1 /*
2 * Copyright (C) 2005 Ole André Vadla Ravnås <oleavr@gmail.com>
3 * Copyright (C) 2008 Ramiro Polla
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <stdlib.h>
23 #include <string.h>
24 #include <stdint.h>
25
26 #include "libavutil/mem_internal.h"
27 #include "libavutil/thread.h"
28
29 #include "avcodec.h"
30 #include "blockdsp.h"
31 #include "internal.h"
32 #include "get_bits.h"
33 #include "bytestream.h"
34 #include "bswapdsp.h"
35 #include "hpeldsp.h"
36 #include "idctdsp.h"
37 #include "thread.h"
38
39 #define MIMIC_HEADER_SIZE 20
40 #define MIMIC_VLC_BITS 11
41
42 typedef struct MimicContext {
43 AVCodecContext *avctx;
44
45 int num_vblocks[3];
46 int num_hblocks[3];
47
48 void *swap_buf;
49 int swap_buf_size;
50
51 int cur_index;
52 int prev_index;
53
54 ThreadFrame frames [16];
55
56 DECLARE_ALIGNED(32, int16_t, dct_block)[64];
57
58 GetBitContext gb;
59 ScanTable scantable;
60 BlockDSPContext bdsp;
61 BswapDSPContext bbdsp;
62 HpelDSPContext hdsp;
63 IDCTDSPContext idsp;
64
65 /* Kept in the context so multithreading can have a constant to read from */
66 int next_cur_index;
67 int next_prev_index;
68 } MimicContext;
69
70 static VLC block_vlc;
71
72 static const uint8_t huffsyms[] = {
73 0x10, 0x20, 0x30, 0x00, 0x11, 0x40, 0x50, 0x12, 0x13, 0x21, 0x31, 0x60,
74 0x14, 0x15, 0x16, 0x22, 0x41, 0x17, 0x18, 0x23, 0x24, 0x25, 0x32, 0x42,
75 0x51, 0x61, 0x70, 0x19, 0x1A, 0x1B, 0x1C, 0x1D, 0x1E, 0x1F, 0x26, 0x27,
76 0x28, 0x29, 0x2A, 0x2B, 0x2C, 0x2D, 0x2E, 0x33, 0x34, 0x35, 0x36, 0x37,
77 0x38, 0x39, 0x3A, 0x3B, 0x3C, 0x3D, 0x3E, 0x43, 0x44, 0x45, 0x46, 0x47,
78 0x48, 0x49, 0x4A, 0x4B, 0x4C, 0x4D, 0x4E, 0x52, 0x53, 0x54, 0x55, 0x56,
79 0x57, 0x58, 0x59, 0x5A, 0x5B, 0x5C, 0x5D, 0x5E, 0x62, 0x63, 0x64, 0x65,
80 0x66, 0x67, 0x68, 0x69, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x71, 0x72, 0x73,
81 0x74, 0x75, 0x76, 0x77, 0x78, 0x79, 0x7A, 0x7B, 0x7C, 0x7D, 0x7E,
82 };
83
84 static const uint8_t huffbits[] = {
85 2, 2, 3, 4, 4, 4, 5, 5, 6, 6, 6, 6, 7, 7, 7, 7, 8, 8,
86 8, 8, 9, 9, 9, 9, 10, 10, 10, 10, 11, 11, 11, 11, 12, 12, 12, 12,
87 13, 13, 13, 13, 14, 14, 14, 14, 15, 15, 15, 15, 16, 16, 16, 16, 17, 17,
88 17, 17, 18, 18, 18, 18, 19, 19, 19, 19, 20, 20, 20, 20, 21, 21, 21, 21,
89 22, 22, 22, 22, 23, 23, 23, 23, 24, 24, 24, 24, 25, 25, 25, 25, 26, 26,
90 26, 26, 27, 27, 27, 27, 28, 28, 28, 28, 29, 29, 29, 29, 30, 30, 30,
91 };
92
93 static const uint8_t col_zag[64] = {
94 0, 8, 1, 2, 9, 16, 24, 17,
95 10, 3, 4, 11, 18, 25, 32, 40,
96 33, 26, 19, 12, 5, 6, 13, 20,
97 27, 34, 41, 48, 56, 49, 42, 35,
98 28, 21, 14, 7, 15, 22, 29, 36,
99 43, 50, 57, 58, 51, 44, 37, 30,
100 23, 31, 38, 45, 52, 59, 39, 46,
101 53, 60, 61, 54, 47, 55, 62, 63,
102 };
103
mimic_decode_end(AVCodecContext * avctx)104 static av_cold int mimic_decode_end(AVCodecContext *avctx)
105 {
106 MimicContext *ctx = avctx->priv_data;
107 int i;
108
109 av_freep(&ctx->swap_buf);
110 ctx->swap_buf_size = 0;
111
112 for (i = 0; i < FF_ARRAY_ELEMS(ctx->frames); i++) {
113 if (ctx->frames[i].f)
114 ff_thread_release_buffer(avctx, &ctx->frames[i]);
115 av_frame_free(&ctx->frames[i].f);
116 }
117
118 return 0;
119 }
120
mimic_init_static(void)121 static av_cold void mimic_init_static(void)
122 {
123 INIT_VLC_STATIC_FROM_LENGTHS(&block_vlc, MIMIC_VLC_BITS, FF_ARRAY_ELEMS(huffbits),
124 huffbits, 1, huffsyms, 1, 1, 0, 0, 4368);
125 }
126
mimic_decode_init(AVCodecContext * avctx)127 static av_cold int mimic_decode_init(AVCodecContext *avctx)
128 {
129 static AVOnce init_static_once = AV_ONCE_INIT;
130 MimicContext *ctx = avctx->priv_data;
131 int i;
132
133 ctx->prev_index = 0;
134 ctx->cur_index = 15;
135
136 ff_blockdsp_init(&ctx->bdsp, avctx);
137 ff_bswapdsp_init(&ctx->bbdsp);
138 ff_hpeldsp_init(&ctx->hdsp, avctx->flags);
139 ff_idctdsp_init(&ctx->idsp, avctx);
140 ff_init_scantable(ctx->idsp.idct_permutation, &ctx->scantable, col_zag);
141
142 for (i = 0; i < FF_ARRAY_ELEMS(ctx->frames); i++) {
143 ctx->frames[i].f = av_frame_alloc();
144 if (!ctx->frames[i].f)
145 return AVERROR(ENOMEM);
146 }
147
148 ff_thread_once(&init_static_once, mimic_init_static);
149
150 return 0;
151 }
152
153 #if HAVE_THREADS
mimic_decode_update_thread_context(AVCodecContext * avctx,const AVCodecContext * avctx_from)154 static int mimic_decode_update_thread_context(AVCodecContext *avctx, const AVCodecContext *avctx_from)
155 {
156 MimicContext *dst = avctx->priv_data, *src = avctx_from->priv_data;
157 int i, ret;
158
159 if (avctx == avctx_from)
160 return 0;
161
162 dst->cur_index = src->next_cur_index;
163 dst->prev_index = src->next_prev_index;
164
165 for (i = 0; i < FF_ARRAY_ELEMS(dst->frames); i++) {
166 ff_thread_release_buffer(avctx, &dst->frames[i]);
167 if (i != src->next_cur_index && src->frames[i].f->data[0]) {
168 ret = ff_thread_ref_frame(&dst->frames[i], &src->frames[i]);
169 if (ret < 0)
170 return ret;
171 }
172 }
173
174 return 0;
175 }
176 #endif
177
178 static const int8_t vlcdec_lookup[9][64] = {
179 { 0, },
180 { -1, 1, },
181 { -3, 3, -2, 2, },
182 { -7, 7, -6, 6, -5, 5, -4, 4, },
183 { -15, 15, -14, 14, -13, 13, -12, 12,
184 -11, 11, -10, 10, -9, 9, -8, 8, },
185 { -31, 31, -30, 30, -29, 29, -28, 28,
186 -27, 27, -26, 26, -25, 25, -24, 24,
187 -23, 23, -22, 22, -21, 21, -20, 20,
188 -19, 19, -18, 18, -17, 17, -16, 16, },
189 { -63, 63, -62, 62, -61, 61, -60, 60,
190 -59, 59, -58, 58, -57, 57, -56, 56,
191 -55, 55, -54, 54, -53, 53, -52, 52,
192 -51, 51, -50, 50, -49, 49, -48, 48,
193 -47, 47, -46, 46, -45, 45, -44, 44,
194 -43, 43, -42, 42, -41, 41, -40, 40,
195 -39, 39, -38, 38, -37, 37, -36, 36,
196 -35, 35, -34, 34, -33, 33, -32, 32, },
197 { -127, 127, -126, 126, -125, 125, -124, 124,
198 -123, 123, -122, 122, -121, 121, -120, 120,
199 -119, 119, -118, 118, -117, 117, -116, 116,
200 -115, 115, -114, 114, -113, 113, -112, 112,
201 -111, 111, -110, 110, -109, 109, -108, 108,
202 -107, 107, -106, 106, -105, 105, -104, 104,
203 -103, 103, -102, 102, -101, 101, -100, 100,
204 -99, 99, -98, 98, -97, 97, -96, 96, },
205 { -95, 95, -94, 94, -93, 93, -92, 92,
206 -91, 91, -90, 90, -89, 89, -88, 88,
207 -87, 87, -86, 86, -85, 85, -84, 84,
208 -83, 83, -82, 82, -81, 81, -80, 80,
209 -79, 79, -78, 78, -77, 77, -76, 76,
210 -75, 75, -74, 74, -73, 73, -72, 72,
211 -71, 71, -70, 70, -69, 69, -68, 68,
212 -67, 67, -66, 66, -65, 65, -64, 64, },
213 };
214
vlc_decode_block(MimicContext * ctx,int num_coeffs,int qscale)215 static int vlc_decode_block(MimicContext *ctx, int num_coeffs, int qscale)
216 {
217 int16_t *block = ctx->dct_block;
218 unsigned int pos;
219
220 ctx->bdsp.clear_block(block);
221
222 block[0] = get_bits(&ctx->gb, 8) << 3;
223
224 for (pos = 1; pos < num_coeffs; pos++) {
225 uint32_t vlc, num_bits;
226 int value;
227 int coeff;
228
229 vlc = get_vlc2(&ctx->gb, block_vlc.table, MIMIC_VLC_BITS, 3);
230 if (!vlc) /* end-of-block code */
231 return 0;
232 if (vlc == -1)
233 return AVERROR_INVALIDDATA;
234
235 /* pos_add and num_bits are coded in the vlc code */
236 pos += vlc & 15; // pos_add
237 num_bits = vlc >> 4; // num_bits
238
239 if (pos >= 64)
240 return AVERROR_INVALIDDATA;
241
242 value = get_bits(&ctx->gb, num_bits);
243
244 /* FFmpeg's IDCT behaves somewhat different from the original code, so
245 * a factor of 4 was added to the input */
246
247 coeff = ((int8_t*)vlcdec_lookup[num_bits])[value];
248 if (pos < 3)
249 coeff *= 16;
250 else /* TODO Use >> 10 instead of / 1001 */
251 coeff = (coeff * qscale) / 1001;
252
253 block[ctx->scantable.permutated[pos]] = coeff;
254 }
255
256 return 0;
257 }
258
decode(MimicContext * ctx,int quality,int num_coeffs,int is_iframe)259 static int decode(MimicContext *ctx, int quality, int num_coeffs,
260 int is_iframe)
261 {
262 int ret, y, x, plane, cur_row = 0;
263
264 for (plane = 0; plane < 3; plane++) {
265 const int is_chroma = !!plane;
266 const int qscale = av_clip(10000 - quality, is_chroma ? 1000 : 2000,
267 10000) << 2;
268 const int stride = ctx->frames[ctx->cur_index ].f->linesize[plane];
269 const uint8_t *src = ctx->frames[ctx->prev_index].f->data[plane];
270 uint8_t *dst = ctx->frames[ctx->cur_index ].f->data[plane];
271
272 for (y = 0; y < ctx->num_vblocks[plane]; y++) {
273 for (x = 0; x < ctx->num_hblocks[plane]; x++) {
274 /* Check for a change condition in the current block.
275 * - iframes always change.
276 * - Luma plane changes on get_bits1 == 0
277 * - Chroma planes change on get_bits1 == 1 */
278 if (is_iframe || get_bits1(&ctx->gb) == is_chroma) {
279 /* Luma planes may use a backreference from the 15 last
280 * frames preceding the previous. (get_bits1 == 1)
281 * Chroma planes don't use backreferences. */
282 if (is_chroma || is_iframe || !get_bits1(&ctx->gb)) {
283 if ((ret = vlc_decode_block(ctx, num_coeffs,
284 qscale)) < 0) {
285 av_log(ctx->avctx, AV_LOG_ERROR, "Error decoding "
286 "block.\n");
287 return ret;
288 }
289 ctx->idsp.idct_put(dst, stride, ctx->dct_block);
290 } else {
291 unsigned int backref = get_bits(&ctx->gb, 4);
292 int index = (ctx->cur_index + backref) & 15;
293 uint8_t *p = ctx->frames[index].f->data[0];
294
295 if (index != ctx->cur_index && p) {
296 ff_thread_await_progress(&ctx->frames[index],
297 cur_row, 0);
298 p += src -
299 ctx->frames[ctx->prev_index].f->data[plane];
300 ctx->hdsp.put_pixels_tab[1][0](dst, p, stride, 8);
301 } else {
302 av_log(ctx->avctx, AV_LOG_ERROR,
303 "No such backreference! Buggy sample.\n");
304 }
305 }
306 } else {
307 ff_thread_await_progress(&ctx->frames[ctx->prev_index],
308 cur_row, 0);
309 ctx->hdsp.put_pixels_tab[1][0](dst, src, stride, 8);
310 }
311 src += 8;
312 dst += 8;
313 }
314 src += (stride - ctx->num_hblocks[plane]) << 3;
315 dst += (stride - ctx->num_hblocks[plane]) << 3;
316
317 ff_thread_report_progress(&ctx->frames[ctx->cur_index],
318 cur_row++, 0);
319 }
320 }
321
322 return 0;
323 }
324
325 /**
326 * Flip the buffer upside-down and put it in the YVU order to revert the
327 * way Mimic encodes frames.
328 */
flip_swap_frame(AVFrame * f)329 static void flip_swap_frame(AVFrame *f)
330 {
331 int i;
332 uint8_t *data_1 = f->data[1];
333 f->data[0] = f->data[0] + ( f->height - 1) * f->linesize[0];
334 f->data[1] = f->data[2] + ((f->height >> 1) - 1) * f->linesize[2];
335 f->data[2] = data_1 + ((f->height >> 1) - 1) * f->linesize[1];
336 for (i = 0; i < 3; i++)
337 f->linesize[i] *= -1;
338 }
339
mimic_decode_frame(AVCodecContext * avctx,void * data,int * got_frame,AVPacket * avpkt)340 static int mimic_decode_frame(AVCodecContext *avctx, void *data,
341 int *got_frame, AVPacket *avpkt)
342 {
343 const uint8_t *buf = avpkt->data;
344 int buf_size = avpkt->size;
345 int swap_buf_size = buf_size - MIMIC_HEADER_SIZE;
346 MimicContext *ctx = avctx->priv_data;
347 GetByteContext gb;
348 int is_pframe;
349 int width, height;
350 int quality, num_coeffs;
351 int res;
352
353 if (buf_size <= MIMIC_HEADER_SIZE) {
354 av_log(avctx, AV_LOG_ERROR, "insufficient data\n");
355 return AVERROR_INVALIDDATA;
356 }
357
358 bytestream2_init(&gb, buf, MIMIC_HEADER_SIZE);
359 bytestream2_skip(&gb, 2); /* some constant (always 256) */
360 quality = bytestream2_get_le16u(&gb);
361 width = bytestream2_get_le16u(&gb);
362 height = bytestream2_get_le16u(&gb);
363 bytestream2_skip(&gb, 4); /* some constant */
364 is_pframe = bytestream2_get_le32u(&gb);
365 num_coeffs = bytestream2_get_byteu(&gb);
366 bytestream2_skip(&gb, 3); /* some constant */
367
368 if (!ctx->avctx) {
369 int i;
370
371 if (!(width == 160 && height == 120) &&
372 !(width == 320 && height == 240)) {
373 av_log(avctx, AV_LOG_ERROR, "invalid width/height!\n");
374 return AVERROR_INVALIDDATA;
375 }
376
377 res = ff_set_dimensions(avctx, width, height);
378 if (res < 0)
379 return res;
380
381 ctx->avctx = avctx;
382 avctx->pix_fmt = AV_PIX_FMT_YUV420P;
383 for (i = 0; i < 3; i++) {
384 ctx->num_vblocks[i] = AV_CEIL_RSHIFT(height, 3 + !!i);
385 ctx->num_hblocks[i] = width >> (3 + !!i);
386 }
387 } else if (width != ctx->avctx->width || height != ctx->avctx->height) {
388 avpriv_request_sample(avctx, "Resolution changing");
389 return AVERROR_PATCHWELCOME;
390 }
391
392 if (is_pframe && !ctx->frames[ctx->prev_index].f->data[0]) {
393 av_log(avctx, AV_LOG_ERROR, "decoding must start with keyframe\n");
394 return AVERROR_INVALIDDATA;
395 }
396
397 ff_thread_release_buffer(avctx, &ctx->frames[ctx->cur_index]);
398 ctx->frames[ctx->cur_index].f->pict_type = is_pframe ? AV_PICTURE_TYPE_P :
399 AV_PICTURE_TYPE_I;
400 if ((res = ff_thread_get_buffer(avctx, &ctx->frames[ctx->cur_index],
401 AV_GET_BUFFER_FLAG_REF)) < 0)
402 return res;
403
404 ctx->next_prev_index = ctx->cur_index;
405 ctx->next_cur_index = (ctx->cur_index - 1) & 15;
406
407 ff_thread_finish_setup(avctx);
408
409 av_fast_padded_malloc(&ctx->swap_buf, &ctx->swap_buf_size, swap_buf_size);
410 if (!ctx->swap_buf)
411 return AVERROR(ENOMEM);
412
413 ctx->bbdsp.bswap_buf(ctx->swap_buf,
414 (const uint32_t *) (buf + MIMIC_HEADER_SIZE),
415 swap_buf_size >> 2);
416 init_get_bits(&ctx->gb, ctx->swap_buf, swap_buf_size << 3);
417
418 res = decode(ctx, quality, num_coeffs, !is_pframe);
419 ff_thread_report_progress(&ctx->frames[ctx->cur_index], INT_MAX, 0);
420 if (res < 0) {
421 if (!(avctx->active_thread_type & FF_THREAD_FRAME))
422 ff_thread_release_buffer(avctx, &ctx->frames[ctx->cur_index]);
423 return res;
424 }
425
426 if ((res = av_frame_ref(data, ctx->frames[ctx->cur_index].f)) < 0)
427 return res;
428 *got_frame = 1;
429
430 flip_swap_frame(data);
431
432 ctx->prev_index = ctx->next_prev_index;
433 ctx->cur_index = ctx->next_cur_index;
434
435 return buf_size;
436 }
437
438 AVCodec ff_mimic_decoder = {
439 .name = "mimic",
440 .long_name = NULL_IF_CONFIG_SMALL("Mimic"),
441 .type = AVMEDIA_TYPE_VIDEO,
442 .id = AV_CODEC_ID_MIMIC,
443 .priv_data_size = sizeof(MimicContext),
444 .init = mimic_decode_init,
445 .close = mimic_decode_end,
446 .decode = mimic_decode_frame,
447 .capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_FRAME_THREADS,
448 .update_thread_context = ONLY_IF_THREADS_ENABLED(mimic_decode_update_thread_context),
449 .caps_internal = FF_CODEC_CAP_ALLOCATE_PROGRESS |
450 FF_CODEC_CAP_INIT_CLEANUP | FF_CODEC_CAP_INIT_THREADSAFE,
451 };
452