WebM Codec SDK: decode_to_md5

WebM Codec SDK

decode_to_md5
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// Frame-by-frame MD5 Checksum
12// ===========================
13//
14// This example builds upon the simple decoder loop to show how checksums
15// of the decoded output can be generated. These are used for validating
16// decoder implementations against the reference implementation, for example.
17//
18// MD5 algorithm
19// -------------
20// The Message-Digest 5 (MD5) is a well known hash function. We have provided
21// an implementation derived from the RSA Data Security, Inc. MD5 Message-Digest
22// Algorithm for your use. Our implmentation only changes the interface of this
23// reference code. You must include the `md5_utils.h` header for access to these
24// functions.
25//
26// Processing The Decoded Data
27// ---------------------------
28// Each row of the image is passed to the MD5 accumulator. First the Y plane
29// is processed, then U, then V. It is important to honor the image's `stride`
30// values.
31
32#include <stdio.h>
33#include <stdlib.h>
34#include <string.h>
35
36#include "vpx/vp8dx.h"
37#include "vpx/vpx_decoder.h"
38
39#include "../md5_utils.h"
40#include "../tools_common.h"
41#include "../video_reader.h"
42#include "./vpx_config.h"
43
44static void get_image_md5(const vpx_image_t *img, unsigned char digest[16]) {
45 int plane, y;
46 MD5Context md5;
47
48 MD5Init(&md5);
49
50 for (plane = 0; plane < 3; ++plane) {
51 const unsigned char *buf = img->planes[plane];
52 const int stride = img->stride[plane];
53 const int w = plane ? (img->d_w + 1) >> 1 : img->d_w;
54 const int h = plane ? (img->d_h + 1) >> 1 : img->d_h;
55
56 for (y = 0; y < h; ++y) {
57 MD5Update(&md5, buf, w);
58 buf += stride;
59 }
60 }
61
62 MD5Final(digest, &md5);
63}
64
65static void print_md5(FILE *stream, unsigned char digest[16]) {
66 int i;
67
68 for (i = 0; i < 16; ++i) fprintf(stream, "%02x", digest[i]);
69}
70
71static const char *exec_name;
72
73void usage_exit(void) {
74 fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
75 exit(EXIT_FAILURE);
76}
77
78int main(int argc, char **argv) {
79 int frame_cnt = 0;
80 FILE *outfile = NULL;
81 vpx_codec_ctx_t codec;
82 VpxVideoReader *reader = NULL;
83 const VpxVideoInfo *info = NULL;
84 const VpxInterface *decoder = NULL;
85
86 exec_name = argv[0];
87
88 if (argc != 3) die("Invalid number of arguments.");
89
90 reader = vpx_video_reader_open(argv[1]);
91 if (!reader) die("Failed to open %s for reading.", argv[1]);
92
93 if (!(outfile = fopen(argv[2], "wb")))
94 die("Failed to open %s for writing.", argv[2]);
95
96 info = vpx_video_reader_get_info(reader);
97
98 decoder = get_vpx_decoder_by_fourcc(info->codec_fourcc);
99 if (!decoder) die("Unknown input codec.");
100
101 printf("Using %s\n", vpx_codec_iface_name(decoder->codec_interface()));
102
103 if (vpx_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
104 die_codec(&codec, "Failed to initialize decoder");
105
106 while (vpx_video_reader_read_frame(reader)) {
107 vpx_codec_iter_t iter = NULL;
108 vpx_image_t *img = NULL;
109 size_t frame_size = 0;
110 const unsigned char *frame =
111 vpx_video_reader_get_frame(reader, &frame_size);
112 if (vpx_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0))
113 die_codec(&codec, "Failed to decode frame");
114
115 while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL) {
116 unsigned char digest[16];
117
118 get_image_md5(img, digest);
119 print_md5(outfile, digest);
120 fprintf(outfile, " img-%dx%d-%04d.i420\n", img->d_w, img->d_h,
121 ++frame_cnt);
122 }
123 }
124
125 printf("Processed %d frames.\n", frame_cnt);
126 if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
127
128 vpx_video_reader_close(reader);
129
130 fclose(outfile);
131 return EXIT_SUCCESS;
132}
vpx_codec_destroy
vpx_codec_err_t vpx_codec_destroy(vpx_codec_ctx_t *ctx)
Destroy a codec instance.
vpx_codec_iter_t
const void * vpx_codec_iter_t
Iterator.
Definition vpx_codec.h:190
vpx_codec_iface_name
const char * vpx_codec_iface_name(vpx_codec_iface_t *iface)
Return the name for a given interface.
vpx_codec_decode
vpx_codec_err_t vpx_codec_decode(vpx_codec_ctx_t *ctx, const uint8_t *data, unsigned int data_sz, void *user_priv, long deadline)
Decode data.
vpx_codec_dec_init
#define vpx_codec_dec_init(ctx, iface, cfg, flags)
Convenience macro for vpx_codec_dec_init_ver()
Definition vpx_decoder.h:143
vpx_codec_get_frame
vpx_image_t * vpx_codec_get_frame(vpx_codec_ctx_t *ctx, vpx_codec_iter_t *iter)
Decoded frames iterator.
vpx_codec_ctx
Codec context structure.
Definition vpx_codec.h:200
vpx_image
Image Descriptor.
Definition vpx_image.h:76
vpx_image::d_h
unsigned int d_h
Definition vpx_image.h:88
vpx_image::d_w
unsigned int d_w
Definition vpx_image.h:87
vpx_image::planes
unsigned char * planes[4]
Definition vpx_image.h:104
vpx_image::stride
int stride[4]
Definition vpx_image.h:105
vp8dx.h
Provides definitions for using VP8 or VP9 within the vpx Decoder interface.
vpx_decoder.h
Describes the decoder algorithm interface to applications.