GCC Code Coverage Report
Directory: ../../../ffmpeg/ Exec Total Coverage
File: src/libavcodec/rpzaenc.c Lines: 0 349 0.0 %
Date: 2020-09-25 23:16:12 Branches: 0 144 0.0 %

Line Branch Exec Source
1
/*
2
 * QuickTime RPZA Video Encoder
3
 *
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 * This file is part of FFmpeg.
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 *
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 * FFmpeg is free software; you can redistribute it and/or
7
 * modify it under the terms of the GNU Lesser General Public
8
 * License as published by the Free Software Foundation; either
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 * version 2.1 of the License, or (at your option) any later version.
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 *
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 * FFmpeg is distributed in the hope that it will be useful,
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 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
14
 * Lesser General Public License for more details.
15
 *
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 * You should have received a copy of the GNU Lesser General Public
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 * License along with FFmpeg; if not, write to the Free Software
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 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19
 */
20
21
/**
22
 * @file rpzaenc.c
23
 * QT RPZA Video Encoder by Todd Kirby <doubleshot@pacbell.net> and David Adler
24
 */
25
26
#include "libavutil/avassert.h"
27
#include "libavutil/common.h"
28
#include "libavutil/opt.h"
29
30
#include "avcodec.h"
31
#include "internal.h"
32
#include "put_bits.h"
33
34
typedef struct RpzaContext {
35
    AVClass *avclass;
36
37
    int skip_frame_thresh;
38
    int start_one_color_thresh;
39
    int continue_one_color_thresh;
40
    int sixteen_color_thresh;
41
42
    AVFrame *prev_frame;    // buffer for previous source frame
43
    PutBitContext pb;       // buffer for encoded frame data.
44
45
    int frame_width;        // width in pixels of source frame
46
    int frame_height;       // height in pixesl of source frame
47
48
    int first_frame;        // flag set to one when the first frame is being processed
49
                            // so that comparisons with previous frame data in not attempted
50
} RpzaContext;
51
52
typedef enum channel_offset {
53
    RED = 2,
54
    GREEN = 1,
55
    BLUE = 0,
56
} channel_offset;
57
58
typedef struct rgb {
59
    uint8_t r;
60
    uint8_t g;
61
    uint8_t b;
62
} rgb;
63
64
#define SQR(x) ((x) * (x))
65
66
/* 15 bit components */
67
#define GET_CHAN(color, chan) (((color) >> ((chan) * 5) & 0x1F) * 8)
68
#define R(color) GET_CHAN(color, RED)
69
#define G(color) GET_CHAN(color, GREEN)
70
#define B(color) GET_CHAN(color, BLUE)
71
72
typedef struct BlockInfo {
73
    int row;
74
    int col;
75
    int block_width;
76
    int block_height;
77
    int image_width;
78
    int image_height;
79
    int block_index;
80
    uint16_t start;
81
    int rowstride;
82
    int blocks_per_row;
83
    int total_blocks;
84
} BlockInfo;
85
86
static void get_colors(uint8_t *min, uint8_t *max, uint8_t color4[4][3])
87
{
88
    uint8_t step;
89
90
    color4[0][0] = min[0];
91
    color4[0][1] = min[1];
92
    color4[0][2] = min[2];
93
94
    color4[3][0] = max[0];
95
    color4[3][1] = max[1];
96
    color4[3][2] = max[2];
97
98
    // red components
99
    step = (color4[3][0] - color4[0][0] + 1) / 3;
100
    color4[1][0] = color4[0][0] + step;
101
    color4[2][0] = color4[3][0] - step;
102
103
    // green components
104
    step = (color4[3][1] - color4[0][1] + 1) / 3;
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    color4[1][1] = color4[0][1] + step;
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    color4[2][1] = color4[3][1] - step;
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108
    // blue components
109
    step = (color4[3][2] - color4[0][2] + 1) / 3;
110
    color4[1][2] = color4[0][2] + step;
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    color4[2][2] = color4[3][2] - step;
112
}
113
114
/* Fill BlockInfo struct with information about a 4x4 block of the image */
115
static int get_block_info(BlockInfo *bi, int block)
116
{
117
    bi->row = block / bi->blocks_per_row;
118
    bi->col = block % bi->blocks_per_row;
119
120
    // test for right edge block
121
    if (bi->col == bi->blocks_per_row - 1 && (bi->image_width % 4) != 0) {
122
        bi->block_width = bi->image_width % 4;
123
    } else {
124
        bi->block_width = 4;
125
    }
126
127
    // test for bottom edge block
128
    if (bi->row == (bi->image_height / 4) && (bi->image_height % 4) != 0) {
129
        bi->block_height = bi->image_height % 4;
130
    } else {
131
        bi->block_height = 4;
132
    }
133
134
    return block ? (bi->col * 4) + (bi->row * bi->rowstride * 4) : 0;
135
}
136
137
static uint16_t rgb24_to_rgb555(uint8_t *rgb24)
138
{
139
    uint16_t rgb555 = 0;
140
    uint32_t r, g, b;
141
142
    r = rgb24[0] >> 3;
143
    g = rgb24[1] >> 3;
144
    b = rgb24[2] >> 3;
145
146
    rgb555 |= (r << 10);
147
    rgb555 |= (g << 5);
148
    rgb555 |= (b << 0);
149
150
    return rgb555;
151
}
152
153
/*
154
 * Returns the total difference between two 24 bit color values
155
 */
156
static int diff_colors(uint8_t *colorA, uint8_t *colorB)
157
{
158
    int tot;
159
160
    tot  = SQR(colorA[0] - colorB[0]);
161
    tot += SQR(colorA[1] - colorB[1]);
162
    tot += SQR(colorA[2] - colorB[2]);
163
164
    return tot;
165
}
166
167
/*
168
 * Returns the maximum channel difference
169
 */
170
static int max_component_diff(uint16_t *colorA, uint16_t *colorB)
171
{
172
    int diff, max = 0;
173
174
    diff = FFABS(R(colorA[0]) - R(colorB[0]));
175
    if (diff > max) {
176
        max = diff;
177
    }
178
    diff = FFABS(G(colorA[0]) - G(colorB[0]));
179
    if (diff > max) {
180
        max = diff;
181
    }
182
    diff = FFABS(B(colorA[0]) - B(colorB[0]));
183
    if (diff > max) {
184
        max = diff;
185
    }
186
    return max * 8;
187
}
188
189
/*
190
 * Find the channel that has the largest difference between minimum and maximum
191
 * color values. Put the minimum value in min, maximum in max and the channel
192
 * in chan.
193
 */
194
static void get_max_component_diff(BlockInfo *bi, uint16_t *block_ptr,
195
                                   uint8_t *min, uint8_t *max, channel_offset *chan)
196
{
197
    int x, y;
198
    uint8_t min_r, max_r, min_g, max_g, min_b, max_b;
199
    uint8_t r, g, b;
200
201
    // fix warning about uninitialized vars
202
    min_r = min_g = min_b = UINT8_MAX;
203
    max_r = max_g = max_b = 0;
204
205
    // loop thru and compare pixels
206
    for (y = 0; y < bi->block_height; y++) {
207
        for (x = 0; x < bi->block_width; x++){
208
            // TODO:  optimize
209
            min_r = FFMIN(R(block_ptr[x]), min_r);
210
            min_g = FFMIN(G(block_ptr[x]), min_g);
211
            min_b = FFMIN(B(block_ptr[x]), min_b);
212
213
            max_r = FFMAX(R(block_ptr[x]), max_r);
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            max_g = FFMAX(G(block_ptr[x]), max_g);
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            max_b = FFMAX(B(block_ptr[x]), max_b);
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        }
217
        block_ptr += bi->rowstride;
218
    }
219
220
    r = max_r - min_r;
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    g = max_g - min_g;
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    b = max_b - min_b;
223
224
    if (r > g && r > b) {
225
        *max = max_r;
226
        *min = min_r;
227
        *chan = RED;
228
    } else if (g > b && g >= r) {
229
        *max = max_g;
230
        *min = min_g;
231
        *chan = GREEN;
232
    } else {
233
        *max = max_b;
234
        *min = min_b;
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        *chan = BLUE;
236
    }
237
}
238
239
/*
240
 * Compare two 4x4 blocks to determine if the total difference between the
241
 * blocks is greater than the thresh parameter. Returns -1 if difference
242
 * exceeds threshold or zero otherwise.
243
 */
244
static int compare_blocks(uint16_t *block1, uint16_t *block2, BlockInfo *bi, int thresh)
245
{
246
    int x, y, diff = 0;
247
    for (y = 0; y < bi->block_height; y++) {
248
        for (x = 0; x < bi->block_width; x++) {
249
            diff = max_component_diff(&block1[x], &block2[x]);
250
            if (diff >= thresh) {
251
                return -1;
252
            }
253
        }
254
        block1 += bi->rowstride;
255
        block2 += bi->rowstride;
256
    }
257
    return 0;
258
}
259
260
/*
261
 * Determine the fit of one channel to another within a 4x4 block. This
262
 * is used to determine the best palette choices for 4-color encoding.
263
 */
264
static int leastsquares(uint16_t *block_ptr, BlockInfo *bi,
265
                        channel_offset xchannel, channel_offset ychannel,
266
                        double *slope, double *y_intercept, double *correlation_coef)
267
{
268
    double sumx = 0, sumy = 0, sumx2 = 0, sumy2 = 0, sumxy = 0,
269
           sumx_sq = 0, sumy_sq = 0, tmp, tmp2;
270
    int i, j, count;
271
    uint8_t x, y;
272
273
    count = bi->block_height * bi->block_width;
274
275
    if (count < 2)
276
        return -1;
277
278
    for (i = 0; i < bi->block_height; i++) {
279
        for (j = 0; j < bi->block_width; j++){
280
            x = GET_CHAN(block_ptr[j], xchannel);
281
            y = GET_CHAN(block_ptr[j], ychannel);
282
            sumx += x;
283
            sumy += y;
284
            sumx2 += x * x;
285
            sumy2 += y * y;
286
            sumxy += x * y;
287
        }
288
        block_ptr += bi->rowstride;
289
    }
290
291
    sumx_sq = sumx * sumx;
292
    tmp = (count * sumx2 - sumx_sq);
293
294
    // guard against div/0
295
    if (tmp == 0)
296
        return -2;
297
298
    sumy_sq = sumy * sumy;
299
300
    *slope = (sumx * sumy - sumxy) / tmp;
301
    *y_intercept = (sumy - (*slope) * sumx) / count;
302
303
    tmp2 = count * sumy2 - sumy_sq;
304
    if (tmp2 == 0) {
305
        *correlation_coef = 0.0;
306
    } else {
307
        *correlation_coef = (count * sumxy - sumx * sumy) /
308
            sqrt(tmp * tmp2);
309
    }
310
311
    return 0; // success
312
}
313
314
/*
315
 * Determine the amount of error in the leastsquares fit.
316
 */
317
static int calc_lsq_max_fit_error(uint16_t *block_ptr, BlockInfo *bi,
318
                                  int min, int max, int tmp_min, int tmp_max,
319
                                  channel_offset xchannel, channel_offset ychannel)
320
{
321
    int i, j, x, y;
322
    int err;
323
    int max_err = 0;
324
325
    for (i = 0; i < bi->block_height; i++) {
326
        for (j = 0; j < bi->block_width; j++){
327
            int x_inc, lin_y, lin_x;
328
            x = GET_CHAN(block_ptr[j], xchannel);
329
            y = GET_CHAN(block_ptr[j], ychannel);
330
331
            /* calculate x_inc as the 4-color index (0..3) */
332
            x_inc = floor( (x - min) * 3.0 / (max - min) + 0.5);
333
            x_inc = FFMAX(FFMIN(3, x_inc), 0);
334
335
            /* calculate lin_y corresponding to x_inc */
336
            lin_y = (int)(tmp_min + (tmp_max - tmp_min) * x_inc / 3.0 + 0.5);
337
338
            err = FFABS(lin_y - y);
339
            if (err > max_err)
340
                max_err = err;
341
342
            /* calculate lin_x corresponding to x_inc */
343
            lin_x = (int)(min + (max - min) * x_inc / 3.0 + 0.5);
344
345
            err = FFABS(lin_x - x);
346
            if (err > max_err)
347
                max_err += err;
348
        }
349
        block_ptr += bi->rowstride;
350
    }
351
352
    return max_err;
353
}
354
355
/*
356
 * Find the closest match to a color within the 4-color palette
357
 */
358
static int match_color(uint16_t *color, uint8_t colors[4][3])
359
{
360
    int ret = 0;
361
    int smallest_variance = INT_MAX;
362
    uint8_t dithered_color[3];
363
364
    for (int channel = 0; channel < 3; channel++) {
365
        dithered_color[channel] = GET_CHAN(color[0], channel);
366
    }
367
368
    for (int palette_entry = 0; palette_entry < 4; palette_entry++) {
369
        int variance = diff_colors(dithered_color, colors[palette_entry]);
370
371
        if (variance < smallest_variance) {
372
            smallest_variance = variance;
373
            ret = palette_entry;
374
        }
375
    }
376
377
    return ret;
378
}
379
380
/*
381
 * Encode a block using the 4-color opcode and palette. return number of
382
 * blocks encoded (until we implement multi-block 4 color runs this will
383
 * always be 1)
384
 */
385
static int encode_four_color_block(uint8_t *min_color, uint8_t *max_color,
386
                                   PutBitContext *pb, uint16_t *block_ptr, BlockInfo *bi)
387
{
388
    int x, y, idx;
389
    uint8_t color4[4][3];
390
    uint16_t rounded_max, rounded_min;
391
392
    // round min and max wider
393
    rounded_min = rgb24_to_rgb555(min_color);
394
    rounded_max = rgb24_to_rgb555(max_color);
395
396
    // put a and b colors
397
    // encode 4 colors = first 16 bit color with MSB zeroed and...
398
    put_bits(pb, 16, rounded_max & ~0x8000);
399
    // ...second 16 bit color with MSB on.
400
    put_bits(pb, 16, rounded_min | 0x8000);
401
402
    get_colors(min_color, max_color, color4);
403
404
    for (y = 0; y < 4; y++) {
405
        for (x = 0; x < 4; x++) {
406
            idx = match_color(&block_ptr[x], color4);
407
            put_bits(pb, 2, idx);
408
        }
409
        block_ptr += bi->rowstride;
410
    }
411
    return 1; // num blocks encoded
412
}
413
414
/*
415
 * Copy a 4x4 block from the current frame buffer to the previous frame buffer.
416
 */
417
static void update_block_in_prev_frame(const uint16_t *src_pixels,
418
                                       uint16_t *dest_pixels,
419
                                       const BlockInfo *bi, int block_counter)
420
{
421
    for (int y = 0; y < 4; y++) {
422
        memcpy(dest_pixels, src_pixels, 8);
423
        dest_pixels += bi->rowstride;
424
        src_pixels += bi->rowstride;
425
    }
426
}
427
428
/*
429
 * update statistics for the specified block. If first_block,
430
 * it initializes the statistics.  Otherwise it updates the statistics IF THIS
431
 * BLOCK IS SUITABLE TO CONTINUE A 1-COLOR RUN. That is, it checks whether
432
 * the range of colors (since the routine was called first_block != 0) are
433
 * all close enough intensities to be represented by a single color.
434
435
 * The routine returns 0 if this block is too different to be part of
436
 * the same run of 1-color blocks. The routine returns 1 if this
437
 * block can be part of the same 1-color block run.
438
439
 * If the routine returns 1, it also updates its arguments to include
440
 * the statistics of this block. Otherwise, the stats are unchanged
441
 * and don't include the current block.
442
 */
443
static int update_block_stats(RpzaContext *s, BlockInfo *bi, uint16_t *block,
444
                              uint8_t min_color[3], uint8_t max_color[3],
445
                              int *total_rgb, int *total_pixels,
446
                              uint8_t avg_color[3], int first_block)
447
{
448
    int x, y;
449
    int is_in_range;
450
    int total_pixels_blk;
451
    int threshold;
452
453
    uint8_t min_color_blk[3], max_color_blk[3];
454
    int total_rgb_blk[3];
455
    uint8_t avg_color_blk[3];
456
457
    if (first_block) {
458
        min_color[0] = UINT8_MAX;
459
        min_color[1] = UINT8_MAX;
460
        min_color[2] = UINT8_MAX;
461
        max_color[0] = 0;
462
        max_color[1] = 0;
463
        max_color[2] = 0;
464
        total_rgb[0] = 0;
465
        total_rgb[1] = 0;
466
        total_rgb[2] = 0;
467
        *total_pixels = 0;
468
        threshold = s->start_one_color_thresh;
469
    } else {
470
        threshold = s->continue_one_color_thresh;
471
    }
472
473
    /*
474
       The *_blk variables will include the current block.
475
       Initialize them based on the blocks so far.
476
     */
477
    min_color_blk[0] = min_color[0];
478
    min_color_blk[1] = min_color[1];
479
    min_color_blk[2] = min_color[2];
480
    max_color_blk[0] = max_color[0];
481
    max_color_blk[1] = max_color[1];
482
    max_color_blk[2] = max_color[2];
483
    total_rgb_blk[0] = total_rgb[0];
484
    total_rgb_blk[1] = total_rgb[1];
485
    total_rgb_blk[2] = total_rgb[2];
486
    total_pixels_blk = *total_pixels + bi->block_height * bi->block_width;
487
488
    /*
489
       Update stats for this block's pixels
490
     */
491
    for (y = 0; y < bi->block_height; y++) {
492
        for (x = 0; x < bi->block_width; x++) {
493
            total_rgb_blk[0] += R(block[x]);
494
            total_rgb_blk[1] += G(block[x]);
495
            total_rgb_blk[2] += B(block[x]);
496
497
            min_color_blk[0] = FFMIN(R(block[x]), min_color_blk[0]);
498
            min_color_blk[1] = FFMIN(G(block[x]), min_color_blk[1]);
499
            min_color_blk[2] = FFMIN(B(block[x]), min_color_blk[2]);
500
501
            max_color_blk[0] = FFMAX(R(block[x]), max_color_blk[0]);
502
            max_color_blk[1] = FFMAX(G(block[x]), max_color_blk[1]);
503
            max_color_blk[2] = FFMAX(B(block[x]), max_color_blk[2]);
504
        }
505
        block += bi->rowstride;
506
    }
507
508
    /*
509
       Calculate average color including current block.
510
     */
511
    avg_color_blk[0] = total_rgb_blk[0] / total_pixels_blk;
512
    avg_color_blk[1] = total_rgb_blk[1] / total_pixels_blk;
513
    avg_color_blk[2] = total_rgb_blk[2] / total_pixels_blk;
514
515
    /*
516
       Are all the pixels within threshold of the average color?
517
     */
518
    is_in_range = (max_color_blk[0] - avg_color_blk[0] <= threshold &&
519
                   max_color_blk[1] - avg_color_blk[1] <= threshold &&
520
                   max_color_blk[2] - avg_color_blk[2] <= threshold &&
521
                   avg_color_blk[0] - min_color_blk[0] <= threshold &&
522
                   avg_color_blk[1] - min_color_blk[1] <= threshold &&
523
                   avg_color_blk[2] - min_color_blk[2] <= threshold);
524
525
    if (is_in_range) {
526
        /*
527
           Set the output variables to include this block.
528
         */
529
        min_color[0] = min_color_blk[0];
530
        min_color[1] = min_color_blk[1];
531
        min_color[2] = min_color_blk[2];
532
        max_color[0] = max_color_blk[0];
533
        max_color[1] = max_color_blk[1];
534
        max_color[2] = max_color_blk[2];
535
        total_rgb[0] = total_rgb_blk[0];
536
        total_rgb[1] = total_rgb_blk[1];
537
        total_rgb[2] = total_rgb_blk[2];
538
        *total_pixels = total_pixels_blk;
539
        avg_color[0] = avg_color_blk[0];
540
        avg_color[1] = avg_color_blk[1];
541
        avg_color[2] = avg_color_blk[2];
542
    }
543
544
    return is_in_range;
545
}
546
547
static void rpza_encode_stream(RpzaContext *s, const AVFrame *pict)
548
{
549
    BlockInfo bi;
550
    int block_counter = 0;
551
    int n_blocks;
552
    int total_blocks;
553
    int prev_block_offset;
554
    int block_offset = 0;
555
    uint8_t min = 0, max = 0;
556
    channel_offset chan;
557
    int i;
558
    int tmp_min, tmp_max;
559
    int total_rgb[3];
560
    uint8_t avg_color[3];
561
    int pixel_count;
562
    uint8_t min_color[3], max_color[3];
563
    double slope, y_intercept, correlation_coef;
564
    uint16_t *src_pixels = (uint16_t *)pict->data[0];
565
    uint16_t *prev_pixels = (uint16_t *)s->prev_frame->data[0];
566
567
    /* Number of 4x4 blocks in frame. */
568
    total_blocks = ((s->frame_width + 3) / 4) * ((s->frame_height + 3) / 4);
569
570
    bi.image_width = s->frame_width;
571
    bi.image_height = s->frame_height;
572
    bi.rowstride = pict->linesize[0] / 2;
573
574
    bi.blocks_per_row = (s->frame_width + 3) / 4;
575
576
    while (block_counter < total_blocks) {
577
        // SKIP CHECK
578
        // make sure we have a valid previous frame and we're not writing
579
        // a key frame
580
        if (!s->first_frame) {
581
            n_blocks = 0;
582
            prev_block_offset = 0;
583
584
            while (n_blocks < 32 && block_counter + n_blocks < total_blocks) {
585
586
                block_offset = get_block_info(&bi, block_counter + n_blocks);
587
588
                // multi-block opcodes cannot span multiple rows.
589
                // If we're starting a new row, break out and write the opcode
590
                /* TODO: Should eventually use bi.row here to determine when a
591
                   row break occurs, but that is currently breaking the
592
                   quicktime player. This is probably due to a bug in the
593
                   way I'm calculating the current row.
594
                 */
595
                if (prev_block_offset && block_offset - prev_block_offset > 12) {
596
                    break;
597
                }
598
599
                prev_block_offset = block_offset;
600
601
                if (compare_blocks(&prev_pixels[block_offset],
602
                                   &src_pixels[block_offset], &bi, s->skip_frame_thresh) != 0) {
603
                    // write out skipable blocks
604
                    if (n_blocks) {
605
606
                        // write skip opcode
607
                        put_bits(&s->pb, 8, 0x80 | (n_blocks - 1));
608
                        block_counter += n_blocks;
609
610
                        goto post_skip;
611
                    }
612
                    break;
613
                }
614
615
                /*
616
                 * NOTE: we don't update skipped blocks in the previous frame buffer
617
                 * since skipped needs always to be compared against the first skipped
618
                 * block to avoid artifacts during gradual fade in/outs.
619
                 */
620
621
                // update_block_in_prev_frame(&src_pixels[block_offset],
622
                //   &prev_pixels[block_offset], &bi, block_counter + n_blocks);
623
624
                n_blocks++;
625
            }
626
627
            // we're either at the end of the frame or we've reached the maximum
628
            // of 32 blocks in a run. Write out the run.
629
            if (n_blocks) {
630
                // write skip opcode
631
                put_bits(&s->pb, 8, 0x80 | (n_blocks - 1));
632
                block_counter += n_blocks;
633
634
                continue;
635
            }
636
637
        } else {
638
            block_offset = get_block_info(&bi, block_counter);
639
        }
640
post_skip :
641
642
        // ONE COLOR CHECK
643
        if (update_block_stats(s, &bi, &src_pixels[block_offset],
644
                               min_color, max_color,
645
                               total_rgb, &pixel_count, avg_color, 1)) {
646
            prev_block_offset = block_offset;
647
648
            n_blocks = 1;
649
650
            /* update this block in the previous frame buffer */
651
            update_block_in_prev_frame(&src_pixels[block_offset],
652
                                       &prev_pixels[block_offset], &bi, block_counter + n_blocks);
653
654
            // check for subsequent blocks with the same color
655
            while (n_blocks < 32 && block_counter + n_blocks < total_blocks) {
656
                block_offset = get_block_info(&bi, block_counter + n_blocks);
657
658
                // multi-block opcodes cannot span multiple rows.
659
                // If we've hit end of a row, break out and write the opcode
660
                if (block_offset - prev_block_offset > 12) {
661
                    break;
662
                }
663
664
                if (!update_block_stats(s, &bi, &src_pixels[block_offset],
665
                                        min_color, max_color,
666
                                        total_rgb, &pixel_count, avg_color, 0)) {
667
                    break;
668
                }
669
670
                prev_block_offset = block_offset;
671
672
                /* update this block in the previous frame buffer */
673
                update_block_in_prev_frame(&src_pixels[block_offset],
674
                                           &prev_pixels[block_offset], &bi, block_counter + n_blocks);
675
676
                n_blocks++;
677
            }
678
679
            // write one color opcode.
680
            put_bits(&s->pb, 8, 0xa0 | (n_blocks - 1));
681
            // write color to encode.
682
            put_bits(&s->pb, 16, rgb24_to_rgb555(avg_color));
683
            // skip past the blocks we've just encoded.
684
            block_counter += n_blocks;
685
        } else { // FOUR COLOR CHECK
686
            int err = 0;
687
688
            // get max component diff for block
689
            get_max_component_diff(&bi, &src_pixels[block_offset], &min, &max, &chan);
690
691
            min_color[0] = 0;
692
            max_color[0] = 0;
693
            min_color[1] = 0;
694
            max_color[1] = 0;
695
            min_color[2] = 0;
696
            max_color[2] = 0;
697
698
            // run least squares against other two components
699
            for (i = 0; i < 3; i++) {
700
                if (i == chan) {
701
                    min_color[i] = min;
702
                    max_color[i] = max;
703
                    continue;
704
                }
705
706
                slope = y_intercept = correlation_coef = 0;
707
708
                if (leastsquares(&src_pixels[block_offset], &bi, chan, i,
709
                                 &slope, &y_intercept, &correlation_coef)) {
710
                    min_color[i] = GET_CHAN(src_pixels[block_offset], i);
711
                    max_color[i] = GET_CHAN(src_pixels[block_offset], i);
712
                } else {
713
                    tmp_min = (int)(0.5 + min * slope + y_intercept);
714
                    tmp_max = (int)(0.5 + max * slope + y_intercept);
715
716
                    av_assert0(tmp_min <= tmp_max);
717
                    // clamp min and max color values
718
                    tmp_min = av_clip_uint8(tmp_min);
719
                    tmp_max = av_clip_uint8(tmp_max);
720
721
                    err = FFMAX(calc_lsq_max_fit_error(&src_pixels[block_offset], &bi,
722
                                                       min, max, tmp_min, tmp_max, chan, i), err);
723
724
                    min_color[i] = tmp_min;
725
                    max_color[i] = tmp_max;
726
                }
727
            }
728
729
            if (err > s->sixteen_color_thresh) { // DO SIXTEEN COLOR BLOCK
730
                uint16_t *row_ptr;
731
                int rgb555;
732
733
                block_offset = get_block_info(&bi, block_counter);
734
735
                row_ptr = &src_pixels[block_offset];
736
737
                for (int y = 0; y < 4; y++) {
738
                    for (int x = 0; x < 4; x++){
739
                        rgb555 = row_ptr[x] & ~0x8000;
740
741
                        put_bits(&s->pb, 16, rgb555);
742
                    }
743
                    row_ptr += bi.rowstride;
744
                }
745
746
                block_counter++;
747
            } else { // FOUR COLOR BLOCK
748
                block_counter += encode_four_color_block(min_color, max_color,
749
                                                         &s->pb, &src_pixels[block_offset], &bi);
750
            }
751
752
            /* update this block in the previous frame buffer */
753
            update_block_in_prev_frame(&src_pixels[block_offset],
754
                                       &prev_pixels[block_offset], &bi, block_counter);
755
        }
756
    }
757
}
758
759
static int rpza_encode_init(AVCodecContext *avctx)
760
{
761
    RpzaContext *s = avctx->priv_data;
762
763
    s->frame_width = avctx->width;
764
    s->frame_height = avctx->height;
765
766
    s->prev_frame = av_frame_alloc();
767
    if (!s->prev_frame)
768
        return AVERROR(ENOMEM);
769
770
    return 0;
771
}
772
773
static int rpza_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
774
                                const AVFrame *frame, int *got_packet)
775
{
776
    RpzaContext *s = avctx->priv_data;
777
    const AVFrame *pict = frame;
778
    uint8_t *buf;
779
    int ret;
780
781
    if ((ret = ff_alloc_packet2(avctx, pkt, 6LL * avctx->height * avctx->width, 0)) < 0)
782
        return ret;
783
784
    init_put_bits(&s->pb, pkt->data, pkt->size);
785
786
    // skip 4 byte header, write it later once the size of the chunk is known
787
    put_bits32(&s->pb, 0x00);
788
789
    if (!s->prev_frame->data[0]) {
790
        s->first_frame = 1;
791
        s->prev_frame->format = pict->format;
792
        s->prev_frame->width = pict->width;
793
        s->prev_frame->height = pict->height;
794
        ret = av_frame_get_buffer(s->prev_frame, 0);
795
        if (ret < 0)
796
            return ret;
797
    } else {
798
        s->first_frame = 0;
799
    }
800
801
    rpza_encode_stream(s, pict);
802
803
    flush_put_bits(&s->pb);
804
805
    av_shrink_packet(pkt, put_bits_count(&s->pb) >> 3);
806
    buf = pkt->data;
807
808
    // write header opcode
809
    buf[0] = 0xe1; // chunk opcode
810
811
    // write chunk length
812
    AV_WB24(buf + 1, pkt->size);
813
814
    *got_packet = 1;
815
816
    return 0;
817
}
818
819
static int rpza_encode_end(AVCodecContext *avctx)
820
{
821
    RpzaContext *s = (RpzaContext *)avctx->priv_data;
822
823
    av_frame_free(&s->prev_frame);
824
825
    return 0;
826
}
827
828
#define OFFSET(x) offsetof(RpzaContext, x)
829
#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
830
static const AVOption options[] = {
831
    { "skip_frame_thresh", NULL, OFFSET(skip_frame_thresh), AV_OPT_TYPE_INT, {.i64=1}, 0, 24, VE},
832
    { "start_one_color_thresh", NULL, OFFSET(start_one_color_thresh), AV_OPT_TYPE_INT, {.i64=1}, 0, 24, VE},
833
    { "continue_one_color_thresh", NULL, OFFSET(continue_one_color_thresh), AV_OPT_TYPE_INT, {.i64=0}, 0, 24, VE},
834
    { "sixteen_color_thresh", NULL, OFFSET(sixteen_color_thresh), AV_OPT_TYPE_INT, {.i64=1}, 0, 24, VE},
835
    { NULL },
836
};
837
838
static const AVClass rpza_class = {
839
    .class_name = "rpza",
840
    .item_name  = av_default_item_name,
841
    .option     = options,
842
    .version    = LIBAVUTIL_VERSION_INT,
843
};
844
845
AVCodec ff_rpza_encoder = {
846
    .name           = "rpza",
847
    .long_name      = NULL_IF_CONFIG_SMALL("QuickTime video (RPZA)"),
848
    .type           = AVMEDIA_TYPE_VIDEO,
849
    .id             = AV_CODEC_ID_RPZA,
850
    .priv_data_size = sizeof(RpzaContext),
851
    .priv_class     = &rpza_class,
852
    .init           = rpza_encode_init,
853
    .encode2        = rpza_encode_frame,
854
    .close          = rpza_encode_end,
855
    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE,
856
    .pix_fmts       = (const enum AVPixelFormat[]) { AV_PIX_FMT_RGB555,
857
                                                     AV_PIX_FMT_NONE},
858
};