in 5col mode */
231
    /* XXX could be squeezed to 0x80 bytes */
232
    for (a = 0; a < 256; a++) {
233
        temp  = colram[charmap[a + 0x000]] << 0;
234
        temp |= colram[charmap[a + 0x100]] << 1;
235
        temp |= colram[charmap[a + 0x200]] << 2;
236
        if(a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
237
        buf[a] = temp << 2;
238
    }
239
}
240

    
241
static int a64multi_encode_frame(AVCodecContext *avctx, unsigned char *buf,
242
                                 int buf_size, void *data)
243
{
244
    A64Context *c = avctx->priv_data;
245
    AVFrame *pict = data;
246
    AVFrame *const p = (AVFrame *) & c->picture;
247

    
248
    int frame;
249
    int x, y;
250
    int b_height;
251
    int b_width;
252

    
253
    int req_size;
254
    int num_frames = c->mc_lifetime;
255

    
256
    int *charmap         = c->mc_charmap;
257
    uint8_t *colram      = c->mc_colram;
258
    uint8_t *charset     = c->mc_charset;
259
    int *meta            = c->mc_meta_charset;
260
    int *best_cb         = c->mc_best_cb;
261

    
262
    int charset_size = 0x800 * (INTERLACED + 1);
263
    int screen_size;
264
    int colram_size  = 0x100 * c->mc_use_5col;
265

    
266
    if(CROP_SCREENS) {
267
        b_height = FFMIN(avctx->height,C64YRES) >> 3;
268
        b_width  = FFMIN(avctx->width ,C64XRES) >> 3;
269
        screen_size = b_width * b_height;
270
    } else {
271
        b_height = C64YRES >> 3;
272
        b_width  = C64XRES >> 3;
273
        screen_size = 0x400;
274
    }
275

    
276
    /* no data, means end encoding asap */
277
    if (!data) {
278
        /* all done, end encoding */
279
        if(!c->mc_lifetime) return 0;
280
        /* no more frames in queue, prepare to flush remaining frames */
281
        if(!c->mc_frame_counter) {
282
            num_frames=c->mc_lifetime;
283
            c->mc_lifetime=0;
284
        }
285
        /* still frames in queue so limit lifetime to remaining frames */
286
        else c->mc_lifetime=c->mc_frame_counter;
287
    }
288
    /* still new data available */
289
    else {
290
        /* fill up mc_meta_charset with data until lifetime exceeds */
291
        if (c->mc_frame_counter < c->mc_lifetime) {
292
            *p = *pict;
293
            p->pict_type = FF_I_TYPE;
294
            p->key_frame = 1;
295
            to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
296
            c->mc_frame_counter++;
297
            /* lifetime is not reached so wait for next frame first */
298
            return 0;
299
        }
300
    }
301

    
302
    /* lifetime reached so now convert X frames at once */
303
    if (c->mc_frame_counter == c->mc_lifetime) {
304
        req_size = 0;
305
        /* any frames to encode? */
306
        if(c->mc_lifetime) {
307
            /* calc optimal new charset + charmaps */
308
            ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
309
            ff_do_elbg  (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
310

    
311
            /* create colorram map and a c64 readable charset */
312
            render_charset(avctx, charset, colram);
313

    
314
            /* copy charset to buf */
315
            memcpy(buf,charset, charset_size);
316

    
317
            /* advance pointers */
318
            buf      += charset_size;
319
            charset  += charset_size;
320
            req_size += charset_size;
321
        }
322
        /* no charset so clean buf */
323
        else memset(buf, 0, charset_size);
324

    
325
        /* write x frames to buf */
326
        for (frame = 0; frame < c->mc_lifetime; frame++) {
327
            /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
328
            for (y = 0; y < b_height; y++) {
329
                for (x = 0; x < b_width; x++) {
330
                    buf[y * b_width + x] = charmap[y * b_width + x];
331
                }
332
            }
333
            /* advance pointers */
334
            buf += screen_size;
335
            req_size += screen_size;
336

    
337
            /* compress and copy colram to buf */
338
            if(c->mc_use_5col) {
339
                a64_compress_colram(buf,charmap,colram);
340
                /* advance pointers */
341
                buf += colram_size;
342
                req_size += colram_size;
343
            }
344

    
345
            /* advance to next charmap */
346
            charmap += 1000;
347
        }
348

    
349
        AV_WB32(avctx->extradata+4,  c->mc_frame_counter);
350
        AV_WB32(avctx->extradata+8,  charset_size);
351
        AV_WB32(avctx->extradata+12, screen_size + colram_size);
352

    
353
        /* reset counter */
354
        c->mc_frame_counter = 0;
355

    
356
        if (req_size > buf_size) {
357
            av_log(avctx, AV_LOG_ERROR, "buf size too small (need %d, got %d)\n", req_size, buf_size);
358
            return -1;
359
        }
360
        return req_size;
361
    }
362
    return 0;
363
}
364

    
365
AVCodec a64multi_encoder = {
366
    .name           = "a64multi",
367
    .type           = AVMEDIA_TYPE_VIDEO,
368
    .id             = CODEC_ID_A64_MULTI,
369
    .priv_data_size = sizeof(A64Context),
370
    .init           = a64multi_init_encoder,
371
    .encode         = a64multi_encode_frame,
372
    .close          = a64multi_close_encoder,
373
    .pix_fmts       = (enum PixelFormat[]) {PIX_FMT_GRAY8, PIX_FMT_NONE},
374
    .long_name      = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
375
    .capabilities   = CODEC_CAP_DELAY,
376
};
377

    
378
AVCodec a64multi5_encoder = {
379
    .name           = "a64multi5",
380
    .type           = AVMEDIA_TYPE_VIDEO,
381
    .id             = CODEC_ID_A64_MULTI5,
382
    .priv_data_size = sizeof(A64Context),
383
    .init           = a64multi_init_encoder,
384
    .encode         = a64multi_encode_frame,
385
    .close          = a64multi_close_encoder,
386
    .pix_fmts       = (enum PixelFormat[]) {PIX_FMT_GRAY8, PIX_FMT_NONE},
387
    .long_name      = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
388
    .capabilities   = CODEC_CAP_DELAY,
389
};