libavformat/mmf.c:242: error: Uninitialized Value
  The value read from size was never initialized.

libavformat/mmf.c:242:5: 
240.         return -1;
241.     }
242.     mmf->data_size = size;
         ^
243. 
244.     st = avformat_new_stream(s, NULL);

static int mmf_read_header(AVFormatContext *s,
                           AVFormatParameters *ap)
{
    MMFContext *mmf = s->priv_data;
    unsigned int tag;
    AVIOContext *pb = s->pb;
    AVStream *st;
    int64_t size;
    int rate, params;
    tag = avio_rl32(pb);
    if (tag != MKTAG('M', 'M', 'M', 'D'))
        return -1;
    avio_skip(pb, 4);
    for(;; avio_skip(pb, size)) {
        tag = avio_rl32(pb);
        size = avio_rb32(pb);
        if(tag == MKTAG('C','N','T','I')) continue;
        if(tag == MKTAG('O','P','D','A')) continue;
        break;
    }
    if ((tag & 0xffffff) == MKTAG('M', 'T', 'R', 0)) {
        av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\n");
        return -1;
    }
    if ((tag & 0xffffff) != MKTAG('A', 'T', 'R', 0)) {
        av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\n", tag);
        return -1;
    }
    avio_r8(pb);
    avio_r8(pb);
    params = avio_r8(pb);
    rate = mmf_rate(params & 0x0f);
    if(rate  < 0) {
        av_log(s, AV_LOG_ERROR, "Invalid sample rate\n");
        return -1;
    }
    avio_r8(pb);
    avio_r8(pb);
    avio_r8(pb);
    for(;; avio_skip(pb, size)) {
        tag = avio_rl32(pb);
        size = avio_rb32(pb);
        if(tag == MKTAG('A','t','s','q')) continue;
        if(tag == MKTAG('A','s','p','I')) continue;
        break;
    }
    if ((tag & 0xffffff) != MKTAG('A', 'w', 'a', 0)) {
        av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\n", tag);
        return -1;
    }
    mmf->data_size = size;
    st = avformat_new_stream(s, NULL);
    if (!st)
        return AVERROR(ENOMEM);
    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
    st->codec->codec_id = CODEC_ID_ADPCM_YAMAHA;
    st->codec->sample_rate = rate;
    st->codec->channels = 1;
    st->codec->bits_per_coded_sample = 4;
    st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_coded_sample;
    av_set_pts_info(st, 64, 1, st->codec->sample_rate);
    return 0;
}
['static int mmf_read_header(AVFormatContext *s,\n                           AVFormatParameters *ap)\n{\n    MMFContext *mmf = s->priv_data;\n    unsigned int tag;\n    AVIOContext *pb = s->pb;\n    AVStream *st;\n    int64_t size;\n    int rate, params;\n    tag = avio_rl32(pb);\n    if (tag != MKTAG(\'M\', \'M\', \'M\', \'D\'))\n        return -1;\n    avio_skip(pb, 4);\n    for(;; avio_skip(pb, size)) {\n        tag = avio_rl32(pb);\n        size = avio_rb32(pb);\n        if(tag == MKTAG(\'C\',\'N\',\'T\',\'I\')) continue;\n        if(tag == MKTAG(\'O\',\'P\',\'D\',\'A\')) continue;\n        break;\n    }\n    if ((tag & 0xffffff) == MKTAG(\'M\', \'T\', \'R\', 0)) {\n        av_log(s, AV_LOG_ERROR, "MIDI like format found, unsupported\\n");\n        return -1;\n    }\n    if ((tag & 0xffffff) != MKTAG(\'A\', \'T\', \'R\', 0)) {\n        av_log(s, AV_LOG_ERROR, "Unsupported SMAF chunk %08x\\n", tag);\n        return -1;\n    }\n    avio_r8(pb);\n    avio_r8(pb);\n    params = avio_r8(pb);\n    rate = mmf_rate(params & 0x0f);\n    if(rate  < 0) {\n        av_log(s, AV_LOG_ERROR, "Invalid sample rate\\n");\n        return -1;\n    }\n    avio_r8(pb);\n    avio_r8(pb);\n    avio_r8(pb);\n    for(;; avio_skip(pb, size)) {\n        tag = avio_rl32(pb);\n        size = avio_rb32(pb);\n        if(tag == MKTAG(\'A\',\'t\',\'s\',\'q\')) continue;\n        if(tag == MKTAG(\'A\',\'s\',\'p\',\'I\')) continue;\n        break;\n    }\n    if ((tag & 0xffffff) != MKTAG(\'A\', \'w\', \'a\', 0)) {\n        av_log(s, AV_LOG_ERROR, "Unexpected SMAF chunk %08x\\n", tag);\n        return -1;\n    }\n    mmf->data_size = size;\n    st = avformat_new_stream(s, NULL);\n    if (!st)\n        return AVERROR(ENOMEM);\n    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;\n    st->codec->codec_id = CODEC_ID_ADPCM_YAMAHA;\n    st->codec->sample_rate = rate;\n    st->codec->channels = 1;\n    st->codec->bits_per_coded_sample = 4;\n    st->codec->bit_rate = st->codec->sample_rate * st->codec->bits_per_coded_sample;\n    av_set_pts_info(st, 64, 1, st->codec->sample_rate);\n    return 0;\n}']