memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
return AVERROR(EIO);
memcpy(pkt->data, preamble, MM_PREAMBLE_SIZE);
if (avio_read(pb, pkt->data + MM_PREAMBLE_SIZE, length) != length)
return AVERROR(EIO);