libavcodec/ac3enc.c:1448: error: Uninitialized Value
  The value read from ch0 was never initialized.

libavcodec/ac3enc.c:1448:9: 
1446.         AC3Block *block = &s->blocks[blk];
1447.         AC3Block *ref_block;
1448.         int av_uninit(ch0);
              ^
1449.         int got_cpl = !block->cpl_in_use;
1450.         // initialize grouped mantissa counts. these are set so that they are

static int bit_alloc(AC3EncodeContext *s, int snr_offset)
{
    int blk, ch;
    int mantissa_bits;
    int mant_cnt[5];
    snr_offset = (snr_offset - 240) << 2;
    reset_block_bap(s);
    mantissa_bits = 0;
    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {
        AC3Block *block = &s->blocks[blk];
        AC3Block *ref_block;
        int av_uninit(ch0);
        int got_cpl = !block->cpl_in_use;
        mant_cnt[0] = mant_cnt[3] = 0;
        mant_cnt[1] = mant_cnt[2] = 2;
        mant_cnt[4] = 1;
        for (ch = 1; ch <= s->channels; ch++) {
            if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {
                ch0     = ch - 1;
                ch      = CPL_CH;
                got_cpl = 1;
            }
            ref_block = block->exp_ref_block[ch];
            if (s->exp_strategy[ch][blk] != EXP_REUSE) {
                s->ac3dsp.bit_alloc_calc_bap(ref_block->mask[ch], ref_block->psd[ch],
                                             s->start_freq[ch], block->end_freq[ch],
                                             snr_offset, s->bit_alloc.floor,
                                             ff_ac3_bap_tab, ref_block->bap[ch]);
            }
            mantissa_bits += s->ac3dsp.compute_mantissa_size(mant_cnt,
                                                             ref_block->bap[ch]+s->start_freq[ch],
                                                             block->end_freq[ch]-s->start_freq[ch]);
            if (ch == CPL_CH)
                ch = ch0;
        }
        mantissa_bits += compute_mantissa_size_final(mant_cnt);
    }
    return mantissa_bits;
}
['static int bit_alloc(AC3EncodeContext *s, int snr_offset)\n{\n    int blk, ch;\n    int mantissa_bits;\n    int mant_cnt[5];\n    snr_offset = (snr_offset - 240) << 2;\n    reset_block_bap(s);\n    mantissa_bits = 0;\n    for (blk = 0; blk < AC3_MAX_BLOCKS; blk++) {\n        AC3Block *block = &s->blocks[blk];\n        AC3Block *ref_block;\n        int av_uninit(ch0);\n        int got_cpl = !block->cpl_in_use;\n        mant_cnt[0] = mant_cnt[3] = 0;\n        mant_cnt[1] = mant_cnt[2] = 2;\n        mant_cnt[4] = 1;\n        for (ch = 1; ch <= s->channels; ch++) {\n            if (!got_cpl && ch > 1 && block->channel_in_cpl[ch-1]) {\n                ch0     = ch - 1;\n                ch      = CPL_CH;\n                got_cpl = 1;\n            }\n            ref_block = block->exp_ref_block[ch];\n            if (s->exp_strategy[ch][blk] != EXP_REUSE) {\n                s->ac3dsp.bit_alloc_calc_bap(ref_block->mask[ch], ref_block->psd[ch],\n                                             s->start_freq[ch], block->end_freq[ch],\n                                             snr_offset, s->bit_alloc.floor,\n                                             ff_ac3_bap_tab, ref_block->bap[ch]);\n            }\n            mantissa_bits += s->ac3dsp.compute_mantissa_size(mant_cnt,\n                                                             ref_block->bap[ch]+s->start_freq[ch],\n                                                             block->end_freq[ch]-s->start_freq[ch]);\n            if (ch == CPL_CH)\n                ch = ch0;\n        }\n        mantissa_bits += compute_mantissa_size_final(mant_cnt);\n    }\n    return mantissa_bits;\n}']