Function LLVMFuzzerTestOneInput

tools/target_dem_fuzzer.c:101–226

const int maxblocks= 50000;

int LLVMFuzzerTestOneInput(const uint8_t *data, size_t size) {
    uint32_t it = 0;
    AVFormatContext *avfmt = avformat_alloc_context();
    AVPacket *pkt;
    char filename[1025] = {0};
    AVIOContext *fuzzed_pb = NULL;
    uint8_t *io_buffer;
    int io_buffer_size = 32768;
    int64_t filesize   = size;
    IOContext opaque;
    static int c;
    int seekable = 0;
    int ret;
    const AVInputFormat *fmt = NULL;
#ifdef FFMPEG_DEMUXER
#define DEMUXER_SYMBOL0(DEMUXER) ff_##DEMUXER##_demuxer
#define DEMUXER_SYMBOL(DEMUXER) DEMUXER_SYMBOL0(DEMUXER)
    extern const FFInputFormat DEMUXER_SYMBOL(FFMPEG_DEMUXER);
    fmt = &DEMUXER_SYMBOL(FFMPEG_DEMUXER).p;
#endif

    if (!c) {
        av_log_set_level(AV_LOG_PANIC);
        c=1;
    }

    if (!avfmt)
        error("Failed avformat_alloc_context()");

    if (IO_FLAT) {
        seekable = 1;
        io_buffer_size = size;
    } else if (size > 2048) {
        int flags;
        char extension[64];

        GetByteContext gbc;
        memcpy (filename, data + size - 1024, 1024);
        bytestream2_init(&gbc, data + size - 2048, 1024);
        size -= 2048;

        io_buffer_size = bytestream2_get_le32(&gbc) & 0xFFFFFFF;
        flags          = bytestream2_get_byte(&gbc);
        seekable       = flags & 1;
        filesize       = bytestream2_get_le64(&gbc) & 0x7FFFFFFFFFFFFFFF;

        if ((flags & 2) && strlen(filename) < sizeof(filename) / 2) {
            const AVInputFormat *avif = NULL;
            void *avif_iter = NULL;
            int avif_count = 0;
            while ((avif = av_demuxer_iterate(&avif_iter))) {
                if (avif->extensions)
                    avif_count ++;
            }
            avif_count =  bytestream2_get_le32(&gbc) % avif_count;

            avif_iter = NULL;
            while ((avif = av_demuxer_iterate(&avif_iter))) {