AOMedia Codec SDK
decode_to_md5
1 /*
2  * Copyright (c) 2016, Alliance for Open Media. All rights reserved
3  *
4  * This source code is subject to the terms of the BSD 2 Clause License and
5  * the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6  * was not distributed with this source code in the LICENSE file, you can
7  * obtain it at www.aomedia.org/license/software. If the Alliance for Open
8  * Media Patent License 1.0 was not distributed with this source code in the
9  * PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10  */
11 
12 // Frame-by-frame MD5 Checksum
13 // ===========================
14 //
15 // This example builds upon the simple decoder loop to show how checksums
16 // of the decoded output can be generated. These are used for validating
17 // decoder implementations against the reference implementation, for example.
18 //
19 // MD5 algorithm
20 // -------------
21 // The Message-Digest 5 (MD5) is a well known hash function. We have provided
22 // an implementation derived from the RSA Data Security, Inc. MD5 Message-Digest
23 // Algorithm for your use. Our implmentation only changes the interface of this
24 // reference code. You must include the `md5_utils.h` header for access to these
25 // functions.
26 //
27 // Processing The Decoded Data
28 // ---------------------------
29 // Each row of the image is passed to the MD5 accumulator. First the Y plane
30 // is processed, then U, then V. It is important to honor the image's `stride`
31 // values.
32 
33 #include <stdio.h>
34 #include <stdlib.h>
35 #include <string.h>
36 
37 #include "aom/aom_decoder.h"
38 #include "aom/aomdx.h"
39 #include "common/md5_utils.h"
40 #include "common/tools_common.h"
41 #include "common/video_reader.h"
42 
43 static void get_image_md5(const aom_image_t *img, unsigned char digest[16]) {
44  int plane, y;
45  MD5Context md5;
46 
47  MD5Init(&md5);
48 
49  for (plane = 0; plane < 3; ++plane) {
50  const unsigned char *buf = img->planes[plane];
51  const int stride = img->stride[plane];
52  const int w = plane ? (img->d_w + 1) >> 1 : img->d_w;
53  const int h = plane ? (img->d_h + 1) >> 1 : img->d_h;
54 
55  for (y = 0; y < h; ++y) {
56  MD5Update(&md5, buf, w);
57  buf += stride;
58  }
59  }
60 
61  MD5Final(digest, &md5);
62 }
63 
64 static void print_md5(FILE *stream, unsigned char digest[16]) {
65  int i;
66 
67  for (i = 0; i < 16; ++i) fprintf(stream, "%02x", digest[i]);
68 }
69 
70 static const char *exec_name;
71 
72 void usage_exit(void) {
73  fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
74  exit(EXIT_FAILURE);
75 }
76 
77 int main(int argc, char **argv) {
78  int frame_cnt = 0;
79  FILE *outfile = NULL;
80  aom_codec_ctx_t codec;
81  AvxVideoReader *reader = NULL;
82  const AvxVideoInfo *info = NULL;
83  const AvxInterface *decoder = NULL;
84 
85  exec_name = argv[0];
86 
87  if (argc != 3) die("Invalid number of arguments.");
88 
89  reader = aom_video_reader_open(argv[1]);
90  if (!reader) die("Failed to open %s for reading.", argv[1]);
91 
92  if (!(outfile = fopen(argv[2], "wb")))
93  die("Failed to open %s for writing.", argv[2]);
94 
95  info = aom_video_reader_get_info(reader);
96 
97  decoder = get_aom_decoder_by_fourcc(info->codec_fourcc);
98  if (!decoder) die("Unknown input codec.");
99 
100  printf("Using %s\n", aom_codec_iface_name(decoder->codec_interface()));
101 
102  if (aom_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
103  die_codec(&codec, "Failed to initialize decoder");
104 
105  while (aom_video_reader_read_frame(reader)) {
106  aom_codec_iter_t iter = NULL;
107  aom_image_t *img = NULL;
108  size_t frame_size = 0;
109  const unsigned char *frame =
110  aom_video_reader_get_frame(reader, &frame_size);
111  if (aom_codec_decode(&codec, frame, frame_size, NULL))
112  die_codec(&codec, "Failed to decode frame");
113 
114  while ((img = aom_codec_get_frame(&codec, &iter)) != NULL) {
115  unsigned char digest[16];
116 
117  get_image_md5(img, digest);
118  print_md5(outfile, digest);
119  fprintf(outfile, " img-%dx%d-%04d.i420\n", img->d_w, img->d_h,
120  ++frame_cnt);
121  }
122  }
123 
124  printf("Processed %d frames.\n", frame_cnt);
125  if (aom_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
126 
127  aom_video_reader_close(reader);
128 
129  fclose(outfile);
130  return EXIT_SUCCESS;
131 }
aom_codec_decode
aom_codec_err_t aom_codec_decode(aom_codec_ctx_t *ctx, const uint8_t *data, size_t data_sz, void *user_priv)
Decode data.
aom_image::planes
unsigned char * planes[3]
Definition: aom_image.h:172
aom_image::d_h
unsigned int d_h
Definition: aom_image.h:157
aom_codec_ctx
Codec context structure.
Definition: aom_codec.h:204
aom_codec_iter_t
const typedef void * aom_codec_iter_t
Iterator.
Definition: aom_codec.h:194
aom_codec_iface_name
const char * aom_codec_iface_name(aom_codec_iface_t *iface)
Return the name for a given interface.
aom_codec_destroy
aom_codec_err_t aom_codec_destroy(aom_codec_ctx_t *ctx)
Destroy a codec instance.
aom_decoder.h
Describes the decoder algorithm interface to applications.
aom_codec_dec_init
#define aom_codec_dec_init(ctx, iface, cfg, flags)
Convenience macro for aom_codec_dec_init_ver()
Definition: aom_decoder.h:135
aom_codec_get_frame
aom_image_t * aom_codec_get_frame(aom_codec_ctx_t *ctx, aom_codec_iter_t *iter)
Decoded frames iterator.
aom_image::d_w
unsigned int d_w
Definition: aom_image.h:156
aomdx.h
Provides definitions for using AOM or AV1 within the aom Decoder interface.
aom_image
Image Descriptor.
Definition: aom_image.h:141
aom_image::stride
int stride[3]
Definition: aom_image.h:173