AOMedia AV1 Codec: decode_to_md5

| AOMedia AV1 Codec

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
43static 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
64static 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
70static const char *exec_name;
71
72void usage_exit(void) {
73 fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
74 exit(EXIT_FAILURE);
75}
76
77int main(int argc, char **argv) {
78 int frame_cnt = 0;
79 FILE *outfile = NULL;
80 AvxVideoReader *reader = NULL;
81 const AvxVideoInfo *info = NULL;
82
83 exec_name = argv[0];
84
85 if (argc != 3) die("Invalid number of arguments.");
86
87 reader = aom_video_reader_open(argv[1]);
88 if (!reader) die("Failed to open %s for reading.", argv[1]);
89
90 if (!(outfile = fopen(argv[2], "wb")))
91 die("Failed to open %s for writing.", argv[2]);
92
93 info = aom_video_reader_get_info(reader);
94
95 aom_codec_iface_t *decoder = get_aom_decoder_by_fourcc(info->codec_fourcc);
96 if (!decoder) die("Unknown input codec.");
97
98 printf("Using %s\n", aom_codec_iface_name(decoder));
99
100 aom_codec_ctx_t codec;
101 if (aom_codec_dec_init(&codec, decoder, NULL, 0))
102 die("Failed to initialize decoder");
103
104 while (aom_video_reader_read_frame(reader)) {
105 aom_codec_iter_t iter = NULL;
106 aom_image_t *img = NULL;
107 size_t frame_size = 0;
108 const unsigned char *frame =
109 aom_video_reader_get_frame(reader, &frame_size);
110 if (aom_codec_decode(&codec, frame, frame_size, NULL))
111 die_codec(&codec, "Failed to decode frame");
112
113 while ((img = aom_codec_get_frame(&codec, &iter)) != NULL) {
114 unsigned char digest[16];
115
116 get_image_md5(img, digest);
117 print_md5(outfile, digest);
118 fprintf(outfile, " img-%ux%u-%04d.i420\n", img->d_w, img->d_h,
119 ++frame_cnt);
120 }
121 }
122
123 printf("Processed %d frames.\n", frame_cnt);
124 if (aom_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
125
126 aom_video_reader_close(reader);
127
128 fclose(outfile);
129 return EXIT_SUCCESS;
130}
aom_decoder.h
Describes the decoder algorithm interface to applications.
aom_image_t
struct aom_image aom_image_t
Image Descriptor.
aomdx.h
Provides definitions for using AOM or AV1 within the aom Decoder interface.
aom_codec_iface_name
const char * aom_codec_iface_name(aom_codec_iface_t *iface)
Return the name for a given interface.
aom_codec_ctx_t
struct aom_codec_ctx aom_codec_ctx_t
Codec context structure.
aom_codec_iface_t
const struct aom_codec_iface aom_codec_iface_t
Codec interface structure.
Definition aom_codec.h:271
aom_codec_destroy
aom_codec_err_t aom_codec_destroy(aom_codec_ctx_t *ctx)
Destroy a codec instance.
aom_codec_iter_t
const void * aom_codec_iter_t
Iterator.
Definition aom_codec.h:305
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_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_codec_dec_init
#define aom_codec_dec_init(ctx, iface, cfg, flags)
Convenience macro for aom_codec_dec_init_ver().
Definition aom_decoder.h:129
aom_image::stride
int stride[3]
Definition aom_image.h:216
aom_image::d_w
unsigned int d_w
Definition aom_image.h:197
aom_image::d_h
unsigned int d_h
Definition aom_image.h:198
aom_image::planes
unsigned char * planes[3]
Definition aom_image.h:215