decode_to_md5.c

/*
 *  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.
 */

// Frame-by-frame MD5 Checksum
// ===========================
//
// This example builds upon the simple decoder loop to show how checksums
// of the decoded output can be generated. These are used for validating
// decoder implementations against the reference implementation, for example.
//
// MD5 algorithm
// -------------
// The Message-Digest 5 (MD5) is a well known hash function. We have provided
// an implementation derived from the RSA Data Security, Inc. MD5 Message-Digest
// Algorithm for your use. Our implmentation only changes the interface of this
// reference code. You must include the `md5_utils.h` header for access to these
// functions.
//
// Processing The Decoded Data
// ---------------------------
// Each row of the image is passed to the MD5 accumulator. First the Y plane
// is processed, then U, then V. It is important to honor the image's `stride`
// values.

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define VPX_CODEC_DISABLE_COMPAT 1

#include "vpx/vp8dx.h"
#include "vpx/vpx_decoder.h"

#include "./md5_utils.h"
#include "./tools_common.h"
#include "./video_reader.h"
#include "./vpx_config.h"

static void get_image_md5(const vpx_image_t *img, unsigned char digest[16]) {
  int plane, y;
  MD5Context md5;

  MD5Init(&md5);

  for (plane = 0; plane < 3; ++plane) {
    const unsigned char *buf = img->planes[plane];
    const int stride = img->stride[plane];
    const int w = plane ? (img->d_w + 1) >> 1 : img->d_w;
    const int h = plane ? (img->d_h + 1) >> 1 : img->d_h;

    for (y = 0; y < h; ++y) {
      MD5Update(&md5, buf, w);
      buf += stride;
    }
  }

  MD5Final(digest, &md5);
}

static void print_md5(FILE *stream, unsigned char digest[16]) {
  int i;

  for (i = 0; i < 16; ++i)