The Tor Browser / file comparison
comparison: media/libvpx/vp8/decoder/dboolhuff.c
media/libvpx/vp8/decoder/dboolhuff.c
- changeset 0
- 6474c204b198
equal
deleted
inserted
replaced
| -1:000000000000 | 0:99b6765490f8 |
|---|---|
| 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 | |
| 12 #include "dboolhuff.h" | |
| 13 | |
| 14 int vp8dx_start_decode(BOOL_DECODER *br, | |
| 15 const unsigned char *source, | |
| 16 unsigned int source_sz, | |
| 17 vp8_decrypt_cb *decrypt_cb, | |
| 18 void *decrypt_state) | |
| 19 { | |
| 20 br->user_buffer_end = source+source_sz; | |
| 21 br->user_buffer = source; | |
| 22 br->value = 0; | |
| 23 br->count = -8; | |
| 24 br->range = 255; | |
| 25 br->decrypt_cb = decrypt_cb; | |
| 26 br->decrypt_state = decrypt_state; | |
| 27 | |
| 28 if (source_sz && !source) | |
| 29 return 1; | |
| 30 | |
| 31 /* Populate the buffer */ | |
| 32 vp8dx_bool_decoder_fill(br); | |
| 33 | |
| 34 return 0; | |
| 35 } | |
| 36 | |
| 37 void vp8dx_bool_decoder_fill(BOOL_DECODER *br) | |
| 38 { | |
| 39 const unsigned char *bufptr = br->user_buffer; | |
| 40 VP8_BD_VALUE value = br->value; | |
| 41 int count = br->count; | |
| 42 int shift = VP8_BD_VALUE_SIZE - 8 - (count + 8); | |
| 43 size_t bytes_left = br->user_buffer_end - bufptr; | |
| 44 size_t bits_left = bytes_left * CHAR_BIT; | |
| 45 int x = (int)(shift + CHAR_BIT - bits_left); | |
| 46 int loop_end = 0; | |
| 47 unsigned char decrypted[sizeof(VP8_BD_VALUE) + 1]; | |
| 48 | |
| 49 if (br->decrypt_cb) { | |
| 50 size_t n = bytes_left > sizeof(decrypted) ? sizeof(decrypted) : bytes_left; | |
| 51 br->decrypt_cb(br->decrypt_state, bufptr, decrypted, (int)n); | |
| 52 bufptr = decrypted; | |
| 53 } | |
| 54 | |
| 55 if(x >= 0) | |
| 56 { | |
| 57 count += VP8_LOTS_OF_BITS; | |
| 58 loop_end = x; | |
| 59 } | |
| 60 | |
| 61 if (x < 0 || bits_left) | |
| 62 { | |
| 63 while(shift >= loop_end) | |
| 64 { | |
| 65 count += CHAR_BIT; | |
| 66 value |= (VP8_BD_VALUE)*bufptr << shift; | |
| 67 ++bufptr; | |
| 68 ++br->user_buffer; | |
| 69 shift -= CHAR_BIT; | |
| 70 } | |
| 71 } | |
| 72 | |
| 73 br->value = value; | |
| 74 br->count = count; | |
| 75 } |
