/*

 *  Copyright (c) 2010 The WebM project authors. All Rights Reserved.

 *

 *  Use of this source code is governed by a BSD-style license

 *  that can be found in the LICENSE file in the root of the source

 *  tree. An additional intellectual property rights grant can be found

 *  in the file PATENTS.  All contributing project authors may

 *  be found in the AUTHORS file in the root of the source tree.

 */

#include <assert.h>

#include <limits.h>

#include "./bitwriter.h"

#if CONFIG_BITSTREAM_DEBUG

#include "vpx_util/vpx_debug_util.h"

#endif

void vpx_start_encode(vpx_writer *br, uint8_t *source, size_t size) {

  br->lowvalue = 0;

  br->range = 255;

  br->count = -24;

  br->error = 0;

  br->pos = 0;

  // Make sure it is safe to cast br->pos to int in vpx_write().

  if (size > INT_MAX) size = INT_MAX;

  br->size = (unsigned int)size;

  br->buffer = source;

  vpx_write_bit(br, 0);

}

int vpx_stop_encode(vpx_writer *br) {

  int i;

#if CONFIG_BITSTREAM_DEBUG

  bitstream_queue_set_skip_write(1);

#endif

  for (i = 0; i < 32; i++) vpx_write_bit(br, 0);

  // Ensure there's no ambigous collision with any index marker bytes

  if (!br->error && (br->buffer[br->pos - 1] & 0xe0) == 0xc0) {

    if (br->pos < br->size) {

      br->buffer[br->pos++] = 0;

    } else {

      br->error = 1;

    }

  }

#if CONFIG_BITSTREAM_DEBUG

  bitstream_queue_set_skip_write(0);

#endif

  return br->error ? -1 : 0;

}