if(!(mov->tracks[0].enc->flags & CODEC_FLAG_BITEXACT))
if(mov->tracks[0].enc && !(mov->tracks[0].enc->flags & CODEC_FLAG_BITEXACT))
static int mov_write_udta_tag(ByteIOContext *pb, MOVContext* mov,                              AVFormatContext *s){    int pos = url_ftell(pb);    int i;    put_be32(pb, 0); /* size */    put_tag(pb, "udta");    /* iTunes meta data */    mov_write_meta_tag(pb, mov, s);    /* Requirements */    for (i=0; i<MAX_STREAMS; i++) {        if(mov->tracks[i].entry <= 0) continue;        if (mov->tracks[i].enc->codec_id == CODEC_ID_AAC ||            mov->tracks[i].enc->codec_id == CODEC_ID_MPEG4) {            int pos = url_ftell(pb);            put_be32(pb, 0); /* size */            put_tag(pb, "\251req");            put_be16(pb, sizeof("QuickTime 6.0 or greater") - 1);            put_be16(pb, 0);            put_buffer(pb, "QuickTime 6.0 or greater",                       sizeof("QuickTime 6.0 or greater") - 1);            updateSize(pb, pos);            break;        }    }    /* Encoder */    if(!(mov->tracks[0].enc->flags & CODEC_FLAG_BITEXACT))    {        int pos = url_ftell(pb);        put_be32(pb, 0); /* size */        put_tag(pb, "\251enc");        put_be16(pb, sizeof(LIBAVFORMAT_IDENT) - 1); /* string length */        put_be16(pb, 0);        put_buffer(pb, LIBAVFORMAT_IDENT, sizeof(LIBAVFORMAT_IDENT) - 1);        updateSize(pb, pos);    }    if( s->title[0] )    {        int pos = url_ftell(pb);        put_be32(pb, 0); /* size */        put_tag(pb, "\251nam");        put_be16(pb, strlen(s->title)); /* string length */        put_be16(pb, 0);        put_buffer(pb, s->title, strlen(s->title));        updateSize(pb, pos);    }    if( s->author[0] )    {        int pos = url_ftell(pb);        put_be32(pb, 0); /* size */        put_tag(pb, /*"\251aut"*/ "\251day" );        put_be16(pb, strlen(s->author)); /* string length */        put_be16(pb, 0);        put_buffer(pb, s->author, strlen(s->author));        updateSize(pb, pos);    }    if( s->comment[0] )    {        int pos = url_ftell(pb);        put_be32(pb, 0); /* size */        put_tag(pb, "\251des");        put_be16(pb, strlen(s->comment)); /* string length */        put_be16(pb, 0);        put_buffer(pb, s->comment, strlen(s->comment));        updateSize(pb, pos);    }    return updateSize(pb, pos);}