[FFmpeg-devel] [PATCH 001/114] avcodec/bitstream: Add second function to create VLCs

[Anton Khirnov]

Quoting Andreas Rheinhardt (2020-11-10 11:46:58)
> +int ff_init_vlc_from_lengths(VLC *vlc_arg, int nb_bits, int nb_codes,
> +                             const int8_t *lens, int lens_wrap,
> +                             const void *symbols, int symbols_wrap, int symbols_size,
> +                             int offset, int flags)
> +{
> +    VLCcode localbuf[LOCALBUF_ELEMS], *buf = localbuf;
> +    VLC localvlc, *vlc;
> +    uint64_t code;
> +    int ret, j, len_max = FFMIN(32, 3 * nb_bits);
> +
> +    ret = vlc_common_init(vlc_arg, nb_bits, nb_codes, &vlc, &localvlc,
> +                          &buf, flags);
> +    if (ret < 0)
> +        return ret;
> +
> +    j = code = 0;
> +    for (int i = 0; i < nb_codes; i++, lens += lens_wrap) {
> +        int len = *lens;
> +        if (len > 0) {
> +            unsigned sym;
> +
> +            buf[j].bits = len;
> +            if (symbols)
> +                GET_DATA(sym, symbols, i, symbols_wrap, symbols_size)
> +            else
> +                sym = i;
> +            buf[j].symbol = sym + offset;
> +            buf[j++].code = code;
> +        } else if (len <  0) {
> +            len = -len;
> +        } else
> +            continue;
> +        if (len > len_max || code & ((1U << (32 - len)) - 1)) {
> +            av_log(NULL, AV_LOG_ERROR, "Invalid VLC (length %u)\n", len);

Can you use a proper logging context here?

-- 
Anton Khirnov