xref: /third_party/ffmpeg/libavcodec/mv30.c (revision cabdff1a)
1/*
2 * MidiVid MV30 decoder
3 *
4 * Copyright (c) 2020 Paul B Mahol
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include <stdio.h>
24#include <stdlib.h>
25#include <string.h>
26
27#include "libavutil/thread.h"
28
29#include "avcodec.h"
30#include "bytestream.h"
31#include "codec_internal.h"
32#include "copy_block.h"
33#include "mathops.h"
34#include "blockdsp.h"
35#include "get_bits.h"
36#include "internal.h"
37#include "aandcttab.h"
38
39#define CBP_VLC_BITS  9
40
41typedef struct MV30Context {
42    GetBitContext  gb;
43
44    int intra_quant;
45    int inter_quant;
46    int is_inter;
47    int mode_size;
48    int nb_mvectors;
49
50    int      block[6][64];
51    int16_t *mvectors;
52    unsigned int mvectors_size;
53    int16_t *coeffs;
54    unsigned int coeffs_size;
55
56    int16_t intraq_tab[2][64];
57    int16_t interq_tab[2][64];
58
59    BlockDSPContext bdsp;
60    AVFrame *prev_frame;
61} MV30Context;
62
63static VLC cbp_tab;
64
65static const uint8_t luma_tab[] = {
66    12, 12, 15, 19, 25, 34, 40, 48,
67    12, 12, 18, 22, 27, 44, 47, 46,
68    17, 18, 21, 26, 35, 46, 52, 47,
69    18, 20, 24, 28, 40, 61, 59, 51,
70    20, 24, 32, 43, 50, 72, 72, 63,
71    25, 31, 42, 48, 58, 72, 81, 75,
72    38, 46, 54, 61, 71, 84, 88, 85,
73    50, 61, 65, 68, 79, 78, 86, 91,
74};
75
76static const uint8_t chroma_tab[] = {
77    12, 16, 24, 47, 99, 99, 99, 99,
78    16, 21, 26, 66, 99, 99, 99, 99,
79    24, 26, 56, 99, 99, 99, 99, 99,
80    47, 66, 99, 99, 99, 99, 99, 99,
81    99, 99, 99, 99, 99, 99, 99, 99,
82    99, 99, 99, 99, 99, 99, 99, 99,
83    99, 99, 99, 99, 99, 99, 99, 99,
84    99, 99, 99, 99, 99, 99, 99, 99,
85};
86
87static const uint8_t zigzag[] = {
88     0,  1,  8,  9, 16,  2,  3, 10,
89    17, 24, 32, 25, 18, 11,  4,  5,
90    12, 19, 26, 33, 40, 48, 41, 34,
91    27, 20, 13,  6,  7, 14, 21, 28,
92    35, 42, 49, 56, 57, 50, 43, 36,
93    29, 22, 15, 23, 30, 37, 44, 51,
94    58, 59, 52, 45, 38, 31, 39, 46,
95    53, 60, 61, 54, 47, 55, 62, 63,
96};
97
98static void get_qtable(int16_t *table, int quant, const uint8_t *quant_tab)
99{
100    int factor = quant < 50 ? 5000 / FFMAX(quant, 1) : 200 - FFMIN(quant, 100) * 2;
101
102    for (int i = 0; i < 64; i++) {
103        table[i] = av_clip((quant_tab[i] * factor + 0x32) / 100, 1, 0x7fff);
104        table[i] = ((int)ff_aanscales[i] * (int)table[i] + 0x800) >> 12;
105    }
106}
107
108static inline void idct_1d(unsigned *blk, int step)
109{
110    const unsigned t0 = blk[0 * step] + blk[4 * step];
111    const unsigned t1 = blk[0 * step] - blk[4 * step];
112    const unsigned t2 = blk[2 * step] + blk[6 * step];
113    const unsigned t3 = ((int)((blk[2 * step] - blk[6 * step]) * 362U) >> 8) - t2;
114    const unsigned t4 = t0 + t2;
115    const unsigned t5 = t0 - t2;
116    const unsigned t6 = t1 + t3;
117    const unsigned t7 = t1 - t3;
118    const unsigned t8 = blk[5 * step] + blk[3 * step];
119    const unsigned t9 = blk[5 * step] - blk[3 * step];
120    const unsigned tA = blk[1 * step] + blk[7 * step];
121    const unsigned tB = blk[1 * step] - blk[7 * step];
122    const unsigned tC = t8 + tA;
123    const unsigned tD = (int)((tB + t9) * 473U) >> 8;
124    const unsigned tE = (((int)(t9 * -669U) >> 8) - tC) + tD;
125    const unsigned tF = ((int)((tA - t8) * 362U) >> 8) - tE;
126    const unsigned t10 = (((int)(tB * 277U) >> 8) - tD) + tF;
127
128    blk[0 * step] = t4 + tC;
129    blk[1 * step] = t6 + tE;
130    blk[2 * step] = t7 + tF;
131    blk[3 * step] = t5 - t10;
132    blk[4 * step] = t5 + t10;
133    blk[5 * step] = t7 - tF;
134    blk[6 * step] = t6 - tE;
135    blk[7 * step] = t4 - tC;
136}
137
138static void idct_put(uint8_t *dst, int stride, int *block)
139{
140    for (int i = 0; i < 8; i++) {
141        if ((block[0x08 + i] |
142             block[0x10 + i] |
143             block[0x18 + i] |
144             block[0x20 + i] |
145             block[0x28 + i] |
146             block[0x30 + i] |
147             block[0x38 + i]) == 0) {
148            block[0x08 + i] = block[i];
149            block[0x10 + i] = block[i];
150            block[0x18 + i] = block[i];
151            block[0x20 + i] = block[i];
152            block[0x28 + i] = block[i];
153            block[0x30 + i] = block[i];
154            block[0x38 + i] = block[i];
155        } else {
156            idct_1d(block + i, 8);
157        }
158    }
159
160    for (int i = 0; i < 8; i++) {
161        idct_1d(block, 1);
162        for (int j = 0; j < 8; j++)
163            dst[j] = av_clip_uint8((block[j] >> 5) + 128);
164        block += 8;
165        dst += stride;
166    }
167}
168
169static void idct_add(uint8_t *dst, int stride,
170                     const uint8_t *src, int in_linesize, int *block)
171{
172    for (int i = 0; i < 8; i++) {
173        if ((block[0x08 + i] |
174             block[0x10 + i] |
175             block[0x18 + i] |
176             block[0x20 + i] |
177             block[0x28 + i] |
178             block[0x30 + i] |
179             block[0x38 + i]) == 0) {
180            block[0x08 + i] = block[i];
181            block[0x10 + i] = block[i];
182            block[0x18 + i] = block[i];
183            block[0x20 + i] = block[i];
184            block[0x28 + i] = block[i];
185            block[0x30 + i] = block[i];
186            block[0x38 + i] = block[i];
187        } else {
188            idct_1d(block + i, 8);
189        }
190    }
191
192    for (int i = 0; i < 8; i++) {
193        idct_1d(block, 1);
194        for (int j = 0; j < 8; j++)
195            dst[j] = av_clip_uint8((block[j] >> 5) + src[j]);
196        block += 8;
197        dst += stride;
198        src += in_linesize;
199    }
200}
201
202static inline void idct2_1d(int *blk, int step)
203{
204    const unsigned int  t0 = blk[0 * step];
205    const unsigned int t1 = blk[1 * step];
206    const unsigned int t2 = (int)(t1 * 473U) >> 8;
207    const unsigned int t3 = t2 - t1;
208    const unsigned int t4 =  ((int)(t1 * 362U) >> 8) - t3;
209    const unsigned int t5 = (((int)(t1 * 277U) >> 8) - t2) + t4;
210
211    blk[0 * step] = t1 + t0;
212    blk[1 * step] = t0 + t3;
213    blk[2 * step] = t4 + t0;
214    blk[3 * step] = t0 - t5;
215    blk[4 * step] = t5 + t0;
216    blk[5 * step] = t0 - t4;
217    blk[6 * step] = t0 - t3;
218    blk[7 * step] = t0 - t1;
219}
220
221static void idct2_put(uint8_t *dst, int stride, int *block)
222{
223    for (int i = 0; i < 2; i++) {
224        if ((block[0x08 + i]) == 0) {
225            block[0x08 + i] = block[i];
226            block[0x10 + i] = block[i];
227            block[0x18 + i] = block[i];
228            block[0x20 + i] = block[i];
229            block[0x28 + i] = block[i];
230            block[0x30 + i] = block[i];
231            block[0x38 + i] = block[i];
232        } else {
233            idct2_1d(block + i, 8);
234        }
235    }
236
237    for (int i = 0; i < 8; i++) {
238        if (block[1] == 0) {
239            for (int j = 0; j < 8; j++)
240                dst[j] = av_clip_uint8((block[0] >> 5) + 128);
241        } else {
242            idct2_1d(block, 1);
243            for (int j = 0; j < 8; j++)
244                dst[j] = av_clip_uint8((block[j] >> 5) + 128);
245        }
246        block += 8;
247        dst += stride;
248    }
249}
250
251static void idct2_add(uint8_t *dst, int stride,
252                      const uint8_t *src, int in_linesize,
253                      int *block)
254{
255    for (int i = 0; i < 2; i++) {
256        if ((block[0x08 + i]) == 0) {
257            block[0x08 + i] = block[i];
258            block[0x10 + i] = block[i];
259            block[0x18 + i] = block[i];
260            block[0x20 + i] = block[i];
261            block[0x28 + i] = block[i];
262            block[0x30 + i] = block[i];
263            block[0x38 + i] = block[i];
264        } else {
265            idct2_1d(block + i, 8);
266        }
267    }
268
269    for (int i = 0; i < 8; i++) {
270        if (block[1] == 0) {
271            for (int j = 0; j < 8; j++)
272                dst[j] = av_clip_uint8((block[0] >> 5) + src[j]);
273        } else {
274            idct2_1d(block, 1);
275            for (int j = 0; j < 8; j++)
276                dst[j] = av_clip_uint8((block[j] >> 5) + src[j]);
277        }
278        block += 8;
279        dst += stride;
280        src += in_linesize;
281    }
282}
283
284static void update_inter_block(uint8_t *dst, int stride,
285                               const uint8_t *src, int in_linesize,
286                               int block)
287{
288    for (int i = 0; i < 8; i++) {
289        for (int j = 0; j < 8; j++)
290            dst[j] = av_clip_uint8(block + src[j]);
291        dst += stride;
292        src += in_linesize;
293    }
294}
295
296static int decode_intra_block(AVCodecContext *avctx, int mode,
297                              GetByteContext *gbyte, int16_t *qtab,
298                              int *block, int *pfill,
299                              uint8_t *dst, int linesize)
300{
301    MV30Context *s = avctx->priv_data;
302    int fill;
303
304    switch (mode) {
305    case 0:
306        s->bdsp.fill_block_tab[1](dst, 128, linesize, 8);
307        break;
308    case 1:
309        fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
310        pfill[0] += fill;
311        block[0] = ((int)((unsigned)pfill[0] * qtab[0]) >> 5) + 128;
312        s->bdsp.fill_block_tab[1](dst, block[0], linesize, 8);
313        break;
314    case 2:
315        memset(block, 0, sizeof(*block) * 64);
316        fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
317        pfill[0] += fill;
318        block[0] = (unsigned)pfill[0] * qtab[0];
319        block[1] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[1];
320        block[8] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[8];
321        block[9] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[9];
322        idct2_put(dst, linesize, block);
323        break;
324    case 3:
325        fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
326        pfill[0] += fill;
327        block[0] = (unsigned)pfill[0] * qtab[0];
328        for (int i = 1; i < 64; i++)
329            block[zigzag[i]] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[zigzag[i]];
330        idct_put(dst, linesize, block);
331        break;
332    }
333
334    return 0;
335}
336
337static int decode_inter_block(AVCodecContext *avctx, int mode,
338                              GetByteContext *gbyte, int16_t *qtab,
339                              int *block, int *pfill,
340                              uint8_t *dst, int linesize,
341                              const uint8_t *src, int in_linesize)
342{
343    int fill;
344
345    switch (mode) {
346    case 0:
347        copy_block8(dst, src, linesize, in_linesize, 8);
348        break;
349    case 1:
350        fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
351        pfill[0] += fill;
352        block[0] = (int)((unsigned)pfill[0] * qtab[0]) >> 5;
353        update_inter_block(dst, linesize, src, in_linesize, block[0]);
354        break;
355    case 2:
356        memset(block, 0, sizeof(*block) * 64);
357        fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
358        pfill[0] += fill;
359        block[0] = (unsigned)pfill[0] * qtab[0];
360        block[1] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[1];
361        block[8] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[8];
362        block[9] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[9];
363        idct2_add(dst, linesize, src, in_linesize, block);
364        break;
365    case 3:
366        fill = sign_extend(bytestream2_get_ne16(gbyte), 16);
367        pfill[0] += fill;
368        block[0] = (unsigned)pfill[0] * qtab[0];
369        for (int i = 1; i < 64; i++)
370            block[zigzag[i]] = sign_extend(bytestream2_get_ne16(gbyte), 16) * qtab[zigzag[i]];
371        idct_add(dst, linesize, src, in_linesize, block);
372        break;
373    }
374
375    return 0;
376}
377
378static int decode_coeffs(GetBitContext *gb, int16_t *coeffs, int nb_codes)
379{
380    memset(coeffs, 0, nb_codes * sizeof(*coeffs));
381
382    for (int i = 0; i < nb_codes;) {
383        int value = get_vlc2(gb, cbp_tab.table, CBP_VLC_BITS, 1);
384
385        if (value > 0) {
386            int x = get_bits(gb, value);
387
388            if (x < (1 << value) / 2) {
389                x =  (1 << (value - 1)) + (x & ((1 << value) - 1 >> 1));
390            } else {
391                x = -(1 << (value - 1)) - (x & ((1 << value) - 1 >> 1));
392            }
393            coeffs[i++] = x;
394        } else {
395            int flag = get_bits1(gb);
396
397            i += get_bits(gb, 3 + flag * 3) + 1 + flag * 8;
398        }
399    }
400
401    return 0;
402}
403
404static int decode_intra(AVCodecContext *avctx, GetBitContext *gb, AVFrame *frame)
405{
406    MV30Context *s = avctx->priv_data;
407    GetBitContext mgb;
408    uint8_t *dst[6];
409    int linesize[6];
410    int ret;
411
412    mgb = *gb;
413    if (get_bits_left(gb) < s->mode_size * 8)
414        return AVERROR_INVALIDDATA;
415
416    skip_bits_long(gb, s->mode_size * 8);
417
418    linesize[0] = frame->linesize[0];
419    linesize[1] = frame->linesize[0];
420    linesize[2] = frame->linesize[0];
421    linesize[3] = frame->linesize[0];
422    linesize[4] = frame->linesize[1];
423    linesize[5] = frame->linesize[2];
424
425    for (int y = 0; y < avctx->height; y += 16) {
426        GetByteContext gbyte;
427        int pfill[3][1] = { {0} };
428        int nb_codes = get_bits(gb, 16);
429
430        av_fast_padded_malloc(&s->coeffs, &s->coeffs_size, nb_codes * sizeof(*s->coeffs));
431        if (!s->coeffs)
432            return AVERROR(ENOMEM);
433        ret = decode_coeffs(gb, s->coeffs, nb_codes);
434        if (ret < 0)
435            return ret;
436
437        bytestream2_init(&gbyte, (uint8_t *)s->coeffs, nb_codes * sizeof(*s->coeffs));
438
439        for (int x = 0; x < avctx->width; x += 16) {
440            dst[0] = frame->data[0] + linesize[0] * y + x;
441            dst[1] = frame->data[0] + linesize[0] * y + x + 8;
442            dst[2] = frame->data[0] + linesize[0] * (y + 8) + x;
443            dst[3] = frame->data[0] + linesize[0] * (y + 8) + x + 8;
444            dst[4] = frame->data[1] + linesize[4] * (y >> 1) + (x >> 1);
445            dst[5] = frame->data[2] + linesize[5] * (y >> 1) + (x >> 1);
446
447            for (int b = 0; b < 6; b++) {
448                int mode = get_bits_le(&mgb, 2);
449
450                ret = decode_intra_block(avctx, mode, &gbyte, s->intraq_tab[b >= 4],
451                                         s->block[b],
452                                         pfill[(b >= 4) + (b >= 5)],
453                                         dst[b], linesize[b]);
454                if (ret < 0)
455                    return ret;
456            }
457        }
458    }
459
460    return 0;
461}
462
463static int decode_inter(AVCodecContext *avctx, GetBitContext *gb,
464                        AVFrame *frame, AVFrame *prev)
465{
466    MV30Context *s = avctx->priv_data;
467    GetBitContext mask;
468    GetBitContext mgb;
469    GetByteContext mv;
470    const int mask_size = ((avctx->height >> 4) * (avctx->width >> 4) * 2 + 7) / 8;
471    uint8_t *dst[6], *src[6];
472    int in_linesize[6];
473    int linesize[6];
474    int ret, cnt = 0;
475    int flags = 0;
476
477    in_linesize[0] = prev->linesize[0];
478    in_linesize[1] = prev->linesize[0];
479    in_linesize[2] = prev->linesize[0];
480    in_linesize[3] = prev->linesize[0];
481    in_linesize[4] = prev->linesize[1];
482    in_linesize[5] = prev->linesize[2];
483
484    linesize[0] = frame->linesize[0];
485    linesize[1] = frame->linesize[0];
486    linesize[2] = frame->linesize[0];
487    linesize[3] = frame->linesize[0];
488    linesize[4] = frame->linesize[1];
489    linesize[5] = frame->linesize[2];
490
491    av_fast_padded_malloc(&s->mvectors, &s->mvectors_size, 2 * s->nb_mvectors * sizeof(*s->mvectors));
492    if (!s->mvectors) {
493        ret = AVERROR(ENOMEM);
494        goto fail;
495    }
496
497    mask = *gb;
498    skip_bits_long(gb, mask_size * 8);
499    mgb = *gb;
500    skip_bits_long(gb, s->mode_size * 8);
501
502    ret = decode_coeffs(gb, s->mvectors, 2 * s->nb_mvectors);
503    if (ret < 0)
504        goto fail;
505
506    bytestream2_init(&mv, (uint8_t *)s->mvectors, 2 * s->nb_mvectors * sizeof(*s->mvectors));
507
508    for (int y = 0; y < avctx->height; y += 16) {
509        GetByteContext gbyte;
510        int pfill[3][1] = { {0} };
511        int nb_codes = get_bits(gb, 16);
512
513        skip_bits(gb, 8);
514        if (get_bits_left(gb) < 0) {
515            ret = AVERROR_INVALIDDATA;
516            goto fail;
517        }
518
519        av_fast_padded_malloc(&s->coeffs, &s->coeffs_size, nb_codes * sizeof(*s->coeffs));
520        if (!s->coeffs) {
521            ret = AVERROR(ENOMEM);
522            goto fail;
523        }
524
525        ret = decode_coeffs(gb, s->coeffs, nb_codes);
526        if (ret < 0)
527            goto fail;
528
529        bytestream2_init(&gbyte, (uint8_t *)s->coeffs, nb_codes * sizeof(*s->coeffs));
530
531        for (int x = 0; x < avctx->width; x += 16) {
532            if (cnt >= 4)
533                cnt = 0;
534            if (cnt == 0) {
535                if (get_bits_left(&mask) < 8) {
536                    ret = AVERROR_INVALIDDATA;
537                    goto fail;
538                }
539                flags = get_bits(&mask, 8);
540            }
541
542            dst[0] = frame->data[0] + linesize[0] * y + x;
543            dst[1] = frame->data[0] + linesize[0] * y + x + 8;
544            dst[2] = frame->data[0] + linesize[0] * (y + 8) + x;
545            dst[3] = frame->data[0] + linesize[0] * (y + 8) + x + 8;
546            dst[4] = frame->data[1] + linesize[4] * (y >> 1) + (x >> 1);
547            dst[5] = frame->data[2] + linesize[5] * (y >> 1) + (x >> 1);
548
549            if ((flags >> (cnt)) & 1) {
550                int mv_x = sign_extend(bytestream2_get_ne16(&mv), 16);
551                int mv_y = sign_extend(bytestream2_get_ne16(&mv), 16);
552
553                int px = x + mv_x;
554                int py = y + mv_y;
555
556                if (px < 0 || px > FFALIGN(avctx->width , 16) - 16 ||
557                    py < 0 || py > FFALIGN(avctx->height, 16) - 16)
558                    return AVERROR_INVALIDDATA;
559
560                src[0] = prev->data[0] + in_linesize[0] * py + px;
561                src[1] = prev->data[0] + in_linesize[0] * py + px + 8;
562                src[2] = prev->data[0] + in_linesize[0] * (py + 8) + px;
563                src[3] = prev->data[0] + in_linesize[0] * (py + 8) + px + 8;
564                src[4] = prev->data[1] + in_linesize[4] * (py >> 1) + (px >> 1);
565                src[5] = prev->data[2] + in_linesize[5] * (py >> 1) + (px >> 1);
566
567                if ((flags >> (cnt + 4)) & 1) {
568                    for (int b = 0; b < 6; b++)
569                        copy_block8(dst[b], src[b], linesize[b], in_linesize[b], 8);
570                } else {
571                    for (int b = 0; b < 6; b++) {
572                        int mode = get_bits_le(&mgb, 2);
573
574                        ret = decode_inter_block(avctx, mode, &gbyte, s->interq_tab[b >= 4],
575                                                 s->block[b],
576                                                 pfill[(b >= 4) + (b >= 5)],
577                                                 dst[b], linesize[b],
578                                                 src[b], in_linesize[b]);
579                        if (ret < 0)
580                            goto fail;
581                    }
582                }
583            } else {
584                for (int b = 0; b < 6; b++) {
585                    int mode = get_bits_le(&mgb, 2);
586
587                    ret = decode_intra_block(avctx, mode, &gbyte, s->intraq_tab[b >= 4],
588                                             s->block[b],
589                                             pfill[(b >= 4) + (b >= 5)],
590                                             dst[b], linesize[b]);
591                    if (ret < 0)
592                        goto fail;
593                }
594            }
595
596            cnt++;
597        }
598    }
599
600fail:
601    return ret;
602}
603
604static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
605                        int *got_frame, AVPacket *avpkt)
606{
607    MV30Context *s = avctx->priv_data;
608    GetBitContext *gb = &s->gb;
609    int ret;
610
611    if ((ret = init_get_bits8(gb, avpkt->data, avpkt->size)) < 0)
612        return ret;
613
614    if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
615        return ret;
616
617    s->intra_quant = get_bits(gb, 8);
618    s->inter_quant = s->intra_quant + get_sbits(gb, 8);
619    s->is_inter = get_bits_le(gb, 16);
620    s->mode_size = get_bits_le(gb, 16);
621    if (s->is_inter)
622        s->nb_mvectors = get_bits_le(gb, 16);
623
624    get_qtable(s->intraq_tab[0], s->intra_quant, luma_tab);
625    get_qtable(s->intraq_tab[1], s->intra_quant, chroma_tab);
626
627    frame->key_frame = s->is_inter == 0;
628
629    if (frame->key_frame) {
630        ret = decode_intra(avctx, gb, frame);
631        if (ret < 0)
632            return ret;
633    } else {
634        get_qtable(s->interq_tab[0], s->inter_quant, luma_tab);
635        get_qtable(s->interq_tab[1], s->inter_quant, chroma_tab);
636
637        if (!s->prev_frame->data[0]) {
638            av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
639            return AVERROR_INVALIDDATA;
640        }
641
642        ret = decode_inter(avctx, gb, frame, s->prev_frame);
643        if (ret < 0)
644            return ret;
645    }
646
647    av_frame_unref(s->prev_frame);
648    if ((ret = av_frame_ref(s->prev_frame, frame)) < 0)
649        return ret;
650
651    *got_frame = 1;
652
653    return avpkt->size;
654}
655
656static const uint8_t cbp_bits[] = {
657    2, 2, 3, 3, 3, 4, 5, 6, 7, 8, 9, 9,
658};
659
660static av_cold void init_static_data(void)
661{
662    INIT_VLC_STATIC_FROM_LENGTHS(&cbp_tab, CBP_VLC_BITS, FF_ARRAY_ELEMS(cbp_bits),
663                                 cbp_bits, 1, NULL, 0, 0, 0, 0, 1 << CBP_VLC_BITS);
664}
665
666static av_cold int decode_init(AVCodecContext *avctx)
667{
668    MV30Context *s = avctx->priv_data;
669    static AVOnce init_static_once = AV_ONCE_INIT;
670
671    avctx->pix_fmt = AV_PIX_FMT_YUV420P;
672    avctx->color_range = AVCOL_RANGE_JPEG;
673
674    ff_blockdsp_init(&s->bdsp, avctx);
675
676    s->prev_frame = av_frame_alloc();
677    if (!s->prev_frame)
678        return AVERROR(ENOMEM);
679
680    ff_thread_once(&init_static_once, init_static_data);
681
682    return 0;
683}
684
685static void decode_flush(AVCodecContext *avctx)
686{
687    MV30Context *s = avctx->priv_data;
688
689    av_frame_unref(s->prev_frame);
690}
691
692static av_cold int decode_close(AVCodecContext *avctx)
693{
694    MV30Context *s = avctx->priv_data;
695
696    av_frame_free(&s->prev_frame);
697    av_freep(&s->coeffs);
698    s->coeffs_size = 0;
699    av_freep(&s->mvectors);
700    s->mvectors_size = 0;
701
702    return 0;
703}
704
705const FFCodec ff_mv30_decoder = {
706    .p.name           = "mv30",
707    .p.long_name      = NULL_IF_CONFIG_SMALL("MidiVid 3.0"),
708    .p.type           = AVMEDIA_TYPE_VIDEO,
709    .p.id             = AV_CODEC_ID_MV30,
710    .priv_data_size   = sizeof(MV30Context),
711    .init             = decode_init,
712    .close            = decode_close,
713    FF_CODEC_DECODE_CB(decode_frame),
714    .flush            = decode_flush,
715    .p.capabilities   = AV_CODEC_CAP_DR1,
716    .caps_internal    = FF_CODEC_CAP_INIT_THREADSAFE |
717                        FF_CODEC_CAP_INIT_CLEANUP,
718};
719