我正在尝试使用以下方法将视频源转换为延时：
ffmpeg -i source.mp4 -an -filter:v "setpts=PTS/360" timelapse.mp4
但由于使用PTS/360选项丢帧，我不喜欢这种断断续续的输出视频。我尝试使用tblend=average,framestep=2,setpts=PTS/360，但它看起来和原来一样，并且使该过滤器像原来一样
tblend=average,framestep=2,tblend=average,framestep=2,tblend=average,framestep=2,...setpts=PTS/180
对我没有任何明显的改变。
ffmpeg是否还有其他选项可将30帧混合为1个平均帧并使用这些帧编译输出30fps视频？
答案 0 :(得分：0)
我知道了！我在计算中错了，因此，具有帧平均的x256慢速视频的正确命令将如下所示：
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#define MAXL 30 /* if you need a constant, #define one (or more) */
struct game_piece
{
char label[MAXL];
};
struct game_board
{
struct game_piece **board;
int row, col;
};
void game_piece_init_default(struct game_piece* piece)
{
strcpy(piece->label, "---");
}
void game_piece_init(struct game_piece* piece, char* new_label)
{
size_t len = strlen (new_label);
if (len < MAXL)
memcpy (piece->label, new_label, len + 1);
else {
fputs ("warning: label truncated.\n", stderr);
memcpy (piece->label, new_label, MAXL-1);
piece->label[MAXL-1] = 0; /* nul-terminate */
}
}
char *game_piece_get_label (struct game_piece *piece)
{
return piece->label;
}
char *game_piece_to_string (struct game_piece *piece)
{
char *tempLabel; /* uninitialized pointer */
size_t len = strlen (game_piece_get_label(piece));
tempLabel = malloc (len + 1);
if (tempLabel == NULL) {
perror ("malloc-tempLabel");
return NULL;
}
memcpy (tempLabel, game_piece_get_label(piece), len + 1);
if (len > 3)
tempLabel[1] = '\0';
for (size_t i = 3; i > len; i--)
strcat(tempLabel, " ");
return tempLabel;
}
void game_board_init(struct game_board* game_board, int rows, int cols)
{
/* allocate row number of pointers */
game_board->board = malloc (sizeof(*game_board->board)*rows);
/* allocate col number of **game_board->board per row
* (e.g. col * sizeof (struct game_piece) per row)
*/
for (int i = 0; i < rows; i++){
game_board->board[i] = malloc(sizeof(struct game_piece) * cols);
}
game_board->row = rows;
game_board->col = cols;
for (int i=0; i < rows; i++){
printf("\n");
for (int j=0; j < cols; j++) {
game_piece_init_default(&game_board->board[i][j]);
printf("%s ",game_board->board[i][j].label);
}
}
}
int game_board_is_space_valid(struct game_board* game_board,
int row, int col)
{
if (row > game_board->row || col > game_board->col)
return 0;
if (row < 0 || col < 0)
return 0;
return 1;
}
int game_board_add_piece(struct game_board* game_board,
struct game_piece* piece, int row, int col)
{
if (game_board_is_space_valid(game_board, row, col) == 0)
return 0;
if (strncmp(game_board->board[row][col].label, "---", 3) == 0) {
game_board->board[row][col] = *piece;
return 1;
}
return 0;
}
int game_board_move_piece(struct game_board* game_board,
int src_row, int src_col, int dest_row, int dest_col)
{
return 0;
if (game_board || src_row || src_col || dest_row || dest_col) {}
}
void game_board_print(struct game_board* game_board)
{
int col = 3;
int row = 3;
printf("try again -kelly");
for (int i=0; i < row; i++) {
printf("\n");
for (int j=0; j < col; j++) {
printf("%s",game_piece_to_string(&game_board->board[i][j]));
}
}
}
int main()
{
/* declare local variables */
int row;
int col;
int destRow;
int destCol;
int rowNum;
int colNum;
struct game_board board;
struct game_piece piece;
char input_string[30];
/* get the size of the game board */
printf("Please enter the number of rows.\n");
scanf("%d", &rowNum);
printf("Please enter the number of columns.\n");
scanf("%d", &colNum);
game_board_init(&board, rowNum, colNum);
/* get the first piece's label */
printf("Please enter a label for a new piece. "
"Enter \"Q\" when done.\n");
scanf("%s", input_string);
while (strcmp(input_string, "Q") != 0 && strcmp(input_string, "q") != 0)
{
game_piece_init(&piece, input_string);
/* get the location to place the piece */
printf("Please enter a row for the piece.\n");
scanf("%d", &row);
printf("Please enter a column for the piece.\n");
scanf("%d", &col);
/* verify the space is valid then add the piece to the board */
if (game_board_is_space_valid(&board, row, col))
{
if (game_board_add_piece(&board, &piece, row, col))
{
printf("New piece \"%s\" added.\n",
game_piece_get_label(&piece));
}
else
{
printf("A piece is already at that space.\n");
}
}
else
{
printf("Invalid row and/or column.\n");
}
/* get the label for the next piece */
printf("Please enter a label for a new piece. "
"Enter \"Q\" when done.");
scanf("%s", input_string);
}
/* print the board and check if user wants to move a piece */
game_board_print(&board);
printf("Would you like to move a piece? Enter \"Y\" to move a piece.\n");
scanf("%s", input_string);
while (strcmp(input_string, "Y") == 0 || strcmp(input_string, "y") == 0)
{
/* get the location of the piece */
printf("Please enter the piece's row.");
scanf("%d", &row);
printf("Please enter the piece's column.");
scanf("%d", &col);
/* get the destination for the piece */
printf("Please enter the piece's new row.");
scanf("%d", &destRow);
printf("Please enter the piece's new column.");
scanf("%d", &destCol);
/* verify both spaces are valid then move the piece */
if (game_board_is_space_valid(&board, row, col) &&
game_board_is_space_valid(&board, destRow, destCol))
{
if (game_board_move_piece(&board, row, col, destRow, destCol))
{
printf("Piece moved to new space.\n");
}
else
{
printf("A piece is already in that space.\n");
}
}
else
{
printf("A row or column is invalid. No piece moved.\n");
}
/* print the board and check if the user wants move another piece */
game_board_print(&board);
printf("Would you like to move a piece? "
"Enter \"Y\" to move a piece.\n");
scanf("%s", input_string);
}
return 0;
}