static inline void encode_dc(MpegEncContext *s, int diff, int component)
{
    if (((unsigned) (diff + 255)) >= 511) {
        int index;

        if (diff < 0) {
            index = av_log2_16bit(-2 * diff);
            diff--;
        } else {
            index = av_log2_16bit(2 * diff);
        }
        if (component == 0)
            put_bits(&s->pb,
                     ff_mpeg12_vlc_dc_lum_bits[index] + index,
                     (ff_mpeg12_vlc_dc_lum_code[index] << index) +
                     (diff & ((1 << index) - 1)));
        else
            put_bits(&s->pb,
                     ff_mpeg12_vlc_dc_chroma_bits[index] + index,
                     (ff_mpeg12_vlc_dc_chroma_code[index] << index) +
                     (diff & ((1 << index) - 1)));
    } else {
        if (component == 0)
            put_bits(&s->pb,
                     mpeg1_lum_dc_uni[diff + 255] & 0xFF,
                     mpeg1_lum_dc_uni[diff + 255] >> 8);
        else
            put_bits(&s->pb,
                     mpeg1_chr_dc_uni[diff + 255] & 0xFF,
                     mpeg1_chr_dc_uni[diff + 255] >> 8);
    }
}