1 /*
2 * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
3 *
4 * Use of this source code is governed by a BSD-style license
5 * that can be found in the LICENSE file in the root of the source
6 * tree. An additional intellectual property rights grant can be found
7 * in the file PATENTS. All contributing project authors may
8 * be found in the AUTHORS file in the root of the source tree.
9 */
10
11 #include <assert.h>
12 #include <limits.h>
13 #include <stdio.h>
14
15 #include "./vp9_rtcd.h"
16 #include "./vpx_dsp_rtcd.h"
17 #include "./vpx_scale_rtcd.h"
18
19 #include "vpx_mem/vpx_mem.h"
20 #include "vpx_ports/system_state.h"
21 #include "vpx_ports/vpx_once.h"
22 #include "vpx_ports/vpx_timer.h"
23 #include "vpx_scale/vpx_scale.h"
24 #include "vpx_util/vpx_thread.h"
25
26 #include "vp9/common/vp9_alloccommon.h"
27 #include "vp9/common/vp9_loopfilter.h"
28 #include "vp9/common/vp9_onyxc_int.h"
29 #if CONFIG_VP9_POSTPROC
30 #include "vp9/common/vp9_postproc.h"
31 #endif
32 #include "vp9/common/vp9_quant_common.h"
33 #include "vp9/common/vp9_reconintra.h"
34
35 #include "vp9/decoder/vp9_decodeframe.h"
36 #include "vp9/decoder/vp9_decoder.h"
37 #include "vp9/decoder/vp9_detokenize.h"
38
initialize_dec(void)39 static void initialize_dec(void) {
40 static volatile int init_done = 0;
41
42 if (!init_done) {
43 vp9_rtcd();
44 vpx_dsp_rtcd();
45 vpx_scale_rtcd();
46 vp9_init_intra_predictors();
47 init_done = 1;
48 }
49 }
50
vp9_dec_setup_mi(VP9_COMMON * cm)51 static void vp9_dec_setup_mi(VP9_COMMON *cm) {
52 cm->mi = cm->mip + cm->mi_stride + 1;
53 cm->mi_grid_visible = cm->mi_grid_base + cm->mi_stride + 1;
54 memset(cm->mi_grid_base, 0,
55 cm->mi_stride * (cm->mi_rows + 1) * sizeof(*cm->mi_grid_base));
56 }
57
vp9_dec_alloc_row_mt_mem(RowMTWorkerData * row_mt_worker_data,VP9_COMMON * cm,int num_sbs,int max_threads,int num_jobs)58 void vp9_dec_alloc_row_mt_mem(RowMTWorkerData *row_mt_worker_data,
59 VP9_COMMON *cm, int num_sbs, int max_threads,
60 int num_jobs) {
61 int plane;
62 const size_t dqcoeff_size = (num_sbs << DQCOEFFS_PER_SB_LOG2) *
63 sizeof(*row_mt_worker_data->dqcoeff[0]);
64 row_mt_worker_data->num_jobs = num_jobs;
65 #if CONFIG_MULTITHREAD
66 {
67 int i;
68 CHECK_MEM_ERROR(
69 &cm->error, row_mt_worker_data->recon_sync_mutex,
70 vpx_malloc(sizeof(*row_mt_worker_data->recon_sync_mutex) * num_jobs));
71 if (row_mt_worker_data->recon_sync_mutex) {
72 for (i = 0; i < num_jobs; ++i) {
73 pthread_mutex_init(&row_mt_worker_data->recon_sync_mutex[i], NULL);
74 }
75 }
76
77 CHECK_MEM_ERROR(
78 &cm->error, row_mt_worker_data->recon_sync_cond,
79 vpx_malloc(sizeof(*row_mt_worker_data->recon_sync_cond) * num_jobs));
80 if (row_mt_worker_data->recon_sync_cond) {
81 for (i = 0; i < num_jobs; ++i) {
82 pthread_cond_init(&row_mt_worker_data->recon_sync_cond[i], NULL);
83 }
84 }
85 }
86 #endif
87 row_mt_worker_data->num_sbs = num_sbs;
88 for (plane = 0; plane < 3; ++plane) {
89 CHECK_MEM_ERROR(&cm->error, row_mt_worker_data->dqcoeff[plane],
90 vpx_memalign(32, dqcoeff_size));
91 memset(row_mt_worker_data->dqcoeff[plane], 0, dqcoeff_size);
92 CHECK_MEM_ERROR(&cm->error, row_mt_worker_data->eob[plane],
93 vpx_calloc(num_sbs << EOBS_PER_SB_LOG2,
94 sizeof(*row_mt_worker_data->eob[plane])));
95 }
96 CHECK_MEM_ERROR(&cm->error, row_mt_worker_data->partition,
97 vpx_calloc(num_sbs * PARTITIONS_PER_SB,
98 sizeof(*row_mt_worker_data->partition)));
99 CHECK_MEM_ERROR(&cm->error, row_mt_worker_data->recon_map,
100 vpx_calloc(num_sbs, sizeof(*row_mt_worker_data->recon_map)));
101
102 // allocate memory for thread_data
103 if (row_mt_worker_data->thread_data == NULL) {
104 const size_t thread_size =
105 max_threads * sizeof(*row_mt_worker_data->thread_data);
106 CHECK_MEM_ERROR(&cm->error, row_mt_worker_data->thread_data,
107 vpx_memalign(32, thread_size));
108 }
109 }
110
vp9_dec_free_row_mt_mem(RowMTWorkerData * row_mt_worker_data)111 void vp9_dec_free_row_mt_mem(RowMTWorkerData *row_mt_worker_data) {
112 if (row_mt_worker_data != NULL) {
113 int plane;
114 #if CONFIG_MULTITHREAD
115 int i;
116 if (row_mt_worker_data->recon_sync_mutex != NULL) {
117 for (i = 0; i < row_mt_worker_data->num_jobs; ++i) {
118 pthread_mutex_destroy(&row_mt_worker_data->recon_sync_mutex[i]);
119 }
120 vpx_free(row_mt_worker_data->recon_sync_mutex);
121 row_mt_worker_data->recon_sync_mutex = NULL;
122 }
123 if (row_mt_worker_data->recon_sync_cond != NULL) {
124 for (i = 0; i < row_mt_worker_data->num_jobs; ++i) {
125 pthread_cond_destroy(&row_mt_worker_data->recon_sync_cond[i]);
126 }
127 vpx_free(row_mt_worker_data->recon_sync_cond);
128 row_mt_worker_data->recon_sync_cond = NULL;
129 }
130 #endif
131 for (plane = 0; plane < 3; ++plane) {
132 vpx_free(row_mt_worker_data->eob[plane]);
133 row_mt_worker_data->eob[plane] = NULL;
134 vpx_free(row_mt_worker_data->dqcoeff[plane]);
135 row_mt_worker_data->dqcoeff[plane] = NULL;
136 }
137 vpx_free(row_mt_worker_data->partition);
138 row_mt_worker_data->partition = NULL;
139 vpx_free(row_mt_worker_data->recon_map);
140 row_mt_worker_data->recon_map = NULL;
141 vpx_free(row_mt_worker_data->thread_data);
142 row_mt_worker_data->thread_data = NULL;
143 }
144 }
145
vp9_dec_alloc_mi(VP9_COMMON * cm,int mi_size)146 static int vp9_dec_alloc_mi(VP9_COMMON *cm, int mi_size) {
147 cm->mip = vpx_calloc(mi_size, sizeof(*cm->mip));
148 if (!cm->mip) return 1;
149 cm->mi_alloc_size = mi_size;
150 cm->mi_grid_base = (MODE_INFO **)vpx_calloc(mi_size, sizeof(MODE_INFO *));
151 if (!cm->mi_grid_base) return 1;
152 return 0;
153 }
154
vp9_dec_free_mi(VP9_COMMON * cm)155 static void vp9_dec_free_mi(VP9_COMMON *cm) {
156 #if CONFIG_VP9_POSTPROC
157 // MFQE allocates an additional mip and swaps it with cm->mip.
158 vpx_free(cm->postproc_state.prev_mip);
159 cm->postproc_state.prev_mip = NULL;
160 #endif
161 vpx_free(cm->mip);
162 cm->mip = NULL;
163 vpx_free(cm->mi_grid_base);
164 cm->mi_grid_base = NULL;
165 cm->mi_alloc_size = 0;
166 }
167
vp9_decoder_create(BufferPool * const pool)168 VP9Decoder *vp9_decoder_create(BufferPool *const pool) {
169 VP9Decoder *volatile const pbi = vpx_memalign(32, sizeof(*pbi));
170 VP9_COMMON *volatile const cm = pbi ? &pbi->common : NULL;
171
172 if (!cm) return NULL;
173
174 vp9_zero(*pbi);
175
176 if (setjmp(cm->error.jmp)) {
177 cm->error.setjmp = 0;
178 vp9_decoder_remove(pbi);
179 return NULL;
180 }
181
182 cm->error.setjmp = 1;
183
184 CHECK_MEM_ERROR(&cm->error, cm->fc,
185 (FRAME_CONTEXT *)vpx_calloc(1, sizeof(*cm->fc)));
186 CHECK_MEM_ERROR(
187 &cm->error, cm->frame_contexts,
188 (FRAME_CONTEXT *)vpx_calloc(FRAME_CONTEXTS, sizeof(*cm->frame_contexts)));
189
190 pbi->need_resync = 1;
191 once(initialize_dec);
192
193 // Initialize the references to not point to any frame buffers.
194 memset(&cm->ref_frame_map, -1, sizeof(cm->ref_frame_map));
195 memset(&cm->next_ref_frame_map, -1, sizeof(cm->next_ref_frame_map));
196
197 init_frame_indexes(cm);
198 pbi->ready_for_new_data = 1;
199 pbi->common.buffer_pool = pool;
200
201 cm->bit_depth = VPX_BITS_8;
202 cm->dequant_bit_depth = VPX_BITS_8;
203
204 cm->alloc_mi = vp9_dec_alloc_mi;
205 cm->free_mi = vp9_dec_free_mi;
206 cm->setup_mi = vp9_dec_setup_mi;
207
208 vp9_loop_filter_init(cm);
209
210 cm->error.setjmp = 0;
211
212 vpx_get_worker_interface()->init(&pbi->lf_worker);
213
214 return pbi;
215 }
216
vp9_decoder_remove(VP9Decoder * pbi)217 void vp9_decoder_remove(VP9Decoder *pbi) {
218 int i;
219
220 if (!pbi) return;
221
222 vpx_get_worker_interface()->end(&pbi->lf_worker);
223 vpx_free(pbi->lf_worker.data1);
224
225 for (i = 0; i < pbi->num_tile_workers; ++i) {
226 VPxWorker *const worker = &pbi->tile_workers[i];
227 vpx_get_worker_interface()->end(worker);
228 }
229
230 vpx_free(pbi->tile_worker_data);
231 vpx_free(pbi->tile_workers);
232
233 if (pbi->num_tile_workers > 0) {
234 vp9_loop_filter_dealloc(&pbi->lf_row_sync);
235 }
236
237 if (pbi->row_mt == 1) {
238 vp9_dec_free_row_mt_mem(pbi->row_mt_worker_data);
239 if (pbi->row_mt_worker_data != NULL) {
240 vp9_jobq_deinit(&pbi->row_mt_worker_data->jobq);
241 vpx_free(pbi->row_mt_worker_data->jobq_buf);
242 #if CONFIG_MULTITHREAD
243 pthread_mutex_destroy(&pbi->row_mt_worker_data->recon_done_mutex);
244 #endif
245 }
246 vpx_free(pbi->row_mt_worker_data);
247 }
248
249 vp9_remove_common(&pbi->common);
250 vpx_free(pbi);
251 }
252
equal_dimensions(const YV12_BUFFER_CONFIG * a,const YV12_BUFFER_CONFIG * b)253 static int equal_dimensions(const YV12_BUFFER_CONFIG *a,
254 const YV12_BUFFER_CONFIG *b) {
255 return a->y_height == b->y_height && a->y_width == b->y_width &&
256 a->uv_height == b->uv_height && a->uv_width == b->uv_width;
257 }
258
vp9_copy_reference_dec(VP9Decoder * pbi,VP9_REFFRAME ref_frame_flag,YV12_BUFFER_CONFIG * sd)259 vpx_codec_err_t vp9_copy_reference_dec(VP9Decoder *pbi,
260 VP9_REFFRAME ref_frame_flag,
261 YV12_BUFFER_CONFIG *sd) {
262 VP9_COMMON *cm = &pbi->common;
263
264 /* TODO(jkoleszar): The decoder doesn't have any real knowledge of what the
265 * encoder is using the frame buffers for. This is just a stub to keep the
266 * vpxenc --test-decode functionality working, and will be replaced in a
267 * later commit that adds VP9-specific controls for this functionality.
268 */
269 if (ref_frame_flag == VP9_LAST_FLAG) {
270 const YV12_BUFFER_CONFIG *const cfg = get_ref_frame(cm, 0);
271 if (cfg == NULL) {
272 vpx_internal_error(&cm->error, VPX_CODEC_ERROR,
273 "No 'last' reference frame");
274 return VPX_CODEC_ERROR;
275 }
276 if (!equal_dimensions(cfg, sd))
277 vpx_internal_error(&cm->error, VPX_CODEC_ERROR,
278 "Incorrect buffer dimensions");
279 else
280 vpx_yv12_copy_frame(cfg, sd);
281 } else {
282 vpx_internal_error(&cm->error, VPX_CODEC_ERROR, "Invalid reference frame");
283 }
284
285 return cm->error.error_code;
286 }
287
vp9_set_reference_dec(VP9_COMMON * cm,VP9_REFFRAME ref_frame_flag,YV12_BUFFER_CONFIG * sd)288 vpx_codec_err_t vp9_set_reference_dec(VP9_COMMON *cm,
289 VP9_REFFRAME ref_frame_flag,
290 YV12_BUFFER_CONFIG *sd) {
291 int idx;
292 YV12_BUFFER_CONFIG *ref_buf = NULL;
293
294 // TODO(jkoleszar): The decoder doesn't have any real knowledge of what the
295 // encoder is using the frame buffers for. This is just a stub to keep the
296 // vpxenc --test-decode functionality working, and will be replaced in a
297 // later commit that adds VP9-specific controls for this functionality.
298 // (Yunqing) The set_reference control depends on the following setting in
299 // encoder.
300 // cpi->lst_fb_idx = 0;
301 // cpi->gld_fb_idx = 1;
302 // cpi->alt_fb_idx = 2;
303 if (ref_frame_flag == VP9_LAST_FLAG) {
304 idx = cm->ref_frame_map[0];
305 } else if (ref_frame_flag == VP9_GOLD_FLAG) {
306 idx = cm->ref_frame_map[1];
307 } else if (ref_frame_flag == VP9_ALT_FLAG) {
308 idx = cm->ref_frame_map[2];
309 } else {
310 vpx_internal_error(&cm->error, VPX_CODEC_ERROR, "Invalid reference frame");
311 return cm->error.error_code;
312 }
313
314 if (idx < 0 || idx >= FRAME_BUFFERS) {
315 vpx_internal_error(&cm->error, VPX_CODEC_ERROR,
316 "Invalid reference frame map");
317 return cm->error.error_code;
318 }
319
320 // Get the destination reference buffer.
321 ref_buf = &cm->buffer_pool->frame_bufs[idx].buf;
322
323 if (!equal_dimensions(ref_buf, sd)) {
324 vpx_internal_error(&cm->error, VPX_CODEC_ERROR,
325 "Incorrect buffer dimensions");
326 } else {
327 // Overwrite the reference frame buffer.
328 vpx_yv12_copy_frame(sd, ref_buf);
329 }
330
331 return cm->error.error_code;
332 }
333
334 /* If any buffer updating is signaled it should be done here. */
swap_frame_buffers(VP9Decoder * pbi)335 static void swap_frame_buffers(VP9Decoder *pbi) {
336 int ref_index = 0, mask;
337 VP9_COMMON *const cm = &pbi->common;
338 BufferPool *const pool = cm->buffer_pool;
339 RefCntBuffer *const frame_bufs = cm->buffer_pool->frame_bufs;
340
341 for (mask = pbi->refresh_frame_flags; mask; mask >>= 1) {
342 const int old_idx = cm->ref_frame_map[ref_index];
343 // Current thread releases the holding of reference frame.
344 decrease_ref_count(old_idx, frame_bufs, pool);
345
346 // Release the reference frame in reference map.
347 if (mask & 1) {
348 decrease_ref_count(old_idx, frame_bufs, pool);
349 }
350 cm->ref_frame_map[ref_index] = cm->next_ref_frame_map[ref_index];
351 ++ref_index;
352 }
353
354 // Current thread releases the holding of reference frame.
355 for (; ref_index < REF_FRAMES && !cm->show_existing_frame; ++ref_index) {
356 const int old_idx = cm->ref_frame_map[ref_index];
357 decrease_ref_count(old_idx, frame_bufs, pool);
358 cm->ref_frame_map[ref_index] = cm->next_ref_frame_map[ref_index];
359 }
360 pbi->hold_ref_buf = 0;
361 cm->frame_to_show = get_frame_new_buffer(cm);
362
363 --frame_bufs[cm->new_fb_idx].ref_count;
364
365 // Invalidate these references until the next frame starts.
366 for (ref_index = 0; ref_index < 3; ref_index++)
367 cm->frame_refs[ref_index].idx = -1;
368 }
369
release_fb_on_decoder_exit(VP9Decoder * pbi)370 static void release_fb_on_decoder_exit(VP9Decoder *pbi) {
371 const VPxWorkerInterface *const winterface = vpx_get_worker_interface();
372 VP9_COMMON *volatile const cm = &pbi->common;
373 BufferPool *volatile const pool = cm->buffer_pool;
374 RefCntBuffer *volatile const frame_bufs = cm->buffer_pool->frame_bufs;
375 int i;
376
377 // Synchronize all threads immediately as a subsequent decode call may
378 // cause a resize invalidating some allocations.
379 winterface->sync(&pbi->lf_worker);
380 for (i = 0; i < pbi->num_tile_workers; ++i) {
381 winterface->sync(&pbi->tile_workers[i]);
382 }
383
384 // Release all the reference buffers if worker thread is holding them.
385 if (pbi->hold_ref_buf == 1) {
386 int ref_index = 0, mask;
387 for (mask = pbi->refresh_frame_flags; mask; mask >>= 1) {
388 const int old_idx = cm->ref_frame_map[ref_index];
389 // Current thread releases the holding of reference frame.
390 decrease_ref_count(old_idx, frame_bufs, pool);
391
392 // Release the reference frame in reference map.
393 if (mask & 1) {
394 decrease_ref_count(old_idx, frame_bufs, pool);
395 }
396 ++ref_index;
397 }
398
399 // Current thread releases the holding of reference frame.
400 for (; ref_index < REF_FRAMES && !cm->show_existing_frame; ++ref_index) {
401 const int old_idx = cm->ref_frame_map[ref_index];
402 decrease_ref_count(old_idx, frame_bufs, pool);
403 }
404 pbi->hold_ref_buf = 0;
405 }
406 }
407
vp9_receive_compressed_data(VP9Decoder * pbi,size_t size,const uint8_t ** psource)408 int vp9_receive_compressed_data(VP9Decoder *pbi, size_t size,
409 const uint8_t **psource) {
410 VP9_COMMON *volatile const cm = &pbi->common;
411 BufferPool *volatile const pool = cm->buffer_pool;
412 RefCntBuffer *volatile const frame_bufs = cm->buffer_pool->frame_bufs;
413 const uint8_t *source = *psource;
414 int retcode = 0;
415 cm->error.error_code = VPX_CODEC_OK;
416
417 if (size == 0) {
418 // This is used to signal that we are missing frames.
419 // We do not know if the missing frame(s) was supposed to update
420 // any of the reference buffers, but we act conservative and
421 // mark only the last buffer as corrupted.
422 //
423 // TODO(jkoleszar): Error concealment is undefined and non-normative
424 // at this point, but if it becomes so, [0] may not always be the correct
425 // thing to do here.
426 if (cm->frame_refs[0].idx > 0) {
427 assert(cm->frame_refs[0].buf != NULL);
428 cm->frame_refs[0].buf->corrupted = 1;
429 }
430 }
431
432 pbi->ready_for_new_data = 0;
433
434 // Check if the previous frame was a frame without any references to it.
435 if (cm->new_fb_idx >= 0 && frame_bufs[cm->new_fb_idx].ref_count == 0 &&
436 !frame_bufs[cm->new_fb_idx].released) {
437 pool->release_fb_cb(pool->cb_priv,
438 &frame_bufs[cm->new_fb_idx].raw_frame_buffer);
439 frame_bufs[cm->new_fb_idx].released = 1;
440 }
441
442 // Find a free frame buffer. Return error if can not find any.
443 cm->new_fb_idx = get_free_fb(cm);
444 if (cm->new_fb_idx == INVALID_IDX) {
445 pbi->ready_for_new_data = 1;
446 release_fb_on_decoder_exit(pbi);
447 vpx_clear_system_state();
448 vpx_internal_error(&cm->error, VPX_CODEC_MEM_ERROR,
449 "Unable to find free frame buffer");
450 return cm->error.error_code;
451 }
452
453 // Assign a MV array to the frame buffer.
454 cm->cur_frame = &pool->frame_bufs[cm->new_fb_idx];
455
456 pbi->hold_ref_buf = 0;
457 pbi->cur_buf = &frame_bufs[cm->new_fb_idx];
458
459 if (setjmp(cm->error.jmp)) {
460 cm->error.setjmp = 0;
461 pbi->ready_for_new_data = 1;
462 release_fb_on_decoder_exit(pbi);
463 // Release current frame.
464 decrease_ref_count(cm->new_fb_idx, frame_bufs, pool);
465 vpx_clear_system_state();
466 return -1;
467 }
468
469 cm->error.setjmp = 1;
470 vp9_decode_frame(pbi, source, source + size, psource);
471
472 swap_frame_buffers(pbi);
473
474 vpx_clear_system_state();
475
476 if (!cm->show_existing_frame) {
477 cm->last_show_frame = cm->show_frame;
478 cm->prev_frame = cm->cur_frame;
479 if (cm->seg.enabled) vp9_swap_current_and_last_seg_map(cm);
480 }
481
482 if (cm->show_frame) cm->cur_show_frame_fb_idx = cm->new_fb_idx;
483
484 // Update progress in frame parallel decode.
485 cm->last_width = cm->width;
486 cm->last_height = cm->height;
487 if (cm->show_frame) {
488 cm->current_video_frame++;
489 }
490
491 cm->error.setjmp = 0;
492 return retcode;
493 }
494
vp9_get_raw_frame(VP9Decoder * pbi,YV12_BUFFER_CONFIG * sd,vp9_ppflags_t * flags)495 int vp9_get_raw_frame(VP9Decoder *pbi, YV12_BUFFER_CONFIG *sd,
496 vp9_ppflags_t *flags) {
497 VP9_COMMON *const cm = &pbi->common;
498 int ret = -1;
499 #if !CONFIG_VP9_POSTPROC
500 (void)*flags;
501 #endif
502
503 if (pbi->ready_for_new_data == 1) return ret;
504
505 pbi->ready_for_new_data = 1;
506
507 /* no raw frame to show!!! */
508 if (!cm->show_frame) return ret;
509
510 pbi->ready_for_new_data = 1;
511
512 #if CONFIG_VP9_POSTPROC
513 if (!cm->show_existing_frame) {
514 ret = vp9_post_proc_frame(cm, sd, flags, cm->width);
515 } else {
516 *sd = *cm->frame_to_show;
517 ret = 0;
518 }
519 #else
520 *sd = *cm->frame_to_show;
521 ret = 0;
522 #endif /*!CONFIG_POSTPROC*/
523 vpx_clear_system_state();
524 return ret;
525 }
526
vp9_parse_superframe_index(const uint8_t * data,size_t data_sz,uint32_t sizes[8],int * count,vpx_decrypt_cb decrypt_cb,void * decrypt_state)527 vpx_codec_err_t vp9_parse_superframe_index(const uint8_t *data, size_t data_sz,
528 uint32_t sizes[8], int *count,
529 vpx_decrypt_cb decrypt_cb,
530 void *decrypt_state) {
531 // A chunk ending with a byte matching 0xc0 is an invalid chunk unless
532 // it is a super frame index. If the last byte of real video compression
533 // data is 0xc0 the encoder must add a 0 byte. If we have the marker but
534 // not the associated matching marker byte at the front of the index we have
535 // an invalid bitstream and need to return an error.
536
537 uint8_t marker;
538
539 assert(data_sz);
540 marker = read_marker(decrypt_cb, decrypt_state, data + data_sz - 1);
541 *count = 0;
542
543 if ((marker & 0xe0) == 0xc0) {
544 const uint32_t frames = (marker & 0x7) + 1;
545 const uint32_t mag = ((marker >> 3) & 0x3) + 1;
546 const size_t index_sz = 2 + mag * frames;
547
548 // This chunk is marked as having a superframe index but doesn't have
549 // enough data for it, thus it's an invalid superframe index.
550 if (data_sz < index_sz) return VPX_CODEC_CORRUPT_FRAME;
551
552 {
553 const uint8_t marker2 =
554 read_marker(decrypt_cb, decrypt_state, data + data_sz - index_sz);
555
556 // This chunk is marked as having a superframe index but doesn't have
557 // the matching marker byte at the front of the index therefore it's an
558 // invalid chunk.
559 if (marker != marker2) return VPX_CODEC_CORRUPT_FRAME;
560 }
561
562 {
563 // Found a valid superframe index.
564 uint32_t i, j;
565 const uint8_t *x = &data[data_sz - index_sz + 1];
566
567 // Frames has a maximum of 8 and mag has a maximum of 4.
568 uint8_t clear_buffer[32];
569 assert(sizeof(clear_buffer) >= frames * mag);
570 if (decrypt_cb) {
571 decrypt_cb(decrypt_state, x, clear_buffer, frames * mag);
572 x = clear_buffer;
573 }
574
575 for (i = 0; i < frames; ++i) {
576 uint32_t this_sz = 0;
577
578 for (j = 0; j < mag; ++j) this_sz |= ((uint32_t)(*x++)) << (j * 8);
579 sizes[i] = this_sz;
580 }
581 *count = frames;
582 }
583 }
584 return VPX_CODEC_OK;
585 }
586