This example is a simple command line application that takes one or more arguments. It demonstrates a typical use of the hashing API with allocation, initialization, updating, and finalizing.
#include "config.h"
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <string.h>
#include <sys/stat.h>
#if HAVE_IO_H
#include <io.h>
#endif
#if HAVE_UNISTD_H
#include <unistd.h>
#endif
#define SIZE 65536
{
printf(
"usage: ffhash [b64:]algorithm [input]...\n");
printf(
"Supported hash algorithms:");
do {
}
{
} else {
}
}
static int check(
char *file)
{
int fd,
flags = O_RDONLY;
#ifdef O_BINARY
#endif
if (file) fd = open(file,
flags);
else fd = 0;
if (fd == -1) {
goto end;
}
for (;;) {
int err = errno;
close(fd);
printf(
"+READ-FAILED: %s", strerror(err));
goto end;
break;
}
close(fd);
end:
if (file)
}
int main(
int argc,
char **argv)
{
const char *hash_name;
if (argc == 1) {
return 0;
}
hash_name = argv[1];
printf(
"Invalid hash type: %s\n", hash_name);
break;
printf(
"%s\n", strerror(errno));
break;
}
return 1;
}
for (
i = 2;
i < argc;
i++)
if (argc < 3)
}
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf default minimum maximum flags name is the option name
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
#define AV_HASH_MAX_SIZE
Maximum value that av_hash_get_size() will currently return.
void av_hash_final_b64(struct AVHashContext *ctx, uint8_t *dst, int size)
Finalize a hash context and store the Base64 representation of the actual hash value as a string.
const char * av_hash_get_name(const AVHashContext *ctx)
int av_hash_alloc(AVHashContext **ctx, const char *name)
Allocate a hash context for the algorithm specified by name.
const char * av_hash_names(int i)
Get the names of available hash algorithms.
void av_hash_init(AVHashContext *ctx)
Initialize or reset a hash context.
void av_hash_update(AVHashContext *ctx, const uint8_t *src, size_t len)
Update a hash context with additional data.
void av_hash_freep(AVHashContext **ctx)
Free hash context and set hash context pointer to NULL.
printf("static const uint8_t my_array[100] = {\n")
int av_strstart(const char *str, const char *pfx, const char **ptr)
Return non-zero if pfx is a prefix of str.
static int check(char *file)
#define i(width, name, range_min, range_max)
int main(int argc, char **argv)
the frame and frame reference mechanism is intended to as much as expensive copies of that data while still allowing the filters to produce correct results The data is stored in buffers represented by AVFrame structures Several references can point to the same frame buffer
void av_hash_final_hex(struct AVHashContext *ctx, uint8_t *dst, int size)
Finalize a hash context and store the hexadecimal representation of the actual hash value as a string...
#define flags(name, subs,...)
static uint32_t BS_FUNC() read(BSCTX *bc, unsigned int n)
Return n bits from the buffer, n has to be in the 0-32 range.