decode_to_md5
/*
* 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>
#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) fprintf(stream, "%02x", digest[i]);
}
static const char *exec_name;
void usage_exit(void) {
fprintf(stderr, "Usage: %s <infile> <outfile>\n", exec_name);
exit(EXIT_FAILURE);
}
int main(int argc, char **argv) {
int frame_cnt = 0;
FILE *outfile = NULL;
vpx_codec_ctx_t codec;
VpxVideoReader *reader = NULL;
const VpxVideoInfo *info = NULL;
const VpxInterface *decoder = NULL;
exec_name = argv[0];
if (argc != 3) die("Invalid number of arguments.");
reader = vpx_video_reader_open(argv[1]);
if (!reader) die("Failed to open %s for reading.", argv[1]);
if (!(outfile = fopen(argv[2], "wb")))
die("Failed to open %s for writing.", argv[2]);
info = vpx_video_reader_get_info(reader);
decoder = get_vpx_decoder_by_fourcc(info->codec_fourcc);
if (!decoder) die("Unknown input codec.");
printf("Using %s\n", vpx_codec_iface_name(decoder->codec_interface()));
if (vpx_codec_dec_init(&codec, decoder->codec_interface(), NULL, 0))
die_codec(&codec, "Failed to initialize decoder");
while (vpx_video_reader_read_frame(reader)) {
vpx_codec_iter_t iter = NULL;
vpx_image_t *img = NULL;
size_t frame_size = 0;
const unsigned char *frame =
vpx_video_reader_get_frame(reader, &frame_size);
if (vpx_codec_decode(&codec, frame, (unsigned int)frame_size, NULL, 0))
die_codec(&codec, "Failed to decode frame");
while ((img = vpx_codec_get_frame(&codec, &iter)) != NULL) {
unsigned char digest[16];
get_image_md5(img, digest);
print_md5(outfile, digest);
fprintf(outfile, " img-%dx%d-%04d.i420\n", img->d_w, img->d_h,
++frame_cnt);
}
}
printf("Processed %d frames.\n", frame_cnt);
if (vpx_codec_destroy(&codec)) die_codec(&codec, "Failed to destroy codec.");
vpx_video_reader_close(reader);
fclose(outfile);
return EXIT_SUCCESS;
}
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:72
vpx_image::d_h
unsigned int d_h
Definition vpx_image.h:84
vpx_image::d_w
unsigned int d_w
Definition vpx_image.h:83
vpx_image::planes
unsigned char * planes[4]
Definition vpx_image.h:100
vpx_image::stride
int stride[4]
Definition vpx_image.h:101
vp8dx.h
Provides definitions for using VP8 or VP9 within the vpx Decoder interface.
vpx_decoder.h
Describes the decoder algorithm interface to applications.