1/*
2 * Cinepak encoder (c) 2011 Tomas Härdin
3 * http://titan.codemill.se/~tomhar/cinepakenc.patch
4 *
5 * Fixes and improvements, vintage decoders compatibility
6 *  (c) 2013, 2014 Rl, Aetey Global Technologies AB
7 *
8 * Permission is hereby granted, free of charge, to any person obtaining a
9 * copy of this software and associated documentation files (the "Software"),
10 * to deal in the Software without restriction, including without limitation
11 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
12 * and/or sell copies of the Software, and to permit persons to whom the
13 * Software is furnished to do so, subject to the following conditions:
14 *
15 * The above copyright notice and this permission notice shall be included
16 * in all copies or substantial portions of the Software.
17 *
18 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
19 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
20 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
21 * THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
22 * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
23 * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
24 * OTHER DEALINGS IN THE SOFTWARE.
25 */
26
27/*
28 * TODO:
29 * - optimize: color space conversion (move conversion to libswscale), ...
30 * MAYBE:
31 * - "optimally" split the frame into several non-regular areas
32 *   using a separate codebook pair for each area and approximating
33 *   the area by several rectangular strips (generally not full width ones)
34 *   (use quadtree splitting? a simple fixed-granularity grid?)
35 */
36
37#include <string.h>
38
39#include "libavutil/avassert.h"
40#include "libavutil/common.h"
41#include "libavutil/internal.h"
42#include "libavutil/intreadwrite.h"
43#include "libavutil/lfg.h"
44#include "libavutil/opt.h"
45
46#include "avcodec.h"
47#include "codec_internal.h"
48#include "elbg.h"
49#include "encode.h"
50
51#define CVID_HEADER_SIZE 10
52#define STRIP_HEADER_SIZE 12
53#define CHUNK_HEADER_SIZE 4
54
55#define MB_SIZE 4           //4x4 MBs
56#define MB_AREA (MB_SIZE * MB_SIZE)
57
58#define VECTOR_MAX     6    // six or four entries per vector depending on format
59#define CODEBOOK_MAX 256    // size of a codebook
60
61#define MAX_STRIPS  32      // Note: having fewer choices regarding the number of strips speeds up encoding (obviously)
62#define MIN_STRIPS   1      // Note: having more strips speeds up encoding the frame (this is less obvious)
63// MAX_STRIPS limits the maximum quality you can reach
64//            when you want high quality on high resolutions,
65// MIN_STRIPS limits the minimum efficiently encodable bit rate
66//            on low resolutions
67// the numbers are only used for brute force optimization for the first frame,
68// for the following frames they are adaptively readjusted
69// NOTE the decoder in ffmpeg has its own arbitrary limitation on the number
70// of strips, currently 32
71
72typedef enum CinepakMode {
73    MODE_V1_ONLY = 0,
74    MODE_V1_V4,
75    MODE_MC,
76
77    MODE_COUNT,
78} CinepakMode;
79
80typedef enum mb_encoding {
81    ENC_V1,
82    ENC_V4,
83    ENC_SKIP,
84
85    ENC_UNCERTAIN
86} mb_encoding;
87
88typedef struct mb_info {
89    int v1_vector;              // index into v1 codebook
90    int v1_error;               // error when using V1 encoding
91    int v4_vector[4];           // indices into v4 codebook
92    int v4_error;               // error when using V4 encoding
93    int skip_error;             // error when block is skipped (aka copied from last frame)
94    mb_encoding best_encoding;  // last result from calculate_mode_score()
95} mb_info;
96
97typedef struct strip_info {
98    int v1_codebook[CODEBOOK_MAX * VECTOR_MAX];
99    int v4_codebook[CODEBOOK_MAX * VECTOR_MAX];
100    int v1_size;
101    int v4_size;
102    CinepakMode mode;
103} strip_info;
104
105typedef struct CinepakEncContext {
106    const AVClass *class;
107    AVCodecContext *avctx;
108    unsigned char *pict_bufs[4], *strip_buf, *frame_buf;
109    AVFrame *last_frame;
110    AVFrame *best_frame;
111    AVFrame *scratch_frame;
112    AVFrame *input_frame;
113    enum AVPixelFormat pix_fmt;
114    int w, h;
115    int frame_buf_size;
116    int curframe;
117    AVLFG randctx;
118    uint64_t lambda;
119    int *codebook_input;
120    int *codebook_closest;
121    mb_info *mb;                // MB RD state
122    int min_strips;             // the current limit
123    int max_strips;             // the current limit
124    // options
125    int max_extra_cb_iterations;
126    int skip_empty_cb;
127    int min_min_strips;
128    int max_max_strips;
129    int strip_number_delta_range;
130    struct ELBGContext *elbg;
131} CinepakEncContext;
132
133#define OFFSET(x) offsetof(CinepakEncContext, x)
134#define VE AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_ENCODING_PARAM
135static const AVOption options[] = {
136    { "max_extra_cb_iterations", "Max extra codebook recalculation passes, more is better and slower",
137      OFFSET(max_extra_cb_iterations),  AV_OPT_TYPE_INT, { .i64 =          2 },          0, INT_MAX,                 VE },
138    { "skip_empty_cb",           "Avoid wasting bytes, ignore vintage MacOS decoder",
139      OFFSET(skip_empty_cb),            AV_OPT_TYPE_BOOL, { .i64 =         0 },          0, 1,                       VE },
140    { "max_strips",              "Limit strips/frame, vintage compatible is 1..3, otherwise the more the better",
141      OFFSET(max_max_strips),           AV_OPT_TYPE_INT, { .i64 =          3 }, MIN_STRIPS, MAX_STRIPS,              VE },
142    { "min_strips",              "Enforce min strips/frame, more is worse and faster, must be <= max_strips",
143      OFFSET(min_min_strips),           AV_OPT_TYPE_INT, { .i64 = MIN_STRIPS }, MIN_STRIPS, MAX_STRIPS,              VE },
144    { "strip_number_adaptivity", "How fast the strip number adapts, more is slightly better, much slower",
145      OFFSET(strip_number_delta_range), AV_OPT_TYPE_INT, { .i64 =          0 },          0, MAX_STRIPS - MIN_STRIPS, VE },
146    { NULL },
147};
148
149static const AVClass cinepak_class = {
150    .class_name = "cinepak",
151    .item_name  = av_default_item_name,
152    .option     = options,
153    .version    = LIBAVUTIL_VERSION_INT,
154};
155
156static av_cold int cinepak_encode_init(AVCodecContext *avctx)
157{
158    CinepakEncContext *s = avctx->priv_data;
159    int x, mb_count, strip_buf_size, frame_buf_size;
160
161    if (avctx->width & 3 || avctx->height & 3) {
162        av_log(avctx, AV_LOG_ERROR, "width and height must be multiples of four (got %ix%i)\n",
163               avctx->width, avctx->height);
164        return AVERROR(EINVAL);
165    }
166
167    if (s->min_min_strips > s->max_max_strips) {
168        av_log(avctx, AV_LOG_ERROR, "minimum number of strips must not exceed maximum (got %i and %i)\n",
169               s->min_min_strips, s->max_max_strips);
170        return AVERROR(EINVAL);
171    }
172
173    if (!(s->last_frame = av_frame_alloc()))
174        return AVERROR(ENOMEM);
175    if (!(s->best_frame = av_frame_alloc()))
176        return AVERROR(ENOMEM);
177    if (!(s->scratch_frame = av_frame_alloc()))
178        return AVERROR(ENOMEM);
179    if (avctx->pix_fmt == AV_PIX_FMT_RGB24)
180        if (!(s->input_frame = av_frame_alloc()))
181            return AVERROR(ENOMEM);
182
183    if (!(s->codebook_input = av_malloc_array((avctx->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4) * (avctx->width * avctx->height) >> 2, sizeof(*s->codebook_input))))
184        return AVERROR(ENOMEM);
185
186    if (!(s->codebook_closest = av_malloc_array((avctx->width * avctx->height) >> 2, sizeof(*s->codebook_closest))))
187        return AVERROR(ENOMEM);
188
189    for (x = 0; x < (avctx->pix_fmt == AV_PIX_FMT_RGB24 ? 4 : 3); x++)
190        if (!(s->pict_bufs[x] = av_malloc((avctx->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4) * (avctx->width * avctx->height) >> 2)))
191            return AVERROR(ENOMEM);
192
193    mb_count = avctx->width * avctx->height / MB_AREA;
194
195    // the largest possible chunk is 0x31 with all MBs encoded in V4 mode
196    // and full codebooks being replaced in INTER mode,
197    // which is 34 bits per MB
198    // and 2*256 extra flag bits per strip
199    strip_buf_size = STRIP_HEADER_SIZE + 3 * CHUNK_HEADER_SIZE + 2 * VECTOR_MAX * CODEBOOK_MAX + 4 * (mb_count + (mb_count + 15) / 16) + (2 * CODEBOOK_MAX) / 8;
200
201    frame_buf_size = CVID_HEADER_SIZE + s->max_max_strips * strip_buf_size;
202
203    if (!(s->strip_buf = av_malloc(strip_buf_size)))
204        return AVERROR(ENOMEM);
205
206    if (!(s->frame_buf = av_malloc(frame_buf_size)))
207        return AVERROR(ENOMEM);
208
209    if (!(s->mb = av_malloc_array(mb_count, sizeof(mb_info))))
210        return AVERROR(ENOMEM);
211
212    av_lfg_init(&s->randctx, 1);
213    s->avctx          = avctx;
214    s->w              = avctx->width;
215    s->h              = avctx->height;
216    s->frame_buf_size = frame_buf_size;
217    s->curframe       = 0;
218    s->pix_fmt        = avctx->pix_fmt;
219
220    // set up AVFrames
221    s->last_frame->data[0]        = s->pict_bufs[0];
222    s->last_frame->linesize[0]    = s->w;
223    s->best_frame->data[0]        = s->pict_bufs[1];
224    s->best_frame->linesize[0]    = s->w;
225    s->scratch_frame->data[0]     = s->pict_bufs[2];
226    s->scratch_frame->linesize[0] = s->w;
227
228    if (s->pix_fmt == AV_PIX_FMT_RGB24) {
229        s->last_frame->data[1]     = s->last_frame->data[0] +   s->w * s->h;
230        s->last_frame->data[2]     = s->last_frame->data[1] + ((s->w * s->h) >> 2);
231        s->last_frame->linesize[1] =
232        s->last_frame->linesize[2] = s->w >> 1;
233
234        s->best_frame->data[1]     = s->best_frame->data[0] +   s->w * s->h;
235        s->best_frame->data[2]     = s->best_frame->data[1] + ((s->w * s->h) >> 2);
236        s->best_frame->linesize[1] =
237        s->best_frame->linesize[2] = s->w >> 1;
238
239        s->scratch_frame->data[1]     = s->scratch_frame->data[0] +   s->w * s->h;
240        s->scratch_frame->data[2]     = s->scratch_frame->data[1] + ((s->w * s->h) >> 2);
241        s->scratch_frame->linesize[1] =
242        s->scratch_frame->linesize[2] = s->w >> 1;
243
244        s->input_frame->data[0]     = s->pict_bufs[3];
245        s->input_frame->linesize[0] = s->w;
246        s->input_frame->data[1]     = s->input_frame->data[0] +   s->w * s->h;
247        s->input_frame->data[2]     = s->input_frame->data[1] + ((s->w * s->h) >> 2);
248        s->input_frame->linesize[1] =
249        s->input_frame->linesize[2] = s->w >> 1;
250    }
251
252    s->min_strips = s->min_min_strips;
253    s->max_strips = s->max_max_strips;
254
255    return 0;
256}
257
258static int64_t calculate_mode_score(CinepakEncContext *s, int h,
259                                    strip_info *info, int report,
260                                    int *training_set_v1_shrunk,
261                                    int *training_set_v4_shrunk)
262{
263    // score = FF_LAMBDA_SCALE * error + lambda * bits
264    int x;
265    int entry_size = s->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4;
266    int mb_count   = s->w * h / MB_AREA;
267    mb_info *mb;
268    int64_t score1, score2, score3;
269    int64_t ret = s->lambda * ((info->v1_size ? CHUNK_HEADER_SIZE + info->v1_size * entry_size : 0) +
270                               (info->v4_size ? CHUNK_HEADER_SIZE + info->v4_size * entry_size : 0) +
271                               CHUNK_HEADER_SIZE) << 3;
272
273    switch (info->mode) {
274    case MODE_V1_ONLY:
275        // one byte per MB
276        ret += s->lambda * 8 * mb_count;
277
278        // while calculating we assume all blocks are ENC_V1
279        for (x = 0; x < mb_count; x++) {
280            mb   = &s->mb[x];
281            ret += FF_LAMBDA_SCALE * mb->v1_error;
282            // this function is never called for report in MODE_V1_ONLY
283            // if (!report)
284            mb->best_encoding = ENC_V1;
285        }
286
287        break;
288    case MODE_V1_V4:
289        // 9 or 33 bits per MB
290        if (report) {
291            // no moves between the corresponding training sets are allowed
292            *training_set_v1_shrunk = *training_set_v4_shrunk = 0;
293            for (x = 0; x < mb_count; x++) {
294                int mberr;
295                mb = &s->mb[x];
296                if (mb->best_encoding == ENC_V1)
297                    score1 = s->lambda * 9 + FF_LAMBDA_SCALE * (mberr = mb->v1_error);
298                else
299                    score1 = s->lambda * 33 + FF_LAMBDA_SCALE * (mberr = mb->v4_error);
300                ret += score1;
301            }
302        } else { // find best mode per block
303            for (x = 0; x < mb_count; x++) {
304                mb     = &s->mb[x];
305                score1 = s->lambda * 9 + FF_LAMBDA_SCALE * mb->v1_error;
306                score2 = s->lambda * 33 + FF_LAMBDA_SCALE * mb->v4_error;
307
308                if (score1 <= score2) {
309                    ret += score1;
310                    mb->best_encoding = ENC_V1;
311                } else {
312                    ret += score2;
313                    mb->best_encoding = ENC_V4;
314                }
315            }
316        }
317
318        break;
319    case MODE_MC:
320        // 1, 10 or 34 bits per MB
321        if (report) {
322            int v1_shrunk = 0, v4_shrunk = 0;
323            for (x = 0; x < mb_count; x++) {
324                mb = &s->mb[x];
325                // it is OK to move blocks to ENC_SKIP here
326                // but not to any codebook encoding!
327                score1 = s->lambda * 1 + FF_LAMBDA_SCALE * mb->skip_error;
328                if (mb->best_encoding == ENC_SKIP) {
329                    ret += score1;
330                } else if (mb->best_encoding == ENC_V1) {
331                    if ((score2 = s->lambda * 10 + FF_LAMBDA_SCALE * mb->v1_error) >= score1) {
332                        mb->best_encoding = ENC_SKIP;
333                        ++v1_shrunk;
334                        ret += score1;
335                    } else {
336                        ret += score2;
337                    }
338                } else {
339                    if ((score3 = s->lambda * 34 + FF_LAMBDA_SCALE * mb->v4_error) >= score1) {
340                        mb->best_encoding = ENC_SKIP;
341                        ++v4_shrunk;
342                        ret += score1;
343                    } else {
344                        ret += score3;
345                    }
346                }
347            }
348            *training_set_v1_shrunk = v1_shrunk;
349            *training_set_v4_shrunk = v4_shrunk;
350        } else { // find best mode per block
351            for (x = 0; x < mb_count; x++) {
352                mb     = &s->mb[x];
353                score1 = s->lambda * 1 + FF_LAMBDA_SCALE * mb->skip_error;
354                score2 = s->lambda * 10 + FF_LAMBDA_SCALE * mb->v1_error;
355                score3 = s->lambda * 34 + FF_LAMBDA_SCALE * mb->v4_error;
356
357                if (score1 <= score2 && score1 <= score3) {
358                    ret += score1;
359                    mb->best_encoding = ENC_SKIP;
360                } else if (score2 <= score3) {
361                    ret += score2;
362                    mb->best_encoding = ENC_V1;
363                } else {
364                    ret += score3;
365                    mb->best_encoding = ENC_V4;
366                }
367            }
368        }
369
370        break;
371    }
372
373    return ret;
374}
375
376static int write_chunk_header(unsigned char *buf, int chunk_type, int chunk_size)
377{
378    buf[0] = chunk_type;
379    AV_WB24(&buf[1], chunk_size + CHUNK_HEADER_SIZE);
380    return CHUNK_HEADER_SIZE;
381}
382
383static int encode_codebook(CinepakEncContext *s, int *codebook, int size,
384                           int chunk_type_yuv, int chunk_type_gray,
385                           unsigned char *buf)
386{
387    int x, y, ret, entry_size = s->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4;
388    int incremental_codebook_replacement_mode = 0; // hardcoded here,
389    // the compiler should notice that this is a constant -- rl
390
391    ret = write_chunk_header(buf,
392                             s->pix_fmt == AV_PIX_FMT_RGB24 ?
393                             chunk_type_yuv  + (incremental_codebook_replacement_mode ? 1 : 0) :
394                             chunk_type_gray + (incremental_codebook_replacement_mode ? 1 : 0),
395                             entry_size * size +
396                             (incremental_codebook_replacement_mode ? (size + 31) / 32 * 4 : 0));
397
398    // we do codebook encoding according to the "intra" mode
399    // but we keep the "dead" code for reference in case we will want
400    // to use incremental codebook updates (which actually would give us
401    // "kind of" motion compensation, especially in 1 strip/frame case) -- rl
402    // (of course, the code will be not useful as-is)
403    if (incremental_codebook_replacement_mode) {
404        int flags = 0;
405        int flagsind;
406        for (x = 0; x < size; x++) {
407            if (flags == 0) {
408                flagsind = ret;
409                ret     += 4;
410                flags    = 0x80000000;
411            } else
412                flags = ((flags >> 1) | 0x80000000);
413            for (y = 0; y < entry_size; y++)
414                buf[ret++] = codebook[y + x * entry_size] ^ (y >= 4 ? 0x80 : 0);
415            if ((flags & 0xffffffff) == 0xffffffff) {
416                AV_WB32(&buf[flagsind], flags);
417                flags = 0;
418            }
419        }
420        if (flags)
421            AV_WB32(&buf[flagsind], flags);
422    } else
423        for (x = 0; x < size; x++)
424            for (y = 0; y < entry_size; y++)
425                buf[ret++] = codebook[y + x * entry_size] ^ (y >= 4 ? 0x80 : 0);
426
427    return ret;
428}
429
430// sets out to the sub picture starting at (x,y) in in
431static void get_sub_picture(CinepakEncContext *s, int x, int y,
432                            uint8_t * in_data[4], int  in_linesize[4],
433                            uint8_t *out_data[4], int out_linesize[4])
434{
435    out_data[0]     = in_data[0] + x + y * in_linesize[0];
436    out_linesize[0] = in_linesize[0];
437
438    if (s->pix_fmt == AV_PIX_FMT_RGB24) {
439        out_data[1]     = in_data[1] + (x >> 1) + (y >> 1) * in_linesize[1];
440        out_linesize[1] = in_linesize[1];
441
442        out_data[2]     = in_data[2] + (x >> 1) + (y >> 1) * in_linesize[2];
443        out_linesize[2] = in_linesize[2];
444    }
445}
446
447// decodes the V1 vector in mb into the 4x4 MB pointed to by data
448static void decode_v1_vector(CinepakEncContext *s, uint8_t *data[4],
449                             int linesize[4], int v1_vector, strip_info *info)
450{
451    int entry_size = s->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4;
452
453    data[0][0] =
454    data[0][1] =
455    data[0][    linesize[0]] =
456    data[0][1 + linesize[0]] = info->v1_codebook[v1_vector * entry_size];
457
458    data[0][2] =
459    data[0][3] =
460    data[0][2 + linesize[0]] =
461    data[0][3 + linesize[0]] = info->v1_codebook[v1_vector * entry_size + 1];
462
463    data[0][    2 * linesize[0]] =
464    data[0][1 + 2 * linesize[0]] =
465    data[0][    3 * linesize[0]] =
466    data[0][1 + 3 * linesize[0]] = info->v1_codebook[v1_vector * entry_size + 2];
467
468    data[0][2 + 2 * linesize[0]] =
469    data[0][3 + 2 * linesize[0]] =
470    data[0][2 + 3 * linesize[0]] =
471    data[0][3 + 3 * linesize[0]] = info->v1_codebook[v1_vector * entry_size + 3];
472
473    if (s->pix_fmt == AV_PIX_FMT_RGB24) {
474        data[1][0] =
475        data[1][1] =
476        data[1][    linesize[1]] =
477        data[1][1 + linesize[1]] = info->v1_codebook[v1_vector * entry_size + 4];
478
479        data[2][0] =
480        data[2][1] =
481        data[2][    linesize[2]] =
482        data[2][1 + linesize[2]] = info->v1_codebook[v1_vector * entry_size + 5];
483    }
484}
485
486// decodes the V4 vectors in mb into the 4x4 MB pointed to by data
487static void decode_v4_vector(CinepakEncContext *s, uint8_t *data[4],
488                             int linesize[4], int *v4_vector, strip_info *info)
489{
490    int i, x, y, entry_size = s->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4;
491
492    for (i = y = 0; y < 4; y += 2) {
493        for (x = 0; x < 4; x += 2, i++) {
494            data[0][x     +  y      * linesize[0]] = info->v4_codebook[v4_vector[i] * entry_size];
495            data[0][x + 1 +  y      * linesize[0]] = info->v4_codebook[v4_vector[i] * entry_size + 1];
496            data[0][x     + (y + 1) * linesize[0]] = info->v4_codebook[v4_vector[i] * entry_size + 2];
497            data[0][x + 1 + (y + 1) * linesize[0]] = info->v4_codebook[v4_vector[i] * entry_size + 3];
498
499            if (s->pix_fmt == AV_PIX_FMT_RGB24) {
500                data[1][(x >> 1) + (y >> 1) * linesize[1]] = info->v4_codebook[v4_vector[i] * entry_size + 4];
501                data[2][(x >> 1) + (y >> 1) * linesize[2]] = info->v4_codebook[v4_vector[i] * entry_size + 5];
502            }
503        }
504    }
505}
506
507static void copy_mb(CinepakEncContext *s,
508                    uint8_t *a_data[4], int a_linesize[4],
509                    uint8_t *b_data[4], int b_linesize[4])
510{
511    int y, p;
512
513    for (y = 0; y < MB_SIZE; y++)
514        memcpy(a_data[0] + y * a_linesize[0], b_data[0] + y * b_linesize[0],
515               MB_SIZE);
516
517    if (s->pix_fmt == AV_PIX_FMT_RGB24) {
518        for (p = 1; p <= 2; p++)
519            for (y = 0; y < MB_SIZE / 2; y++)
520                memcpy(a_data[p] + y * a_linesize[p],
521                       b_data[p] + y * b_linesize[p],
522                       MB_SIZE / 2);
523    }
524}
525
526static int encode_mode(CinepakEncContext *s, int h,
527                       uint8_t *scratch_data[4], int scratch_linesize[4],
528                       uint8_t *last_data[4], int last_linesize[4],
529                       strip_info *info, unsigned char *buf)
530{
531    int x, y, z, bits, temp_size, header_ofs, ret = 0, mb_count = s->w * h / MB_AREA;
532    int needs_extra_bit, should_write_temp;
533    uint32_t flags;
534    unsigned char temp[64]; // 32/2 = 16 V4 blocks at 4 B each -> 64 B
535    mb_info *mb;
536    uint8_t *sub_scratch_data[4] = { 0 }, *sub_last_data[4] = { 0 };
537    int sub_scratch_linesize[4] = { 0 }, sub_last_linesize[4] = { 0 };
538
539    // encode codebooks
540    ////// MacOS vintage decoder compatibility dictates the presence of
541    ////// the codebook chunk even when the codebook is empty - pretty dumb...
542    ////// and also the certain order of the codebook chunks -- rl
543    if (info->v4_size || !s->skip_empty_cb)
544        ret += encode_codebook(s, info->v4_codebook, info->v4_size, 0x20, 0x24, buf + ret);
545
546    if (info->v1_size || !s->skip_empty_cb)
547        ret += encode_codebook(s, info->v1_codebook, info->v1_size, 0x22, 0x26, buf + ret);
548
549    // update scratch picture
550    for (z = y = 0; y < h; y += MB_SIZE)
551        for (x = 0; x < s->w; x += MB_SIZE, z++) {
552            mb = &s->mb[z];
553
554            get_sub_picture(s, x, y, scratch_data, scratch_linesize,
555                            sub_scratch_data, sub_scratch_linesize);
556
557            if (info->mode == MODE_MC && mb->best_encoding == ENC_SKIP) {
558                get_sub_picture(s, x, y, last_data, last_linesize,
559                                sub_last_data, sub_last_linesize);
560                copy_mb(s, sub_scratch_data, sub_scratch_linesize,
561                        sub_last_data, sub_last_linesize);
562            } else if (info->mode == MODE_V1_ONLY || mb->best_encoding == ENC_V1)
563                decode_v1_vector(s, sub_scratch_data, sub_scratch_linesize,
564                                 mb->v1_vector, info);
565            else
566                decode_v4_vector(s, sub_scratch_data, sub_scratch_linesize,
567                                 mb->v4_vector, info);
568        }
569
570    switch (info->mode) {
571    case MODE_V1_ONLY:
572        ret += write_chunk_header(buf + ret, 0x32, mb_count);
573
574        for (x = 0; x < mb_count; x++)
575            buf[ret++] = s->mb[x].v1_vector;
576
577        break;
578    case MODE_V1_V4:
579        // remember header position
580        header_ofs = ret;
581        ret       += CHUNK_HEADER_SIZE;
582
583        for (x = 0; x < mb_count; x += 32) {
584            flags = 0;
585            for (y = x; y < FFMIN(x + 32, mb_count); y++)
586                if (s->mb[y].best_encoding == ENC_V4)
587                    flags |= 1U << (31 - y + x);
588
589            AV_WB32(&buf[ret], flags);
590            ret += 4;
591
592            for (y = x; y < FFMIN(x + 32, mb_count); y++) {
593                mb = &s->mb[y];
594
595                if (mb->best_encoding == ENC_V1)
596                    buf[ret++] = mb->v1_vector;
597                else
598                    for (z = 0; z < 4; z++)
599                        buf[ret++] = mb->v4_vector[z];
600            }
601        }
602
603        write_chunk_header(buf + header_ofs, 0x30, ret - header_ofs - CHUNK_HEADER_SIZE);
604
605        break;
606    case MODE_MC:
607        // remember header position
608        header_ofs = ret;
609        ret       += CHUNK_HEADER_SIZE;
610        flags      = bits = temp_size = 0;
611
612        for (x = 0; x < mb_count; x++) {
613            mb                = &s->mb[x];
614            flags            |= (uint32_t)(mb->best_encoding != ENC_SKIP) << (31 - bits++);
615            needs_extra_bit   = 0;
616            should_write_temp = 0;
617
618            if (mb->best_encoding != ENC_SKIP) {
619                if (bits < 32)
620                    flags |= (uint32_t)(mb->best_encoding == ENC_V4) << (31 - bits++);
621                else
622                    needs_extra_bit = 1;
623            }
624
625            if (bits == 32) {
626                AV_WB32(&buf[ret], flags);
627                ret  += 4;
628                flags = bits = 0;
629
630                if (mb->best_encoding == ENC_SKIP || needs_extra_bit) {
631                    memcpy(&buf[ret], temp, temp_size);
632                    ret      += temp_size;
633                    temp_size = 0;
634                } else
635                    should_write_temp = 1;
636            }
637
638            if (needs_extra_bit) {
639                flags = (uint32_t)(mb->best_encoding == ENC_V4) << 31;
640                bits  = 1;
641            }
642
643            if (mb->best_encoding == ENC_V1)
644                temp[temp_size++] = mb->v1_vector;
645            else if (mb->best_encoding == ENC_V4)
646                for (z = 0; z < 4; z++)
647                    temp[temp_size++] = mb->v4_vector[z];
648
649            if (should_write_temp) {
650                memcpy(&buf[ret], temp, temp_size);
651                ret      += temp_size;
652                temp_size = 0;
653            }
654        }
655
656        if (bits > 0) {
657            AV_WB32(&buf[ret], flags);
658            ret += 4;
659            memcpy(&buf[ret], temp, temp_size);
660            ret += temp_size;
661        }
662
663        write_chunk_header(buf + header_ofs, 0x31, ret - header_ofs - CHUNK_HEADER_SIZE);
664
665        break;
666    }
667
668    return ret;
669}
670
671// computes distortion of 4x4 MB in b compared to a
672static int compute_mb_distortion(CinepakEncContext *s,
673                                 uint8_t *a_data[4], int a_linesize[4],
674                                 uint8_t *b_data[4], int b_linesize[4])
675{
676    int x, y, p, d, ret = 0;
677
678    for (y = 0; y < MB_SIZE; y++)
679        for (x = 0; x < MB_SIZE; x++) {
680            d = a_data[0][x + y * a_linesize[0]] - b_data[0][x + y * b_linesize[0]];
681            ret += d * d;
682        }
683
684    if (s->pix_fmt == AV_PIX_FMT_RGB24) {
685        for (p = 1; p <= 2; p++) {
686            for (y = 0; y < MB_SIZE / 2; y++)
687                for (x = 0; x < MB_SIZE / 2; x++) {
688                    d = a_data[p][x + y * a_linesize[p]] - b_data[p][x + y * b_linesize[p]];
689                    ret += d * d;
690                }
691        }
692    }
693
694    return ret;
695}
696
697// return the possibly adjusted size of the codebook
698#define CERTAIN(x) ((x) != ENC_UNCERTAIN)
699static int quantize(CinepakEncContext *s, int h, uint8_t *data[4],
700                    int linesize[4], int v1mode, strip_info *info,
701                    mb_encoding encoding)
702{
703    int x, y, i, j, k, x2, y2, x3, y3, plane, shift, mbn;
704    int entry_size      = s->pix_fmt == AV_PIX_FMT_RGB24 ? 6 : 4;
705    int *codebook       = v1mode ? info->v1_codebook : info->v4_codebook;
706    int size            = v1mode ? info->v1_size : info->v4_size;
707    uint8_t vq_pict_buf[(MB_AREA * 3) / 2];
708    uint8_t     *sub_data[4],     *vq_data[4];
709    int      sub_linesize[4],  vq_linesize[4];
710    int ret;
711
712    for (mbn = i = y = 0; y < h; y += MB_SIZE) {
713        for (x = 0; x < s->w; x += MB_SIZE, ++mbn) {
714            int *base;
715
716            if (CERTAIN(encoding)) {
717                // use for the training only the blocks known to be to be encoded [sic:-]
718                if (s->mb[mbn].best_encoding != encoding)
719                    continue;
720            }
721
722            base = s->codebook_input + i * entry_size;
723            if (v1mode) {
724                // subsample
725                for (j = y2 = 0; y2 < entry_size; y2 += 2)
726                    for (x2 = 0; x2 < 4; x2 += 2, j++) {
727                        plane   = y2 < 4 ? 0 : 1 + (x2 >> 1);
728                        shift   = y2 < 4 ? 0 : 1;
729                        x3      = shift ? 0 : x2;
730                        y3      = shift ? 0 : y2;
731                        base[j] = (data[plane][((x + x3) >> shift) +      ((y + y3) >> shift)      * linesize[plane]] +
732                                   data[plane][((x + x3) >> shift) + 1 +  ((y + y3) >> shift)      * linesize[plane]] +
733                                   data[plane][((x + x3) >> shift) +     (((y + y3) >> shift) + 1) * linesize[plane]] +
734                                   data[plane][((x + x3) >> shift) + 1 + (((y + y3) >> shift) + 1) * linesize[plane]]) >> 2;
735                    }
736            } else {
737                // copy
738                for (j = y2 = 0; y2 < MB_SIZE; y2 += 2) {
739                    for (x2 = 0; x2 < MB_SIZE; x2 += 2)
740                        for (k = 0; k < entry_size; k++, j++) {
741                            plane = k >= 4 ? k - 3 : 0;
742
743                            if (k >= 4) {
744                                x3 = (x + x2) >> 1;
745                                y3 = (y + y2) >> 1;
746                            } else {
747                                x3 = x + x2 + (k & 1);
748                                y3 = y + y2 + (k >> 1);
749                            }
750
751                            base[j] = data[plane][x3 + y3 * linesize[plane]];
752                        }
753                }
754            }
755            i += v1mode ? 1 : 4;
756        }
757    }
758
759    if (i == 0) // empty training set, nothing to do
760        return 0;
761    if (i < size)
762        size = i;
763
764    ret = avpriv_elbg_do(&s->elbg, s->codebook_input, entry_size, i, codebook,
765                         size, 1, s->codebook_closest, &s->randctx, 0);
766    if (ret < 0)
767        return ret;
768
769    // set up vq_data, which contains a single MB
770    vq_data[0]     = vq_pict_buf;
771    vq_linesize[0] = MB_SIZE;
772    vq_data[1]     = &vq_pict_buf[MB_AREA];
773    vq_data[2]     = vq_data[1] + (MB_AREA >> 2);
774    vq_linesize[1] =
775    vq_linesize[2] = MB_SIZE >> 1;
776
777    // copy indices
778    for (i = j = y = 0; y < h; y += MB_SIZE)
779        for (x = 0; x < s->w; x += MB_SIZE, j++) {
780            mb_info *mb = &s->mb[j];
781            // skip uninteresting blocks if we know their preferred encoding
782            if (CERTAIN(encoding) && mb->best_encoding != encoding)
783                continue;
784
785            // point sub_data to current MB
786            get_sub_picture(s, x, y, data, linesize, sub_data, sub_linesize);
787
788            if (v1mode) {
789                mb->v1_vector = s->codebook_closest[i];
790
791                // fill in vq_data with V1 data
792                decode_v1_vector(s, vq_data, vq_linesize, mb->v1_vector, info);
793
794                mb->v1_error = compute_mb_distortion(s, sub_data, sub_linesize,
795                                                     vq_data, vq_linesize);
796            } else {
797                for (k = 0; k < 4; k++)
798                    mb->v4_vector[k] = s->codebook_closest[i + k];
799
800                // fill in vq_data with V4 data
801                decode_v4_vector(s, vq_data, vq_linesize, mb->v4_vector, info);
802
803                mb->v4_error = compute_mb_distortion(s, sub_data, sub_linesize,
804                                                     vq_data, vq_linesize);
805            }
806            i += v1mode ? 1 : 4;
807        }
808    // check that we did it right in the beginning of the function
809    av_assert0(i >= size); // training set is no smaller than the codebook
810
811    return size;
812}
813
814static void calculate_skip_errors(CinepakEncContext *s, int h,
815                                  uint8_t *last_data[4], int last_linesize[4],
816                                  uint8_t *data[4], int linesize[4],
817                                  strip_info *info)
818{
819    int x, y, i;
820    uint8_t *sub_last_data    [4], *sub_pict_data    [4];
821    int      sub_last_linesize[4],  sub_pict_linesize[4];
822
823    for (i = y = 0; y < h; y += MB_SIZE)
824        for (x = 0; x < s->w; x += MB_SIZE, i++) {
825            get_sub_picture(s, x, y, last_data, last_linesize,
826                            sub_last_data, sub_last_linesize);
827            get_sub_picture(s, x, y, data, linesize,
828                            sub_pict_data, sub_pict_linesize);
829
830            s->mb[i].skip_error =
831                compute_mb_distortion(s,
832                                      sub_last_data, sub_last_linesize,
833                                      sub_pict_data, sub_pict_linesize);
834        }
835}
836
837static void write_strip_keyframe(unsigned char *buf, int keyframe)
838{
839    // actually we are exclusively using intra strip coding (how much can we win
840    // otherwise? how to choose which part of a codebook to update?),
841    // keyframes are different only because we disallow ENC_SKIP on them -- rl
842    // (besides, the logic here used to be inverted: )
843    //    buf[0] = keyframe ? 0x11: 0x10;
844    buf[0] = keyframe ? 0x10 : 0x11;
845}
846
847static void write_strip_header(CinepakEncContext *s, int y, int h, int keyframe,
848                               unsigned char *buf, int strip_size)
849{
850    write_strip_keyframe(buf, keyframe);
851    AV_WB24(&buf[1], strip_size + STRIP_HEADER_SIZE);
852    // AV_WB16(&buf[4], y); /* using absolute y values works -- rl */
853    AV_WB16(&buf[4], 0); /* using relative values works as well -- rl */
854    AV_WB16(&buf[6], 0);
855    // AV_WB16(&buf[8], y + h); /* using absolute y values works -- rl */
856    AV_WB16(&buf[8], h); /* using relative values works as well -- rl */
857    AV_WB16(&buf[10], s->w);
858}
859
860static int rd_strip(CinepakEncContext *s, int y, int h, int keyframe,
861                    uint8_t *last_data[4], int last_linesize[4],
862                    uint8_t *data[4], int linesize[4],
863                    uint8_t *scratch_data[4], int scratch_linesize[4],
864                    unsigned char *buf, int64_t *best_score, int *no_skip)
865{
866    int64_t score = 0;
867    int best_size = 0;
868    strip_info info;
869    // for codebook optimization:
870    int v1enough, v1_size, v4enough, v4_size;
871    int new_v1_size, new_v4_size;
872    int v1shrunk, v4shrunk;
873
874    if (!keyframe)
875        calculate_skip_errors(s, h, last_data, last_linesize, data, linesize,
876                              &info);
877
878    // try some powers of 4 for the size of the codebooks
879    // constraint the v4 codebook to be no bigger than v1 one,
880    // (and no less than v1_size/4)
881    // thus making v1 preferable and possibly losing small details? should be ok
882#define SMALLEST_CODEBOOK 1
883    for (v1enough = 0, v1_size = SMALLEST_CODEBOOK; v1_size <= CODEBOOK_MAX && !v1enough; v1_size <<= 2) {
884        for (v4enough = 0, v4_size = 0; v4_size <= v1_size && !v4enough; v4_size = v4_size ? v4_size << 2 : v1_size >= SMALLEST_CODEBOOK << 2 ? v1_size >> 2 : SMALLEST_CODEBOOK) {
885            CinepakMode mode;
886            // try all modes
887            for (mode = 0; mode < MODE_COUNT; mode++) {
888                // don't allow MODE_MC in intra frames
889                if (keyframe && mode == MODE_MC)
890                    continue;
891
892                if (mode == MODE_V1_ONLY) {
893                    info.v1_size = v1_size;
894                    // the size may shrink even before optimizations if the input is short:
895                    if ((new_v1_size = quantize(s, h, data, linesize, 1,
896                                                &info, ENC_UNCERTAIN)) < 0)
897                        return new_v1_size;
898                    info.v1_size = new_v1_size;
899                    if (info.v1_size < v1_size)
900                        // too few eligible blocks, no sense in trying bigger sizes
901                        v1enough = 1;
902
903                    info.v4_size = 0;
904                } else { // mode != MODE_V1_ONLY
905                    // if v4 codebook is empty then only allow V1-only mode
906                    if (!v4_size)
907                        continue;
908
909                    if (mode == MODE_V1_V4) {
910                        info.v4_size = v4_size;
911                        new_v4_size = quantize(s, h, data, linesize, 0,
912                                               &info, ENC_UNCERTAIN);
913                        if (new_v4_size < 0)
914                            return new_v4_size;
915                        info.v4_size = new_v4_size;
916                        if (info.v4_size < v4_size)
917                            // too few eligible blocks, no sense in trying bigger sizes
918                            v4enough = 1;
919                    }
920                }
921
922                info.mode = mode;
923                // choose the best encoding per block, based on current experience
924                score = calculate_mode_score(s, h, &info, 0,
925                                             &v1shrunk, &v4shrunk);
926
927                if (mode != MODE_V1_ONLY) {
928                    int extra_iterations_limit = s->max_extra_cb_iterations;
929                    // recompute the codebooks, omitting the extra blocks
930                    // we assume we _may_ come here with more blocks to encode than before
931                    info.v1_size = v1_size;
932                    new_v1_size = quantize(s, h, data, linesize, 1, &info, ENC_V1);
933                    if (new_v1_size < 0)
934                        return new_v1_size;
935                    if (new_v1_size < info.v1_size)
936                        info.v1_size = new_v1_size;
937                    // we assume we _may_ come here with more blocks to encode than before
938                    info.v4_size = v4_size;
939                    new_v4_size = quantize(s, h, data, linesize, 0, &info, ENC_V4);
940                    if (new_v4_size < 0)
941                        return new_v4_size;
942                    if (new_v4_size < info.v4_size)
943                        info.v4_size = new_v4_size;
944                    // calculate the resulting score
945                    // (do not move blocks to codebook encodings now, as some blocks may have
946                    // got bigger errors despite a smaller training set - but we do not
947                    // ever grow the training sets back)
948                    for (;;) {
949                        score = calculate_mode_score(s, h, &info, 1,
950                                                     &v1shrunk, &v4shrunk);
951                        // do we have a reason to reiterate? if so, have we reached the limit?
952                        if ((!v1shrunk && !v4shrunk) || !extra_iterations_limit--)
953                            break;
954                        // recompute the codebooks, omitting the extra blocks
955                        if (v1shrunk) {
956                            info.v1_size = v1_size;
957                            new_v1_size = quantize(s, h, data, linesize, 1, &info, ENC_V1);
958                            if (new_v1_size < 0)
959                                return new_v1_size;
960                            if (new_v1_size < info.v1_size)
961                                info.v1_size = new_v1_size;
962                        }
963                        if (v4shrunk) {
964                            info.v4_size = v4_size;
965                            new_v4_size = quantize(s, h, data, linesize, 0, &info, ENC_V4);
966                            if (new_v4_size < 0)
967                                return new_v4_size;
968                            if (new_v4_size < info.v4_size)
969                                info.v4_size = new_v4_size;
970                        }
971                    }
972                }
973
974                if (best_size == 0 || score < *best_score) {
975                    *best_score = score;
976                    best_size = encode_mode(s, h,
977                                            scratch_data, scratch_linesize,
978                                            last_data, last_linesize, &info,
979                                            s->strip_buf + STRIP_HEADER_SIZE);
980                    // in theory we could have MODE_MC without ENC_SKIP,
981                    // but MODE_V1_V4 will always be more efficient
982                    *no_skip = info.mode != MODE_MC;
983
984                    write_strip_header(s, y, h, keyframe, s->strip_buf, best_size);
985                }
986            }
987        }
988    }
989
990    best_size += STRIP_HEADER_SIZE;
991    memcpy(buf, s->strip_buf, best_size);
992
993    return best_size;
994}
995
996static int write_cvid_header(CinepakEncContext *s, unsigned char *buf,
997                             int num_strips, int data_size, int isakeyframe)
998{
999    buf[0] = isakeyframe ? 0 : 1;
1000    AV_WB24(&buf[1], data_size + CVID_HEADER_SIZE);
1001    AV_WB16(&buf[4], s->w);
1002    AV_WB16(&buf[6], s->h);
1003    AV_WB16(&buf[8], num_strips);
1004
1005    return CVID_HEADER_SIZE;
1006}
1007
1008static int rd_frame(CinepakEncContext *s, const AVFrame *frame,
1009                    int isakeyframe, unsigned char *buf, int buf_size, int *got_keyframe)
1010{
1011    int num_strips, strip, i, y, nexty, size, temp_size, best_size;
1012    uint8_t *last_data    [4], *data    [4], *scratch_data    [4];
1013    int      last_linesize[4],  linesize[4],  scratch_linesize[4];
1014    int64_t best_score = 0, score, score_temp;
1015    int best_nstrips, best_strip_offsets[MAX_STRIPS];
1016
1017    if (s->pix_fmt == AV_PIX_FMT_RGB24) {
1018        int x;
1019        // build a copy of the given frame in the correct colorspace
1020        for (y = 0; y < s->h; y += 2)
1021            for (x = 0; x < s->w; x += 2) {
1022                uint8_t *ir[2];
1023                int32_t r, g, b, rr, gg, bb;
1024                ir[0] = frame->data[0] + x * 3 + y * frame->linesize[0];
1025                ir[1] = ir[0] + frame->linesize[0];
1026                get_sub_picture(s, x, y,
1027                                s->input_frame->data, s->input_frame->linesize,
1028                                scratch_data, scratch_linesize);
1029                r = g = b = 0;
1030                for (i = 0; i < 4; ++i) {
1031                    int i1, i2;
1032                    i1 = (i & 1);
1033                    i2 = (i >= 2);
1034                    rr = ir[i2][i1 * 3 + 0];
1035                    gg = ir[i2][i1 * 3 + 1];
1036                    bb = ir[i2][i1 * 3 + 2];
1037                    r += rr;
1038                    g += gg;
1039                    b += bb;
1040                    // using fixed point arithmetic for portable repeatability, scaling by 2^23
1041                    // "Y"
1042                    // rr = 0.2857 * rr + 0.5714 * gg + 0.1429 * bb;
1043                    rr = (2396625 * rr + 4793251 * gg + 1198732 * bb) >> 23;
1044                    if (rr < 0)
1045                        rr = 0;
1046                    else if (rr > 255)
1047                        rr = 255;
1048                    scratch_data[0][i1 + i2 * scratch_linesize[0]] = rr;
1049                }
1050                // let us scale down as late as possible
1051                //                r /= 4; g /= 4; b /= 4;
1052                // "U"
1053                // rr = -0.1429 * r - 0.2857 * g + 0.4286 * b;
1054                rr = (-299683 * r - 599156 * g + 898839 * b) >> 23;
1055                if (rr < -128)
1056                    rr = -128;
1057                else if (rr > 127)
1058                    rr = 127;
1059                scratch_data[1][0] = rr + 128; // quantize needs unsigned
1060                // "V"
1061                // rr = 0.3571 * r - 0.2857 * g - 0.0714 * b;
1062                rr = (748893 * r - 599156 * g - 149737 * b) >> 23;
1063                if (rr < -128)
1064                    rr = -128;
1065                else if (rr > 127)
1066                    rr = 127;
1067                scratch_data[2][0] = rr + 128; // quantize needs unsigned
1068            }
1069    }
1070
1071    // would be nice but quite certainly incompatible with vintage players:
1072    // support encoding zero strips (meaning skip the whole frame)
1073    for (num_strips = s->min_strips; num_strips <= s->max_strips && num_strips <= s->h / MB_SIZE; num_strips++) {
1074        int strip_offsets[MAX_STRIPS];
1075        int all_no_skip = 1;
1076        score = 0;
1077        size  = 0;
1078
1079        for (y = 0, strip = 1; y < s->h; strip++, y = nexty) {
1080            int strip_height, no_skip;
1081
1082            strip_offsets[strip-1] = size + CVID_HEADER_SIZE;
1083            nexty = strip * s->h / num_strips; // <= s->h
1084            // make nexty the next multiple of 4 if not already there
1085            if (nexty & 3)
1086                nexty += 4 - (nexty & 3);
1087
1088            strip_height = nexty - y;
1089            if (strip_height <= 0) { // can this ever happen?
1090                av_log(s->avctx, AV_LOG_INFO, "skipping zero height strip %i of %i\n", strip, num_strips);
1091                continue;
1092            }
1093
1094            if (s->pix_fmt == AV_PIX_FMT_RGB24)
1095                get_sub_picture(s, 0, y,
1096                                s->input_frame->data, s->input_frame->linesize,
1097                                data, linesize);
1098            else
1099                get_sub_picture(s, 0, y,
1100                                (uint8_t **)frame->data, (int *)frame->linesize,
1101                                data, linesize);
1102            get_sub_picture(s, 0, y,
1103                            s->last_frame->data, s->last_frame->linesize,
1104                            last_data, last_linesize);
1105            get_sub_picture(s, 0, y,
1106                            s->scratch_frame->data, s->scratch_frame->linesize,
1107                            scratch_data, scratch_linesize);
1108
1109            if ((temp_size = rd_strip(s, y, strip_height, isakeyframe,
1110                                      last_data, last_linesize, data, linesize,
1111                                      scratch_data, scratch_linesize,
1112                                      s->frame_buf + strip_offsets[strip-1],
1113                                      &score_temp, &no_skip)) < 0)
1114                return temp_size;
1115
1116            score += score_temp;
1117            size += temp_size;
1118            all_no_skip &= no_skip;
1119        }
1120
1121        if (best_score == 0 || score < best_score) {
1122            best_score = score;
1123            best_size = size + write_cvid_header(s, s->frame_buf, num_strips, size, all_no_skip);
1124
1125            FFSWAP(AVFrame *, s->best_frame, s->scratch_frame);
1126            memcpy(buf, s->frame_buf, best_size);
1127            best_nstrips = num_strips;
1128            *got_keyframe = all_no_skip; // no skip MBs in any strip -> keyframe
1129            memcpy(best_strip_offsets, strip_offsets, sizeof(strip_offsets));
1130        }
1131        // avoid trying too many strip numbers without a real reason
1132        // (this makes the processing of the very first frame faster)
1133        if (num_strips - best_nstrips > 4)
1134            break;
1135    }
1136
1137    // update strip headers
1138    for (i = 0; i < best_nstrips; i++) {
1139        write_strip_keyframe(s->frame_buf + best_strip_offsets[i], *got_keyframe);
1140    }
1141
1142    // let the number of strips slowly adapt to the changes in the contents,
1143    // compared to full bruteforcing every time this will occasionally lead
1144    // to some r/d performance loss but makes encoding up to several times faster
1145    if (!s->strip_number_delta_range) {
1146        if (best_nstrips == s->max_strips) { // let us try to step up
1147            s->max_strips = best_nstrips + 1;
1148            if (s->max_strips >= s->max_max_strips)
1149                s->max_strips = s->max_max_strips;
1150        } else { // try to step down
1151            s->max_strips = best_nstrips;
1152        }
1153        s->min_strips = s->max_strips - 1;
1154        if (s->min_strips < s->min_min_strips)
1155            s->min_strips = s->min_min_strips;
1156    } else {
1157        s->max_strips = best_nstrips + s->strip_number_delta_range;
1158        if (s->max_strips >= s->max_max_strips)
1159            s->max_strips = s->max_max_strips;
1160        s->min_strips = best_nstrips - s->strip_number_delta_range;
1161        if (s->min_strips < s->min_min_strips)
1162            s->min_strips = s->min_min_strips;
1163    }
1164
1165    return best_size;
1166}
1167
1168static int cinepak_encode_frame(AVCodecContext *avctx, AVPacket *pkt,
1169                                const AVFrame *frame, int *got_packet)
1170{
1171    CinepakEncContext *s = avctx->priv_data;
1172    int ret, got_keyframe;
1173
1174    s->lambda = frame->quality ? frame->quality - 1 : 2 * FF_LAMBDA_SCALE;
1175
1176    if ((ret = ff_alloc_packet(avctx, pkt, s->frame_buf_size)) < 0)
1177        return ret;
1178    ret       = rd_frame(s, frame, (s->curframe == 0), pkt->data, s->frame_buf_size, &got_keyframe);
1179    pkt->size = ret;
1180    if (got_keyframe) {
1181        pkt->flags |= AV_PKT_FLAG_KEY;
1182        s->curframe = 0;
1183    }
1184    *got_packet = 1;
1185
1186    FFSWAP(AVFrame *, s->last_frame, s->best_frame);
1187
1188    if (++s->curframe >= avctx->gop_size)
1189        s->curframe = 0;
1190
1191    return 0;
1192}
1193
1194static av_cold int cinepak_encode_end(AVCodecContext *avctx)
1195{
1196    CinepakEncContext *s = avctx->priv_data;
1197    int x;
1198
1199    avpriv_elbg_free(&s->elbg);
1200    av_frame_free(&s->last_frame);
1201    av_frame_free(&s->best_frame);
1202    av_frame_free(&s->scratch_frame);
1203    if (avctx->pix_fmt == AV_PIX_FMT_RGB24)
1204        av_frame_free(&s->input_frame);
1205    av_freep(&s->codebook_input);
1206    av_freep(&s->codebook_closest);
1207    av_freep(&s->strip_buf);
1208    av_freep(&s->frame_buf);
1209    av_freep(&s->mb);
1210
1211    for (x = 0; x < (avctx->pix_fmt == AV_PIX_FMT_RGB24 ? 4 : 3); x++)
1212        av_freep(&s->pict_bufs[x]);
1213
1214    return 0;
1215}
1216
1217const FFCodec ff_cinepak_encoder = {
1218    .p.name         = "cinepak",
1219    .p.long_name    = NULL_IF_CONFIG_SMALL("Cinepak"),
1220    .p.type         = AVMEDIA_TYPE_VIDEO,
1221    .p.id           = AV_CODEC_ID_CINEPAK,
1222    .priv_data_size = sizeof(CinepakEncContext),
1223    .init           = cinepak_encode_init,
1224    FF_CODEC_ENCODE_CB(cinepak_encode_frame),
1225    .close          = cinepak_encode_end,
1226    .p.pix_fmts     = (const enum AVPixelFormat[]) { AV_PIX_FMT_RGB24, AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE },
1227    .p.priv_class   = &cinepak_class,
1228    .caps_internal  = FF_CODEC_CAP_INIT_THREADSAFE | FF_CODEC_CAP_INIT_CLEANUP,
1229};
1230