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37 for (
i = 8;
i < 64;
i += 4) {
56 w = x1 * x1 + x2 * x2;
59 w = sqrt((-2.0 * log(
w)) /
w);
65 unsigned int beg,
end, segm;
79 for (segm = 0;segm < 64;segm++) {
82 c->state[segm] = (
unsigned int)crc;
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
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
static av_cold int end(AVCodecContext *avctx)
void av_md5_sum(uint8_t *dst, const uint8_t *src, const int len)
Hash an array of data.
static unsigned int av_lfg_get(AVLFG *c)
Get the next random unsigned 32-bit number using an ALFG.
void av_bmg_get(AVLFG *lfg, double out[2])
Get the next two numbers generated by a Box-Muller Gaussian generator using the random numbers issued...
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Context structure for the Lagged Fibonacci PRNG.
const AVCRC * av_crc_get_table(AVCRCId crc_id)
Get an initialized standard CRC table.
int av_lfg_init_from_data(AVLFG *c, const uint8_t *data, unsigned int length)
Seed the state of the ALFG using binary data.
#define i(width, name, range_min, range_max)
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
uint32_t av_crc(const AVCRC *ctx, uint32_t crc, const uint8_t *buffer, size_t length)
Calculate the CRC of a block.