libavcodec/ac3enc_template.c:357: error: Uninitialized Value
  The value read from block0 was never initialized.

libavcodec/ac3enc_template.c:357:5: 
355.     int nb_coefs;
356.     int blk, bnd, i;
357.     AC3Block *block, *av_uninit(block0);
         ^
358. 
359.     if (s->channel_mode != AC3_CHMODE_STEREO)

static void compute_rematrixing_strategy(AC3EncodeContext *s)
{
    int nb_coefs;
    int blk, bnd, i;
    AC3Block *block, *av_uninit(block0);
    if (s->channel_mode != AC3_CHMODE_STEREO)
        return;
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
        block = &s->blocks[blk];
        block->new_rematrixing_strategy = !blk;
        if (!s->rematrixing_enabled) {
            block0 = block;
            continue;
        }
        block->num_rematrixing_bands = 4;
        if (block->cpl_in_use) {
            block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);
            block->num_rematrixing_bands -= (s->start_freq[CPL_CH] == 37);
            if (blk && block->num_rematrixing_bands != block0->num_rematrixing_bands)
                block->new_rematrixing_strategy = 1;
        }
        nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);
        for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {
            int start = ff_ac3_rematrix_band_tab[bnd];
            int end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);
            CoefSumType sum[4] = {0,};
            for (i = start; i < end; i++) {
                CoefType lt = block->mdct_coef[1][i];
                CoefType rt = block->mdct_coef[2][i];
                CoefType md = lt + rt;
                CoefType sd = lt - rt;
                MAC_COEF(sum[0], lt, lt);
                MAC_COEF(sum[1], rt, rt);
                MAC_COEF(sum[2], md, md);
                MAC_COEF(sum[3], sd, sd);
            }
            if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))
                block->rematrixing_flags[bnd] = 1;
            else
                block->rematrixing_flags[bnd] = 0;
            if (blk &&
                block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {
                block->new_rematrixing_strategy = 1;
            }
        }
        block0 = block;
    }
}
['static void compute_rematrixing_strategy(AC3EncodeContext *s)\n{\n    int nb_coefs;\n    int blk, bnd, i;\n    AC3Block *block, *av_uninit(block0);\n    if (s->channel_mode != AC3_CHMODE_STEREO)\n        return;\n    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {\n        block = &s->blocks[blk];\n        block->new_rematrixing_strategy = !blk;\n        if (!s->rematrixing_enabled) {\n            block0 = block;\n            continue;\n        }\n        block->num_rematrixing_bands = 4;\n        if (block->cpl_in_use) {\n            block->num_rematrixing_bands -= (s->start_freq[CPL_CH] <= 61);\n            block->num_rematrixing_bands -= (s->start_freq[CPL_CH] == 37);\n            if (blk && block->num_rematrixing_bands != block0->num_rematrixing_bands)\n                block->new_rematrixing_strategy = 1;\n        }\n        nb_coefs = FFMIN(block->end_freq[1], block->end_freq[2]);\n        for (bnd = 0; bnd < block->num_rematrixing_bands; bnd++) {\n            int start = ff_ac3_rematrix_band_tab[bnd];\n            int end   = FFMIN(nb_coefs, ff_ac3_rematrix_band_tab[bnd+1]);\n            CoefSumType sum[4] = {0,};\n            for (i = start; i < end; i++) {\n                CoefType lt = block->mdct_coef[1][i];\n                CoefType rt = block->mdct_coef[2][i];\n                CoefType md = lt + rt;\n                CoefType sd = lt - rt;\n                MAC_COEF(sum[0], lt, lt);\n                MAC_COEF(sum[1], rt, rt);\n                MAC_COEF(sum[2], md, md);\n                MAC_COEF(sum[3], sd, sd);\n            }\n            if (FFMIN(sum[2], sum[3]) < FFMIN(sum[0], sum[1]))\n                block->rematrixing_flags[bnd] = 1;\n            else\n                block->rematrixing_flags[bnd] = 0;\n            if (blk &&\n                block->rematrixing_flags[bnd] != block0->rematrixing_flags[bnd]) {\n                block->new_rematrixing_strategy = 1;\n            }\n        }\n        block0 = block;\n    }\n}']