ivfconcat.c

/* One-off IVF concat */

#include <stdbool.h>
#include <stdio.h>
#include <stdint.h>
#include <stdlib.h>
#include <string.h>

#include <libavutil/intreadwrite.h>

#define TICKS 1
#define NO_FILES 46

int main()
{
    uint64_t timestamp = 0;
    bool first = true;
    FILE *out;

    out = fopen("out.ivf", "wb");
    if (out == NULL) {
        printf("Could't open output file.\n");
        return 1;
    }

    for (int i = 0; i < NO_FILES; i++) {
        FILE *in;
        size_t size;
        char name[100] = {0};

        snprintf(&name[0], 100, "out/%d.ivf", i);

        in = fopen(name, "rb");
        if (in == NULL) {
            printf("Couldn't open %s.\n");
            fclose(out);
            return 1;
        }

        fseeko(in, 0, SEEK_END);
        size = ftello(in);
        fseeko(in, 0, SEEK_SET);

        printf("File %s (%zu bytes)\n", name, size);

        if (first) {
            uint8_t header[32];

            fread(&header[0], 1, 32, in);
            fwrite(&header[0], 1, 32, out);
            first = false;
        } else {
            fseeko(in, 32, SEEK_SET);
        }
        size -= 32;

        while (size > 0) {
            uint8_t fheader[12];
            uint8_t ftimestamp[8];
            uint32_t fsize;
            uint8_t *buf;

            fread(&fheader[0], 1, 12, in);
	    size -= 12;
            fwrite(&fheader[0], 1, 4, out);

            fsize = AV_RL32(&fheader[0]);
            AV_WL64(&ftimestamp[0], timestamp);
            timestamp += TICKS;
            fwrite(&ftimestamp[0], 1, 8, out);

            buf = malloc(fsize);
            if (buf == NULL) {
                printf("No memory... bailing.\n");
                fclose(in);
                fclose(out);
                return 1;
            }

            fread(buf, 1, fsize, in);
            size -= fsize;
            fwrite(buf, 1, fsize, out);

            free(buf);
        }
        if (size < 0) {
            printf("Something is wrong.\n");
            fclose(in);
            fclose(out);
            return 1;
        }

        fclose(in);
    }

    fclose(out);

    return 0;
}