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 14 #include "./bitwriter.h" 15 16 #if CONFIG_BITSTREAM_DEBUG 17 #include "vpx_util/vpx_debug_util.h" 18 #endif 19 vpx_start_encode(vpx_writer * br,uint8_t * source,size_t size)20void vpx_start_encode(vpx_writer *br, uint8_t *source, size_t size) { 21 br->lowvalue = 0; 22 br->range = 255; 23 br->count = -24; 24 br->error = 0; 25 br->pos = 0; 26 // Make sure it is safe to cast br->pos to int in vpx_write(). 27 if (size > INT_MAX) size = INT_MAX; 28 br->size = (unsigned int)size; 29 br->buffer = source; 30 vpx_write_bit(br, 0); 31 } 32 vpx_stop_encode(vpx_writer * br)33int vpx_stop_encode(vpx_writer *br) { 34 int i; 35 36 #if CONFIG_BITSTREAM_DEBUG 37 bitstream_queue_set_skip_write(1); 38 #endif 39 for (i = 0; i < 32; i++) vpx_write_bit(br, 0); 40 41 // Ensure there's no ambigous collision with any index marker bytes 42 if (!br->error && (br->buffer[br->pos - 1] & 0xe0) == 0xc0) { 43 if (br->pos < br->size) { 44 br->buffer[br->pos++] = 0; 45 } else { 46 br->error = 1; 47 } 48 } 49 50 #if CONFIG_BITSTREAM_DEBUG 51 bitstream_queue_set_skip_write(0); 52 #endif 53 54 return br->error ? -1 : 0; 55 } 56