libavcodec/wmaenc.c:76: error: Uninitialized Value
  The value read from extradata was never initialized.

libavcodec/wmaenc.c:76:5: 
74.         assert(0);
75.     }
76.     avctx->extradata          = extradata;
        ^
77.     s->use_exp_vlc            = flags2 & 0x0001;
78.     s->use_bit_reservoir      = flags2 & 0x0002;

static av_cold int encode_init(AVCodecContext *avctx)
{
    WMACodecContext *s = avctx->priv_data;
    int i, flags1, flags2, block_align;
    uint8_t *extradata;
    s->avctx = avctx;
    if (avctx->channels > MAX_CHANNELS) {
        av_log(avctx, AV_LOG_ERROR,
               "too many channels: got %i, need %i or fewer",
               avctx->channels, MAX_CHANNELS);
        return AVERROR(EINVAL);
    }
    if (avctx->sample_rate > 48000) {
        av_log(avctx, AV_LOG_ERROR, "sample rate is too high: %d > 48kHz",
               avctx->sample_rate);
        return AVERROR(EINVAL);
    }
    if (avctx->bit_rate < 24 * 1000) {
        av_log(avctx, AV_LOG_ERROR,
               "bitrate too low: got %i, need 24000 or higher\n",
               avctx->bit_rate);
        return AVERROR(EINVAL);
    }
    flags1 = 0;
    flags2 = 1;
    if (avctx->codec->id == AV_CODEC_ID_WMAV1) {
        extradata             = av_malloc(4);
        avctx->extradata_size = 4;
        AV_WL16(extradata, flags1);
        AV_WL16(extradata + 2, flags2);
    } else if (avctx->codec->id == AV_CODEC_ID_WMAV2) {
        extradata             = av_mallocz(10);
        avctx->extradata_size = 10;
        AV_WL32(extradata, flags1);
        AV_WL16(extradata + 4, flags2);
    } else {
        assert(0);
    }
    avctx->extradata          = extradata;
    s->use_exp_vlc            = flags2 & 0x0001;
    s->use_bit_reservoir      = flags2 & 0x0002;
    s->use_variable_block_len = flags2 & 0x0004;
    if (avctx->channels == 2)
        s->ms_stereo = 1;
    ff_wma_init(avctx, flags2);
    for (i = 0; i < s->nb_block_sizes; i++)
        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0, 1.0);
    block_align        = avctx->bit_rate * (int64_t) s->frame_len /
                         (avctx->sample_rate * 8);
    block_align        = FFMIN(block_align, MAX_CODED_SUPERFRAME_SIZE);
    avctx->block_align = block_align;
    avctx->bit_rate    = avctx->block_align * 8LL * avctx->sample_rate /
                         s->frame_len;
    avctx->frame_size  =
    avctx->delay       = s->frame_len;
    return 0;
}
['static av_cold int encode_init(AVCodecContext *avctx)\n{\n    WMACodecContext *s = avctx->priv_data;\n    int i, flags1, flags2, block_align;\n    uint8_t *extradata;\n    s->avctx = avctx;\n    if (avctx->channels > MAX_CHANNELS) {\n        av_log(avctx, AV_LOG_ERROR,\n               "too many channels: got %i, need %i or fewer",\n               avctx->channels, MAX_CHANNELS);\n        return AVERROR(EINVAL);\n    }\n    if (avctx->sample_rate > 48000) {\n        av_log(avctx, AV_LOG_ERROR, "sample rate is too high: %d > 48kHz",\n               avctx->sample_rate);\n        return AVERROR(EINVAL);\n    }\n    if (avctx->bit_rate < 24 * 1000) {\n        av_log(avctx, AV_LOG_ERROR,\n               "bitrate too low: got %i, need 24000 or higher\\n",\n               avctx->bit_rate);\n        return AVERROR(EINVAL);\n    }\n    flags1 = 0;\n    flags2 = 1;\n    if (avctx->codec->id == AV_CODEC_ID_WMAV1) {\n        extradata             = av_malloc(4);\n        avctx->extradata_size = 4;\n        AV_WL16(extradata, flags1);\n        AV_WL16(extradata + 2, flags2);\n    } else if (avctx->codec->id == AV_CODEC_ID_WMAV2) {\n        extradata             = av_mallocz(10);\n        avctx->extradata_size = 10;\n        AV_WL32(extradata, flags1);\n        AV_WL16(extradata + 4, flags2);\n    } else {\n        assert(0);\n    }\n    avctx->extradata          = extradata;\n    s->use_exp_vlc            = flags2 & 0x0001;\n    s->use_bit_reservoir      = flags2 & 0x0002;\n    s->use_variable_block_len = flags2 & 0x0004;\n    if (avctx->channels == 2)\n        s->ms_stereo = 1;\n    ff_wma_init(avctx, flags2);\n    for (i = 0; i < s->nb_block_sizes; i++)\n        ff_mdct_init(&s->mdct_ctx[i], s->frame_len_bits - i + 1, 0, 1.0);\n    block_align        = avctx->bit_rate * (int64_t) s->frame_len /\n                         (avctx->sample_rate * 8);\n    block_align        = FFMIN(block_align, MAX_CODED_SUPERFRAME_SIZE);\n    avctx->block_align = block_align;\n    avctx->bit_rate    = avctx->block_align * 8LL * avctx->sample_rate /\n                         s->frame_len;\n    avctx->frame_size  =\n    avctx->delay       = s->frame_len;\n    return 0;\n}']